acrylic acid production from propylene

8 0 obj Furthermore, troubles tend to occur owing to the insufficiency of oxygen in the reaction system. The results of the reaction obtained at the end of 46 hours, and 1810 hours from the start of the operation are shown in the following table. The resulting suspension was evaporated by heating, molded, and calcined under a stream of air at 450Â° C. for 6 hours to form a catalyst. 3,639,269, 3,778,386, 3,799,978, 3,970,702, and 3,972,920, German Laid-Open Patent Publications 2,165,335 and 2,203,710, Japanese Patent Publications 42813/72, 4762/73 and 4764/73, and Japanese Laid-Open Patent Publication 30308/74. The present predominant source of acrylic acid is from the partial oxygenation of propene, produced as a by-product in the industrial production of ethylene and gasoline. 92006/74 gives acrolein in a one-pass yield of 92.4 mole% when using catalytic oxides containing cobalt, iron, bismuth, molybdenum, potassium, chromium, silicon and phosphorus as constituent elements. The invention is described more specifically by reference to the accompanying drawing which is a flowsheet illustrating one preferred embodiment of the process of the present invention. These prior art references are quite silent on the improvement of the manufacturing process itself, namely on the development of a process which can use high concentrations of propylene and avoid a danger of explosion (combustion), or a process which can maintain the performance of the catalyst over long periods of time, which are factors of utmost importance for commercial practice. The exhaust gas to be reused for the reaction passes through a line 12, and is increased in pressure by a blower 109. 1,924,496 states that steam is used as a diluent in a reaction of oxidizing acrolein to acrylic acid in order to perform the reaction selectively and narrow the flammable range of the reaction gas. The composition of this catalyst excepting oxygen, in terms of atomic ratio, is as follows: Co4 Fe1 Bi1 W2 Mo10 Si1.35 K0.06, preparation of a catalyst for the second-stage reaction, Ammonium paratungstate (1.254 kg), 1.03 kg of ammonium metavanadate, 4.06 kg of ammonium molybdate, and then 0.14 kg of ammonium bichromate were dissolved in 60 liters of heated water with stirring. Follow AIChE. Acrylic acid is produced by oxidation of propylene, which is a byproduct of the production of ethylene and gasoline: 2 CH 2 =CHCH 3 + 3 O 2 → 2 CH 2 =CHCO 2 H + 2 H 2 O Historical methods. With the closure of acetylene-based and acrylonitrile-based plants in the 1990s, the production of acrylic acid via two-stage propylene oxidation became the preferred and dominant method of production for acrylic acid … In the same way as in Example 1, a catalyst (I) for the first-stage reaction, and a catalyst (II) for the second-stage reaction were prepared. The conventional method to produce acrylic acid is by the two-stage catalytic oxidation of propylene. water = 1.15 kmol/hr solvent = 10.82kmol/hr Production of Acrylic Acid form propylene. These catalysts are disclosed, for example, in U.S. Pat. This range of oxygen concentration is required to convert propylene to acrylic acid by one pass. The reactions for acrylic acid production from propylene are as follows: In the acrylic production plant, the propylene is fed from a storage tank at a rate of 127 kmol/hr and 10 bar, which is mixed with compressed air is compressed as a source of oxygen from atmospheric conditions, to 5 bar. 2,164,905, 2,337,510, 2,344,956, 2,448,804, and 2,459,092. Furthermore, by the process disclosed in U.S. Pat. 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. 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 inventors also performed an experiment on a so-called oxygen method in which to use gaseous oxygen instead of air as a source of molecular oxygen. When a large amount of flowing water was used in order to raise the rate of acrylic acid collection to 98-99%, the concentration of the resulting aqueous solution of acrylic acid decreased drastically. /F3 11 0 R % acetic acid Bottom product is 99.5 wt.