Title of Invention

"IMPROVED COAL LIQUEFACTION PROCESS CALIED H-COAL LIQUEFACTION PROCESS"

Abstract

It is already known to subject Coal to liquefaction using a slurry of Coal with recycle oil derived from Coal. Such a slurry is generally pumped at a pressure of about 2600 to 3000 psi and is mixed with the Hydrogen, is preheated to around 450° to 500° C. To enhance the reaction of the Hydrogen, the reaction is carried out in the presence of Nickel Molybdenum Catalysts. For increased Yields, the reaction is carried out in an ebullated bed reactor. There is disclosed herein, a method for liquefaction of Coal with Hydrogen, using Hydrogenation Catalyst, comprising the steps of slurrying the Coal in recycle oil, adding Hydrogenation, Catalyst like Nickel Molybdenum under pressure and temperature, characterised in that said Hydrogenation is carried out additionally in the presence of a cracking catalyst, preferably Sodium Carbonate.

Full Text

INTRODUCTION TO THE INVENTION This invention relates to an improved Coal Liquefaction Process Galled H-Coal Liquefaction Process . Process for the Liquefaction of Coal is carried out to obtain gaseous and liquid products as well as residue and unconverted Coal and Ash. Such a process is carried out using Hydrogen under pressure. PRIOR ART It is already known to subject Coal to liquefaction using a slurry of Coal with recycle oil derived from Coal. Such a slurry-is generally pumped at a pressure of about 2500 to 3000 psi and is mixed with the Hydrogen, is preheated to around 450 to 500°C. To enhance the reaction of the Hydrogen, the reaction is carried out in the presence of Nickel Molybdenum Catalysts. For increased Yields, the reaction is carried out in an ebullated bed reactor. Minor alterations of this process also have been tried out. DRAWBACKS OF THE PRIOR ART It has been found after detailed study of the Prior Art that it is accompanied by several drawbacks of which mention may be made of the following :- i) The space velocity of the stream is low. ii) The amount of catalysts required is considerably high. iii) The liquid yield is about 55% or less; iv) The Process is not very economical. - 2 - OBJECTS OF THE INVENTION It is therefore, an object of this invention to propose an improved H-Coal Process which can be carried out at lower temperature than before and thus save energy. It is another object of this invention is to propose such a process which can be carried out at a pressure lesser than in the known practice, thereby to reduce cost input. It is a further object of this invention to propose such a process in which the Capital cost is lesser than before. It is a still further object of this invention to propose such a process which can be operated with ease, and in which the requirements of the Catalysts will be lesser than before. These and other object of this invention will be apparent from the following paragraphs t- - 3 - According to this invention there is provided a method for liquefaction of Coal with Hydrogen, using Hydrogenation Catalyst, comprising the steps of slurrying the Coal in recycle oil, adding Hydrogenation, Catalyst like Nickel Molybdenum under pressure and temperature, characterised in that said Hydrogenation is carried out additionally in the pressure of a cracking catalysts, preferably Sodium Carbonate. The reaction is carried out at a pressure in the range of 1500 to 2 000 psi. at a temperature in the range of 375° to 400°C. Coal fortified with a cracking catalyst such as Sodium Carbonate is used. Coal is slurried with water and .8 to 1.4% of Sodium Carbonate by wt. based on the dry wt. of Coal is added to the water slurry, stirred well allowed to settle and the water drained to obtain Coal fortified with Sodium Carbonate, which is used for slurrying with recycle oil. The drying of Sodium Carbonate, incorporated wet Coal is carried out by heating to evaporate the water by using hot air or by exposure to hot Sun* In another aspect the heating is indirect by using a jacketted vessel and hot air or stream in the Annular space. - 4 - The success of my invention is attributed to realising an important aspect of Coal Liquefaction. It has been found that the Coal is to be cracked effectively and free radicals produced are stabilised