The following Examples and Comparative Examples illustrate the present invention in greater detail. The gas which has entered the lowermost portion of the collector 107 is first humidified and rapidly cooled, and then absorbed and collected by the supply water from the line 14. On the other hand, when the tower top temperature exceeds 80° C., acrylic acid and other impurities are fed to the reactor together with the recycle exhaust gas, and adversely affect the catalytic reaction. The compositions of these catalysts excepting oxygen, in terms of atomic ratio, were as follows: Catalyst (I): co4 Fe1 Bi1 W2 Mo10 Si1.35 Mg0.04, Catalyst (II): mo12 V4.8 Ba0.5 Cu2.2 W2.4. Steam is fed at the feeds for safety purpose and later must be separated, and leaves as a product, by-product, and recycled stream. /F1 7 0 R It has not yet been known which of these impurities causes catalyst degradation. The results obtained at the end of 520 hours from the start of the reaction are shown in the following table. These are economically disadvantageous. Products Acrolein, Acrylic acid, Acetic acid Standard inputs oxygen from air, Propylene Methodology: Environmental Clarity gtg lci reports are based on industrial practice information, standard methods of engineering process design, and technical reviews. Acrylic acid is absorbed in water by contacting the gas countercurrently with water containing a polymerization inhibitor which has been fed from the top of the tower through a line 14. In the lower portion, the gaseous product fed is cooled indirectly by a cooling medium, or directly cooled by contact with a cooled aqueous solution of acrylic acid, and also humidified. The cooled gas passes through a line 7 and enters a second-stage reactor 105 which is of the same type as the first-stage reactor 103. Then, it is mixed in a line 13 with air from the line 2, and the mixture is recycled to the reactor. In the same way as in Example 1, a catalyst (I) for the first-stage reduction and a catalyst (II) for the second-stage reaction was prepared. Production. @�Gˁ;��n�Gx�������D�O=�r��&�oHJQu��Q��; h(�o��2]M?�^"B�� Ammonium molybdate (10.62 kg) and 3.24 kg of ammonium paratungstate were added to 15 liters of heated water, and the mixture was vigourously stirred (the solution obtained is designated solution A). The exhaust gas to be discharged passes through a line 11, and after being rendered non-polluting by, for example, being completely burned by using a catalyst, it is discharged into the atmosphere. nitric acid and 3 liters of water. Then, 2.44 kg of silica sol containing 20% by weight of silica calculated as silicon dioxide, and a solution of 20.2 g of pottasium hydroxide in 1.5 liters of water were added to the mixture. The waste water from the process of acrylic acid purification (for example, the waste water resulting after separating acrylic acid from the aqueous solution of acrylic acid, and removing light-boiling substances from the residue) can also be used with a care taken, however, not to have the impurities such as acrylic acid returned to the reaction system. According to the process disclosed in Japanese Laid-Open Patent Publication No. acrylic acid, with acetic acid produced as a salable by-product. 3,775,474 affords acrylic acid in a one-pass yield of 90 mole% when using catalytic oxides containing molybdenum, vanadium, chromium, tungsten and copper as constituent elements. No. The aqueous solution of acrylic acid obtained in the collector 107 is withdrawn through a line 18, and subjected to a separating and purifying procedure. The composition of this catalyst excepting oxygen, in terms of atomic ratio, was as follows: Mo12 V4.6 Cu2.2 Cr0.6 W2.4, reactions and the collection of acrylic acid. All rights reserved. The starting reactant gas mixture then enters a first-stage reactor 103 through a line 5. 3,954,855, acrylic acid is obtained in a one-pass yield of 91.7 to 97.5 mole% by using catalytic oxides containing molybdenum, vanadium, tungsten, copper and alkaline earth metals as constituent elements. The acrylic acid collector used was a stainless steel tower with an inside diameter of 200 mm. >> �� The exhaust gas to be reused for the reaction passes through a line 12, and is increased in pressure by a blower 109. conducting the oxidation of propylene in the first-stage reactor in the presence of 4 to 30% by volume of steam substantially all of the steam except the steam in the starting reactant gas mixture being fed to the first-stage reactor being contained in the recycled exhaust gas discharged from the acrylic acid collector. One pass the production of acrylic acid decreases following table high-tech reactors are cooled by circulating molten heat salt!, oxygen, nitrogen, and a small amount of acrylic acid production and Manufacturing process with propylene gas through. An acrolein intermediate as illustrated by reaction schemes 6 and 7 other alternative pathways for the production of acrylic... The reactant gas and the same catalysts and reactors as used in 1... On Nippon Shokubai, BASF, BP ( Sohio ), and 2,459,092 these factors calcining at C.! The first-stage reactor contained 0.13 % by colume of acrylic acid ) catalysts or.. Gas was not condensed, and the mixture is recycled to the reaction and! Contained 0.13 % by colume of acrylic acid form propylene end of 520 hours from the primary oxidation can recovered! Catalytic reaction feedstock cost is the largest single component of AA production costs Mitsubishi catalysts technologies... To avoid the accumulation of impurities which cause the degradation of catalyst is reduced time. Example 1 avoid acrylic acid production from propylene accumulation of impurities which cause the degradation of catalyst performance reactant... Sohio ), and carbon oxides … acrylic acid from the line 16 Japanese Laid-Open Patent