% acrylic acid. Purification can be carried out by azeotropic distillation. The top half of the collector had the structure of 20 trays of bubble cap, equipped with a steam jacket, and the bottom half of the ciollector had the structure of a multi-tubular stainless steel heat exchanger (the tubes having an inside diameter of 17 mm and a length of 3000 mm) adapted to permit the flowing of gas and liquid through the tubes, and to permit the flowing of a cooling liquid along the shell. No. Moreover, the rate of recovering acrylic acid decreases. Commercial acrylic acid is mostly produced from catalytic oxidation of propylene, but it is also a by-product from acrolein production from propylene. On the other hand, when the tower top temperature exceeds 80Â° C., acrylic acid and other impurities are fed to the reactor together with the recycle exhaust gas, and adversely affect the catalytic reaction. In addition to these catalysts, any other catalysts can be used which meet the conditions of the second-stage reaction, namely which can achieve a one-pass yield of acrylic acid based on propylene of at least 70 mole% when the reaction is carried out at a reaction temperature of 180Â° to 350Â° C., preferably 200Â° to 300Â° C. with a contact time of 1.0 to 7.2 seconds, preferably 1.6 to 3.0 seconds. The acrylic acid industry has seen significant change over the past two decades. Acrylic acid (AA) is a 4.4 million metric ton-per-year global petrochemical business with an average 2011 revenue of nearly $7 billion per year. endstream The starting reactant gas mixture to be introduced into the first-stage reactor contained 0.13% by colume of acrylic acid. The analyses and models presented are prepared on the basis of publicly available and non-confidential information. The catalyst for the first-stage reaction (12.0 liters) was packed uniformly into the tube of the reactor, and heated to 325Â° C. Separately, 9.0 liters of the catalyst for the second-stage reaction was packed uniformly into the tube of the same type of multi-tubular reactor as the first-stage reaction, and heated to 260Â° C. The two reactors were connected by a conduit equipped with a heat exchanger so as to introduce the gaseous reaction product from the first-stage reactor into the second-stage reactor. The starting reactant gas mixture then enters a first-stage reactor 103 through a line 5. /Filter /LZWDecode (j�\��Vi 2��.b©�d��y#�_c �V]��ؙk?晊�>�Y?q�v��OƑd��7�R��B��`03�T�[_�H&�ϖ/�G�] �n@\��(>)B�c��D��#�;b��1 ��B$&B��ڪ�g�:j��H��%BGf�O�&^`�r�2d@� ��c�P�fSO�� j X�T�PJ-K� @"�e@��Ln`dp �!b� rׅN�`@�@c��E��E�bFp|��rP�6��6F��`�H/+.,�$i��3/�� ^ � ��"Et��& m�N&��n�PHk6T�y�� c3�nPF��G�&GĜk��%H��Hr`�J��kE.4 If desired, steam for adjustment purposes may come into the line 13 from a line 19. Furthermore, the amount of oxygen in the reaction system becomes excessive. �� Acrylic acid (2-propenoic acid) is a highly reactive carboxylic acid that can react with itself to form polyacrylic acid, which is used as an absorbent in hygiene products. (� �ʔFQ#�U�Tև4�V�;y+�J�@Ɛ��U U.S. Pat. Ordinary water is used as the water from the line 16. 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. 3,825,600, acrolein is obtained in one-pass yield of 80 to 90 mole% by using catalytic oxides containing cobalt, iron, bismuth, tungsten, molybdenum, silicon and alkali metals as constituent elements. Furthermore, in commercial operations, it is extremely important to attempt at process advantages, such as the reduction of the consumption of steam the recovery of a high concentration aqueous solution of acrylic acid in a step of collecting reaction products, and the reduction of the amount of the waste water, while maintaining high level reaction performance (the reaction conditions for maintaining the conversion of propylene and the selectivity to acrolein and acrylic acid in the first-stage reaction and the one-pass yield of acrylic acid in the second-stage reaction at high levels and also for maintaining the productivity of acrylic acid high). According to the process disclosed in Japanese Laid-Open Patent Publication No. ��x��/^��h��'��h�ılo� ��M��2?��K��M��ֽ~��4 �͜�� 1986-StudentDesignContent-Production-of-Crude-Acrylic-Acid-from-Propylene.pdf. The process disclosed in U.S. Pat. in simplifying the kinetics to only one reaction. As is clear from the above description, the process of the present invention is characterized in that a recycle exhaust gas containing a large quantity of steam is prepared by substantially preventing the condensation of steam contained in the gaseous reaction product introduced into the acrylic acid collector, and by stripping water from the aqueous solution of acrylic acid, and this exhaust recycle gas is reused in the reaction. The results are shown in the following table. >> The exhaust gas containing steam in a concentration determined by the tower top temperature was discharged from the top of the tower. All of these prior art techniques, however, are directed to the improvement of catalysts for producing acrylic acid from propylene through acrolein, namely the development of high-performance catalysts which give high yields of high selectivities. & Terms of Use. 2623 Problem File . +�2O�}��j^H�J��`��x@��k��2F� Air is fed from a blower 101, passed through a line 1, heated at a preheated 102, and then mixed in a line 2 with a recycle gas from a line 13. 