Jumat, 08 Januari 2010

ACRYLIC ACID : Kumpulan Informasi Paten

1. Method for purifying acrylic acid obtained by oxidation of propylene and/or acrolein

United States Patent 6,995,282 / Fauconet , et al. / February 7, 2006

Abstract

The gas reaction mixture (1), formed of propylene, if the case arises, of ultimate oxidation products, of acrylic acid, of acrolein, of steam, of acetic acid and of heavy products, is sent to the bottom of an absorption column (C1) fed countercurrentwise at the top with a heavy hydrophobic absorption solvent. The gas flow (7), formed of propylene and of ultimate oxidation products, of major amounts of water and acetic acid, and of acrolein, is obtained at the top of (C1) and a flow (4), formed of acrylic acid, of the heavy solvent, of heavy products and of minor amounts of acetic acid and of water, is obtained at the bottom of (C1). The flow (7) is sent to a heat exchanger (C3), where it is brought into contact with a descending liquid stream (8), fed at the top of (C3), composed of the recycling of a portion of the flow (9), cooled beforehand, from the bottom of (C3), in order to obtain, at the top, a gas flow (10) comprising the compounds present in the flow (7), except for most of the water and all the acetic acid, removed in the flow (9) from the bottom of (C3).

2. Preparation of acrylic acid and esters

United States Patent 5,817,865 / Machhammer , et al. / October 6, 1998

Abstract

A process for preparing acrylic acid and/or esters comprises the steps of: (a) catalytic gas phase oxidation of propene and/or acrolein to acrylic acid to obtain a gaseous reaction product comprising acrylic acid, (b) solvent absorption of the reaction product, (c) distillation of the solvent loaded with acrylic acid to obtain a crude acrylic acid and the solvent, (d) purification of the crude acrylic acid by crystallization and (e) optionally esterification of the crystalline acrylic acid.

3. Process for preparing and purifying acrylic acid from propylene having improved capacity

United States Patent 6,639,106 / Elder , et al. / October 28, 2003

Abstract

This invention relates to an improved process for preparing acrylic acid from propylene using a tandem reactor and utilizing an increased amount of propylene reactant, thereby providing increased capacity and throughput. An improved process for purifying acrylic acid is also disclosed.

4. Process for producing acrylic acid

United States Patent 4,873,368 / Kadowaki , et al. / October 10, 1989

Abstract

Propylene in admixture with molecular oxygen and steam is subjected to a two-step, vapor-phase, catalytic oxidation to convert into acrolein and then into acrylic acid. At least the first-step reaction is conducted in tubes of an apparatus of a shell-and-tube heat-exchanger type structure, and the reaction product of the first-step reaction is quenched before it is subjected to the second-step reaction. Reaction conditions in both the steps are specified.

5. Process for producing acrylic acid from propylene

United States Patent 4,147,885 / Shimizu , et al. / April 3, 1979

Abstract

A process for producing acrylic acid from propylene through acrolein as an intermediate by catalytic vapor phase oxidation, which comprises passing a starting reactant gas mixture containing propylene, a molecular oxygen-containing gas and steam through a first-stage reactor packed with a molybdenum-containing multi-component catalyst, passing the resulting acrolein-containing gas through a second-stage reactor packed with a multi-component catalyst containing vanadium and molybdenum, introducing the resulting acrylic acid-containing gas to an acrylic acid collector thereby to recover acrylic acid in the form of an aqueous solution, and incorporating a part of the exhaust gas from the collector in the starting reactant gas mixture.

6. Manufacture of acrylic acid by oxidation of propylene with oxygen-containing gases in two separate catalyst stages

United States Patent 4,031,135 / Engelbach , et al. / June 21, 1977

Abstract

In the oxidation of propylene to acrylic acid in the gas phase in two spatially separate oxidation stages, a part of the off-gas, which has been freed from condensable products, is fed to the oxidation stages in addition to freshly charged propylene and air, under the following conditions: A. The recycled off-gas and air are in part fed to the first oxidation stage and in part to the second oxidation stage, B. The molar ratio of propylene : oxygen : residual gases fed to the first stage is 1 : 1.5-2.3 : 11-19, C. The molar ratio of the total propylene fed in, to the total oxygen fed in, in the form of air or off-gas, before and after the first stage, and to the total residual gases fed in is 1 : 1.9-2.5 : 13-25, with the proviso that D. The air and the recycled off-gas are divided between the two feed points in such a way that from 10 to 50% by volume of the total quantity of air and off-gas fed in are added after the first stage and E. The air and off-gas are admixed to the reaction gas mixture after the first stage, immediately after it leaves the catalyst zone, so that the mixture is rapidly cooled to a temperature of from 150.degree. to 320.degree. C.

