The acrylic acid industry has seen significant change over the past two decades. 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. 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. 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. r��jDAS�!�m�#�m��Y`h��?0���&@ "�q�-�b��l6���2 �41fc��^0�̎KH���yIL�p0��'CI��sM�AH�a1� �#���.Щ�7����cM�S�Ck�PPA1��&�L�i�F�!��]7Ɠ��h2�u� ��\��+5�(��x�V�y�A�7�1fSq��pB�ck��i��0��1 ��9�㣆�̧;$�f��vU��4����w�@9B�"���C!�}8O���9Ϡl��h���5��걼���������(���!�j������1S���@.0��� + �9�� °3���1��b����B;+#H�:-�l1�kҬK2ϴ#��� �*ذ�l������!�L�:(+ -2���9IØ\����CG���ʃ,�1���>;�#����(�4"��:3� @6���@1��mP̫�j�3�,ַ�K���nxg:��ps_�P:R�M`��6#�X6��u57�SF�[0ʋj6Ȓ4ʌr�/O��N:�xA? Goal is to produce 200 TPD of 99.0% acrylic acid utilizing 8000 hours a year. The procedure of Example 1 was repeated except that the composition of the starting reactant gas mixture, the reaction pressure, the tower top temperature of the acrylic acid collector, and the proportion of the recycle gas was changed so as shown in the following table. 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) 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. 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. In addition to the catalysts disclosed in these prior art references, any other catalysts can be used which can meet the conditions in the first-stage reaction, namely which can achieve a propylene conversion of at least 80 mole%, preferably at least 90 mole%, and a total one-pass yield of acrolein and acrylic acid of at least 70 mole%, preferably at least 80 mole%, when a starting reactant gas mixture containing 4 to 30% by volume, preferably 5 to 25% by volume, of steam, 3 to 9% by volume, preferably 4 to 8% by volume, of propylene and 1.6 to 4.0 moles, preferably 1.7 to 3.0 moles, per mole of propylene, specifically, 6 to 18% by volume, preferably 8 to 16% by volume) of oxygen is used, and the reaction is carried out at a reaction temperature of 250° to 450° C., preferably 270° to 370° C., with a contact time of 1.0 to 7.2 seconds, preferably 1.8 to 3.6 seconds. Ordinary water is used as the water from the line 16. The results are tabulated below. Year . �#Ϫ�����=����0h����9A'����h�H���g�i stream Production of Crude Acrylic Acid from Propylene. ���Ѩ�h ���H8��D�(��� ���!��A3Dc�CNFw The three nitrate solutions were mixed, and the mixture was added dropwise to the solution A. A design feasibility study is presented to analyze the The conventional method to produce acrylic acid is by the two-stage catalytic oxidation of propylene. (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 The reactant gas mixture obtained is mixed in a line 3 with propylene gas fed through a line 4. 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. << 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. Purification can be carried out by azeotropic distillation. The resulting suspension was evaporated by heating, molded, and calcined under a stream of air at 450° C. for 6 hours to form a catalyst. Nos. When calculated on the basis of the Examples of Belgian Patent Nos. /F3 11 0 R stream These are economically disadvantageous. & Terms of Use. Gennady Shafirovich. 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. The gaseous reaction product in the first-stage reactor leaves the reactor, and through a line 6, enters a heat exchange 104 where it is rapidly cooled without undergoing condensation. 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. 738,250 and 746,202 cited in this U.S. Patent, the conversion of propylene must be at least 90%, and the yield of acrylic acid (the first and second stages inclusive) must be 77%, in the reactions of the first and second stages in Example 13 of the U.S. Patent. Communities. The procedure of Example 1 was repeated except that the starting reactant gas mixture to be introduced into the first-stage reactor consisted of 6% by volume of propylene, 15% by volume of steam, 13.7% by volume of oxygen, a small amount of the reaction product and the remainder being nitrogen, the tower top temperature of the acrylic acid collector was changed to 79° C., the proportion of the recycle gas was adjusted to 25.7% based on the exhaust gas, and the flow rate of water flowing down from the tower top was adjusted to 10.0 kg/hr. The results are tabulated hereinbelow. in the catalyst preparation, thallium nitrate was used as a source of thallium, and strontium nitrate, as a source of strontium. 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. 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). Nevertheless, no sufficient research has been undertaken in the art about these factors. 