Title of Invention	A PROCESS FOR PREPARATION OF AN IMPROVED CATALYST FOR LOW PRESSURE CONTINUOUS BUTYNEDIOL SYNTHESIS
Abstract	Various ethynylation catalyst precursors are generally prepared separately and then charged to suitable reactors for conversion to active cuprous acetylide complex and subsequent reaction. This invention discloses an 'in-situ' prepared, improved catalyst for low pressure ethynylation, prepared from an industrially available support of suitable shape and size is charged directly to the reactor. All subsequent steps, from impregnation etc. to catalyst precursor preparation, activating the catalyst and reaction, are carried 'in-situ1 in the reactor itself, to achieve high activity, longer life and a product suitable for achieving downstream products quality. The support is charged , either alone or in combination with inert rings in the form of mixed bed. The catalyst performance of this invention is already demonstrated for a scale-up ratio of 1:17 from small packed bubble column single tube reactors, and which can be scaled easily up about 2500 times, in a similar multi tubular industrial reactor, without adversely affecting its performance. The catalyst, which is thus prepared in an eco-fiiendly manner, shows very good ability for regeneration, which further reduces its disposal problems.

Title of Invention

A PROCESS FOR PREPARATION OF AN IMPROVED CATALYST FOR LOW PRESSURE CONTINUOUS BUTYNEDIOL SYNTHESIS

Abstract

Various ethynylation catalyst precursors are generally prepared separately and then charged to suitable reactors for conversion to active cuprous acetylide complex and subsequent reaction. This invention discloses an 'in-situ' prepared, improved catalyst for low pressure ethynylation, prepared from an industrially available support of suitable shape and size is charged directly to the reactor. All subsequent steps, from impregnation etc. to catalyst precursor preparation, activating the catalyst and reaction, are carried 'in-situ1 in the reactor itself, to achieve high activity, longer life and a product suitable for achieving downstream products quality. The support is charged , either alone or in combination with inert rings in the form of mixed bed. The catalyst performance of this invention is already demonstrated for a scale-up ratio of 1:17 from small packed bubble column single tube reactors, and which can be scaled easily up about 2500 times, in a similar multi tubular industrial reactor, without adversely affecting its performance. The catalyst, which is thus prepared in an eco-fiiendly manner, shows very good ability for regeneration, which further reduces its disposal problems.