7. Process for the production of acrolein and acrylic acid

United States Patent 3,956,376 / Ferlazzo , et al. / May 11, 1976

Abstract

An improved process for the production of acrolein from propylene and of acrylic acid from propylene or acrolein or mixtures of propylene and acrolein which essentially comprises catalytic oxidation of propylene and/or acrolein with oxygen or a gas containing molecular oxygen in the presence of an oxidation catalyst and of methanol in a quantity of from 0.01 to 1% by volume with respect to the total gaseous mixture of the reactants. Acrolein and acrylic acid are formed in the process at high conversion rates and selectivities.

8. Process for inhibiting post reactions in the catalytic oxidation of propylene and/or acrolein to produce acrolein and/or acrylic acid

United States Patent 3,876,693 / Erpenbach , et al. / April 8, 1975

Abstract

Vapour-phase oxidation of propylene and/or acrolein with oxygen in the presence of steam to produce acrolein and/or acrylic acid, wherein post-reactions are inhibited. The oxidation is carried out in a reaction zone on a fixed bed catalyst at temperatures between 320.degree. and 450.degree.C. More particularly, the resulting hot reaction gas mixture leaving the reaction zone is directly introduced into a heat exchanger zone placed directly downstream of the reaction zone, and the reaction gas mixture is cooled in said heat exchanger zone, with water having a temperature at least 25.degree.C above the dew point of the reaction gas mixture, down to temperatures between 200.degree. and 300.degree.C. The reaction zone is bounded by a generally cylindrical casing receiving a plurality of individual tubular structures. The structures are adapted to have a fixed bed catalyst placed therein, bundled together and spaced apart from each other by means of two perforated plates sealing the upper end and lower end, respectively, of the casing, and heated by means of a salt melt. The heat exchanger zone receives a similar number of empty, watercoolable tubular structures. The tubular structures accommodated in the two zones are flanged together, so as to open directly into each other, by means of the perforated plates.

9. PROCESS FOR ISOLATING ACRYLIC ACID FROM THE REACTION GASES OBTAINED BY THE OXIDATION OF PROPYLENE OR A ACROLEIN

United States Patent 3,717,675 / Sennewald , et al. / February 20, 1973

Abstract

Process for isolating acrylic acid from the reaction gases obtained by the oxidation of propylene or acrolein, wherein the hot reaction gases, which have a temperature of 300.degree. to 600.degree.C, are pre-cooled, wherein the resulting aqueous acrylic acid solution is heated to be freed from the acrolein contained therein, and wherein the resulting vapors, together with non-liquefied, acrolein-containing residual gas, are returned to the oxidation zone, the said process comprising the steps of pre-cooling the reaction gas inside a heat exchanger down to a temperature of 100.degree. to 200.degree.C, subjecting thereafter the pre-cooled gases to direct scrubbing with water having a temperature of 10.degree. to 50.degree.C and thereby cooling them further down to a temperature between 30.degree. and 90.degree.C, and heating the resulting aqueous, 10 to 45 percent acrylic acid solution to a temperature of about 100.degree. to 120.degree.C to expel residual acrolein therefrom.

10. Production of acrylic acid

United States Patent 4,365,087 / Kadowaki , et al. / December 21, 1982

Abstract

In the production of acrylic acid by a two-stage, vapor-phase catalytic oxidation of propylene, a composite oxide catalyst expressed by the formula Mo.sub.a Bi.sub.b Ni.sub.c Co.sub.d Fe.sub.e Na.sub.f Mn.sub.g B.sub.h K.sub.i Si.sub.j O.sub.x is used in the first-stage reaction, which is carried out under specific reaction and operational conditions, and the second-stage reaction is carried under specific reaction and operational conditions while oxygen is supplied by a specific mode.

11. Process for production of acrylic acid

United States Patent 3,903,149 / Kadowaki , et al. / September 2, 1975

Abstract

Acrolein is subjected to vapor phase oxidation to acrylic acid over an oxide catalyst which has the following atomic ratio of the components except for oxygen: Sb.sub.a Ni.sub.b Mo.sub.c V.sub.d W.sub.e Where: A = 100 B = 5 to 200 C = 10 to 1,000 D = 5 to 300 E = 1 to 200.

12. Single reactor process for preparing acrylic acid from propylene having improved capacity

United States Patent 6,384,274 / Elder , et al. / May 7, 2002

Abstract

This invention relates to an improved process for preparing acrylic acid from propylene using a single reactor utilizing an increased amount of propylene reactant thereby providing increased capacity and throughput.