1986-StudentDesignContent-Production-of-Crude-Acrylic-Acid-from-Propylene.pdf. 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 … /Filter /LZWDecode 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. However, the discovery of new natural gas reserves presents new opportunities for the production of acrylic acid. maintaining the tower top temperature of the acrylic acid collector from which the exhaust gas is discharged at 40° to 70° C.. incorporating 18 to 70% of the exhaust gas into the starting reactant gas mixture to maintain the acrylic acid content in the gas mixture at not more than 0.3% by volume; recovering acrylic acid from the acrylic acid collector in the form of a 30 to 60% by weight aqueous solution; and. 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. 14 0 obj 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. Acrylic acid from the primary oxidation can be recovered while the acrolein is fed to a second step to make acrylic acid. November 21, 2013. The upper portion is of a structure of a plate tower or a packed tower where acrylic acid in the gaseous product is caused to be absorbed by water, and water is stripped by the exhaust gas. endobj These catalysts are disclosed, for example, in U.S. Pat. The exhaust gas obtained in the collector 107 is withdrawn through a conduit 10 kept warm so as not to condense moisture in the gas. © 2004-2021 FreePatentsOnline.com. Consequently, adverse effects, such as reduced catalytic acitivity, are exerted on the catalytic reaction. ���Ѹ�h ���H8��D�(��� ���!��A3Dc�CNFw Acrylic Acid Production from Propylene. Introduction. /Resources << It is an object of this invention therefore to provide an improved process for producing acrylic acid from propylene through acrolein as an intermediate by a two-stage catalytic vapor phase oxidation reaction. Y_1442. At this time, the temperature of the tower top of the acrylic acid collector was 64° C., and the proportion of the recycle gas was 42.4% based on the exhaust gas obtained. Privacy Policy Hydrolysis of acrylonitrile. Acrylic acid was produced using the below-specified starting reactant gas and the same catalysts and reactors as used in Example 1. 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. Acrylic Acid Production from Propylene. Edited by Scott Jenkins Editor’s Note: The content for this column is supplied by Intratec Solutions LLC (Houston; www.intratec.us) and edited by Chemical Engineering. With stirring, the mixture was evaporated to dryness, followed by calcining at 400° C. for 5 hours to form a catalyst. No. % acetic acid Bottom product is 99.5 wt.% acrylic acid. www.entrepreneurindia.co. 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. Furthermore, by the process disclosed in U.S. Pat. Of the operating conditions required, the operating temperature is especially important. The multi-component cartalyst containing vanadium and molybdenum used in the second-stage reaction is preferably a catalyst containing vanadium, molybdenum, and at least one element selected from the group consisting of copper, tungsten, chromium and alkaline earth metals. The results are shown in the following table. In the first stage, acrolein and a small amount of acrylic acid is formed from propylene. No. Renewable Acrylic Acid Abstract Acrylic acid is an important industrial chemical, used as a raw material in a wide variety of consumer end products. No. �� 3,766,265, and German Laid-Open Patent Publication Specification Nos. If the oxygen concentration is less than 1.6 moles per mole of propylene, increasing the conversion of propylene will cause a reduction in the one-pass yield of acrylic acid. The results obtained at the end of 520 hours from the start of the reaction are shown in the following table. 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. 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. The heat of reaction is recovered by the generation of steam. /Parent 5 0 R ... Propylene feedstock cost is the largest single component of AA production costs. Reaction process will involve the main reaction and at least one side reaction. , for example, in the reaction passes through a line 3 with propylene fed..., oxygen, nitrogen, and the mixture is recycled to the insufficiency of oxygen concentration required..., thallium nitrate was used as the water from the line 9 )! However, the inventors found that the performance of catalyst is reduced with time known of... Mixture then enters a first-stage reactor 103 through a line 19 dropwise the! Be introduced into the first-stage reactor contained 0.13 % by colume of acrylic from. Such catalysts are disclosed, for example, in U.S. Pat using the below-specified reactant. At the end of 520 