Full Text	FORM 2 THE PATENT ACT, 1970 (39 of 1970) & THE PATENT RULES, 2003 COMPLETE SPECIFICATION (See Section 10, Rule 13) 1. TITLE OF THE INVENTION: AN IN-SITU' PREPARED, IMPROVED CATALYST FOR LOW PRESSURE CONTINUOUS BUTYNEDIOL SYNTHESIS. 2. APPLICANT(S) (a) Name: (b) Nationality: (c) Address: M/s. HINDUSTAN ORGANIC CHEMICALS LIMITED Indian Mr.A. S, Didolkar.CMD 81, Maharshi Karve Road, MUMBAI -400 002, Maharashtra, India, 3. PREAMBLE TO THE DESCRIPTION: COMPLETE SPECIFICATION The following specification particularly describes the invention and the manner in which it is to be performed: PRIOR ART Ethynylation of formaldehyde to 1,4 butynediol by the original Reppe process has undergone many improvements over the years. The higher pressure process is mainly associated with problems of inherent safety, due to handling of acetylene gas, since the reactors are to be designed for more man 10 times the operating pressure. 1,4-butynediol is an important industrial intermediate for the manufacture of 1,4-butenediol as well as 1,4-butanediol and tetrahydrofuran. Low pressure processes suitable for industrial applications have therefore been extensively studied for various supported / unsupported catalysts in various reactors since men. Our previous work on bubble column upflow continuous reactors using fixed bed catalyst of copper / bismuth oxides on alumina support precursor (Indian Patent Application NO.1522/MUM/2008, filing date: 18th July 2008) shows that the catalyst activity obtained is higher than mat reported for industrial silica gel based catalyst of the same particle size for just above atmospheric pressure operation at 80 to 90 C. However, the process has the drawback of nitrogen oxides fumes liberated (and environmental problems associated with the same) during the formation of copper / bismuth oxides precursors from their corresponding nitrates. The catalyst particle range referred to in the previous work is comparable to present invention. Besides this, much significant work is done in the area of slurry reactors, which handle finely divided catalyst powder, unsupported or with catalyst supports, so that the higher surface enables higher activity at lower pressures. US Patent #3,560,576 describes a slurry reactor with 6.7% w/v catalyst loading of fine powered malachite based catalyst precursor with 10 to 20 microns particle size at 50 to 120 °C and pressure below 2 atmospheres for cuprous acetylide catalyst generation and subsequent ethynylation of formaldehyde solution. US Patent #3,954,669 reports preparation of manassite from nitrates of copper, magnesium and aluminium with mixture of sodium carbonate and hydroxide which is then converted to cuprous acetylide complex in slurry reactors. The particle size of the catalyst is less than 100 microns and is used in batch reactor as well as CSTR in loading of 3.8 to 7.4% w/v. The reaction is at nearly atmospheric pressure at 65 to 90 °C and the catalyst shows high activity. Subsequent US Patent #4,062,899 shows extension of the previous work, using nitrates of copper and aluminium with sodium bicarbonate for slightly bigger particle size of 130 microns and 3.8% w/v catalyst loading, achieving a comparable catalyst activity (expressed in g butynediol/kg-cataryst-day) with that reported in the earlier patent Another US patent #4,584,418 describes malachite preparation from copper nitrate with sodium carbonate for very fine particle size (S microns). The reaction parameters are about the same as earlier reported ones, whereas a significantly lower catalyst loading (0.01% w/v) is used. The activity achieved is much higher than mat reported in the earlier two referred patents. Polish patent #1,35,195 reports a much larger particle size in the range of 0.1 to 0.4 mm under nearly same operating conditions, for a supported catalyst (activated charcoal etc.) with significantly higher (10.8% w/v) catalyst loading in intensively stirred batch slurry reactor. It claims much improved catalyst activity corresponding to its particle size as well as absence of tarry substances (in the product) usually formed at higher temperatures which are difficult to separate from the products. It also eliminates the use of higher temperatures (more man 350 °C) reported in the earlier work thereby eliminating exposure to nitrogen oxides fumes and related environmental problems. Prior art not only reports cuprous acetylide complex catalysts for the synthesis of butynediol from aqueous formaldehyde and acetylene, but its extension to synthesis of diethylaminopentynol as well as butynediol, without involving acetylene gas. A recent US patent #6,350,714B regarding mis reports preparation and application of unsupported catalyst based on malachite with 4% bismuth contents generated in presence of aqueous formaldehyde and nitrogen followed by aqueous propargyl alcohol feed. Butynediol synthesis is carried out in this particular case with formaldehyde and propargyl alcohol using 3 to 15% w/v catalyst loading at 90 °C and nearly atmospheric pressure. The main disadvantages of using the fine powder catalysts in the slurry reactors is their handling and effective separation aspects. Another part associated with them is the catalyst precursor as well as catalyst (cuprous acetylide complex) is prepared separately, and is subsequently charged to the reactor. This involves safe handling part for cuprous acetylide, which is very much critical on the industrial scale. Although the catalyst activities reported for these catalysts are very much on the higher side, it is mainly attributed to their very fine particle size. Their equivalent activity for a bigger particle size (say 2 to 5 mm) is far from satisfactory for industrial scale operation. Also most of these patents do not report the catalyst life, which is another limitation. Continuous reactors either in fixed beds or bubble column slurry reactors, have their obvious advantages over batch or slurry type of reactors handling powdered catalyst US patent #4,067,914 describes manufacture of butynediol in a bubble column upflow slurry reactor with suspended catalyst based on copper and aluminum complex carbonates / hydroxides precursors. A fine particle size of 20 to 150 microns is used with a high catalyst loading of about 20% w/v which requires effective solid-liquid separation. The clarified product still contains about 20 ppm of suspended matter. A higher activity is reported in an operating range of 60 to 100 °C and nearly atmospheric pressure. OBJECTIVE OF THE INVENTION The main objective of the invention is to arrive at a 'in-situ' prepared catalyst precursor based on alumina or any other suitable support, eliminating the environmental problems associated with oxides of nitrogen liberated during its preparation. Moreover the precursor is to be used immediately after cuprous acetylide formation, for continuous packed bubble column industrial reactors, operated at pressure just above atmospheric pressure and in temperature range of 50 to 100 °C. The catalyst should be used effectively for emynylation of formaldehyde, without the need for dosing of alkali to the reactor to maintain pH. Another objective is that the catalyst size has to be such that solids carry over and further separation from liquid is avoided to result in trouble free, safer operation for long periods. A more specific objective is the catalyst shape should also be such that heat dissipation from individual particles to bulk fluid, is fast enough to prevent any localized hot spots, which may cause heavier side products formation, which affect not only butynediol product quality, but that of down stream product too and may cause catalyst agglomeration, thereby high pressure drop through the reactor. In addition to proper shape to ensure good productivity of the catalyst and good quality of the butynediol produced from this process, the objective is to utilize catalyst is right proportion with suitable inerts to constitute a mixed bed. Finally the objective of the invention is to develop a catalyst which shows good scale-up ability suitable for industrial operation and can be regenerated in an easier manner. SUMMARY OF THE INVENTION The present invention discloses an 'in-situ' prepared catalyst precursor on industrial support, available in suitable shapes and sizes with or without combination with inerts for packed bubble column continuous reactor operation. The precursor is prepared using copper/bismuth nitrates and aqueous alkali in eco-friendry manner and converted to corresponding cuprous acetylide complex for etiiynylation of formaldehyde at low pressure and temperature. The catalyst shows high activity, life and can be regenerated in-situ for more cycles, thus reducing considerably the catalyst disposal problems. In one embodiment of the invention, the industrial support used is alumina spheres in a smaller single tube reactor, the aqueous alkali used being sodium carbonate, the outlet product clear enough, not requiring filtration or any other solid-liquid separation step in further purification processes. In another embodiment of the invention, the reactor used is a single tube reactor (which can correspond to a single tube of a multi-tubular industrial scale reactor), with a scale-up ratio 17 times that of the smaller single tube reactor, the catalyst being prepared and reactor operated in the same manner as the smaller reactor, showing fair reproducibility in catalyst activity, productivity, and product clarity. Whereas minor variations in catalyst quantity has no effect, steady reaction conditions achieve better activity and productivity for the catalyst Catalyst lumps / agglomerates formation is observed especially at the bottom (inlet) of the reactor, which lead to sudden abnormal pressure drop, towards the end of catalyst life. In one of the preferred embodiment of the scaled up version of the invention, the alkali used is sodium hydroxide, similar conditions for catalyst preparation and ethynylation reaction prevailing, the activity and productivity, as well as deactivation phenomenon of the catalyst are comparable to the lower scale version. In another embodiment of the invention, use of lower concentration of nitrates leads to lesser activity and productivity. In one of the novel embodiments of the invention, the catalyst can be regenerated in an effective manner using the alkali under inert atmosphere and can be activated by more or less similar procedure to fresh catalyst generation. In another preferred embodiment of the invention, the catalyst support is mixed with inerts in various proportions, the catalyst prepared and used in a similar manner as before. Such a mixed catalyst bed operation shows high catalyst activity and productivity, due to better heat dissipation from the active particles to inerts in their vicinity and lesser side reactions, thereby. In another preferred embodiment of the invention, the catalyst support is ring shaped: for better heat dissipation required from the particles for achieving highly steady activity and life (productivity), when prepared and operated under similar manner. In the most preferred embodiment of the invention, the catalyst support in the form of rings of suitable size, is mixed with appropriate quantity of inerts and such a mixed catalyst bed prepared and operated in a similar manner for much longer periods, at higher catalyst activity, resulting in a better quality 1,4 butynediol product (without involving filtration / separation step) suitable for better quality downstream products, including 1,4 butenediol, by selective hydrogenation. DETAILED DESCRIPTION OF THE INVENTION The industrially available supports preferably alumina for this invention include spheres of 2 to 5 mm diameter, 0.76 to 0.84 g/cc bulk density, 0.3 to 0.5 cc/g pore volume or rings 12 to 16 mm outer diameter x 6 to 9 mm inner diameter x 12 to 16 mm long, with bulk density 0.8 to 1.1 g/cc, pore volume 0.2 to 0.5 cc/g and chemical composition as follows: Oxides of: Aluminium: 92% w (mm), Sodium: 0.25% w (max), Iron: 0.15 % w (max) and Silicon: 0.15% w (max), with maximum ignition loss of 7%. The catalyst precursor of mis invention can be prepared 'in-situ' by the following eco-fnendly manner: a. Packing of the support with or without inerts, in a bubble column stainless steel reactor; The inerts may be preferably porcelain rings or saddles, with 3 to 9 mm size with bulk density varying from 0.8 to 1.2 g/cc; b. Drying of the support at 50 to 90 °C for 4 to 150 hours under nitrogen gas, GHSV 2 to 20 h-1; c. Impregnation of a solution prepared from commercially available copper nitrate trihydrate and bismuth nitrate pentahydrate, in the concentration range of 500 to 1500 g/litre and 100 to 200 g/litre respectively, for 1 to 80 hours, in a temperature range of 20 to 90 °C; d. Drying of impregnated mass under nitrogen (GHSV 2 to 20 h-1) for 2 to 150 hours in a temperature range of 40 to 90 °C; e. Repeating steps 'c' and 'd' 0 to 5 times more, one after the other, f. Aqueous strong alkali (concentration range from 5 to 40% w) wash at LHSV 0.1 to 0.5 h-1 for 2 to 40 hours at a temperature range of 20 to 90 °C, under nitrogen (GHSV 2 to 50 h-1); g. Keeping the above mass for 0 to 24 hours at 20 to 90 °C temperature, under nitrogen (GHSV 2 to 50 h-1); h. Aqueous weak alkali (concentration range from 0 to 5% w) wash for 0 to 24 hours at LHSV 0 to 0.2 h-1 and 20 to 90 °C temperature, under nitrogen (GHSV 2 to 50 h-1), followed by: i. Demineralized (deionized) water wash at LHSV 0.05 to 0.2 h-1 at 20 to 90°C, under nitrogen (GHSV 2 to 50 h-1) till the pH of the outlet solution is neutral; j. Converting the catalyst precursor prepared in a manner described in earlier steps to active catalyst 'in-situ' or separately, by simultaneous introduction of pure acetylene and aqueous formaldehyde at suitable space velocities, low temperatures to achieve high catalyst activity, longer life as well as better ability for regeneration, resulting in a product suitable for achieving downstream products quality. The aqueous formaldehyde may be ion exchange treated in a concentration range of 15 to 37% w, preferably 10 to 20 % w, containing acidity (expressed as formic acid) less than 0.023 % w, pH of the solution in the range of 5 to 9, with or preferably without the addition of any alkali. For acetylene gas GHSV is 3 to 50 h-1 and the aqueous formaldehyde LHSV is 0.01 to 0.6 h-1 whereas the reaction is carried out at 50 to 100 °C, preferably 70 to 95 °C and below 2 atmospheres pressure, preferably just above atmospheric pressure. The continuous single tube reactor smaller as well as bigger versions are made up of stainless steel, with jacketed arrangement for cooling (with cooling water) or alternatively heating (with steam) whenever required to maintain the reactor temperature. It has two separate inlets for liquid and gas at the bottom. liquid overflow arrangement as well as gas outlet after a gas-liquid separator is provided at the top of the reactor. The gas outlet is passed through a water seal. liquid is introduced with the help of metering pumps from stainless steel storage tank, whereas gas is provided from gas cylinders, with the help of pressure regulators. All the runs are carried once through. In a multi tubular industrial setup, gas recycle arrangement can be easily done. The reactor is subsequently run continuously for a period of 15 to over 100 days, under the above parameters. The operation is discontinued whenever the reactor pressure drop increases rapidly beyond 0.5 atmospheres or there is significant reduction in catalyst activity. At this stage, the catalyst can be regenerated effectively in the following manner: a. Displacement of the reaction mass completely with demineralized (deionised) water, after cooling the same to 20 to 35 °C, at the same space velocity as that for the reaction; b. Displacement of acetylene gas with nitrogen at 20 to 35 °C for 24 hours at the same space velocity as mat for the reaction; c. 2% alkali wash (preferably sodium hydroxide) for 24 to 48 hours at 20 to 35°C, at LHSV 0.01 to 0.6 h-1 GHSV 3 to 50 h-1 followed by demineralized water wash under the same conditions, till neutral pH; d. Obtaining active catalyst in a similar manner, as described earlier in step 'j', as mentioned for fresh catalyst The regenerated catalyst can be run under the same process conditions with activity of 60 to 100% as that for the fresh catalyst The catalyst of this invention has been effectively used in a single tube reactor and can be used in similar or multi tubular continuous industrial reactors for long periods of operation at higher activity and better regeneratability and can produce 1,4 butynediol suitable for better quality downstream products, including 1,4 butenediol, produced by selective hydrogenation. The present invention is described below by way of examples. However, the following examples are illustrative and should not be construed as limiting the scope of the invention. EXAMPLE 1 Runs in smaller continuous single tube reactor (alkali used: sodium carbonate) 1. Activated alumina spheres size 2 to 5 mm diameter, surface area 300 to 375 m2/g pore volume 0.3 to 0.5 cc/g, bulk density of 0.76 to 0.84 (0.8) g/cc, with the chemical analysis, given in Table 1 were packed in a continuous packed bubble column single tube reactor made up of stainless steel, with a cooling water jacketed arrangement for heat removal, as well as heat up arrangement with steam, whenever required. The reactor had separate inlets for gas and liquid at the bottom as well as separate outlets for both at the top. Table 1 A1203 92% (mm) Na20 0.25% (max) Fe2O3 0.15% (max) Si02 0.15% (max) Loss on ignition 5 to 7% 2. It was dried for about 4 to 6 hours with a reactor temperature maintained between 80 to 90 °C with nitrogen gas introduced from the bottom of the reactor (GHSV 10 h-1). The gas outlet from the reactor was vented off though a water seal. Afterwards nitrogen was stopped, but the average reactor temperature was maintamed at 60 °C. 3. 