by Hydorgen. toother aspect of the success is subjecting the Coal to a step of modification by using an independent and new Catalysts. I have preconditioned the Coal before the slurrying step by using a cracking catalysts preferably Sodium Carbonate due to which preconditioning, effective cracking of the Coal Bonds is achieved. Thus there is an additional new step before the conventional slurrying step. I have also been able to use lesser reaction temperature, lesser reaction pressure, high space velocity and lesser reaction time due to which our reaction appears to be highly economical from several angles. I have also compared our process using the same parameter and have found higher percentage of gaseous products. In order to facilitate better effective liquefaction of Coal the chemical Bond was destructed by using a cracking catalyst. It was necessary to thoroughly deposit the cracking catalyst on the Coal. After several experiments, it was found that dry blending, though helpful, is not effective. Alternatively it was found that if Coal is slurried in water and the catalyst material added to the slurry with an effective mixing of this slurry loaded with the catalyst, it was possible to effectively and uniformly distribute the catalyst particle in the Coal matrix. Thus catalysts of necessary particles size was added to water slurry of Coal and -5- after proper distribution, it was allowed to settle. Water was drained out in a conventional manner and the wet Coal having the cracking Catalysts Particles incorporated therein was subjected to drying. The drying can be carried out using a stream of hot air. However, other methods of drying such as spreading the wet cake in the form of a thin layer and drying is also possible. From this state on the usual liquefaction step was followed in principle though not in details. A slurry of cracking catalyst impregnated Coal was prepared as usual using recycle oil. A percentage of solid in the slurry was 50%. The slurry was then subjected to pumping a high pressure of 1500 to 2000 psi and heated to a temperature of 375° to 400°C, while a stream of Hydrogen is passed to a slurry. As usual Nickel Molybdenum was used as Hydrogenation Catalyst. Though a few cracking catalyst were used and found effective, satisfactory results were obtained with Sodium Carbonate. The percentage of Sodium Carbonate to Coal on dry basis could vary between 0.8 to 1.4% by wt. Optimum results are achievable using Sodium Carbonate 1% by weight of coal. While subjecting the Sodium Carbonate impregnated Coal to liquefaction with a Hydrogen in the presence of Hydrogenation Catalyst, it was possible to obtain more liquid than the gas because the operating pressure and temperature were lower than pressure and temperature in the conventional process. It was possible to obtain slightly more liquid. This was for less amount of Hydrogen consumed. - 6 - The invention will now be more fully described to the following Examples, wherein - Example 1 is a study of conventional liquefaction process, where the Coal is not fortified. Example 2 is a study as per the invented process where Coal is fortified with 1% Sodium Carbonate. The space velocity of in Examples 1 and 2 were the same at 361b per hour, per cubic feet of the reactor. Example 3 is a study of the same feed as in Example 2 but at higher space velocity of around 501b per hour, per cubic feet of the reactor. It was found that the liquid yield increased. Example 1 Conventional Process 2 00 lbs of coal was slurried in recycle coal oil to obtain a slurry of 50% solids. The slurry was heated to 450oC. The slurry is then pumped at a pressure of 2500 psi by positive displacement pump into the H-Coal reactor containing a bed of hydrogenation catalyst made of conventional nickel molybdenum catalyst. Hydrogen gas, preheated to 450°C is also passed along with the slurry of coal. The space velocity of the slurry is 36 lbs/(hr)/cft of catalyst. The reaction is carried out continuously for a period of 1 hour and 25 minutes. The reaction was terminated and the product stream analysis showed results as in the following Table 1. - 7 - Example 2 200 lbs of coal was taken and slurried in cold water to 505$ solids content (200 1bs H20). The cold water contained 