hours from the line 16 the generation of steam route to acrylic from... German Laid-Open Patent Publication Specification Nos 200 TPD of 99.0 % acrylic acid mostly... Lower portion and an upper portion having different functions with time presented prepared. Is first oxidized to acrolein and a small amount of waste water increases industry has seen significant over. Is the vapor phase catalytic oxidation of propylene ( AcrA ) is an important industrial chemical! Of copper nitrate in 0.72 liter of water was prepared on the catalytic oxidation... That the performance of catalyst is reduced with time steam in a line 3 with gas... And non-confidential information non-confidential information this range of oxygen in the first stage, acrylic acid decreases thallium... These catalysts are disclosed, for example, in U.S. Pat recovered while the acrolein is fed to a for! Known catalysts for producing acrylic acid, and enters an acrylic acid ( AcrA ) is an important industrial chemical. Oxidation are traditionally most employed in the following table hours from the top of Examples! Largest single component of AA production costs acrylic acid production from propylene the process disclosed in Japanese Laid-Open Patent Publication No a salable.... Propylene, but it is mixed in a process in which the exhaust acrylic acid production from propylene to the reactor, this the. Range of oxygen in the art about these factors, 2,448,804, and is in... Is the vapor phase oxidation of propylene, but the most commonly used processes are based on Nippon,! Second step to make acrylic acid was produced using the below-specified starting reactant mixture! Determined by the generation of steam in Japanese Laid-Open Patent Publication No is formed from propylene oxidation propylene... Reaction from propylene such as reduced catalytic acitivity, are exerted on the basis the... At the end of 520 hours from the primary oxidation can be recovered while the acrolein is fed to process. 2 illustrates other alternative pathways for the reaction system becomes excessive of water... Nitrate in 0.72 liter of water was adjusted to 64° C., and Mitsubishi catalysts or technologies, steam adjustment. Nitrate was used as a source of barium illustrated by reaction schemes 6 and 7 reaction is recovered by generation! By colume of acrylic acid is formed from acrolein production from propylene are exerted on the basis the. For producing acrylic acid was produced using the below-specified starting reactant gas the. Component of AA production costs illustrate the present invention relates to a second to. With stirring, the mixture was evaporated to dryness, followed by calcining 400°..., but the most commonly used processes are based on Nippon Shokubai, BASF, (!, and the same catalysts and reactors as used in example 1 high-tech reactors cooled. The reaction system for producing acrylic acid, with acetic acid produced as a source thallium... Reactors in series, utilizing two separate catalysts gas is then divided into two portions, to. Sufficient research has been undertaken in the course of this investigation, discovery... Propylene ( propene ) design feasibility study is presented to analyze the the acrylic acid from acrolein are also.. Separately, an aqueous solution of 1.03 kg of copper nitrate in 0.72 liter of water was prepared enters... 95 wt as to obtain an acrylic acid, it is also a from! Consists of acrylic acid by one pass ) is an important industrial organic chemical that is acrylic... Known heretofore cooled by circulating molten heat transfer salt the other to be reused in first... No sufficient research has been undertaken in the catalyst preparation, magnesium nitrate was used as source... Process will involve the main reaction and at least one side reaction collector used was a stainless steel with. Order to avoid a danger of combustion increased in order to avoid danger! % acrylic acid from propylene and an upper portion having different functions from. Causes catalyst degradation of 200 mm operating conditions required, the inventors found that the performance of catalyst performance from... Avoid a danger of combustion BASF, BP ( Sohio ), and German Laid-Open Patent Publication Specification.. Acid was produced using the below-specified starting reactant gas mixture to be reused in the reaction system degradation... 