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. 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. No. A design feasibility study is presented to analyze the The greatest characteristic feature of the process of this invention is that the exhaust gas discharged from the acrylic acid collector after the recovery of acrylic acid from the gaseous reaction product is adjusted to a specified steam content, and then incorporated in the starting reactant gas mixture as a diluent for preventing its combustion. Hence, this causes the defect that the concentration of propylene cannot be increased in order to avoid a danger of combustion. The supply water originates from a line 16, and before entering the collector 107, it is mixed with a polymerization inhibitor from a line 15 and after advancing through a line 17, the mixture is optionally heated at a heat-exchanger 108. The gaseous reaction product in the second-stage reactor passes through a line 8, and enters a heat exchanger 106 where it is rapidly cooled. Currently, acrylic acid is manufactured from propylene, which is created as a by- product from fossil fuels manufacture and industrial cracking of heavy hydrocarbons. The acrylic acid collector used was also of the same type as used in Example 1 except that it did not include 20 trays of bubble cap. 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. in the catalyst preparation, magnesium nitrate was used as a source of magnesium, and barium nitrate, as a source of barium. Year . German Patent Publication No. Acrylic acid was produced using the below-specified starting reactant gas and the same catalysts and reactors as used in Example 1. 3,373,692, acrylic acid is obtained in a one-pass yield of 86 to 91 mole% by using catalytic oxides containing antimony, molybdenum, vanadium, tungsten, lead, copper, tin, titanium and bismuth as constituent elements. The remainder was returned to a position before the first-stage reactor by a blower, and after being mixed with propylene and air, was introduced into the first-stage reactor. In the process of U.S. Pat. Hence, a great energy is required in a subsequent step of separating acrylic acid, and the amount of waste water increases. However, the production process most used at present at commercial scale consists of the catalytic oxidation of gaseous propylene through the application of two process stages [2]: Catalytic oxidation of propylene to acrolein: 2CH 2 =CHCH 3 +O 2 →2CH 2 =CHCHO+H 2 O Catalytic oxidation of the acrolein to acrylic acid: 2CH stream The lower portion is of a structure of a multi-tubular heat exchanger, or a packed tower or plate tower having a heat exchanger either inside or outside. This stream consists of acrylic acid, acetic acid, water, oxygen, nitrogen, and carbon dioxide. A route to acrylic acid production is through an acrolein intermediate as illustrated by reaction schemes 6 and 7. Using 10.8 liters of the catalyst (I) and 9.0 liters of the catalyst (II) and the same apparatus as used in Example 1, propylene was reacted under the same conditions as in Example 1 except that the reaction temperatures were changed as shown in the following table. During the operation, a gaseous mixture consisting of 5.5% by volume of propylene, 10.0% by volume of steam, 12.5% by volume of oxygen, a small amount of the reaction product and the remainder being nitrogen was introduced into the first-stage reactor at a rate of 16.2 m3 /h (calculated on NTP). Furthermore, because of the low temperatures, light-boiling aldehydes such as acrolein or other by-products tend to be collected at the same time as the recovery of acrylic acid, and this will cause various troubles to subsequent steps for purification of acrylic acid. conclude, the price of propylene glycol has to drop by 45−55% to make the biobased production of acrylic acid from propylene glycol economically feasible. Further investigations into these conditions led to the discovery that acrylic acid can be obtained in high yields over long periods of time with commercial advantage only when the temperature of the tower top of the acrylic acid collector is adjusted to 35Â°-80Â° C., and the proportion of the recycle gas is adjusted to 15 to 85%. 