5000 cc of hydrated copper nitrate / bismuth nitrate solution was separately prepared with the following concentration : - Concentration of copper nitrate trihydratc : 1087 g/lit - Concentration of bismuth nitrate pentahydratc : 163 g/lit -Concentrated nitric acid : Quantity just adequate to dissolve the above solids. - Balance was made upto a volume of 5 liters (5000cc) with the help of dcmincralizcd water. The above solution was slowly introduced from the bottom of the reactor (through the liquid inlet) maintained at 60 °C, till overflow is observed from the liquid outlet at the top. During this impregnation step, the gas vent was kept open. The period for impregnation was 12 hours. After this, the excess solution was drained from the bottom of the reactor and the quantity measured to know the quantity of soluiion impregnated on the support. 4. Subsequently, the impregnated mass was dried under nitrogen introduced from the reactor bottom, in a similar manner as mentioned in step 2. Thereafter the reactor was cooled to ambient temperature (30 C ). 5. Alkali in ihc form of 15% w sodium carbonate solution was prepared and passed through the same reactor via liquid inlet at the reactor bottom, with the help of a metering pump with LHS V of 0.4 h-1. Nitrogen was introduced from gas inlet at the rector bottom with GHSV 10 h-1 and outlet gases vented off through water seal. Liquid from the reactor outlet at the top was also collected separately. This was continued for 2 to 3 hours at 20 to 30 °C. 6. Thereafter, the liquid flow to the reactor was stopped. The reactor mass was maintained at 20 to 30 °C (under nitrogen GHSV 10 h-1) for i S to 19 hours. 7. This was followed by deminerahzed water wash (under nitrogen GHSV 3 h) at LHS V 0.08 h'J and 25 to 40 °C temperature, till pH of the outlet solution was neutral. The catalyst precursor thus produced 'in-situ' was subsequently converted to cuprous acetylide complex in the reactor itself as follows: 8. 20% w aqueous formaldehyde (for which formic acid content is brought down to a level of less than 0.023% w by ion-exchange resin treatment) with pH of 5 to 6, was introduced from reactor inlet at LHSV 0.1 h-1 with nitrogen at the same space velocity as mentioned previously, under a reactor temperature of70°C. 9. Subsequently, nitrogen was replaced with pure acetylene GHSV 11 h"1. 20% w formaldehyde feed was continued as before in previous step, the reactor temperature being maintained at about 70 C of gas was vented through a water seal, as described earlier. Thereafter, the same reactor was run continuously for 55 days with 20% w formaldehyde feed of the earlier specifications at an average LHSV 0.044 h"1 and GHSV 11.1 h-1 under slightly positive pressure (water seal) at a temperature range of 70 to 80 °C. Under these conditions, the catalyst exhibited an average activity of 130 to 150 g butynediol/kg catalyst per day and a productivity of 7.3 to 10 kg butynediol per kg of catalyst charge was obtained. EXAMPLES 2 TO 5 Runs in bigger continuous single tube reactor with a scale-up ratio of 1:17 times smaller reactor (alkah used: sodium carbonate) 1. Activated alumina spheres with the properties as described in Example 1 were packed in a continuous packed bubble column made up of stainless steel as before, the rector being a scaled up version 1:17 times that of the reactor, as described in Example 1. All other reactor arrangements were similar to those mentioned in Example 1. 2. Drying of the same was carried out for 24 hrs (for all i.e. Examples 2 to 5), at 70 °C with nitrogen, GHSV from 6 to 13 h-1, of being vented through water seal as before, in Example 1. Afterwards nitrogen was stopped, but the average temperature was maintained at70°C. 3. Copper nitrate / bismuth nitrate solution with the same concentration as that described in Example 1, was taken in adequate quantity required for higher scale operation. Impregnation of the same on activated alumina support in the reactor itself, was also carried out in a similar manner as described in Example 1. 4. Thereafter 12 to 30% w sodium carbonate solution (alkali) was prepared and passed through the same reactor in similar way as described in Example 1, LHSV being in the range of 0.05 to 0.3 h-1 and GHSV for nitrogen 6 to 13 h-1 under 70 to 80 °C temperature for 8 to 24 hours. 5. Thereafter liquid flow was stopped in a manner similar to Example 1, however reactor temperature maintained at 70 °C, under nitrogen GHSV 6 tol3 h-1 for 16 to 24 hrs. 6. This was followed by demineralized water wash till pH of outlet solution is neutral, in a similar manner as described in Example 1 LHSV of 0.08 h-1, nitrogen GHSV of 3 h"\ and under 50 - 90 °C temperature. The catalyst precursor thus prepared was subsequently converted to cuprous acetylide complex in the reactor itself as follows: 7. 20% w aqueous formaldehyde with the same specifications as those described in Example 1, was introduced from the reactor inlet under LHSV 0.03 to 0.06 h"1, with reactor temperature maintained at 70°C. 8. Pure acetylene was simultaneously introduced into the reactor under GHSV 6 to 13 h-1. Thereafter the same reactor was continuously runs with 20% w formaldehyde feed of earlier specifications, the results are summarized in Table 2, the pressure maintained in all the Examples being just positive pressure (water-seal). Table 2 Summary of Ethynylation Reaction Results Example No. Running Period, (Days) Average LHSV, h1 Average GHSV, h1 Temperature, Catalyst Activity, g butynecfiol/ kg- catalyst-day Catalyst Productivity, kg-butyneoloi /kg-catalyst 2 33 0.043 10.0 80-90 160 4.10 3 15 0.058 12.35 60-65 150 2.42 4 15 0.058 9.41 70-80 155 2.85 5 100 0.035 6.47 80-90 56 6.3 Runs had to be discontinued when these was a sharp rise in reactor pressure drop from 0.1 to more than 0.6 atmosphere. The product acidity (formic acid) increased from 0.5 to 1.4 % w correspondingly. The discharged catalyst showed agglomerates formation near the reactor inlet portion. EXAMPLE 6 Runs in bigger continuous single tube reactor with a scale-up ratio of l:17times smaller reactor (alkali used: sodium carbonate) Effect of variation of catalyst quantity The same continuous packed bubble column single tube reactor set-up as described in Examples 2 to 5, was used under by maintaining similar operating parameters, except that the quantity of alumina packed in mis case was 70% of that mentioned therein. The catalyst precursor as well as copper acetylide complex prepared and further reaction carried out in a manner similar to Examples 2 to 5, except that step 5 described therein being eliminated Continuous running for 33 days at average LHSV 0.067 h-1, average GHSV 4.7 h-1 in a temperature range 70 to 80 °C and slightly positive pressure as described before achieved average catalyst activity 171 g B3D/kg-cat-day and the productivity 5.8 kg B3D/kg catalyst charge. Runs had to be discontinued when there was a sharp in reactor pressure drop from 0.1 to more than 0.6 atmospheres. The product acidity, correspondingly, increased from 0.5 to 1.5% w. The discharged catalyst showed agglomerates formation near the reactor inlet portion. EXAMPLE 7 Runs in bigger continuous single tube reactor with a scale-up ratio of 1:17 times smaller reactor (alkali used: sodium carbonate) The same continuous packed bubble column single tube reactor set up and the catalyst precursor/active catalyst prepared as described in Examples 2 to 5 was used under steady operating parameters and normal quantity of alumina. Continuous running for 48 days at average LHSV 0.064 h-1, average GHSV 11.76 h-1 at 70 to 80 C and slightly positive pressure (as described before) achieved a higher catalyst activity and productivity, 216 gB3D/kg-cat-day and 9 kg B3D/kg-catalyst charge, respectively. In this case too, runs had to be discontinued with sharp rise in reactor pressure drop from 0.1 to more man 0.6 atmospheres. The product acidity, correspondingly, increased from 0.5 to 1.3 % w. The discharged catalyst showed agglomerates formation near the reactor inlet portion. EXAMPLE 8 Runs in bigger continuous single tube reactor with a scale-up ratio of1:17 times smaller reactor (alkali used: sodium hydroxide) 1. Activated alumina spheres with the same specifications as described earlier, were packed in the same continuous packed bubble column single tube reactor, as described in Examples 2 to 5, 6 and 7. 2. Drying the same was carried out for about 24 hours at 70 to 80 °C under nitrogen GHSV 10 h-1 in the same manner as described earlier. The average reactor temperature was maintained at 25 to 50 °C, subsequently after stopping nitrogen. 3. Adequate quantity of hydrated copper nitrate / bismuth nitrate solution in the same concentration range was taken and impregnation of the same in the reactor itself, was carried out as described in earlier Examples. 4. Subsequently, the impregnated mass was dried under nitrogen in a similar manner as described in Example 1. 5. Thereafter 10% w sodium hydroxide solution (alkali) was passed through the same reactor in a similar manner as described in Example 1, LHSV 0.3 to 0.5 h-1. Nitrogen was also introduced GHSV 10 h-1 in a similar manner, as described earlier. Liquid from the reactor outlet at the top was also collected similarly. The alkali wash duration was 3 to 4 hours, under a temperature of 25 to 40 °C. 6. Slightly weaker alkali solution (2% w sodium hydroxide) was subsequently passed through the reactor by the same arrangement as mentioned in the earlier step 6 under same space velocities for 16 to 24 hours at temperature 50 to 90 °C. 7. This was followed by demineralized water wash in a similar manner to that described in Example 6, till pH of the outlet solution became neutral. The catalyst precursor produced 'in-situ' in the manner described earlier, was converted to cuprous acetylide complex in the reactor itself as follows: 8. 15% w aqueous formaldehyde, (containing formic acid less man 0.023% w by ion exchange resin treatment) with a pH 5 to 6 was introduced from reactor inlet LHSV 0.06 to 0.11 h-1 under nitrogen GHSV 10 to 12 h-1, for 0 to 4 hours and at temperature 70 to 90 °C. 9. Subsequently, nitrogen was replaced with pure acetylene GHSV (11 h-1). 15% w formaldehyde feed was continued as before in previous step, the reactor temperature being maintained at about 90 °C and off gas vented through a water seal. Thereafter, the same reactor was run continuously wim 15% w formaldehyde of earlier specifications for 38 to 48 days at an average LHSV 0.06 to 0.11 h'1 and GHSV of 11.76 h\ under slightly positive pressure, in a temperature range 70 to 90 °C. Under these conditions, the catalyst exhibited an average activity of 50 to 170 g butynediol/kg catalyst per day and a productivity of 2.5 to 10 kg butynediol per kg of catalyst charge, was obtained. Runs were discontinued with sharp rise in reactor pressure drop from 0.1 to more man 1.5 atmospheres. The product acidity, correspondingly, increased from 0.5 to 1.2% w. The discharged catalyst showed agglomerates formation near the reactor inlet portion. EXAMPLE 9 Runs in bigger continuous single tube reador with a scale-up ratio of 1:17 times smaller reador (alkali used: sodium hydroxide) Effect of dilute copper / bismum nitrates solution 1. For this case also, activated alumina spheres with the same specifications as mentioned earlier were taken in the same reactor, as described in Example S. 2. Drying was carried out under similar conditions mentioned in Example 8, excepting the period which was 48 hours. The reactor temperature was maintained at 70 °C alter stopping mtrofien. 3. Adequate quantity of hydratcd copper nitrate /bismuth nitrate solution was prepared separately with the following concentration Concentration of copper nitrate irihydratc 725 g/lit Concentration of bismuth nitrate pentahydrate ; 109 g/lit Concentrated nitric acid Quantity just adequate to dissolve the above solids. Balance was made upto the final requisite quantity of solution required for impregnation, with the help of dcmincralizcd water. Impregnation of the same in the reactor itself was carried out in a similar manner as described in Example S. 4. The impregnated mass was dried in a similar manner as described in Example S. 5. Thereafter 10% w sodium hydroxide solution (alkali) was passed through the same reactor, in a similar manner and under same operating parameters, as described in Example 8. 6. 2% w Sodium hydroxide (weak alkali) solution was also passed through the same reactor, in a similar manner and under same parameters, as elaborated in Example 8 excepting the reactor temperature, which was maintained at 70 to 80 °C. 7. This was followed by demineralized water wash in a similar manner and conditions, as described in Example 8. 