13. Process for production of acrylic acid

United States Patent 5,218,146 / Takata , et al. / June 8, 1993

Abstract

A process for the production of acrylic acid by the two-stage catalytic vapor-phase oxidation of propylene with molecular oxygen, the first stage for oxidizing propylene to produce mainly acrolein and the second stage for oxidizing acrolein to produce mainly acrylic acid, which process comprises supplying to the first-stage reaction a raw gas containing a saturated aliphatic hydrocarbon having 1 to 5 carbon atoms in an amount in the range of 5 to 70% by volume, carbon dioxide in an amount in the range of 3 to 50% by volume, and the aliphatic hydrocarbon and the carbon dioxide in a total amount in the range of 20 to 80% by volume and further containing steam in an amount in the range of 0.5 to 8 mol per mol of propylene.

14. Purification of acrylic acid obtained by catalytic oxidation of propylene

United States Patent 6,281,386 / Fauconet , et al. / August 28, 2001

Abstract

The method consists in extracting acrylic acid by countercurrent filtration washing of reaction gases by at least a hydrophobic absorbing heavy solvent, then recuperating the purified acrylic acid from the solution obtained at the end of this extracting step. As hydrophobic absorbing heavy solvent at least a hydrophobic aromatic compound is used having: a boiling point under atmospheric pressure between 260.degree. C. and 380.degree. C.; a crystallisation temperature less than 35.degree. C. and a viscosity less than 10 mPa.multidot.s in a range of temperature between 30-80.degree. C.

15. Vapor phase catalytic oxidation of propylene to acrylic acid

United States Patent 6,281,384 / Contracter , et al./ August 28, 2001

Abstract

An improved method for manufacturing acrylic acid by vapor phase oxidation of propylene in a single step or reaction stage using as solid phase oxidant a mixture of two particulate solids comprising a bismuth molybdate multimetal oxide (e.g., Mo.sub.12 Co.sub.3.5 Bi.sub.1.1 Fe.sub.0.8 W.sub.0.5 Si.sub.1.4 K.sub.0.05 O.sub.x) and a molybdenum vanadate multimetal oxide (e.g., Mo.sub.12 V.sub.4.8 Sr.sub.0.5 W.sub.2.4 Cu.sub.2.2 O.sub.x). Such a process is advantageously carried out in a recirculating solids reactor system wherein the particulate mixture of solids in an oxidized state reacts with a feed gas containing propylene in a vertical riser reactor and after separation from the acrylic acid gaseous product the particulate mixture of solids in a reduced state is regenerated by contact with an oxygen containing gas in a separate regeneration reactor before recirculation to the riser for further reaction.

16. Process for the purification of acrylic acid obtained by catalytic oxidation of propylene

United States Patent 5,705,688 / Fauconet , et al./ January 6, 1998

Abstract

Acrylic acid obtained by catalytic oxidation of propylene, extracted by countercurrent washing of the reaction gases which at least one hydrophobic heavy solvent in an extraction column (C1) is purified. To this end, a distillation of the stream (5) obtained at the bottom of the column (C1) is conducted in a column (C3) so as to obtain a very pure acrylic acid stream (6) at the top of the column (C3), allowing acrylic acid to pass at the bottom (7); the bottom stream (7) is conveyed as feed into the lower part of a distillation column (C4) from which a stream (9) rich in maleic anhydride and impurities of boiling temperatures situated between that of acrylic acid and that of the heavy solvent is drawn off sideways on a tray situated between the feed and the top of the column; a stream (8) rich in acrylic acid, which is returned as feed to the column (C3) is distilled at the top of the column (C4); and a stream (1) containing heavy solvent and heavy impurities, which is recycled to the top of the column (C1), is recovered at the bottom of the column (C4).

17. Continuous heterogeneously catalyzed gas-phase oxidation of propylene to acrolein, acrylic acid or a mixture thereof

United States Patent 5,684,188/ Hefner , et al./ November 4, 1997

Abstract

In a process for the continuous heterogeneously catalyzed gas-phase oxidation of propylene to acrolein, acrylic acid or a mixture thereof in an oxidation reactor whose feed gas mixture comprises, apart from propylene and molecular oxygen as oxidant, only at least one diluent gas which is essentially inert under the conditions of the heterogeneously catalyzed gas-phase oxidation and where, in continuous operation, at least a part of the essentially inert diluent gases present in the product gas mixture is separated off therefrom and is reused as a constituent of the feed gas mixture to the oxidation reactor, the essentially inert diluent gas mixture comprises more than 85% by volume of at least one saturated hydrocarbon having from 1 to 5 carbon atoms.

18. Process for producing acrolein and acrylic acid

United States Patent 4,837,360/ Kadowaki , et al./ June 6, 1989

Abstract

Acrolein and acrylic acid are produced by vapor-phase catalytic oxidation of propylene in a multi-tubular, fixed-bed reaction vessel with the use of a composite oxide catalyst represented by the formula Mo.sub.a Bi.sub.b Fe.sub.c A.sub.d B.sub.e C.sub.f D.sub.g Si.sub.h O.sub.x, wherein A, B, C, and D represent components selectable from respective groups of elements, and the subscripts a through h and x are specific numbers of atoms of respective elements and groups of elements. This catalyst is adapted and packed in each reaction tube in a manner such that its activity is controlled to increase from the inlet toward the outlet of the tube.

19. Process for the catalytic oxidation of propylene to acrylic acid

United States Patent 4,435,598 / Hinnenkamp / March 6, 1984

Abstract

An improved process for the catalytic oxidation of propylene to acrylic acid the improvement comprising conducting the process in the presence of an effective amount of hydroquinone. The improved process is particularly applicable to the aqueous liquid phase reaction of propylene with molecular oxygen using a supported palladium catalyst.

20. Process for producing acrylic acid from propylene

United States Patent 4,147,885 / Shimizu , et al. / April 3, 1979

Abstract

A process for producing acrylic acid from propylene through acrolein as an intermediate by catalytic vapor phase oxidation, which comprises passing a starting reactant gas mixture containing propylene, a molecular oxygen-containing gas and steam through a first-stage reactor packed with a molybdenum-containing multi-component catalyst, passing the resulting acrolein-containing gas through a second-stage reactor packed with a multi-component catalyst containing vanadium and molybdenum, introducing the resulting acrylic acid-containing gas to an acrylic acid collector thereby to recover acrylic acid in the form of an aqueous solution, and incorporating a part of the exhaust gas from the collector in the starting reactant gas mixture.

21. Manufacture of acrylic acid by oxidation of propylene with oxygen-containing gases in two separate catalyst stages

United States Patent 4,031,135 / Engelbach , et al. / June 21, 1977

Abstract

In the oxidation of propylene to acrylic acid in the gas phase in two spatially separate oxidation stages, a part of the off-gas, which has been freed from condensable products, is fed to the oxidation stages in addition to freshly charged propylene and air, under the following conditions: A. The recycled off-gas and air are in part fed to the first oxidation stage and in part to the second oxidation stage, B. The molar ratio of propylene : oxygen : residual gases fed to the first stage is 1 : 1.5-2.3 : 11-19, C. The molar ratio of the total propylene fed in, to the total oxygen fed in, in the form of air or off-gas, before and after the first stage, and to the total residual gases fed in is 1 : 1.9-2.5 : 13-25, with the proviso that D. The air and the recycled off-gas are divided between the two feed points in such a way that from 10 to 50% by volume of the total quantity of air and off-gas fed in are added after the first stage and E. The air and off-gas are admixed to the reaction gas mixture after the first stage, immediately after it leaves the catalyst zone, so that the mixture is rapidly cooled to a temperature of from 150.degree. to 320.degree. C.

22. Preparation of acrylic acid by heterogeneously catalyzed partial gas phase oxidation of propylene

United States Patent Application 20060004229 / Dieterle; Martin ; et al. / January 5, 2006

Abstract

The present invention relates to a process for preparing acrylic acid by two-stage heterogeneously catalyzed partial gas phase oxidation of propylene, in which the propylene source used is a preceding propane dehydrogenation and in which the first oxidation stage is operated with restricted propylene conversion, and unconverted propane and propylene present in the product gas mixture of the second partial oxidation stage are recycled substantially into the preceding propane dehydrogenation.

23. Preparation of acrolein or acrylic acid or a mixture thereof by heterogeneously catalyzed partial gas phase oxidation of propylene

United States Patent Application 20060004227 / Dieterle; Martin ; et al. / January 5, 2006

Abstract

A process for preparing acrolein or acrylic acid or a mixture thereof by heterogeneously catalyzed partial gas oxidation of propylene, in which the starting reaction gas mixture has the following contents: from 6 to 9% by volume of propylene, from 8 to 18% by volume of molecular oxygen, from 6 to 30% by volume of propane and from 32 to 72% by volume of molecular nitrogen.

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