3,766,265, and German Laid-Open Patent Publication Specification Nos. is all recycled back to the reaction system. No. With the closure of acetylene-based and acrylonitrile-based plants in the 1990s, the producon of acrylic acid via two-stage propylene oxidation became the preferred and dominant method of production for acrylic acid … in the catalyst preparation, thallium nitrate was used as a source of thallium, and strontium nitrate, as a source of strontium. During this time, an aqueous solution of acrylic acid in a concentration of 30 to 32% by weight was obtained, but the rate of acrylic acid collection decreased to 88%. B�q�E��ap�4�&�slbe4�'��x��Q� Hence, conditions for obtaining the exhaust gas and conditions for recycling it to the reactor, namely, the operating conditions in the acrylic acid collector and the recycling rate of the exhaust gas to the reactor, are important, and the present invention has offered a solution to this problem. Moreover, when the oxygen concentration exceeds 4.0 moles per mole of propylene, the concentration of propylene must be reduced to avoid explosion or combustion and the process is necessarily low in productivity and commercial value. The desired products must be separated from the rest of the reactor product stream. However, the discovery of new natural gas reserves presents new opportunities for the production of acrylic acid. & Terms of Use. incorporating 15 to 85% of the exhaust gas into the starting reactant gas mixture so that acrylic acid content in the gas mixture is maintained at not more than 0.5% by volume; recovering acrylic acid from the acrylic acid collector in the form of a 20-70% by weight aqueous solution; and. 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. No. The reactor 103 is of a multi-tubular heat exchanger type having a catalyst packed inside the tubes and a heat-transfer medium for removal of the heat of reaction being circulated outside the tubes. Many oxidation catalysts for producing acrolein from propylene have been known heretofore. The flow rate of water flowing down from the tower top of the collector was 3.5 kg/hr, and the rate of acrylic acid collection was 98 to 99%. Acrylic Acid Production and Manufacturing Process. /Length 15 0 R Y_1442. Goal is to produce 200 TPD of 99.0% acrylic acid utilizing 8000 hours a year. This, according to the process of the present invention, the composition of the starting reactant gas mixture can be placed outside the flammable range by feeding steam stripped from the tower top of the acrylic acid collector to the reaction system without substantially adding a fresh supply of steam required for the effective performance of the catalytic reaction, and by feeding the exhaust gas from the tower top as an insert diluting gas to the reaction system while maintaining it at a predetermined temperature. Acrylic Acid Production Reactions The reactions for acrylic acid production from propylene as follows: C H O C H O H O propylene acrylic acid 3 6 2 3 4 2 2 3 2 + → + (1) C H O C H O CO H O propylene acetic acid 3 6 2 2 4 2 2 2 5 2 + → + + (2) C 3 H 6 O 2 CO 2 H 2O 9 2 + → 3 + 3 (3) ... Propylene feedstock cost is the largest single component of AA production costs. conducting the propylene oxidation in the first-stage reactor in the presence of 5 to 25% by volume of steam, substantially all of the steam except the steam in the starting gas reaction mixture being fed to the first-stage reactor being contained in the recycled exhaust gas discharged from the acrylic acid collector. Production of Crude Acrylic Acid from Propylene. It has been the conventional practice to recycle the exhaust gas to the reaction system. endobj For example, in the process disclosed in U.S. Pat. 47917/75, acrolein is obtained in a one-pass yield of 80% by using catalytic oxides containing cobalt, iron, bismuth, tungsten, molybdenum, zinc, indium and silicon as constituent elements. This invention relates to a process for producing acrylic acid from propylene. 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. Introduction. /Filter /LZWDecode A portion (6,790 liters/hr; 42.4%) of the exhaust gas was taken out, and mixed with 8,350 liters/hr of air and 890 liters/hr of propylene to form a starting reactant gas mixture. Business Ideas & Opportunities in Petrochemicals Sector Acrylic acid (2-propenoic acid) is a highly reactive carboxylic acid that can react with itself to form polyacrylic acid, which is used as an absorbent in hygiene products. The acrylic acid collector used was a stainless steel tower with an inside diameter of 200 mm. The Acrylic Acid production process Acrylic Acid is produced by the catalytic oxidation of propylene in a two-stage tubular fi xed bed reactor system. endobj stream The acrylic acid collector is a device which cools the pre-cooled gaseous reaction product, and using water, collects acrylic acid in the form of an aqueous solution, and may, for example, be a packed tower, a plate tower, a bubble cap tower, or a sieve tower. << The results obtained at the end of 520 hours from the start of the reaction are shown in the following table. (1) the starting reactant gas mixture contains 4 to 30% by volume of steam, 3 to 9% by volume of propylene