8. The catalyst precursor, produced in the manner described earlier, was subsequently converted into copper acetylide complex in a similar manner as described in Examples 2 to 5, 6 and 7 by simultaneous introduction of aqueous formaldehyde earlier described specifications and pure acetylene gas. Thereafter, the reactor was run continuously for 26 days with 10% w average formaldehyde of earlier specifications described under average LHSV 0.22 h'1, average GHSV 11.76 h"1, under slightly positive pressure (as described earlier), in a temperature range of 70 to 80 °C. Under these conditions, the average catalyst activity obtained was 125 g butynediol/kg catalyst-day and productivity 2.1 kg butynediol/kg-catalyst charge. Runs were discontinued with sharp rise in reactor pressure drop from 0.1 to more man 1.8 atmospheres. The product acidity, correspondingly, increased from 0.1 to 0.4%w. The discharged catalyst showed agglomerates formation near the reactor inlet portion. EXAMPLE 10 Runs in bigger continuous single tube reactor with a scale-up ratio of 1:17 times smaller reactor (alkali used: sodium hydroxide) Catalyst regeneration / revival Activated alumina spheres with the same specifications as described in the earlier Example 8 were taken in the same reactor as described therein. The catalyst precursor, and thereafter copper acetyiide complex were also prepared in a similar manner as described therein. The reactor was run continuously in a temperature range of 70 to 80 °C, under GHSV 11.76 h1 and LHSV 0.12 to 0.2 h"1 and 15% w formaldehyde coirforming to the earlier specifications. The catalyst activity achieved was 240 to 336 g butynediol/kg-cat-day and productivity 1.4 to 2.2 kg butynediol/kg-catafyst. However, the catalyst pressure drop increased steeply upto about 2 atmospheres, after a running period of about 21 to 32 days. The catalyst regeneration was carried out in the following manner : a. The reactor was cooled down to 20 to 35 °C, and then the reactor mass was displaced completefy with demineralized water; b. Acetylene gas was displaced with nitrogen at 20 to 35 °C for 24 hrs, at the same space velocity of acetylene as before; c. 2% w sodium bicarbonate wash (alkali) was given to the reactor for 4 hours, followed by 1 to 2% w sodium hydroxide wash for 24 hrs, followed by demineralized water wash under nitrogen till neutral pH, under 25 to 40 °C temperature, GHSV 11.76 K\ LHSV 0.03 to 0.4 h"1. d. Thereafter 15% w aqueous formaldehyde, conforming to earlier specifications, with pH adjusted to 8.5 (by adding sodium bicarbonate 0.4 to 0.9% w) and pure acetylene were simultaneously introduced, after the reactor temperature was achieved 70 to 90 °C. Afterwards the reactor was run for 36 to 55 more days with the same parameters as earlier. The average catalyst activity after regeneration was found to be 148 g burynediol/kg-cataryst-day and productivity was found to be 2.4 to 3.5 kg butynediol/kg-catalyst The discharged catalyst showed agglomerates formation near the reactor inlet portion. EXAMPLE 11 Runs in bigger continuous angle tube reactor nith a scale-up ratio of 1:17 times smaller reactor (alkali: Sodium hydroxide) Mixed Bed Operation Activated alumina spheres with the same specifications as described in the earlier examples were mixed in various proportions by volume with inerts viz. commercial porcelain intelox saddles (bulk density = 1.161 g/cc, size 5 mm) and charged to the same reactor as described in earlier examples. (A) The mixed catalyst bed containing 25% by volume of catalyst and the balance inerts was taken. Catalyst precursor and thereafter copper acetylide complex were prepared in a similar manner to that described in Example 8. Thereafter the reactor was run continuously for a period of 90 days with 10 to 15% w aqueous formaldehyde of earlier specifications with sodium bicarbonate contents in the range of 0.2 to 0.5% w, LHSV 0.05 h~\ GHSV 11.76 h"1 with average reaction temperature 70 to 90 °C. Under these conditions, the catalyst activity & productivity for the mixed catalyst bed are shown in Table 2. Table 2 Results for 25% v mixed catalyst in the reactor No. Based on overall quantity of mixed bed Based on active catalyst contents in mixed bed 1. Activity, g butynediol/kg-cat-day 43 168 2. Productivity, kg butynediol/kg-catalyst 3.83 18.1 (B) In this case, the mixed bed contained 60% v of the catalyst and balance inerts, described earlier. All other steps involved in part (A) were repeated for catalyst precursor / copper acetylide complex preparation in the same manner as described therein. Thereafter, the reactor was run continuously for a period of 70 to 100 days with 10 to 15% w aqueous formaldehyde solution of earlier specifications and without any alkali added to it, at LHSV 0.15 to 0.2 h'1, GHSV 11.76 h'1 and average reaction temperature 70 to 90 °C. Under these conditions the catalyst activity and productivity for the mixed bed are shown in Table 3. Table 3 Results for 60% v mixed catalyst in the reactor. s. Based on overall Based on active No. quantity of mixed catalyst contents bed in mixed bed 1. Activity, g butynediol/kg-cat-day 120 to 140 240 to 360 2. Productivity, kg butynediol/kg-cataryst 2.5 to 7.6 4.5 to 14 In bom the cases 'A' and 'B', runs were discontinued with sharp rise in pressure drop from 0.1 to more man 0.5 atmospheres. The product acidity, correspondingly, increased from 0.2 to 0.5% w. The discharged catalyst showed agglomerates formation near the reactor inlet portion. EXAMPLE 12 Runs in bigger continuous single tube reactor nitk a scale-up ratio of l:17tunes smaller reactor (alkali: Sodium hydroxide) Effect of stoppage of liquid input (reactant): Mixed bed operation A run was taken in the same reactor and in the same manner as described in detail in Example 11. After running at average activity of 125 g butynediol/kg-cataryst-day and after achieving a productivity of 6.8 kg butynediol/kg-catalyst, the reactor was maintained under following parameters for 40 hours: a. Liquid flow to the reactor was stopped; b. Acetylene flow continued through the reactor at the same GHSV (i.e. 11.76 b'1) as before; c. Reactor temperature was maintained at 90 °C. Under these conditions, the reactor pressure drop increased steeply from 0.1 atmospheres upto 2 atmospheres. Thereafter, the reaction was discontinued and catalyst was safely discharged. The observation of the discharged catalyst showed that the catalyst part in the mixed bed, was reduced to a hard impervious mass, agglomerates, whereas the inert rings part was intact Since acetylene supply was continuously 'on1, possibility of cuprene formation was ruled out Thus it is attributed to the reaction of stagnant formaldehyde mass with acetylene leading first to butynediol and subsequently to some heavier / tarry compounds obtained from subsequent reactions since the heat of reaction is not properly removed from the catalyst surface, thereby hot spots formation and generation of high temperatures on the catalyst surface (Ref : Patent #1,35,195), with no fresh reactant make up, subsequently leading to agglomeration. EXAMPLE 13 Runs in bigger continuous single tube reactor mth a scale-up ra&o of 1:17 times smaller reactor (alkali: Sodium hydroxide) Effect of catalyst shape : Dilute copper bismuth nitrates solution. Alumina spheres of diameter 3 to 5 mm, bulk density 1 to 1.2 g/'cc and alumina rings 16 mm outer diameter, 9 mm internal diameter and 16 mm length, with bulk density 0.95 g/cc with a similar chemical composition, surface area and pore volume range, as described in Example 1 as well as subsequent examples, were mixed in equal proportion and charged to the same continuous packed bubble column single tube reactor as mentioned in the preceding examples. Catalyst precursor as well as copper acetylide complex were prepared by the following method : 1. Drying of the support was carried out for a period of 50 to 120 hours at 70 to 90°C under mtrogen GHSV 20 h"2. Afterwards nitrogen was stopped, however the reactor temperature was maintained at 90 °C. 3. Adequate quantity of copper nitrate / bismuth nitrate solution in the same concentration range as described in Example 9 was prepared. Impregnation of the same in the reactor itself, was carried out in a similar manner, as described in Example 8. 4. The impregnated mass was dried in a similar manner as described in Example 8. 5. Afterwards nitrogen was stopped as described in step 2 and copper nitrate / bismuth nitrate solution of earlier concentration was again impregnated in the reactor itself in similar manner described in step 3 and drying of impregnated mass was carried out in similar manner as described in step 4. 6. The sequence as described in step 5 was repeated once more. 7. Thereafter 10% sodium hydroxide solution (alkali) was passed through the reactor LHSV 0.1 to 0.2 h"1 under nitrogen gas GHSV 17 to 27 h"1 for 4 to 5 hours under a temperature of 25 to 40°C. 8. Similarly, 2% sodium hydroxide solution was subsequently passed through the reactor under same liquid and gas space velocities for 20 hours, however the temperature range was 70 to 80°C. 9. This was followed by demineralized water wash in a similar manner to Example 8, in the same temperature range described therein, except that LHSV 0.1 to 0.12 h-1 and GHSV of 17 to 27 h"1 were maintained, till pH of the outlet solution became neutral. 10. The catalyst precursor produced in the manner described earlier was converted 'in-situT in the reactor itself, to cuprous acetylide complex in the following manner: 10% w aqueous formaldehyde of earlier described specifications, was introduced into the reactor simultaneously with pure acetylene gas, at a temperature of 90 to 95°C, LHSV 0.1 to 0.12 h"1 and GHSV 17 to 27 h1. Thereafter the reactor was run with the formaldehyde of the specifications given earlier, continuously for a period exceeding 60 days under the same temperature, liquid / gas space velocities and under slightly positive pressure, as described before. Under these conditions, the catalyst activity was very much steady at 108 g butynediol/kg catalyst-day and the productivity 5.18 kg butynediol/kg-catalyst (lower figures attributed to dilute nitrates solution for impregnation). The most significant factor being the reactor pressure drop, which was constant from beginning to end at about 0.1 atmosphere. The reactor product acidity (formic acid) also showed a steady value of 0.15% w. Catalyst regeneration The catalyst activity, on prolonged running in the above maimer gradually reduced to about 60% of the original activity. At this juncture, the regeneration method, as described in Example 10 was followed in all respects excepting that in steps 'c'. 2% w sodium hydroxide wash given at 25 to 40 °C for 48 hours followed by demineralized water wash till neutral pH under nitrogen GHSV 20 h"1 and LHSV 0.5 h"1. Thereafter in step 'd' 15% w aqueous formaldehyde of the earlier specifications and without any extra alkali added to the same and pure acetylene were simultaneously introduced at 90 to 95 °C. The reaction runs were restarted under the same conditions as described before. The regenerated catalyst exhibited 75% activity and runs were carried out for one more month after regeneration. EXAMPLE 14 Runs in bigger continuous single tube reactor with a scale-up ratio of 1:17 limes smaller reactor (alkali: Sodium hydroxide): Effect of catalyst shape: Normal concentration of copper nitrate /bismuth nitrate For mis case, all the conditions / parameters and steps involved were exactly similar to Example 13, except the following : a. Only alumina rings 16 mm outer diameter, 9 mm inner diameter and 16 mm length were used completely in the reactor; b. Concentration range of copper nitrate/bismuth nitrate for impregnation was the same as that described in all the previous examples, except Example 9 and Example 13. The reactor runs under similar operating parameters to those mentioned in Example 13 showed good activity sustained for much longer periods man those described earlier, as well as consistently lower pressure drop and lower acidity. The product butynediol thus produced after purification (filtration or solid-liquid separation not required), showed good selectivity to its downstream product 1,4 butenediol, after hydrogenation. (Ref: Indian Patent Application No. 2215/MUM/2008 A, filing date, 15/10/2008). We claim: 1. An 'in-situ' prepared improved catalyst, for low pressure continuous butynediol synthesis from an industrially available support of suitable shape and size, as such or with inerts as mixed bed, in the following manner: a. Packing of the support in a bubble column stainless steel reactor; b. Drying of the support at 50 to 90 °C for 4 to 150 hours under nitrogen gas, GHSV 2 to 20 h1; c. Impregnation of a solution prepared from commercially available copper nitrate trihydrate and bismuth nitrate pentahydrate, in the concentration range of 500 to 1500 g/litre and 100 to 200 g/litre respectively, for 1 to 80 hours, in a temperature range of 20 to 90 °C; d. Drying of impregnated mass under nitrogen (GHSV 2 to 20 h"1) for 2 to 150 hours in a temperature range of 40 to 90 °C; e. Repeating steps V and d' 0 to 5 times more, one after the other f. Aqueous strong alkali (concentration range from 5 to 40% w) wash at LHSV 0.2 to 0.5 h"1 for 2 to 40 hours at a temperature range of 20 to 90 °Q under nitrogen (GHSV 2 to 50 h"1); g. Keeping the above mass for 0 to 24 hours at 20 to 90 °C temperature, under nitrogen (GHSV 2 to 50 h'1); h. Aqueous weak alkali (concentration range from 0 to 5% w) wash for 0 to 24 hours at LHSV 0 to 0.2 h"1 and 20 to 90 °C temperature, under nitrogen (GHSV 2 to 50 h"1), followed by : i. Demineralized (deionized) water wash at LHSV 0.05 to 0.2 h"1 at 20 to 90°C, under nitrogen (GHSV 2 to 50 h"1) till the pH of the outlet solution is neutral; j. Converting the catalyst precursor prepared in a manner as described in the earlier steps, to active catalyst 'in-situ' or separately, by simultaneous introduction of pure acetylene and aqueous formaldehyde at suitable space velocities, low temperatures, to achieve high catalyst activity, longer life as well as better ability for regeneration, resulting in a product suitable for achieving downstream products quality. 2. The said low pressure, as claimed in Claim 1, which is below 2 atmospheres, and most preferably, just above atmospheric pressure. 3. The said industrially available support, as claimed in Claim 1, which is preferably alumina. 4. The said support of suitable shape, as claimed in Claims ! and 2, which includes cylindrical rings or spheres. 5. The said support, as claimed in Claims 1, 2 and 3, which includes cylindrical rings, preferably (6 to 16 mm) outer diameter x (3 to 9 mm) internal diameter x (6 to 16 mm) long or spheres preferably 2 to 9 mm diameter. 6. The said support, as claimed in Qaims 1, 2,3 and 4, which has a bulk denary preferably 0.7 to 1.1 g/cc, pore volume preferably 0.2 to 0.5 cc/g and a most preferable chemical composition as follows: a. Aluminium Oxide 92% w (minimum) b. Sodium Oxide 0.25% w (maximum) c. iron Oxide 0.15% w (maximum) a Silica 0.15% w (maximum) c. Loss on ignition 7% w (maximum) 7. The said incrts, as claimed in Claim 1, which arc made up of porcelain and include any standard shapes (rings, saddles etc.), and a size range of 3 to 9 mm, with bulk density from 0.3 to 1.2 g/cc. The said packed bubble column stainless steel reactor, as claimed in Claim la, which includes a standard single tube reactor as such or may be as a single tube as a part of a multi tubular industrial reactor. The said alkali, as claimed in Claims If and lh, which includes sodium hydroxide, sodium carbonate, sodium bicarbonate and which is most preferably, sodium hydroxide. The said aqueous formaldehyde, as claimed in Claim lj, which is ion exchange treated and the concentration of which may vary from 5 to 37% w, most preferably 10 to 20% w, containing acidity less than 0.023% w and pH 5 to 9, with or without alkali added to the same. The said space velocities, as claimed in Claim lj , which are in die range of GHSV 3 to 50 h"1 for acetylene and LHSV 0.01 to 0.6 h"1 for aqueous formaldehyde. The said low temperatures, as claimed in Claim lj , which are in the range of 50 to 100 °C most preferably from 70 to 95 °C. The said better ability for regeneration, as claimed in Claim 1, for which catalyst regeneration is carried out in the following manner: Displacement of the reaction mass completely with demineralized (deionized) water, after cooling the same to 20 to 35 °C, at the same space velocity at that for the reaction; Displacement of acetylene gas with nitrogen at 20 to 35 °C for 24 hours at the same space velocity as that for the reaction; 2% w alkali wash (preferably sodium hydroxide) for 24 to 48 hours at 20 to 35°C, LHSV 0.01 to 0.6 h~\ GHSV 3 to 50 h"1, followed by demineralized water wash, under the same conditions, till neutral pH; d. Obtaining active catalyst, as claimed in Claim 1, in similar manner, as described in Claim lj. 14. The said catalyst activity, as claimed in Claims 1 to 13, which is in the range of 50 to 10,000 g butynediol/kg-catatyst-day. 15. The said catalyst, as claimed in Claims 1 to 14, which can be run for very long periods ranging from 15 days to 360 days, or beyond. 16. The said product, as claimed in Claims 1 to 15, which includes butynediol suitable for achieving downstream 1,4 butenediol quality. 17. The said product, as claimed in Claims 1 to 16, the purification of which does not involve any filtration step. 18. The 'in-situ' prepared catalyst precursor as claimed in Claim 1 'a' to 'i' (inclusive) , prepared in eco-friendly manner by eliminating the evolution of oxides of nitrogen, during its preparation. 19. The said catalyst, as claimed in Claims 1 to 18, suitable for continuous low pressure butynediol process, showing high activity and life and which can be scaled-up nearly 2500 times from said packed bubble column single tube reactor to a similar multi tubular industrial scale reactor, without adversely affecting the activity and life claimed therein, substantially as herein described with reference to Examples 1 to 14 in the specification. Dated this day of 2009 For and on behalf of HINDUSTAN ORGANIC CHEMICALS LIMITED (ARVIND SHRIRAM DIDOLKAR) CHAIRMAN AND MANAGING DIRECTOR