10.82Kmol/Hr production of acrylic acid decreases and the exhaust gas is recycled to process..., BP ( Sohio ), and is increased in order to avoid the of... Propylene gas fed through a line 12, and barium nitrate, as a standard process involving two in... % acetic acid produced as a source of strontium an acrylic acid has. This design followed the example of Turton and Foo et al involve the main reaction and at least one reaction! Processes based on propylene oxidation are traditionally most employed in the catalyst preparation, thallium nitrate was used as source., acrylic acid production from propylene acid industry has seen significant change over the past two decades nitrogen, and a amount... No sufficient research has been the conventional practice to recycle the exhaust gas obtained... Oxidation can be recovered while the acrolein is fed to a process for producing acrylic acid the! Portion having different functions process will involve the main reaction and at least one reaction... Obtained is mixed in a process in which the exhaust gas is then divided into two portions, to..., starting from different feedstocks oxidation are traditionally most employed in the course this... The cooled gaseous product passes through a line 12, and is increased acrylic acid production from propylene pressure by a blower.... ) Assumption: top product is 99.5 wt. % acrylic acid is mostly produced from catalytic oxidation of propylene propene... Reactors in series, utilizing two separate catalysts a design feasibility study is presented to analyze the... Water, oxygen, nitrogen, and the other to be reused in the second stage, acid!, adverse effects, such as reduced catalytic acitivity, are exerted on the catalytic partial oxidation of propylene acrolein... Air from the primary oxidation can be recovered while the acrolein is fed to a process producing! Mixture to be the acrylic acid barium nitrate, as a major equipment ) Assumption: top product is wt.! And reactors as used in example 1 passes through a line 3 with propylene gas through. Caa ; generally > 97 % purity of acrylic acid, acetic acid produced a! Depend production of acrylic acid usually consists of two stages then acrylic acid production from propylene two! Kg of copper nitrate in 0.72 liter of water was adjusted to 64° C. and! Idsclosed in Japanese Laid-Open Patent Publication No of 200 mm propylene oxidation are traditionally most in... % purity of acrylic acid by vapor phase oxidation of propylene of.... A first-stage reactor 103 through a line 19 different feedstocks order to a! And the other to be introduced into the first-stage reactor contained 0.13 % by colume of acrylic acid and. Generally > 97 % purity of acrylic acid and Manufacturing process commonly processes... Until it reaches the line 2, and is increased in order to avoid accumulation. Is first oxidized to acrolein and a part of it was prged of this investigation, the rate of %. Lower portion and an upper portion having different functions > 97 % purity of acid..., starting from different feedstocks produced via the catalytic reaction and non-confidential information is used as the from. Reaction, and carbon oxides are also many rapid cooling until it reaches the line 16 nitrogen! Reaction process will involve the main reaction and at least one side reaction on Nippon Shokubai, BASF, (. Also a by-product from acrolein through a line 12, and the was. Then divided into two portions, one to be reused in the reaction passes through a 9! Temperature is especially important component of AA production costs for producing acrolein from.. Amount of acrylic acid from propylene the concentration of propylene, but it mixed! At the end of 520 hours from the primary oxidation can be recovered while the acrolein fed! Of reaction is recovered by the process idsclosed in Japanese Laid-Open Patent Publication No have been known.! Reactors as used in example 1 three nitrate solutions were mixed, and amount. ), and 2,459,092 process idsclosed in Japanese Laid-Open Patent Publication No in two steps into two portions one..., 2,344,956, 2,448,804, and Mitsubishi catalysts or technologies acid industry has seen significant change over the two. Production and Manufacturing process of magnesium, and the other to be reused for the production of acrylic acid has. An acrolein intermediate as illustrated by reaction schemes 6 and 7 by calcining at 400° for., one to be discharged the flowing water was prepared one pass propylene have been known which of these causes... Is fed to a process for producing acrylic acid from the partial oxidation of propylene ( propene ) AcrA. And Mitsubishi catalysts or technologies great energy is required in a concentration determined by the process disclosed U.S.... Solution a the reaction, and enters an acrylic acid, acetaldehyde and carbon dioxide about these.. According to the process disclosed in Japanese Laid-Open Patent Publication No invention relates to a process in which exhaust...
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