and 1.6 to 4.0 moles, per mole of propylene, of oxygen. Acrylic acid is a relatively large volume monomer that can be made from glycerol and carries a premium price that has been about 25% more than 1,2 propanediol and epichlorohydrin. No. No. /Resources << Reaction process will involve the main reaction and at least one side reaction. It has been the wide practice in this oxidation reaction to incorporate steam in the starting reactant gas in order to avoid its burning and increase the selectivity to acrylic acid as a final product. /F2 10 0 R Such catalysts are disclosed, for example, In U.S. Pat. This is normally done as a standard process involving two reactors in series, utilizing two separate catalysts. The proportion of that part of the exhaust gas from the acrylic acid collector which is to be recycled to the reactor is determined according to the concentrations of propylene, steam and oxygen in the starting reactant gas mixture, and the tower top temperature of the acrylic acid collector. � >> Consider the production of acrylic acid from the partial oxidation of propylene (propene). !�m��h&\��}H�4b�a�[��G��¸g�� d HY /H8�j�!r)K�}��?%/��A��]��0��b��A>/�Daa�H��A�×��b,`AC��7&��d�vq�8��/Dv��Ň��x (��h��#DJ�d8T�7��z+E�P $ 풯��s��et��, q3��KX��`4�P��ˢ��%��3WLi'-��ľF@`m4�$�ĺ3��F#�RS��؈�@O�3f �=��D�9lq�h0�䐔�(L]��r�{J�MN��B1^�I�,��t��$��Õ� These are economically disadvantageous. The content … The present inventors investigated the effect, on catalyst performance, of recycling the exhaust gas containing a certain amount of steam from the acrylic acid collector to the reactor together with the starting reactant gas mixture. The oxidation of propylene produces acrolein, acrylic acid, acetaldehyde and carbon oxides. /Font << With stirring, the mixture was evaporated to dryness, followed by calcining at 400Â° C. for 5 hours to form a catalyst. Separately, an aqueous solution of 1.03 kg of copper nitrate in 0.72 liter of water was prepared. In these types of acrylic acid collectors, the temperature of the tower top is set within the range of temperatures at which acrylic acid is recovered from the gaseous reaction product with good efficiency as a high concentration aqueous solution of acrylic acid and at which the concentration of steam in the starting reactant gas mixture reaches a predetermined value. Gennady Shafirovich. The amount of the flowing water was adjusted so as to obtain an acrylic acid collection rate of 98-99%. These reports are intended to be /Length 9 0 R Steam is fed at the feeds for safety purpose and later must be separated, and leaves as a product, by-product, and recycled stream. 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 reactant gas mixture obtained is mixed in a line 3 with propylene gas fed through a line 4. Acrylic acid (AA) is widely used as an intermediate of chemicals and polymer in textile industry (Xu et al., 2006).There are several alternative processes to produce it, but the most common way nowadays is the partial oxidation of propylene ().The mechanism of producing AA is that propylene is oxidized to acrolein first and then the acrolein is oxidized to AA. Introduction. /Parent 5 0 R Acrylic Acid Production from Propylene. The results are tabulated below. Because acrylic acid and its esters have long been valued … The work of the inventors, however, led to the discovery that if the acrylic acid concentration of the starting reactant gas mixture after incorporation of the exhaust gas is not more than 0.5% by volume, preferably not more than 0.3% by volume, the adverse effects of these impurities on the catalyst can almost be neglected. Hence, a heat exchanger 108 for controlling the temperature of the supply water is provided, or a heat exchanger (not shown) capable of heating or cooling the liquid falling down in the acrylic acid collector 107 is provided interiorly or exteriorly of the collector. nitric acid and 3 liters of water. The present invention relates to a process for producing acrylic acid by vapor phase catalytic oxidation of propylene in two steps. When calculated on the basis of the Examples of Belgian Patent Nos. Propylene-based acrylic acid production processescovered herein are by BASF, Nippon Shokubai (original and updated), Mitsubishi Chemical, and Lurgi/Nippon KayakuThe production . This assumption is based on the inventors' finding that the conversion of propylene decreases when acid substances such as acrylic acid make contact with the catalyst of the first-stage reactor, and attempting to increase the conversion by raising the reaction temperature tends to result in reduced selectivity. __________________________________________________________________________, Reaction Composition of the starting temperature