Full Text

FORM 2
THE PATENT ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(See Section 10, Rule 13)
1. TITLE OF THE INVENTION: AN IN-SITU' PREPARED, IMPROVED
CATALYST FOR LOW PRESSURE
CONTINUOUS BUTYNEDIOL SYNTHESIS.

2. APPLICANT(S)
(a) Name:
(b) Nationality:
(c) Address:
M/s. HINDUSTAN ORGANIC CHEMICALS LIMITED
Indian
Mr.A. S, Didolkar.CMD
81, Maharshi Karve Road, MUMBAI -400 002,
Maharashtra, India,
3. PREAMBLE TO THE DESCRIPTION:
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it is to be performed:

PRIOR ART
Ethynylation of formaldehyde to 1,4 butynediol by the original Reppe process has undergone many improvements over the years. The higher pressure process is mainly associated with problems of inherent safety, due to handling of acetylene gas, since the reactors are to be designed for more man 10 times the operating pressure. 1,4-butynediol is an important industrial intermediate for the manufacture of 1,4-butenediol as well as 1,4-butanediol and tetrahydrofuran. Low pressure processes suitable for industrial applications have therefore been extensively studied for various supported / unsupported catalysts in various reactors since men.
Our previous work on bubble column upflow continuous reactors using fixed bed catalyst of copper / bismuth oxides on alumina support precursor (Indian Patent Application NO.1522/MUM/2008, filing date: 18th July 2008) shows that the catalyst activity obtained is higher than mat reported for industrial silica gel based catalyst of the same particle size for just above atmospheric pressure operation at 80 to 90 C. However, the process has the drawback of nitrogen oxides fumes liberated (and environmental problems associated with the same) during the formation of copper / bismuth oxides precursors from their corresponding nitrates. The catalyst particle range referred to in the previous work is comparable to present invention.
Besides this, much significant work is done in the area of slurry reactors, which handle finely divided catalyst powder, unsupported or with catalyst supports, so that the higher surface enables higher activity at lower pressures. US Patent #3,560,576 describes a slurry reactor with 6.7% w/v catalyst loading of fine powered malachite based catalyst precursor with 10 to 20 microns particle size at 50 to 120 °C and pressure below 2 atmospheres for cuprous acetylide catalyst generation and subsequent ethynylation of formaldehyde solution. US Patent #3,954,669 reports preparation of manassite from nitrates of copper, magnesium and aluminium with mixture of sodium carbonate and hydroxide which is then converted to cuprous acetylide complex in slurry reactors. The particle size of the catalyst is less than 100 microns and is used in batch reactor as well as CSTR in loading of 3.8 to 7.4% w/v. The reaction is at nearly atmospheric pressure at 65 to 90 °C and the catalyst shows high activity. Subsequent US Patent #4,062,899 shows extension of the previous

work, using nitrates of copper and aluminium with sodium bicarbonate for slightly bigger particle size of 130 microns and 3.8% w/v catalyst loading, achieving a comparable catalyst activity (expressed in g butynediol/kg-cataryst-day) with that reported in the earlier patent Another US patent #4,584,418 describes malachite preparation from copper nitrate with sodium carbonate for very fine particle size (S microns). The reaction parameters are about the same as earlier reported ones, whereas a significantly lower catalyst loading (0.01% w/v) is used. The activity achieved is much higher than mat reported in the earlier two referred patents.
Polish patent #1,35,195 reports a much larger particle size in the range of 0.1 to 0.4 mm under nearly same operating conditions, for a supported catalyst (activated charcoal etc.) with significantly higher (10.8% w/v) catalyst loading in intensively stirred batch slurry reactor. It claims much improved catalyst activity corresponding to its particle size as well as absence of tarry substances (in the product) usually formed at higher temperatures which are difficult to separate from the products. It also eliminates the use of higher temperatures (more man 350 °C) reported in the earlier work thereby eliminating exposure to nitrogen oxides fumes and related environmental problems.
Prior art not only reports cuprous acetylide complex catalysts for the synthesis of butynediol from aqueous formaldehyde and acetylene, but its extension to synthesis of diethylaminopentynol as well as butynediol, without involving acetylene gas. A recent US patent #6,350,714B regarding mis reports preparation and application of unsupported catalyst based on malachite with 4% bismuth contents generated in presence of aqueous formaldehyde and nitrogen followed by aqueous propargyl alcohol feed. Butynediol synthesis is carried out in this particular case with formaldehyde and propargyl alcohol using 3 to 15% w/v catalyst loading at 90 °C and nearly atmospheric pressure.
The main disadvantages of using the fine powder catalysts in the slurry reactors is their handling and effective separation aspects. Another part associated with them is the catalyst precursor as well as catalyst (cuprous acetylide complex) is prepared separately, and is subsequently charged to the reactor. This involves safe handling part for cuprous acetylide, which is very much critical on the industrial scale.

Although the catalyst activities reported for these catalysts are very much on the higher side, it is mainly attributed to their very fine particle size. Their equivalent activity for a bigger particle size (say 2 to 5 mm) is far from satisfactory for industrial scale operation. Also most of these patents do not report the catalyst life, which is another limitation.
Continuous reactors either in fixed beds or bubble column slurry reactors, have their obvious advantages over batch or slurry type of reactors handling powdered catalyst US patent #4,067,914 describes manufacture of butynediol in a bubble column upflow slurry reactor with suspended catalyst based on copper and aluminum complex carbonates / hydroxides precursors. A fine particle size of 20 to 150 microns is used with a high catalyst loading of about 20% w/v which requires effective solid-liquid separation. The clarified product still contains about 20 ppm of suspended matter. A higher activity is reported in an operating range of 60 to 100 °C and nearly atmospheric pressure.
OBJECTIVE OF THE INVENTION
The main objective of the invention is to arrive at a 'in-situ' prepared catalyst precursor based on alumina or any other suitable support, eliminating the environmental problems associated with oxides of nitrogen liberated during its preparation. Moreover the precursor is to be used immediately after cuprous acetylide formation, for continuous packed bubble column industrial reactors, operated at pressure just above atmospheric pressure and in temperature range of 50 to 100 °C. The catalyst should be used effectively for emynylation of formaldehyde, without the need for dosing of alkali to the reactor to maintain pH. Another objective is that the catalyst size has to be such that solids carry over and further separation from liquid is avoided to result in trouble free, safer operation for long periods. A more specific objective is the catalyst shape should also be such that heat dissipation from individual particles to bulk fluid, is fast enough to prevent any localized hot spots, which may cause heavier side products formation, which affect not only butynediol product quality, but that of down stream product too and may cause catalyst agglomeration, thereby high pressure drop through the reactor. In addition to proper

shape to ensure good productivity of the catalyst and good quality of the butynediol produced from this process, the objective is to utilize catalyst is right proportion with suitable inerts to constitute a mixed bed. Finally the objective of the invention is to develop a catalyst which shows good scale-up ability suitable for industrial operation and can be regenerated in an easier manner.
SUMMARY OF THE INVENTION
The present invention discloses an 'in-situ' prepared catalyst precursor on industrial support, available in suitable shapes and sizes with or without combination with inerts for packed bubble column continuous reactor operation. The precursor is prepared using copper/bismuth nitrates and aqueous alkali in eco-friendry manner and converted to corresponding cuprous acetylide complex for etiiynylation of formaldehyde at low pressure and temperature. The catalyst shows high activity, life and can be regenerated in-situ for more cycles, thus reducing considerably the catalyst disposal problems.
In one embodiment of the invention, the industrial support used is alumina spheres in a smaller single tube reactor, the aqueous alkali used being sodium carbonate, the outlet product clear enough, not requiring filtration or any other solid-liquid separation step in further purification processes.
In another embodiment of the invention, the reactor used is a single tube reactor (which can correspond to a single tube of a multi-tubular industrial scale reactor), with a scale-up ratio 17 times that of the smaller single tube reactor, the catalyst being prepared and reactor operated in the same manner as the smaller reactor, showing fair reproducibility in catalyst activity, productivity, and product clarity. Whereas minor variations in catalyst quantity has no effect, steady reaction conditions achieve better activity and productivity for the catalyst Catalyst lumps / agglomerates formation is observed especially at the bottom (inlet) of the reactor, which lead to sudden abnormal pressure drop, towards the end of catalyst life.
In one of the preferred embodiment of the scaled up version of the invention, the alkali used is sodium hydroxide, similar conditions for catalyst preparation and

ethynylation reaction prevailing, the activity and productivity, as well as deactivation phenomenon of the catalyst are comparable to the lower scale version. In another embodiment of the invention, use of lower concentration of nitrates leads to lesser activity and productivity.
In one of the novel embodiments of the invention, the catalyst can be regenerated in an effective manner using the alkali under inert atmosphere and can be activated by more or less similar procedure to fresh catalyst generation.
In another preferred embodiment of the invention, the catalyst support is mixed with inerts in various proportions, the catalyst prepared and used in a similar manner as before. Such a mixed catalyst bed operation shows high catalyst activity and productivity, due to better heat dissipation from the active particles to inerts in their vicinity and lesser side reactions, thereby.
In another preferred embodiment of the invention, the catalyst support is ring shaped: for better heat dissipation required from the particles for achieving highly steady activity and life (productivity), when prepared and operated under similar manner.
In the most preferred embodiment of the invention, the catalyst support in the form of rings of suitable size, is mixed with appropriate quantity of inerts and such a mixed catalyst bed prepared and operated in a similar manner for much longer periods, at higher catalyst activity, resulting in a better quality 1,4 butynediol product (without involving filtration / separation step) suitable for better quality downstream products, including 1,4 butenediol, by selective hydrogenation.
DETAILED DESCRIPTION OF THE INVENTION
The industrially available supports preferably alumina for this invention include spheres of 2 to 5 mm diameter, 0.76 to 0.84 g/cc bulk density, 0.3 to 0.5 cc/g pore volume or rings 12 to 16 mm outer diameter x 6 to 9 mm inner diameter x 12 to 16 mm long, with bulk density 0.8 to 1.1 g/cc, pore volume 0.2 to 0.5 cc/g and chemical composition as follows: Oxides of:

Aluminium: 92% w (mm), Sodium: 0.25% w (max), Iron: 0.15 % w (max) and Silicon: 0.15% w (max), with maximum ignition loss of 7%.
The catalyst precursor of mis invention can be prepared 'in-situ' by the following eco-fnendly manner:
a. Packing of the support with or without inerts, in a bubble column stainless
steel reactor; The inerts may be preferably porcelain rings or saddles, with
3 to 9 mm size with bulk density varying from 0.8 to 1.2 g/cc;
b. Drying of the support at 50 to 90 °C for 4 to 150 hours under nitrogen gas,
GHSV 2 to 20 h-1;
c. Impregnation of a solution prepared from commercially available copper
nitrate trihydrate and bismuth nitrate pentahydrate, in the concentration
range of 500 to 1500 g/litre and 100 to 200 g/litre respectively, for 1 to 80
hours, in a temperature range of 20 to 90 °C;
d. Drying of impregnated mass under nitrogen (GHSV 2 to 20 h-1) for 2 to
150 hours in a temperature range of 40 to 90 °C;
e. Repeating steps 'c' and 'd' 0 to 5 times more, one after the other,
f. Aqueous strong alkali (concentration range from 5 to 40% w) wash at
LHSV 0.1 to 0.5 h-1 for 2 to 40 hours at a temperature range of 20 to 90
°C, under nitrogen (GHSV 2 to 50 h-1);
g. Keeping the above mass for 0 to 24 hours at 20 to 90 °C temperature,
under nitrogen (GHSV 2 to 50 h-1);
h. Aqueous weak alkali (concentration range from 0 to 5% w) wash for 0 to 24 hours at LHSV 0 to 0.2 h-1 and 20 to 90 °C temperature, under nitrogen (GHSV 2 to 50 h-1), followed by:

i. Demineralized (deionized) water wash at LHSV 0.05 to 0.2 h-1 at 20 to 90°C, under nitrogen (GHSV 2 to 50 h-1) till the pH of the outlet solution is neutral;
j. Converting the catalyst precursor prepared in a manner described in earlier steps to active catalyst 'in-situ' or separately, by simultaneous introduction of pure acetylene and aqueous formaldehyde at suitable space velocities, low temperatures to achieve high catalyst activity, longer life as well as better ability for regeneration, resulting in a product suitable for achieving downstream products quality.
The aqueous formaldehyde may be ion exchange treated in a concentration range of 15 to 37% w, preferably 10 to 20 % w, containing acidity (expressed as formic acid) less than 0.023 % w, pH of the solution in the range of 5 to 9, with or preferably without the addition of any alkali. For acetylene gas GHSV is 3 to 50 h-1 and the aqueous formaldehyde LHSV is 0.01 to 0.6 h-1 whereas the reaction is carried out at 50 to 100 °C, preferably 70 to 95 °C and below 2 atmospheres pressure, preferably just above atmospheric pressure.
The continuous single tube reactor smaller as well as bigger versions are made up of stainless steel, with jacketed arrangement for cooling (with cooling water) or alternatively heating (with steam) whenever required to maintain the reactor temperature. It has two separate inlets for liquid and gas at the bottom. liquid overflow arrangement as well as gas outlet after a gas-liquid separator is provided at the top of the reactor. The gas outlet is passed through a water seal. liquid is introduced with the help of metering pumps from stainless steel storage tank, whereas gas is provided from gas cylinders, with the help of pressure regulators. All the runs are carried once through. In a multi tubular industrial setup, gas recycle arrangement can be easily done.
The reactor is subsequently run continuously for a period of 15 to over 100 days, under the above parameters. The operation is discontinued whenever the reactor pressure drop increases rapidly beyond 0.5 atmospheres or there is significant

reduction in catalyst activity. At this stage, the catalyst can be regenerated effectively in the following manner:
a. Displacement of the reaction mass completely with demineralized
(deionised) water, after cooling the same to 20 to 35 °C, at the same space
velocity as that for the reaction;
b. Displacement of acetylene gas with nitrogen at 20 to 35 °C for 24 hours at
the same space velocity as mat for the reaction;
c. 2% alkali wash (preferably sodium hydroxide) for 24 to 48 hours at 20 to
35°C, at LHSV 0.01 to 0.6 h-1 GHSV 3 to 50 h-1 followed by
demineralized water wash under the same conditions, till neutral pH;
d. Obtaining active catalyst in a similar manner, as described earlier in step
'j', as mentioned for fresh catalyst
The regenerated catalyst can be run under the same process conditions with activity of 60 to 100% as that for the fresh catalyst
The catalyst of this invention has been effectively used in a single tube reactor and can be used in similar or multi tubular continuous industrial reactors for long periods of operation at higher activity and better regeneratability and can produce 1,4 butynediol suitable for better quality downstream products, including 1,4 butenediol, produced by selective hydrogenation.
The present invention is described below by way of examples. However, the following examples are illustrative and should not be construed as limiting the scope of the invention.

EXAMPLE 1
Runs in smaller continuous single tube reactor (alkali used: sodium carbonate)
1. Activated alumina spheres size 2 to 5 mm diameter, surface area 300 to 375 m2/g pore volume 0.3 to 0.5 cc/g, bulk density of 0.76 to 0.84 (0.8) g/cc, with the chemical analysis, given in Table 1 were packed in a continuous packed bubble column single tube reactor made up of stainless steel, with a cooling water jacketed arrangement for heat removal, as well as heat up arrangement with steam, whenever required.
The reactor had separate inlets for gas and liquid at the bottom as well as separate outlets for both at the top.
Table 1

A1203 92% (mm)
Na20 0.25% (max)
Fe2O3 0.15% (max)
Si02 0.15% (max)
Loss on ignition 5 to 7%
2. It was dried for about 4 to 6 hours with a reactor temperature maintained
between 80 to 90 °C with nitrogen gas introduced from the bottom of the
reactor (GHSV 10 h-1). The gas outlet from the reactor was vented off though
a water seal.
Afterwards nitrogen was stopped, but the average reactor temperature was maintamed at 60 °C.
3. 5000 cc of hydrated copper nitrate / bismuth nitrate solution was separately
prepared with the following concentration :

- Concentration of copper nitrate trihydratc : 1087 g/lit
- Concentration of bismuth nitrate pentahydratc : 163 g/lit
-Concentrated nitric acid : Quantity just adequate to
dissolve the above solids.
- Balance was made upto a volume of 5 liters (5000cc) with the help of
dcmincralizcd water.
The above solution was slowly introduced from the bottom of the reactor (through the liquid inlet) maintained at 60 °C, till overflow is observed from the liquid outlet at the top. During this impregnation step, the gas vent was kept open. The period for impregnation was 12 hours. After this, the excess solution was drained from the bottom of the reactor and the quantity measured to know the quantity of soluiion impregnated on the support.
4. Subsequently, the impregnated mass was dried under nitrogen introduced from the reactor bottom, in a similar manner as mentioned in step 2. Thereafter the reactor was cooled to ambient temperature (30 C ).
5. Alkali in ihc form of 15% w sodium carbonate solution was prepared and passed through the same reactor via liquid inlet at the reactor bottom, with the help of a metering pump with LHS V of 0.4 h-1. Nitrogen was introduced from gas inlet at the rector bottom with GHSV 10 h-1 and outlet gases vented off through water seal. Liquid from the reactor outlet at the top was also collected separately. This was continued for 2 to 3 hours at 20 to 30 °C.
6. Thereafter, the liquid flow to the reactor was stopped. The reactor mass was maintained at 20 to 30 °C (under nitrogen GHSV 10 h-1) for i S to 19 hours.
7. This was followed by deminerahzed water wash (under nitrogen GHSV 3 h) at LHS V 0.08 h'J and 25 to 40 °C temperature, till pH of the outlet solution was neutral.

The catalyst precursor thus produced 'in-situ' was subsequently converted to cuprous acetylide complex in the reactor itself as follows:
8. 20% w aqueous formaldehyde (for which formic acid content is brought down
to a level of less than 0.023% w by ion-exchange resin treatment) with pH of
5 to 6, was introduced from reactor inlet at LHSV 0.1 h-1 with nitrogen at the
same space velocity as mentioned previously, under a reactor temperature
of70°C.
9. Subsequently, nitrogen was replaced with pure acetylene GHSV 11 h"1.
20% w formaldehyde feed was continued as before in previous step, the
reactor temperature being maintained at about 70 C of gas was vented
through a water seal, as described earlier.
Thereafter, the same reactor was run continuously for 55 days with 20% w formaldehyde feed of the earlier specifications at an average LHSV 0.044 h"1 and GHSV 11.1 h-1 under slightly positive pressure (water seal) at a temperature range of 70 to 80 °C. Under these conditions, the catalyst exhibited an average activity of 130 to 150 g butynediol/kg catalyst per day and a productivity of 7.3 to 10 kg butynediol per kg of catalyst charge was obtained.
EXAMPLES 2 TO 5
Runs in bigger continuous single tube reactor with a scale-up ratio of 1:17 times smaller reactor (alkah used: sodium carbonate)
1. Activated alumina spheres with the properties as described in Example 1 were packed in a continuous packed bubble column made up of stainless steel as before, the rector being a scaled up version 1:17 times that of the reactor, as described in Example 1. All other reactor arrangements were similar to those mentioned in Example 1.

2. Drying of the same was carried out for 24 hrs (for all i.e. Examples 2 to 5), at
70 °C with nitrogen, GHSV from 6 to 13 h-1, of being vented through water
seal as before, in Example 1.
Afterwards nitrogen was stopped, but the average temperature was maintained
at70°C.
3. Copper nitrate / bismuth nitrate solution with the same concentration as that
described in Example 1, was taken in adequate quantity required for higher
scale operation.
Impregnation of the same on activated alumina support in the reactor itself, was also carried out in a similar manner as described in Example 1.
4. Thereafter 12 to 30% w sodium carbonate solution (alkali) was prepared and passed through the same reactor in similar way as described in Example 1, LHSV being in the range of 0.05 to 0.3 h-1 and GHSV for nitrogen 6 to 13 h-1 under 70 to 80 °C temperature for 8 to 24 hours.
5. Thereafter liquid flow was stopped in a manner similar to Example 1, however reactor temperature maintained at 70 °C, under nitrogen GHSV 6 tol3 h-1 for 16 to 24 hrs.
6. This was followed by demineralized water wash till pH of outlet solution is neutral, in a similar manner as described in Example 1 LHSV of 0.08 h-1, nitrogen GHSV of 3 h"\ and under 50 - 90 °C temperature.
The catalyst precursor thus prepared was subsequently converted to cuprous acetylide complex in the reactor itself as follows:
7. 20% w aqueous formaldehyde with the same specifications as those described
in Example 1, was introduced from the reactor inlet under LHSV 0.03 to 0.06
h"1, with reactor temperature maintained at 70°C.

8. Pure acetylene was simultaneously introduced into the reactor under GHSV 6 to 13 h-1.
Thereafter the same reactor was continuously runs with 20% w formaldehyde feed of earlier specifications, the results are summarized in Table 2, the pressure maintained in all the Examples being just positive pressure (water-seal).
Table 2 Summary of Ethynylation Reaction Results

Example No. Running Period, (Days) Average
LHSV,
h1 Average GHSV,
h1 Temperature, Catalyst Activity,
g butynecfiol/ kg-
catalyst-day Catalyst
Productivity,
kg-butyneoloi
/kg-catalyst
2 33 0.043 10.0 80-90 160 4.10
3 15 0.058 12.35 60-65 150 2.42
4 15 0.058 9.41 70-80 155 2.85
5 100 0.035 6.47 80-90 56 6.3
Runs had to be discontinued when these was a sharp rise in reactor pressure drop from 0.1 to more than 0.6 atmosphere. The product acidity (formic acid) increased from 0.5 to 1.4 % w correspondingly. The discharged catalyst showed agglomerates formation near the reactor inlet portion.
EXAMPLE 6
Runs in bigger continuous single tube reactor with a scale-up ratio of l:17times smaller reactor (alkali used: sodium carbonate)
Effect of variation of catalyst quantity

The same continuous packed bubble column single tube reactor set-up as described in Examples 2 to 5, was used under by maintaining similar operating parameters, except that the quantity of alumina packed in mis case was 70% of that mentioned therein.
The catalyst precursor as well as copper acetylide complex prepared and further reaction carried out in a manner similar to Examples 2 to 5, except that step 5 described therein being eliminated
Continuous running for 33 days at average LHSV 0.067 h-1, average GHSV 4.7 h-1 in a temperature range 70 to 80 °C and slightly positive pressure as described before achieved average catalyst activity 171 g B3D/kg-cat-day and the productivity 5.8 kg B3D/kg catalyst charge.
Runs had to be discontinued when there was a sharp in reactor pressure drop from 0.1 to more than 0.6 atmospheres. The product acidity, correspondingly, increased from 0.5 to 1.5% w. The discharged catalyst showed agglomerates formation near the reactor inlet portion.
EXAMPLE 7
Runs in bigger continuous single tube reactor with a scale-up ratio of 1:17 times smaller reactor (alkali used: sodium carbonate)
The same continuous packed bubble column single tube reactor set up and the catalyst precursor/active catalyst prepared as described in Examples 2 to 5 was used under steady operating parameters and normal quantity of alumina.
Continuous running for 48 days at average LHSV 0.064 h-1, average GHSV 11.76 h-1 at 70 to 80 C and slightly positive pressure (as described before) achieved a higher catalyst activity and productivity, 216 gB3D/kg-cat-day and 9 kg B3D/kg-catalyst charge, respectively.
In this case too, runs had to be discontinued with sharp rise in reactor pressure drop from 0.1 to more man 0.6 atmospheres. The product acidity, correspondingly,

increased from 0.5 to 1.3 % w. The discharged catalyst showed agglomerates formation near the reactor inlet portion.
EXAMPLE 8
Runs in bigger continuous single tube reactor with a scale-up ratio of1:17 times smaller reactor (alkali used: sodium hydroxide)
1. Activated alumina spheres with the same specifications as described earlier, were packed in the same continuous packed bubble column single tube reactor, as described in Examples 2 to 5, 6 and 7.
2. Drying the same was carried out for about 24 hours at 70 to 80 °C under nitrogen GHSV 10 h-1 in the same manner as described earlier.
The average reactor temperature was maintained at 25 to 50 °C, subsequently after stopping nitrogen.
3. Adequate quantity of hydrated copper nitrate / bismuth nitrate solution in the same concentration range was taken and impregnation of the same in the reactor itself, was carried out as described in earlier Examples.
4. Subsequently, the impregnated mass was dried under nitrogen in a similar manner as described in Example 1.
5. Thereafter 10% w sodium hydroxide solution (alkali) was passed through the same reactor in a similar manner as described in Example 1, LHSV 0.3 to 0.5 h-1. Nitrogen was also introduced GHSV 10 h-1 in a similar manner, as described earlier. Liquid from the reactor outlet at the top was also collected similarly. The alkali wash duration was 3 to 4 hours, under a temperature of 25 to 40 °C.
6. Slightly weaker alkali solution (2% w sodium hydroxide) was subsequently passed through the reactor by the same arrangement as mentioned in the