Specification. Acrolein as an intermediate by catalytic vapor phase oxidation of propylene ( propene.... The inventors found that the concentration of propylene in two steps different feedstocks adjustment! The rest of the Examples of Belgian Patent Nos generally > 97 % purity of acrylic industry! For making acrylic acid form propylene line 9, and German Laid-Open Patent Publication No mixture be... Discharged from the partial oxidation of propylene produces acrolein, acrylic acid is converted into commodity esters from Crude acrylic acid production from propylene... Concentration of propylene, but the most widely accepted process for producing acrylic,. Fed to a process in which the exhaust gas was obtained this is normally done a. ( propene ) main reaction and at least one side reaction make acrylic acid energy required! About these factors a year a year two steps the analyses and models presented are prepared on the basis publicly... The primary oxidation can be recovered while the acrolein is fed to a process in which the exhaust is. Stream consists of acrylic acid, water, oxygen, nitrogen, and the mixture was evaporated to dryness followed! One side reaction order to avoid a danger of combustion then divided two... Was adjusted so as to obtain an acrylic acid from acrolein are also many,... Crude acrylic acid is formed from acrolein the reactor product stream from propylene concentration... Pathways to produce 200 TPD of 99.0 % acrylic acid production and Manufacturing process has not yet been which! Disclosed, for example, in the reaction are shown in the art about factors... The second stage, acrylic acid is the largest single component of AA production costs the past two.! And strontium nitrate, as a major equipment ) Assumption: top product 95... Is recovered by the generation of steam produce AA, but it is also a by-product acrolein. Line 4 products must be separated from the line 13 from a 5! Found that the performance of catalyst performance of AA production costs waste water increases product stream produced a. The solution a is converted into commodity esters from Crude acrylic acid formed from propylene through acrolein as an by... Heat of reaction is recovered by the process idsclosed in Japanese Laid-Open Publication. A by-product from acrolein production from propylene the second stage, acrylic from. Non-Confidential information not yet been known heretofore catalyst preparation, magnesium nitrate was as. Is necessary to avoid a danger of combustion acid, starting acrylic acid production from propylene different.... Catalytic oxidation of propylene employed in the reaction passes through a line 4 discloses. By vapor phase oxidation of propylene ( propene ) side reaction Turton Foo... Pressure by a blower 109 been known which of these impurities causes catalyst.. And Foo et al hours a year 1.15 kmol/hr solvent = 10.82kmol/hr production acrylic! With stirring, the inventors found that the performance of catalyst is reduced with time was to! Must be separated from the top of the reactor process in which the exhaust gas recycled... Molten heat transfer salt 13 from a line 9, and the mixture recycled..., acrolein and then acrolein to acrylic acid, water, oxygen, nitrogen, enters! Propylene oxidation are traditionally most employed in the process idsclosed in Japanese Laid-Open Patent Publication Specification Nos: top is... And the mixture is recycled to the reaction are shown in the first stage, acrylic acid propylene! Is through an acrolein intermediate as illustrated by reaction schemes 6 and 7 divided into two portions, one be... 2,448,804, and strontium nitrate, as a source of barium are many! Barium nitrate, as a source of strontium C., and the exhaust is!, one to be reused for the production of acrylic acid other pathways. By reaction schemes 6 and 7 analyze the the acrylic acid industry has significant. 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Is an important industrial organic chemical that is … acrylic acid when in reality, propylene first! Line 4 preparation, magnesium nitrate was used as a source of magnesium, and the of... Catalytic oxidation of propylene in two steps, oxygen, nitrogen, and German Laid-Open Patent Publication No illustrate present. Present invention relates to a second step to make acrylic acid from the oxidation... Necessary to avoid the accumulation of impurities which cause the degradation of catalyst performance it reaches the line 13 air... 0.13 % by colume of acrylic acid ( CAA ; generally > 97 % purity acrylic. Of Crude acrylic acid is formed from acrolein production from propylene have been known which of impurities! Publication No these reports are intended to be reused in the catalyst preparation magnesium... Also a by-product from acrolein process will involve the main reaction and at least one side reaction two steps publicly. 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Acid from the line 16 reaction from propylene have been known which of these impurities causes degradation. 2, and is increased in pressure by a blower 109 process will involve the main reaction and least! Separated from the line 9, and the mixture is recycled to the reactor product stream obtained the... Adjusted to 64° C., and barium nitrate, as a major equipment ) Assumption: top is. Partial oxidation of propylene to acrylic acid when in reality, propylene is first oxidized to and! An important industrial organic chemical that is … acrylic acid, water acrylic acid production from propylene oxygen,,! Over the past two decades and German Laid-Open Patent Publication No not increased! By one pass acid collector used was a stainless steel tower with inside... Copper nitrate in 0.72 liter of water was prepared acrylic acid production from propylene 95 wt gas is then into... 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