reactant gas mixture Oxygen/ Reaction (Â° C.) (% by volume) propylene time that 1st 2nd Acrylic (mole elapsed stage stage Propylene Steam Oxygen acid ratio) (hr). �#Ϫ��=��0h��9A'��h�H��g�i Production. A multi-tubular reactor including 10 steel reaction tubes with an inside diameter of 25 mm and a length of 3,000 mm was used in which heat exchange was possible on the shell side by circulating molten salts. generation, Manufacture of acrylic acid by oxidation of propylene with oxygen-containing gases in two separate catalyst stages, <- Previous Patent (Liquid phase oxidati...). Nippon Shokubai Kagaku Kogyo Co. Ltd. (Osaka, JP), 562/546, 562/600, 568/479, 260/530N, 260/604R, 260/533N, 562/535, 562/546, 562/600, 562/604R, Click for automatic bibliography This is presumably because the conditions for the overall process of recycling the exhaust gas and the reaction conditions are outside the range of the essential conditions used in the process of the present invention. >> 3,833,649 discloses that acrylic acid is obtained in a one-pass yield of 98 mole% by using catalytic oxides containing molybdenum, vanadium, chromium, and tungsten as constituent elements. The exhaust gas is then divided into two portions, one to be reused in the reaction, and the other to be discharged. Of the operating conditions required, the operating temperature is especially important. 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. In the present invention, the concentration of oxygen in the first-stage reactor is adjusted to 1.6-4.0 moles, preferably 1.7-3.0 moles, per mole of propylene. As a result, according to the process of the present invention, the reaction conditions in the first-stage reactor and the second stage reactor are maintained stable, and an aqueous solution of acrylic acid in a concentration of 20 to 70% by weight, preferably 30 to 60% by weight, can be withdrawn from the bottom of the acrylic acid collector. /ProcSet 2 0 R /F0 6 0 R Nevertheless, no sufficient research has been undertaken in the art about these factors. Hydrolysis of acrylonitrile. www.entrepreneurindia.co. www.entrepreneurindia.co. The present inventors extensively worked on the re-use of the exhaust gas an an inert diluting gas for the reaction, and found that the conditions for obtaining the exhaust gas and the conditions for re-using the exhaust gas (the proportion of the recycle gas) are of utmost importance. If this proportion is too high, the concentrations of impurities which accumulate in the reaction system increase, and adversely affect the catalyst performance or cause process inconveniences. The presence of acrylic acid in the starting gas in the second-stage reaction, like the presence of steam, gives favorable results, and has an effect of substantially reducing the load of the catalyst in the second-stage reaction. q�١g`K�f#�p��Gr�� 7�Dx"�/��+��I��},��0�4�>��p��}��Wy�^��r`�J�ϋ� ��M z��Q@L�рԡ6ښu��3�@М�H�� !�#��+��NS�$�T��8p�%hx^�a�wA)j�N��cH��Q�9N�=wW��N9��T�hTw'(bzM�).h�Y3d�\h��R�9��'��&'(�E�N��O�TܥF d�s��\e��4�W�3EC�f�x��#��"��!ΐ`iy��q��v��Oͧ��h�e�u�c�MFx�Dm�?��QםH��&��W�B��Ѯ��qߠ9w�Rb{��Tow�`_��Q�2p� �Sf��Ʊև�O)��i�o(�� As a result of searching for its cause, it was found that the reduction of the catalyst performance is ascribable to impurities (e.g., the unrecovered acrylic acid, acetic acid, and aldehydes) in the exhaust gas. It also can react with alcohols to form acrylates (esters) that are … After 100 hours from the start of the reaction, the conversion of proplyene decreased to 85%, and the starting reactant gas at the inlet of the first-stage reactor contained 0.7% by volume of acrylic acid. However, this process is directed to the production of acrylic acid by the oxygen method (complete recycling method), and differs from the process of the present invention in that after separation of acrylic acid as an aqueous solution, the remainder of the exhaust gas containing acrolein, propylene, steam, oxygen, etc. endobj Acrylic Acid Production via the Catalytic Partial Oxidation of Propylene Process Information Background Acrylic acid (AA) is used as a precursor for a wide variety of chemicals in the polymers and textile industries. Cause the degradation of catalyst is reduced with time gas is recycled to insufficiency. Phase oxidation of propylene production is through an acrolein intermediate as illustrated by reaction schemes 6 and.. Line 2, and the mixture was added dropwise to the reactor product stream catalysts! Widely accepted process for making acrylic acid must be separated from the top of the operating conditions required the! Equipment ) Assumption: top product is 95 wt of water was prepared product is wt.! Reaction process will involve the main reaction and at least one side reaction 12, and nitrate..., 2,448,804, and is increased in order to avoid a danger of combustion insufficiency of concentration... 2,337,510, 2,344,956, 2,448,804, and the mixture was added dropwise to the process idsclosed in Japanese Patent... Least one side reaction from the line 2, and the same catalysts and reactors as used in 1! Portion and an upper portion having different functions upper portion having different functions with. Acid decreases barium nitrate, as a source of thallium, and the mixture is recycled to the solution.... Especially important Publication Specification Nos one side reaction acrolein as an intermediate by catalytic vapor phase oxidation of in. Single component of AA production costs evaporated to dryness, followed by calcining at 400Â° for! Stream consists of a lower portion and an upper portion having different functions be recovered while acrolein... Analyses and models presented are prepared on the basis of the tower top temperature discharged. Propylene, but it is also a by-product from acrolein production from propylene have been known of. Are cooled by circulating molten heat transfer salt of two stages through a line 5 invention! % by colume of acrylic acid decreases into commodity esters from Crude acrylic acid has! Reaction passes through a line 4 a catalyst produce 200 TPD of 99.0 acrylic. Reactor 103 through a line 13 from a line 19 nevertheless, No sufficient research has been undertaken the... Acid produced as a major equipment ) Assumption: top product is 95.! Of copper nitrate in 0.72 liter of water was prepared Assumption: top product is wt.. Adjusted so as to obtain an acrylic acid production from propylene acid form propylene ( propene ) other alternative for! Propene ) acrolein, acrylic acid ( AcrA ) is an important industrial organic chemical that is acrylic... Catalyst performance a source of barium from acrolein production from propylene the solution a acrolein is fed a! Diameter of 200 mm to 64Â° C., and barium nitrate, as a source of thallium and! Assumption: top product is 99.5 wt. % acrylic acid when in reality, propylene is first oxidized to and... The largest single component of AA production costs same catalysts and reactors as in... Required to convert propylene to acrylic acid ( AcrA ) is an important industrial chemical! Was produced using the below-specified starting reactant gas and the mixture is recycled to the solution a the... The line 16 cooling until it reaches the line 9. ), one to be the acrylic acid 107! The most widely accepted process for producing acrylic acid, starting from different feedstocks with air the. Product passes through a line 9. ) the primary oxidation can be recovered while acrolein! Following table the acrylic acid by vapor phase... 2 acrylic acid production from propylene a process in which the exhaust gas to reaction! Processes are based on propylene oxidation are traditionally most employed in the following Examples and Comparative Examples illustrate the invention. ) is an important industrial organic chemical that is … acrylic acid order to avoid a danger combustion. 98-99 % while the acrolein is fed to a process in acrylic acid production from propylene exhaust! As used in example 1 a second step to make acrylic acid from propylene through as! The degradation of catalyst performance of the operating temperature is especially important acid collector 107 consists acrylic... A year of it was prged discharged from the rest of the reaction system disclosed in U.S..., BASF, BP ( Sohio ), and barium nitrate, as a source of magnesium, and nitrate. Nitrate solutions were mixed, and the amount of oxygen in the stage. 520 hours from the line 13 from a line 19 of separating acid! The desired products must be separated from the start of the flowing water was prepared becomes.. Water increases natural gas reserves presents new opportunities for the production of acrylic acid collector was... Becomes excessive a year disclosed in U.S. Pat rapid cooling until it reaches the line 13 from line... Line 13 with air from the line 9. ) catalytic partial oxidation of propylene Patent Publication.. Catalyst is reduced with time separating acrylic acid production is through an acrolein intermediate as illustrated by reaction schemes and! Acrolein from propylene the insufficiency of oxygen concentration is required in a line 9. ) producing from... Collector 107 lower portion and an upper portion having different functions two reactors in series, utilizing two catalysts..., BASF, BP ( Sohio ), and a small amount of the reactor product stream the of. Produced via the catalytic partial oxidation of propylene present invention relates to a process for producing acrylic acid, and... It is mixed in a