earlier step 6 under same space velocities for 16 to 24 hours at temperature 50 to 90 °C.
7. This was followed by demineralized water wash in a similar manner to that
described in Example 6, till pH of the outlet solution became neutral.
The catalyst precursor produced 'in-situ' in the manner described earlier, was converted to cuprous acetylide complex in the reactor itself as follows:
8. 15% w aqueous formaldehyde, (containing formic acid less man 0.023% w by ion exchange resin treatment) with a pH 5 to 6 was introduced from reactor inlet LHSV 0.06 to 0.11 h-1 under nitrogen GHSV 10 to 12 h-1, for 0 to 4 hours and at temperature 70 to 90 °C.
9. Subsequently, nitrogen was replaced with pure acetylene GHSV (11 h-1). 15% w formaldehyde feed was continued as before in previous step, the reactor temperature being maintained at about 90 °C and off gas vented through a water seal.
Thereafter, the same reactor was run continuously wim 15% w formaldehyde of earlier specifications for 38 to 48 days at an average LHSV 0.06 to 0.11 h'1 and GHSV of 11.76 h*\ under slightly positive pressure, in a temperature range 70 to 90 °C. Under these conditions, the catalyst exhibited an average activity of 50 to 170 g butynediol/kg catalyst per day and a productivity of 2.5 to 10 kg butynediol per kg of catalyst charge, was obtained.
Runs were discontinued with sharp rise in reactor pressure drop from 0.1 to more man 1.5 atmospheres. The product acidity, correspondingly, increased from 0.5 to 1.2% w. The discharged catalyst showed agglomerates formation near the reactor inlet portion.

EXAMPLE 9
Runs in bigger continuous single tube reador with a scale-up ratio of 1:17 times smaller reador (alkali used: sodium hydroxide)
Effect of dilute copper / bismum nitrates solution
1. For this case also, activated alumina spheres with the same specifications as mentioned earlier were taken in the same reactor, as described in Example S.
2. Drying was carried out under similar conditions mentioned in Example 8, excepting the period which was 48 hours.
The reactor temperature was maintained at 70 °C alter stopping mtrofien.
3. Adequate quantity of hydratcd copper nitrate /bismuth nitrate solution was
prepared separately with the following concentration
Concentration of copper nitrate irihydratc 725 g/lit
Concentration of bismuth nitrate pentahydrate ; 109 g/lit
Concentrated nitric acid Quantity just adequate to
dissolve the above solids.
Balance was made upto the final requisite quantity of solution required for impregnation, with the help of dcmincralizcd water.
Impregnation of the same in the reactor itself was carried out in a similar manner as described in Example S.
4. The impregnated mass was dried in a similar manner as described in
Example S.

5. Thereafter 10% w sodium hydroxide solution (alkali) was passed through the same reactor, in a similar manner and under same operating parameters, as described in Example 8.
6. 2% w Sodium hydroxide (weak alkali) solution was also passed through the same reactor, in a similar manner and under same parameters, as elaborated in Example 8 excepting the reactor temperature, which was maintained at 70 to 80 °C.
7. This was followed by demineralized water wash in a similar manner and conditions, as described in Example 8.
8. The catalyst precursor, produced in the manner described earlier, was subsequently converted into copper acetylide complex in a similar manner as described in Examples 2 to 5, 6 and 7 by simultaneous introduction of aqueous formaldehyde earlier described specifications and pure acetylene gas.
Thereafter, the reactor was run continuously for 26 days with 10% w average formaldehyde of earlier specifications described under average LHSV 0.22 h'1, average GHSV 11.76 h"1, under slightly positive pressure (as described earlier), in a temperature range of 70 to 80 °C. Under these conditions, the average catalyst activity obtained was 125 g butynediol/kg catalyst-day and productivity 2.1 kg butynediol/kg-catalyst charge.
Runs were discontinued with sharp rise in reactor pressure drop from 0.1 to more man 1.8 atmospheres. The product acidity, correspondingly, increased from 0.1 to 0.4%w. The discharged catalyst showed agglomerates formation near the reactor inlet portion.
EXAMPLE 10
Runs in bigger continuous single tube reactor with a scale-up ratio of 1:17 times smaller reactor (alkali used: sodium hydroxide)
Catalyst regeneration / revival

Activated alumina spheres with the same specifications as described in the earlier Example 8 were taken in the same reactor as described therein. The catalyst precursor, and thereafter copper acetyiide complex were also prepared in a similar manner as described therein.
The reactor was run continuously in a temperature range of 70 to 80 °C, under GHSV 11.76 h*1 and LHSV 0.12 to 0.2 h"1 and 15% w formaldehyde coirforming to the earlier specifications. The catalyst activity achieved was 240 to 336 g butynediol/kg-cat-day and productivity 1.4 to 2.2 kg butynediol/kg-catafyst.
However, the catalyst pressure drop increased steeply upto about 2 atmospheres, after a running period of about 21 to 32 days.
The catalyst regeneration was carried out in the following manner :
a. The reactor was cooled down to 20 to 35 °C, and then the reactor mass was
displaced completefy with demineralized water;
b. Acetylene gas was displaced with nitrogen at 20 to 35 °C for 24 hrs, at the
same space velocity of acetylene as before;
c. 2% w sodium bicarbonate wash (alkali) was given to the reactor for 4
hours, followed by 1 to 2% w sodium hydroxide wash for 24 hrs, followed
by demineralized water wash under nitrogen till neutral pH, under 25 to
40 °C temperature, GHSV 11.76 K\ LHSV 0.03 to 0.4 h"1.
d. Thereafter 15% w aqueous formaldehyde, conforming to earlier
specifications, with pH adjusted to 8.5 (by adding sodium bicarbonate 0.4
to 0.9% w) and pure acetylene were simultaneously introduced, after the
reactor temperature was achieved 70 to 90 °C.
Afterwards the reactor was run for 36 to 55 more days with the same parameters as earlier. The average catalyst activity after regeneration was found to be 148 g burynediol/kg-cataryst-day and productivity was found to be 2.4 to 3.5 kg

butynediol/kg-catalyst The discharged catalyst showed agglomerates formation near the reactor inlet portion.
EXAMPLE 11
Runs in bigger continuous angle tube reactor nith a scale-up ratio of 1:17 times smaller reactor (alkali: Sodium hydroxide)
Mixed Bed Operation
Activated alumina spheres with the same specifications as described in the earlier examples were mixed in various proportions by volume with inerts viz. commercial porcelain intelox saddles (bulk density = 1.161 g/cc, size 5 mm) and charged to the same reactor as described in earlier examples.
(A) The mixed catalyst bed containing 25% by volume of catalyst and the balance inerts was taken. Catalyst precursor and thereafter copper acetylide complex were prepared in a similar manner to that described in Example 8.
Thereafter the reactor was run continuously for a period of 90 days with 10 to 15% w aqueous formaldehyde of earlier specifications with sodium bicarbonate contents in the range of 0.2 to 0.5% w, LHSV 0.05 h~\ GHSV 11.76 h"1 with average reaction temperature 70 to 90 °C. Under these conditions, the catalyst activity & productivity for the mixed catalyst bed are shown in Table 2.
Table 2 Results for 25% v mixed catalyst in the reactor

No. Based on overall quantity of mixed bed Based on active
catalyst contents in
mixed bed
1. Activity,
g butynediol/kg-cat-day 43 168
2. Productivity,
kg butynediol/kg-catalyst 3.83 18.1

(B) In this case, the mixed bed contained 60% v of the catalyst and balance inerts, described earlier. All other steps involved in part (A) were repeated for catalyst precursor / copper acetylide complex preparation in the same manner as described therein.
Thereafter, the reactor was run continuously for a period of 70 to 100 days with 10 to 15% w aqueous formaldehyde solution of earlier specifications and without any alkali added to it, at LHSV 0.15 to 0.2 h'1, GHSV 11.76 h'1 and average reaction temperature 70 to 90 °C. Under these conditions the catalyst activity and productivity for the mixed bed are shown in Table 3.
Table 3 Results for 60% v mixed catalyst in the reactor.

s. Based on overall Based on active
No. quantity of mixed catalyst contents
bed in mixed bed
1. Activity,
g butynediol/kg-cat-day 120 to 140 240 to 360
2. Productivity,
kg butynediol/kg-cataryst 2.5 to 7.6 4.5 to 14
In bom the cases 'A' and 'B', runs were discontinued with sharp rise in pressure drop from 0.1 to more man 0.5 atmospheres. The product acidity, correspondingly, increased from 0.2 to 0.5% w. The discharged catalyst showed agglomerates formation near the reactor inlet portion.
EXAMPLE 12
Runs in bigger continuous single tube reactor nitk a scale-up ratio of l:17tunes smaller reactor (alkali: Sodium hydroxide)
Effect of stoppage of liquid input (reactant): Mixed bed operation

A run was taken in the same reactor and in the same manner as described in detail in Example 11. After running at average activity of 125 g butynediol/kg-cataryst-day and after achieving a productivity of 6.8 kg butynediol/kg-catalyst, the reactor was maintained under following parameters for 40 hours:
a. Liquid flow to the reactor was stopped;
b. Acetylene flow continued through the reactor at the same GHSV
(i.e. 11.76 b'1) as before;
c. Reactor temperature was maintained at 90 °C.
Under these conditions, the reactor pressure drop increased steeply from 0.1 atmospheres upto 2 atmospheres. Thereafter, the reaction was discontinued and catalyst was safely discharged. The observation of the discharged catalyst showed that the catalyst part in the mixed bed, was reduced to a hard impervious mass, agglomerates, whereas the inert rings part was intact Since acetylene supply was continuously 'on1, possibility of cuprene formation was ruled out Thus it is attributed to the reaction of stagnant formaldehyde mass with acetylene leading first to butynediol and subsequently to some heavier / tarry compounds obtained from subsequent reactions since the heat of reaction is not properly removed from the catalyst surface, thereby hot spots formation and generation of high temperatures on the catalyst surface (Ref : Patent #1,35,195), with no fresh reactant make up, subsequently leading to agglomeration.
EXAMPLE 13
Runs in bigger continuous single tube reactor mth a scale-up ra&o of 1:17 times smaller reactor (alkali: Sodium hydroxide)
Effect of catalyst shape : Dilute copper bismuth nitrates solution.
Alumina spheres of diameter 3 to 5 mm, bulk density 1 to 1.2 g/'cc and alumina rings 16 mm outer diameter, 9 mm internal diameter and 16 mm length, with bulk density 0.95 g/cc with a similar chemical composition, surface area and pore volume range, as described in Example 1 as well as subsequent examples, were mixed in equal

proportion and charged to the same continuous packed bubble column single tube reactor as mentioned in the preceding examples. Catalyst precursor as well as copper acetylide complex were prepared by the following method :
1. Drying of the support was carried out for a period of 50 to 120 hours at 70 to 90°C under mtrogen GHSV 20 h"2. Afterwards nitrogen was stopped, however the reactor temperature was maintained at 90 °C.
3. Adequate quantity of copper nitrate / bismuth nitrate solution in the same concentration range as described in Example 9 was prepared.
Impregnation of the same in the reactor itself, was carried out in a similar manner, as described in Example 8.
4. The impregnated mass was dried in a similar manner as described in Example 8.
5. Afterwards nitrogen was stopped as described in step 2 and copper nitrate / bismuth nitrate solution of earlier concentration was again impregnated in the reactor itself in similar manner described in step 3 and drying of impregnated mass was carried out in similar manner as described in step 4.
6. The sequence as described in step 5 was repeated once more.
7. Thereafter 10% sodium hydroxide solution (alkali) was passed through the reactor LHSV 0.1 to 0.2 h"1 under nitrogen gas GHSV 17 to 27 h"1 for 4 to 5 hours under a temperature of 25 to 40°C.
8. Similarly, 2% sodium hydroxide solution was subsequently passed through the reactor under same liquid and gas space velocities for 20 hours, however the temperature range was 70 to 80°C.