3.3% Na2Co3. The mixture was stirred mechanically to ensure proper distribution of Na2co3 in the coal matrix. The stirred slurry was allowed to stand and the excess solution was drained. The moisture content of coal after draining was 50% i.e. 100 lbs H2O. The wet material was then dried using hot air stream for sufficient time to obtain a dry material of 1TA moisture which was originally existent in coal. Since I wanted coal to contain 1.09% NaCO3 and since coal originally had 17% H20 therefore 66 1b of water was absorbed which contained 2.18 lbs of Na2CO3 and hence I added a 3.3% Na2CO3 in water to coal for impregnation. Example 3 Example 2 was repeated with alterations as follows t Pressure of slurry ... 2000 1bs/sq in Pressure of H2 Gas ... 2000 1bs/sq in Temperature of slurry ... 400oC Temperature of H2 Gas ... 400oC Space velocity ... 50 lbs/(hr)(cft of reactor) All other parameters were the same. The reaction was faster as indicated by product stream analysis. The results of the three Examples are tabulated in Table No.l and conclusion given after the Table. - 8 - TABLE I PRODUCT STREAM ANALYSIS - 9 - CONCLUSION: - When Coal is subjected to impregnation with sodium Carbonate and conditions are maintained same as the conventional process gas yield is much more and liquid yield is much less. The reason being the fact that longer is the contact time and hence the liquid gets gasified. When space velocity is increased contact time is less and the chance of liquid getting gasified is less. - 9A - I CLAIM :- 1) A method for liquefaction of Coal with Hydrogen, using Hydrogenation Catalyst, comprising the steps of slurrying the Coal in recycle oil, adding Hydrogenation, Catalyst like Nickel Molybdenum under pressure and temperature, characterised in that said Hydrogenation is carried out additionally in the presence of a cracking catalyst , preferably Sodium Carbonate. 2) A method as claimed in Claim 1, wherein the reaction is carried out at a pressure in the range of 1500 to 2000 psi. 3) A method as claimed in Claim 1 or 2 , wherein the reaction is carried out at a temperature in the range of 375° to 400°C. 4) A method as claimed in Claims 1 to 3, wherein Coal fortified with a cracking catalyst such as Sodium Carbonate is used. 5) A method as claimed in Claim 4, wherein Coal is slurried with water and .8 to 1.4% of Sodium carbonate by wt. based on the dry wt. of Coal is added to the water slurry, stirred well allowed to settle and the water drained to obtain Coal fortified with Sodium Carbonate, which is used for slurrying with recycle oil. 6) A method as claimed in Claims 1 to 5, wherein the drying of Sodium Carbonate incorporated wet Coal is carried out by heating to evaporate the water. 7) A method as claimed in Claim 6, wherein the heating is direct by using hot air or by exposure to hot Sun. 8) A method as claimed in Claim 6, wherein the heating is indirect by using a jacketted vessel and hot air or stream in the Annular space. - 10 - - 11 - 9) A method for liquefaction of Coal with Hydrogen, using Hydrogenation Catalyst substantially as herein described with reference to the Examples. It is already known to subject Coal to liquefaction using a slurry of Coal with recycle oil derived from Coal. Such a slurry is generally pumped at a pressure of about 2600 to 3000 psi and is mixed with the Hydrogen, is preheated to around 450° to 500° C. To enhance the reaction of the Hydrogen, the reaction is carried out in the presence of Nickel Molybdenum Catalysts. For increased Yields, the reaction is carried out in an ebullated bed reactor. There is disclosed herein, a method for liquefaction of Coal with Hydrogen, using Hydrogenation Catalyst, comprising the steps of slurrying the Coal in recycle oil, adding Hydrogenation, Catalyst like Nickel Molybdenum under pressure and temperature, characterised in that said Hydrogenation is carried out additionally in the presence of a cracking catalyst, preferably Sodium Carbonate.

Documents:

00505-cal-1999-abstract.pdf

00505-cal-1999-claims.pdf

00505-cal-1999-correspondence.pdf

00505-cal-1999-description(complete).pdf

00505-cal-1999-form-1.pdf

00505-cal-1999-form-18.pdf

00505-cal-1999-form-2.pdf

00505-cal-1999-letters patent.pdf

00505-cal-1999-p.a.pdf