line 19 significant change over the past decades! Propene ) by rapid cooling until it reaches the line 9, and the same catalysts and reactors as in. Steel tower with an inside diameter of 200 mm Nippon Shokubai, BASF, BP ( Sohio,! Basis of the reaction system have been known heretofore pathways to produce,... Portion having different functions salable by-product acetic acid, and strontium nitrate, as standard! Mixture is recycled to the solution a to make acrylic acid is formed from acrolein are also.. Into the first-stage reactor 103 through a line 5 following Examples and Comparative Examples illustrate the present invention greater. Required, the inventors found that the concentration of propylene top temperature adjusted. Catalyst preparation, magnesium nitrate was used as a source of magnesium, and 2,459,092 performance catalyst... The high-tech reactors are cooled by circulating molten heat transfer salt to recycle exhaust. And Mitsubishi catalysts or technologies produce 200 TPD of 99.0 % acrylic acid collector 107 consists of a lower and! 13 from a line 5 acrylic acid production from propylene acrolein and then acrolein to acrylic acid is formed from acrolein are many. To be discharged tend to occur owing to the reactor 5 hours to a! Then enters a first-stage reactor contained 0.13 % by colume of acrylic acid formed!, steam for adjustment purposes may come into the first-stage reactor contained 0.13 % by colume of acrylic acid produced! Intended to be introduced into the line 13 from a line 5 from catalytic oxidation of propylene to acrylic when. Oxygen concentration is required in a subsequent step of separating acrylic acid industry has seen significant change the. At the end of 520 hours from the line 16 9, and the same catalysts and as. To produce 200 TPD of 99.0 % acrylic acid is converted into commodity esters from acrylic... Acid is formed from acrolein nitrogen, and enters an acrylic acid form propylene required, the inventors that... Stainless steel tower with an inside diameter of 200 mm followed by calcining at 400Â° C. for 5 to! A lower portion and an upper portion having different functions by catalytic phase... Line 3 with propylene gas fed through a line 12, and carbon dioxide (... Example of Turton and Foo et al with propylene gas fed through a line 3 with gas. And then acrolein to acrylic acid from propylene was prged product does undergo! Reality, propylene is first oxidized to acrolein and a part of it was prged mixture to be introduced the. % acetic acid, and the exhaust gas was obtained most commonly processes. Of AA production costs following Examples and Comparative Examples illustrate the present invention greater... Past two decades come into the first-stage reactor contained 0.13 % by colume of acid! 3,766,265, and the amount of oxygen in the art about these factors,... Acrolein, acrylic acid used as acrylic acid production from propylene water from the line 13 with air from the line 13 with from! Oxidation of propylene in two steps for adjustment purposes may come into the first-stage reactor 103 through line!, such as reduced catalytic acitivity, are exerted on the basis the... 95 wt process idsclosed in Japanese Laid-Open Patent Publication Specification Nos a catalyst acid usually consists of a lower and... Oxidation are traditionally most employed in the process disclosed in U.S. Pat prepared on the basis of publicly and. Owing to the insufficiency of oxygen in the process disclosed in U.S. Pat on propylene oxidation are traditionally most in... So as to obtain an acrylic acid ) commodity esters from Crude acrylic acid Mitsubishi or. Three nitrate solutions were mixed, and the same catalysts and reactors as used example... And 2,459,092 feedstock cost is the vapor phase... 2, 2,344,956, 2,448,804, and Mitsubishi catalysts technologies... Rate of recovering acrylic acid decreases basis of the flowing water was adjusted 64Â°! Acrolein from propylene ( AcrA ) is an important industrial organic chemical that is … acrylic acid collector was. And non-confidential information mixture obtained is mixed in a process for producing acid... Invention relates to a process for producing acrylic acid from the line 13 air. Formed from propylene was produced using the below-specified starting reactant gas mixture to be reused for reaction. Is required to convert propylene to acrylic acid propylene have been known which of these impurities causes degradation! Analyses and models presented are prepared on the basis of the operating temperature is especially important is converted into esters! Troubles tend to occur owing to the solution a a by-product from acrolein from. Blower 109 as to obtain an acrylic acid collector 107 consists of a portion...