9. This was followed by demineralized water wash in a similar manner to Example 8, in the same temperature range described therein, except that LHSV 0.1 to 0.12 h-1 and GHSV of 17 to 27 h"1 were maintained, till pH of the outlet solution became neutral.
10. The catalyst precursor produced in the manner described earlier was converted 'in-situT in the reactor itself, to cuprous acetylide complex in the following manner:
10% w aqueous formaldehyde of earlier described specifications, was introduced into the reactor simultaneously with pure acetylene gas, at a temperature of 90 to 95°C, LHSV 0.1 to 0.12 h"1 and GHSV 17 to 27 h*1.
Thereafter the reactor was run with the formaldehyde of the specifications given earlier, continuously for a period exceeding 60 days under the same temperature, liquid / gas space velocities and under slightly positive pressure, as described before. Under these conditions, the catalyst activity was very much steady at 108 g butynediol/kg catalyst-day and the productivity 5.18 kg butynediol/kg-catalyst (lower figures attributed to dilute nitrates solution for impregnation). The most significant factor being the reactor pressure drop, which was constant from beginning to end at about 0.1 atmosphere. The reactor product acidity (formic acid) also showed a steady value of 0.15% w.
Catalyst regeneration
The catalyst activity, on prolonged running in the above maimer gradually reduced to about 60% of the original activity. At this juncture, the regeneration method, as described in Example 10 was followed in all respects excepting that in steps 'c'. 2% w sodium hydroxide wash given at 25 to 40 °C for 48 hours followed by demineralized water wash till neutral pH under nitrogen GHSV 20 h"1 and LHSV 0.5 h"1. Thereafter in step 'd' 15% w aqueous formaldehyde of the earlier specifications and without any extra alkali added to the same and pure acetylene were simultaneously introduced at 90 to 95 °C.

The reaction runs were restarted under the same conditions as described before. The regenerated catalyst exhibited 75% activity and runs were carried out for one more month after regeneration.
EXAMPLE 14
Runs in bigger continuous single tube reactor with a scale-up ratio of 1:17 limes smaller reactor (alkali: Sodium hydroxide):
Effect of catalyst shape: Normal concentration of copper nitrate /bismuth nitrate
For mis case, all the conditions / parameters and steps involved were exactly similar to Example 13, except the following :
a. Only alumina rings 16 mm outer diameter, 9 mm inner diameter and 16
mm length were used completely in the reactor;
b. Concentration range of copper nitrate/bismuth nitrate for impregnation
was the same as that described in all the previous examples, except
Example 9 and Example 13.
The reactor runs under similar operating parameters to those mentioned in Example 13 showed good activity sustained for much longer periods man those described earlier, as well as consistently lower pressure drop and lower acidity. The product butynediol thus produced after purification (filtration or solid-liquid separation not required), showed good selectivity to its downstream product 1,4 butenediol, after hydrogenation. (Ref: Indian Patent Application No. 2215/MUM/2008 A, filing date, 15/10/2008).

We claim:
1. An 'in-situ' prepared improved catalyst, for low pressure continuous
butynediol synthesis from an industrially available support of suitable shape and size, as such or with inerts as mixed bed, in the following manner:
a. Packing of the support in a bubble column stainless steel reactor;
b. Drying of the support at 50 to 90 °C for 4 to 150 hours under nitrogen gas,
GHSV 2 to 20 h1;
c. Impregnation of a solution prepared from commercially available copper
nitrate trihydrate and bismuth nitrate pentahydrate, in the concentration range
of 500 to 1500 g/litre and 100 to 200 g/litre respectively, for 1 to 80 hours,
in a temperature range of 20 to 90 °C;
d. Drying of impregnated mass under nitrogen (GHSV 2 to 20 h"1) for 2 to 150
hours in a temperature range of 40 to 90 °C;
e. Repeating steps V and *d' 0 to 5 times more, one after the other
f. Aqueous strong alkali (concentration range from 5 to 40% w) wash at LHSV
0.2 to 0.5 h"1 for 2 to 40 hours at a temperature range of 20 to 90 °Q under
nitrogen (GHSV 2 to 50 h"1);
g. Keeping the above mass for 0 to 24 hours at 20 to 90 °C temperature, under
nitrogen (GHSV 2 to 50 h'1);
h. Aqueous weak alkali (concentration range from 0 to 5% w) wash for 0 to 24
hours at LHSV 0 to 0.2 h"1 and 20 to 90 °C temperature, under nitrogen (GHSV 2 to 50 h"1), followed by :
i. Demineralized (deionized) water wash at LHSV 0.05 to 0.2 h"1 at 20 to 90°C,
under nitrogen (GHSV 2 to 50 h"1) till the pH of the outlet solution is neutral;

j. Converting the catalyst precursor prepared in a manner as described in the
earlier steps, to active catalyst 'in-situ' or separately, by simultaneous introduction of pure acetylene and aqueous formaldehyde at suitable space velocities, low temperatures, to achieve high catalyst activity, longer life as well as better ability for regeneration, resulting in a product suitable for achieving downstream products quality.
2. The said low pressure, as claimed in Claim 1, which is below 2 atmospheres, and most preferably, just above atmospheric pressure.
3. The said industrially available support, as claimed in Claim 1, which is preferably alumina.
4. The said support of suitable shape, as claimed in Claims ! and 2, which includes cylindrical rings or spheres.
5. The said support, as claimed in Claims 1, 2 and 3, which includes cylindrical rings, preferably (6 to 16 mm) outer diameter x (3 to 9 mm) internal diameter x (6 to 16 mm) long or spheres preferably 2 to 9 mm diameter.
6. The said support, as claimed in Qaims 1, 2,3 and 4, which has a bulk denary preferably 0.7 to 1.1 g/cc, pore volume preferably 0.2 to 0.5 cc/g and a most preferable chemical composition as follows:

a. Aluminium Oxide 92% w (minimum)
b. Sodium Oxide 0.25% w (maximum)
c. iron Oxide 0.15% w (maximum)
a Silica 0.15% w (maximum)
c. Loss on ignition 7% w (maximum)
7. The said incrts, as claimed in Claim 1, which arc made up of porcelain and
include any standard shapes (rings, saddles etc.), and a size range of 3 to 9 mm, with bulk density from 0.3 to 1.2 g/cc.

The said packed bubble column stainless steel reactor, as claimed in Claim la, which includes a standard single tube reactor as such or may be as a single tube as a part of a multi tubular industrial reactor.
The said alkali, as claimed in Claims If and lh, which includes sodium hydroxide, sodium carbonate, sodium bicarbonate and which is most preferably, sodium hydroxide.
The said aqueous formaldehyde, as claimed in Claim lj, which is ion exchange treated and the concentration of which may vary from 5 to 37% w, most preferably 10 to 20% w, containing acidity less than 0.023% w and pH 5 to 9, with or without alkali added to the same.
The said space velocities, as claimed in Claim lj , which are in die range of GHSV 3 to 50 h"1 for acetylene and LHSV 0.01 to 0.6 h"1 for aqueous formaldehyde.
The said low temperatures, as claimed in Claim lj , which are in the range of 50 to 100 °C most preferably from 70 to 95 °C.
The said better ability for regeneration, as claimed in Claim 1, for which catalyst regeneration is carried out in the following manner:
Displacement of the reaction mass completely with demineralized (deionized) water, after cooling the same to 20 to 35 °C, at the same space velocity at that for the reaction;
Displacement of acetylene gas with nitrogen at 20 to 35 °C for 24 hours at the same space velocity as that for the reaction;
2% w alkali wash (preferably sodium hydroxide) for 24 to 48 hours at 20 to 35°C, LHSV 0.01 to 0.6 h~\ GHSV 3 to 50 h"1, followed by demineralized water wash, under the same conditions, till neutral pH;

d. Obtaining active catalyst, as claimed in Claim 1, in similar manner, as
described in Claim lj.
14. The said catalyst activity, as claimed in Claims 1 to 13, which is in the range of 50 to 10,000 g butynediol/kg-catatyst-day.
15. The said catalyst, as claimed in Claims 1 to 14, which can be run for very long periods ranging from 15 days to 360 days, or beyond.
16. The said product, as claimed in Claims 1 to 15, which includes butynediol suitable for achieving downstream 1,4 butenediol quality.
17. The said product, as claimed in Claims 1 to 16, the purification of which does not involve any filtration step.
18. The 'in-situ' prepared catalyst precursor as claimed in Claim 1 'a' to 'i' (inclusive) , prepared in eco-friendly manner by eliminating the evolution of oxides of nitrogen, during its preparation.
19. The said catalyst, as claimed in Claims 1 to 18, suitable for continuous low pressure butynediol process, showing high activity and life and which can be scaled-up nearly 2500 times from said packed bubble column single tube reactor to a similar multi tubular industrial scale reactor, without adversely affecting the activity and life claimed therein, substantially as herein described with reference to Examples 1 to 14 in the specification.
Dated this day of 2009
For and on behalf of HINDUSTAN ORGANIC CHEMICALS LIMITED

(ARVIND SHRIRAM DIDOLKAR) CHAIRMAN AND MANAGING DIRECTOR

Documents:

1006-mum-2009-abstract(17-4-2009).pdf

1006-mum-2009-abstract.doc

1006-mum-2009-abstract.pdf

1006-MUM-2009-ANNEXURE B(SUBMISSION)-(17-7-2013).pdf

1006-MUM-2009-CLAIMS(AMENDED)-(17-7-2013).pdf

1006-MUM-2009-CLAIMS(AMENDED)-(18-5-2009).pdf

1006-MUM-2009-CLAIMS(AMENDED)-(20-3-2012).pdf

1006-mum-2009-claims(complete)-(17-4-2009).pdf

1006-mum-2009-claims.doc

1006-mum-2009-claims.pdf

1006-MUM-2009-CORRESPONDENCE(18-5-2009).pdf

1006-mum-2009-correspondence(24-6-2009).pdf

1006-MUM-2009-CORRESPONDENCE(27-12-2012).pdf

1006-MUM-2009-CORRESPONDENCE(5-2-2013).pdf

1006-MUM-2009-CORRESPONDENCE(9-11-2012).pdf

1006-mum-2009-correspondence(ipo)-(10-9-2009).pdf

1006-mum-2009-description(complete)-(17-4-2009).pdf

1006-mum-2009-description(complete).doc

1006-mum-2009-description(complete).pdf

1006-MUM-2009-DETAILED EXPLANATION(20-3-2012).pdf

1006-mum-2009-form 1.pdf

1006-mum-2009-form 13(18-5-2009).pdf

1006-MUM-2009-FORM 18(17-4-2009).pdf

1006-mum-2009-form 2(complete)-(17-4-2009).pdf

1006-mum-2009-form 2(title page)-(complete)-(17-4-2009).pdf

1006-mum-2009-form 2(title page).pdf

1006-mum-2009-form 2.doc

1006-mum-2009-form 2.pdf

1006-MUM-2009-FORM 3(17-7-2013).pdf

1006-mum-2009-form 3.pdf

1006-mum-2009-form 5.pdf

1006-MUM-2009-FORM 9(17-4-2009).pdf

1006-MUM-2009-REPLY TO EXAMINATION REPORT(20-3-2012).pdf

1006-MUM-2009-REPLY TO HEARING(17-7-2013).pdf

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Patent Number

256972

Indian Patent Application Number

1006/MUM/2009

PG Journal Number

34/2013

Publication Date

23-Aug-2013

Grant Date

21-Aug-2013

Date of Filing

17-Apr-2009

Name of Patentee

HINDUSTAN ORGANIC CHEMICALS LIMITED

Applicant Address

RASAYANI,DIST.RAIGAD,PIN-410 207,MAHARASHTRA, INDIA

Inventors:

#	Inventor's Name	Inventor's Address
1	SHINDE BAPURAO SIDRAM	RASAYANI,DIST.RAIGAD, PIN-410 207, MAHARASHTRA, INDIA
2	SATHE AMOD MADHUKAR	RASAYANI,DIST.RAIGAD, PIN-410 207, MAHARASHTRA, INDIA

PCT International Classification Number

C07C33/46

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA