Title of Invention

"PROCESS FOR PRODUCING AROMATIC CARBOXYLIC ACID"

Abstract

A process for producing an aromatic carboxylic acid by subjecting an alkyl aromatic compound such as herein describe to oxidation reaction in liquid phase using acetic acid as a solvent in a manner as herein described to form aromatic carboxylic acid containing slurry, characterized in that the step after the oxidation reaction step is one or more steps selected from a crystallization step, a solid-liquid separation step and a drying step.

Full Text

I The present invention relates to a process for producing an aromatic carboxylic acid. In detail, the invention relates to a process for producing an aromatic " carboxylic acid using acetic acid as a solvent or the like at the time of production. In general, as a process for industrially producing an aromatic carboxylic acid such as terephthalic acid, there is known a process in which an alkyl aromatic hydrocarbon such as p-xylene is subjected to oxidation reaction in a liquid phase with molecular oxygen in an acetic acid solvent in the presence of a catalyst containing cobalt, manganese and bromine, slurry containing a crystal of generated terephthalic acid or other aromatic carboxylic acid is subjected to a solidliquid separation treatment and a subsequent drying step to form a crude aromatic carboxylic acid, the resulting crude aromatic carboxylic acid is then dissolved into water, and this aqueous solution is subjected to a purification treatment by hydrogenation to produce a highpurity aromatic carboxylic acid. Such a process for producing an aromatic carboxylic acid involves such a problem that the acetic acid which is a solvent is consumed during the oxidation reaction, that is, a loss of acetic acid occurs during the production step. One of causes thereof is the formation of methyl acetate as a by-product due to heterogeneous reaction of acetic acid. In order to inhibit the formation of methyl acetate as a by-product, there is known a technology in which a condensing component which is contained in an oxidation exhaust gas as generated from a reactor is condensed by a condenser, methyl acetate which is contained in an uncondensed gas is recovered by bringing into contact with and absorbing on acetic acid, and the recovered material is circulated into the reactor, thereby increasing a concentration of methyl acetate in a reaction mother liquid and inhibiting the reaction for forming a byproduct from acetic acid to methyl acetate (see Patent Document 1). Furthermore, there is known a technology in which an oxidation exhaust gas is directly introduced into a distillation tower to achieve distillation, an aliphatic carboxylic acid ester such as methyl acetate, which is contained in an exhaust gas of the distillation tower, is then brought into contact with and absorbed on an aliphatic carboxylic acid such as acetic acid, and the treated gas is brought into contact with washing water, thereby absorbing the aliphatic carboxylic acid (see Patent Document 2) . There is also known a method in which methyl acetate which is contained in distilled water as obtained in a solvent recovery step for dehydrating water as formed by oxidation from an acetic acid solvent is recovered by a distillation treatment and returned to an oxidation reactor (see Patent Document 3). As a method for recovering methyl acetate, there is also known a method in which in a solvent recovery method employing azeotropic distillation, a vapor as distilled by distillation is subjected to partial condensation, thereby recovering methyl acetate from a methyl acetate-entrained vapor (see Patent Document 4). [Patent Document 1] JP-A-53-84933 (left-hand lower column of page 2) [Patent Document 2] JP-A-2000-72714 [Patent Document 3] JP-A-53-84932 [Patent Document 4] WO 98/45239 DISCLOSURE OF THE INVENTION> However, as described previously, in order to inhibit the formation of methyl acetate as a by-product, mere recovery of methyl acetate which is contained in the oxidation exhaust gas as generated from the reactor or distilled water in the solvent recovery step is insufficient for reducing the amount of consumption of acetic acid, and it is further necessary to reduce a loss of acetic acid, thereby efficiently producing an aromatic carboxylic acid. Furthermore, an exhaust gas composed mainly of an inert gas after partially condensing a distilled vapor by distillation in the solvent recovery step and recovering methyl acetate from the methyl acetate-entrained vapor is still entrained with methyl acetate, and a point for effectively utilizing this has not been solved yet. These problems are problems common in the production of terephthalic acid and other aromatic carboxylic acids using acetic acid as a solvent. Then, a problem of the invention is to solve the foregoing problems and to advantageously produce an aromatic carboxylic acid such as terephthalic acid by making the amount of consumption of an acetic acid solvent in the production step of an aromatic carboxylic acid small as far as possible and industrially enhancing production efficiency. In order to solve the foregoing problems, the invention is concerned with a process for producing an aromatic carboxylic acid by subjecting an alkyl aromatic compound to oxidation reaction in a liquid phase using - K - 5 acetic acid as a solvent to form aromatic carboxylic acidcontaining slurry, characterized by separating and recovering methyl acetate which is contained in an exhaust gas as generated in a step after the foregoing oxidation reaction step and returning the recovered methyl acetate to the foregoing oxidation reaction step. According to the thus constructed process for producing an aromatic carboxylic acid according to the invention, since not only methyl acetate which is contained in an oxidation exhaust gas as generated from a reactor is recovered, but also methyl acetate which is contained in an exhaust gas as generated in a step after the oxidation reaction, for example, one step or plural steps selected from a crystallization step, a solid-liquid separation step, a drying step, and a solvent recovery step is returned to the oxidation reaction step, the formation of methyl acetate as a by-product is inhibited, a loss of acetic acid as a solvent during the reaction is reduced, and a production efficiency is enhanced. The invention is also concerned with a process for producing an aromatic carboxylic acid by subjecting an alkyl aromatic compound to oxidation reaction in a liquid phase using acetic acid as a solvent to form aromatic carboxylic acid-containing slurry and subjecting this slurry to at least a solid-liquid separation step, characterized by recovering acetic acid which is contained - 6 - in a liquid or vapor as generated in the oxidation reaction step, solid-liquid separation step or the both steps by a distillation operation and recovering methyl acetate in an exhaust gas as generated in this distillation operation and returning it to the oxidation reaction step. According to the foregoing process for producing an aromatic carboxylic acid, in the solvent recovery step, since not only methyl acetate in distilled water as obtained by the distillation operation but also a condensing component in the distilled gas are condensed as far as possible and methyl acetate in an exhaust gas composed mainly of a generated inert gas is also recovered and returned to the oxidation reaction step, recovery efficiency of methyl acetate is further increased so that a loss of acetic acid which is a solvent during the reaction can be extremely efficiently lowered. As a method for recovering methyl acetate in the foregoing exhaust gas, a method for absorbing methyl acetate in an acetic acid liquid and recovering it is efficient and preferable. Also, as the acetic acid which is used for recovering methyl acetate, it is preferred to use one as obtained by a separation treatment of acetic acid and water in the solvent recovery step. Furthermore, in addition to the dissolution of the foregoing problems, for the purpose of solving a problem that the treated gas after absorbing methyl acetate into acetic acid is entrained with a part of acetic acid, in the foregoing process for producing an aromatic carboxylic' t acid which is characterized by recovering methyl acetate in the exhaust gas and returning it to the oxidation reaction step, methyl acetate is absorbed into acetic acid and recovered; the acetic acid component which is contained in the treated gas is then absorbed into water; and the acetic acid component which has been recovered as an acetic acid aqueous solution is used as a part of the solvent. Also, this acetic acid aqueous solution may be used in a washing step of a cake in the solid-liquid separation step or may be fed into the solvent recovery step to reduce the water content and then reused together with other recovered acetic acid. As the foregoing water for absorbing acetic acid, water resulting from fractional distillation by a separation treatment of acetic acid and water in the solvent recovery step can be used. Furthermore, in the foregoing step, p-xylene can be employed as the alkyl aromatic compound, and terephthalic acid can be employed as the aromatic carboxylic acid. 8 An embodiment of the present invention relates to a process for producing an aromatic carboxylic acid by subjecting an alkyl aromatic compound such as herein describe to oxidation reaction in liquid phase using acetic acid as a solvent in a manner as herein described to form aromatic carboxylic acid containing slurry, characterized in that the step after the oxidation reaction step is one or more steps selected from a crystallization step, a solid-liquid separation step and a drying step. Fig. 1 is a flow chart of an apparatus for producing an aromatic carboxylic acid, which shows an embodiment of one example of the invention. Incidentally, with respect to the symbols in the drawing, 1^ stands for a reactor; 2 stands for a condenser; 3 stands for an exhaust gas; £ stands for a condensed liquid; ^ stands for a crystallization tank; 6 stands for a solid-liquid separator; T. stands for a solvent recovery tower; £ stands for a dehydration tower; !9 stands for a dryer; K) stands for a high-pressure absorption tower; and 11 stands for a low-pressure absorption tower. The invention will be hereunder described in detail. Examples of the alkyl aromatic compound to be used in the invention include alkylbenzenes and alkylnaphthalenes which are converted into an aromatic carboxylic acid such as aromatic monocarboxylic acids, aromatic dicarboxylic acids, and aromatic tricarboxylic acids by liquid phase oxidation, for example, mono-, di-, or trialkylbenzenes, inclusive of those in which a part of the alkyl groups thereof is oxidized. Furthermore, the process for producing an aromatic carboxylic acid which is used in the invention typically includes the respective steps of: (i) an oxidation reaction step for subjecting an alkyl aromatic compound to liquid phase oxidation in acetic acid as a solvent in the presence of a catalyst containing • ,o cobalt, manganese and bromine to form aromatic carboxylic acid-containing slurry, (ii) a step for crystallizing the aromatic carboxylic acid as dissolved in a mother liquor of the formed slurry, (iii) a step for subjecting the aromatic carboxylic acid slurry as obtained in the crystallization step to solid-liquid separation into a mother liquor and a cake containing an aromatic carboxylic acid, (iv) a drying step for removing a liquid adhered onto the separated cake, and (v) a solvent recovery step for recovering acetic acid from a vapor or liquid containing acetic acid as generated from at least one of the step (i) to the step (iv) . Especially, the invention is applied to the production of terephthalic acid, and the alkyl aromatic compound as a preferred starting material is p-xylene. An embodiment regarding the case of producing terephthalic acid by oxidation of p-xylene will be hereunder described below. An amount of acetic acid as a solvent which is used in the invention is usually from 2 to 6 times by weight based on p-xylene as the starting material. As the acetic acid solvent, one containing a slight amount of water, specifically one containing not more than 15 % by weight of water can also be used. In order to subject p-xylene to oxidation reaction in a liquid phase, a molecular oxygen-containing gas is used. Air is usually used because it can be used by simple equipment and at low costs, and diluted air, oxygen-rich air, and the like can also be used. In order to oxidize p-xylene, a catalyst containing cobalt (Co) , manganese (Mn) and bromine (Br) as constituent elements is usually used as the catalyst. The reaction for oxidizing p-xylene in a liquid phase is carried out by oxidizing p-xylene while continuously feeding a molecular oxygen-containing gas in an acetic acid solvent in the presence of a catalyst at a temperature of from 140 to 230°C, and preferably from 150 to 210°C. A pressure in the oxidation reaction step is a pressure under which the mixture can at least keep the liquid phase at the reaction temperature or a higher pressure than that pressure and is usually from 0.2 to 5 MPa, and preferably from 1 to 2 MPa. While a reactor is usually a stirrer-equipped tank, the stirrer is not always necessary, and it may be a bubble tower type. The reactor is provided with a condenser in the upper portion thereof and a molecular oxygen gas-containing gas feed port in the lower portion thereof. And, the molecular oxygen-containing gas as fed from the lower portion is utilized for the oxidation reaction -hand then discharged out as an exhaust gas entraining a large amount of a solvent vapor from the reactor; subsequently, after condensing and separating a condensing component from the exhaust gas by a reflux condenser, the resulting gas is discharged out as an oxidation exhaust gas. The condensed liquid, after purging a part thereof out the system for the purpose of regulating the water content of the reaction mother liquor, is refluxed into the reactor. Furthermore, the oxidation exhaust gas is introduced into a high-pressure absorption tower, and methyl acetate in the exhaust gas is subjected to gas-liquid contact with acetic acid or an acetic acid-containing liquid and absorbed therein. As the acetic acid, it is preferred to use acetic acid as recovered from the solvent recovery step. The thus methyl acetate-absorbed acetic acid is returned to the oxidation reactor, provided for oxidation reaction, and then used for formation reaction of terephthalic acid. And, in the crystallization step regarding slurry of a reaction product as obtained in the oxidation reaction step, the reaction slurry is dropped to proper temperature and pressure to obtain terephthalic acid slurry. With respect to the crystallization condition, the number of stage of the crystallization is from I to 6 stages, and - VS. - 13 preferably from 2 to 4 stages. For a series of crystallization steps, flash cooling is employed, and it is preferable that a final step is carried out in a boiling state under a reduced pressure. Terephthalic acid is usually recovered through a solid-liquid separation step and a drying step of the slurry having been subjected to a crystallization treatment and sent to a hydrogenation purification step. By omitting this drying step, the acetic acid solvent may be displaced by a water solvent through a solvent displacement step, which is then sent directly to the hydrogenation purification step. As a device for carrying out the solid-liquid separation, a device such as a centrifuge, a horizontal belt filter, and a rotary vacuum filter is usually used, but it should not be construed that the invention is limited thereto. Furthermore, the solvent recovery step is a step for recovering acetic acid by purifying an oxidation exhaust gas condensed liquid or a mother liquor as aliquoted during the solid-liquid separation. The solvent recovery step is also called as an acetic acid dehydration step because water as formed by the oxidation is removed. In order to recover methyl acetate and acetic acid from exhaust gases as generated from the foregoing crystallization step, solid-liquid separation step, drying step and solvent recovery step, the recovery can be carried out by gathering one or more exhaust gases containing methyl acetate and acetic acid as generated in the respective steps to form a gathered gas, introducing this gathered gas into an absorption tower and bringing it into contact with acetic acid as adjusted in a droplet form or the like to absorb it therein. With respect to the absorption condition, it is preferable that the temperature is as low as possible in view of absorption efficiency, and the recovery is usually carried out at not higher than 50°C. The hydrogenation purification step is a method in which a water-containing liquid is added to crude terephthalic acid to form slurry, hydrogenation treatment is carried out in the presence of a catalyst in the state that this slurry is dissolved by heating, and the resulting treated material is subjected to crystallization and solid-liquid separation to produce high-purity terephthalic acid. On this occasion, the crude terephthalic acid is fed as slurry of usually from 20 to 35 % by weight based on the water-containing liquid into a hydrogenation reaction system. As the hydrogenation catalyst, arbitrary catalysts which have hitherto been known can be used. Examples thereof include palladium, ruthenium, rhodium, osmium, iridium, and platinum, each of which is supported on if active carbon. These catalysts may be used jointly. With respect to the condition of the hydrogenation purification reaction, usually, it is general to carry out the hydrogenation purification reaction at a reaction temperature of from 255 to 300°C under a reaction pressure of from 1 to 12 MPa and a hydrogen partial pressure of from 0.05 to 3 MPa. However, it should not be construed that the invention is limited thereto. It is general to separate terephthalic acid as purified by the hydrogenation reaction as a solid by crystallization and solid-liquid separation. The condition of the crystallization is chosen while taking into account a yield of the solid as deposited, a purity of the same solid, and so -on. Usually, the crystallization is carried out in plural stages, and the crystallization condition in the final stage is at from 140 to 180°C under from 0.3 to 1.0 MPa. On this occasion, a residence time in each crystallization tank is fixed at from about 5 to 200 minutes. When the temperature of the crystallization tank in the final stage is lower than the foregoing range, since the amount of deposition of impurities such as p-TA rapidly increases, the purity of terephthalic acid as separated as a solid becomes low, and therefore, such is not preferable. In general, by achieving solid-liquid separation after carrying out the crystallization, terephthalic acid as deposited in the crystallization step is separated from a liquid containing water as the major component. As the temperature and pressure condition for achieving the solid-liquid separation, there is chosen a condition substantially the same as the condition in the crystallization tank and when the crystallization step is of multiple stages, the condition in the final crystallization tank. As a device for carrying out the solid-liquid separation, a device such as a centrifuge, a horizontal belt filter, and a rotary vacuum filter is usually used, but it should not be construed that the invention is limited thereto. It is also possible to use a combination of two or more of these devices. Terephthalic acid as obtained by solid-liquid separation of the solid which has been deposited after the purification step may be dried as it is and then provided as a product. Alternatively, after forming terephthalic acid together with fresh water into slurry and washing in a suspension and washing tank, a solid as separated by solid-liquid separation may be dried and then provided as a product. Next, one examples of representative embodiments regarding the process for producing terephthalic acid according to the invention will be described with reference to a flow chart of an apparatus of Fig. 1. First of all, a mixture of a catalyst containing Co/Mn/Br, an acetic acid solvent and starting p-xylene and a molecular oxygen-containing gas are fed into a reactor (also called as "an oxidation reactor") 1. A gas component as discharged from this reactor 1, after condensing and separating a condensing component such as acetic acid by a condenser (gas-liquid separator) 2, is discharged as an oxidation exhaust gas from the heat exchanger . A condensed liquid 4, after discharging a part thereof as a purging fraction out the system for the purpose of regulating the water content thereof, is refluxed into the reactor 1. Slurry as obtained by an oxidation treatment in the reactor 1 is transferred into a low-temperature additional oxidation tank (not illustrated) and subjected to an oxidation treatment with a small amount of a molecular oxygen-containing gas at a temperature lower than .the reactor 1. The slurry having been subjected to an oxidation treatment is further crystallized in a crystallization tank 5. The number of stage of the crystallization is usually from 1 to 6 stages. This slurry having been subjected to a crystallization treatment is separated into a mother liquor component and a crude terephthalic acid cake in a solid-liquid separator 6, and crude terephthalic acid is obtained through a dryer 9. Furthermore, the crude terephthalic acid is formed 18 into slurry with a water-containing liquid in a nonillustrated mixing tank, and after dissolution, the solution is transferred into a hydrogenation purification reactor and subjected to a purification treatment into high-purity terephthalic acid. On the other hand, the oxidation exhaust gas condensed liquid and the mother liquor component as separated in the solid-liquid separator 6 are transferred into a solvent recovery step having a solvent recovery tower 7 and a dehydration tower 8, whereby acetic acid is recovered. An exhaust gas 3 is discharged from not only the reactor 1 but also the crystallization tank 5, the solidliquid separator 6, the dryer 9, and the dehydration tower 8. Such an exhaust gas composed of a gathering of exhaust gases from one or more locals is introduced into a highpressure absorption tower 10 or a low-pressure absorption tower 11, and methyl acetate as entrained in the exhaust gas is absorbed by using acetic acid for an absorbing liquid and recovered in the reactor 1. In the case where a solid-liquid separator of a filtration type such as a horizontal belt filter and a rotary vacuum filter is used as the solid-liquid separator, a filtrate and a gas are discharged from a vacuum device and subjected to suction filtration while feeding a gas in the upstream side of a filtration section within the separator. At this time, the discharged filtrate and gas are subjected to gas-liquid separation, and at least a part of the resulting gas is discharged out the step. However, since methyl acetate is contained in this gas, it is preferred to apply the recovery measure of methyl acetate according to the invention. Furthermore, in the case of using a measure in which in a rotary dryer or a fluidized bed dry as the dryer, the solvent component as vaporized within the dryer is entrained in the foregoing gas by circulating an inert gas such as a process gas within the dryer and discharged out the dryer, since methyl acetate is contained in the gas, it is preferred to apply the recovery measure of methyl acetate according to the invention. As the acetic acid to be used for the purpose of recovering methyl acetate in the absorption tower 10 or 11, acetic acid as obtained by the separation treatment of acetic acid and water in the solvent recovery step (7 and 8) is preferable. Furthermore, it is preferred to provide a device for absorbing acetic acid by using water and recovering it in the downstream side of the high-pressure absorption tower 10 or the low-pressure absorption tower 11. An absorption device of methyl acetate and an absorption device of acetic acid may be a tower as separately provided or may be provided integrally in the same tower. At this time, the water to be used for the absorption of acetic acid is preferably water as obtained by the separation treatment of acetic acid and water in the solvent recovery step (7 and 8) or a separated mother liquor containing, as the major component, water as obtained by solid-liquid separation in the hydrogenation purification step. In this way, methyl acetate is recovered from the exhaust gas composed of a gathering of methyl acetatecontaining exhaust gases as generated in one or plural steps selected from the crystallization step, the solidliquid separation step, the drying step, and the solvent recovery step and returned to the oxidation reaction step, whereby formation reaction of methyl acetate as a byproduct is inhibited, a loss of acetic acid as a solvent during the reaction is reduced, and production efficiency is enhanced. While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. This application is based on a Japanese patent application filed February 21, 2003 (Patent Application No. 2003-044121), the entire contents thereof being hereby incorporated by reference. According to the invention, since not only methyl acetate which is contained in an oxidation exhaust gas as generated from a reactor is recovered, but also methyl acetate obtainable from exhaust gases as generated in a step after an oxidation reaction step, namely one or plural steps selected from a crystallization step, a solid-liquid separation step, a drying step, and a solvent recovery step is returned to the oxidation reaction step, there are given such advantages that a recovery efficiency of methyl acetate is increased, a loss of acetic acid as a solvent during the reaction is reduced, and production efficiency is enhanced. Furthermore, in an invention in which in absorbing methyl acetate into acetic acid and recovering it, the absorption treated gas-entrained acetic acid is returned to a prescribed step, since a loss of acetic acid is reduced, there is given such an advantage that an aromatic carboxylic acid such as terephthalic acid can be extremely advantageously produced with industrially enhanced production efficient. We Claim: 1. A process for producing terephthalic acid by using acetic acid as a solvent and subjecting p-xylene in a liquid phase to an oxidation reaction to produce a slurry containing terephthalic acid, wherein methyl acetate contained in an exhaust gas generated in the oxidation reaction step is separated and recovered by a high-pressure absorption tower and the recovered methyl acetate is returned to the above oxidation reaction step, methyl acetate contained in the exhaust gas generated in the step after the oxidation reaction step is separated and recovered by a low-pressure absorption tower and the recovered methyl acetate is returned to the above oxidation reaction step, pressure of the high-pressure absorption tower is same as or lower than the pressure of the oxidation reaction step and is higher than the pressure of the low-pressure absorption tower, pressure of the low-pressure absorption tower is same as or lower than the pressure of the above oxidation reaction step, and the step(s) after the above oxidation reaction step comprise(s) one or more step(s) selected from a crystallization step, a solid-liquid separation step, a drying step and a solvent recovery step. 2. A process for producing terephthalic acid as claimed in claim 1, the exhaust gas is composed of methyl acetate-containing exhaust gases as generated in plural steps selected from a crystallization step, a solid-liquid separation step, a drying step and a solvent recovery step. 3. A process for producing terephthalic acid as claimed in claim 1, wherein the terephthalic acid containing slurry is subjected to solid-liquid separation step, wherein acetic acid contained in a liquid or vapour as generated in the oxidation reaction step, solid-liquid separation step or both steps are recovered by a distillation operation; and the methyl acetate in an exhaust gas as generated in this distillation operation is recovered and returned to the oxidation reaction step. 4. A process for producing terephthalic acid as claimed in any of claims 1 to 3, wherein the recovery of methyl acetate in the exhaust gas is carried out by absorbing methyl acetate into acetic acid. 5. A process for producing terephthalic acid as claimed in claim 4, wherein the methyl acetate in the exhaust gas is absorbed into acetic acid and subjected to a recovery treatment; that acetic acid contained in the gas after the treatment is absorbed into water to obtain an acetic acid aqueous solution; and that this acetic acid aqueous solution is used as a part of the solvent directly or after lowering the content of water. 6. A process for producing terephthalic acid as claimed in claim 5, wherein the water to be used for the absorption of acetic acid is water as obtained by a separation treatment of acetic acid and water in the solvent recovery step 7. A process for producing terephthalic acid as claimed in any one of claims 4 to 6, wherein the acetic acid to be used for the absorption of methyl acetate is acetic acid as obtained by a separation treatment of acetic acid and water in the solvent recovery step 8. A process for producing terephthalic acid substantially as herein described with reference to the forgoing examples and as illustrated in the foregoing drawing.

Documents:

3627-DELNP-2005-Abstract (26.OCT.2007).pdf

3627-DELNP-2005-Abstract-25-04-2008.pdf

3627-delnp-2005-abstract.pdf

3627-DELNP-2005-Claims (26.OCT.2007).pdf

3627-DELNP-2005-Claims-25-04-2008.pdf

3627-delnp-2005-claims.pdf

3627-DELNP-2005-Correspondence-Others (26.OCT.2007).pdf

3627-delnp-2005-correspondence-others.pdf

3627-DELNP-2005-Correspondence-Othes-25-04-2008.pdf

3627-DELNP-2005-Description (Complete) (26.OCT.2007).pdf

3627-delnp-2005-description (complete).pdf

3627-DELNP-2005-Description (Complete)25-04-2008.pdf

3627-DELNP-2005-Drawings (26.OCT.2007).pdf

3627-delnp-2005-drawings.pdf

3627-delnp-2005-form-1.pdf

3627-DELNP-2005-Form-13 (26.OCT.2007).pdf

3627-delnp-2005-form-18.pdf

3627-DELNP-2005-Form-2 (26.OCT.2007).pdf

3627-DELNP-2005-Form-2-25-04-2008.pdf

3627-delnp-2005-form-2.pdf

3627-DELNP-2005-Form-26- (26.OCT.2007).pdf

3627-delnp-2005-form-26.pdf

3627-DELNP-2005-Form-3 (26.OCT.2007).pdf

3627-DELNP-2005-Form-3-25-04-2008.pdf

3627-delnp-2005-form-3.pdf

3627-delnp-2005-form-5.pdf

3627-delnp-2005-pct-304.pdf

3627-delnp-2005-pct-308.pdf

3627-DELNP-2005-Petition-137 (26.OCT.2007).pdf