Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
  • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
  • B01J23/84—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
  • B01J23/85—Chromium, molybdenum or tungsten
  • B01J23/86—Chromium
  • B01J23/868—Chromium copper and chromium
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
  • C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation
  • C07C51/21—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen
  • C07C51/25—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of unsaturated compounds containing no six-membered aromatic ring
  • C07C51/252—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of unsaturated compounds containing no six-membered aromatic ring of propene, butenes, acrolein or methacrolein

Definitions

• This invention relates to a process for producing unsaturated carboxylic acids. More specifically, the invention relates to a process for producing unsaturated carboxylic acids by catalytically oxidizing unsaturated aldehydes having not less than 3 carbon atoms in the vapor phase in the presence of a catalyst, for example, a process for producing acrylic acid from acrolein, or methacrylic acid from methacrolein.
• Examples of the conventional catalysts for use in the production of acrylic acid or methacrylic acid by the catalytic vapor phase oxidation of acrolein or methacrolein include a catalytic oxide composed of molybdenum and vanadium as disclosed in Japanese Patent Publication No. 1,775/ 66, and a catalytic oxide composed of molybdenum, vanadium, aluminum and copper as disclosed in Japanese Patent Publication No. 26,287/69.
• the specification of Japanese Patent Publication No. 1,775/ 66 discloses that with the catalyst used there, the maximum one-pass yield of acrylic acid is 76.4%. Such a yield is still unsatisfactory for commercial operation. According to the specification of Japanese Patent Publication No.
• the yield of acrylic acid can be 9797.5% at a space velocity of 500 to 1000 hrrl when aluminum sponge is used as a carrier and the catalyst is used in a strongly reduced condition by pre-treatment (in a state where oxygen is insufiicient).
• pre-treatment in a state where oxygen is insufiicient
• the space velocity is reduced to 2000 hl. the yield abruptly goes down to 89.5%.
• the pretreatment for strongly reducing the catalysts includes a step of treating the catalyst with a reaction gas at a temperature higher than the reaction temperature, and therefore, various difficulties are encountered.
• an object of the present invention is to provide a process for producing unsaturated carboxylic acids, which can be operated on a commercial basis using a novel catalyst.
• unsaturated carboxylic acid for example acrylic acid or methacrylic acid
• unsaturated aldehydes for example acrolein or methacrolein
• the catalytic oxide used in the present invention is characterized in that the metallic elements which constitute it are present in the following atomic ratios:
• Oxygen in the catalytic oxide need not be present in a specially reduced condition. It is assumed that oxygen is present in the catalytic oxide in the form of a complex metal oxide or metal acid salt. Therefor, the amount of oxygen present in the catalytic oxide varies according to the atomic ratios of the metal elements that constitute the catalytic oxide.
• inert carrier for supporting the catalytic oxide in the present invention natural, inert porous substances, may be exemplified, or inert porous substances. Specific examples include alpha-alumina, silicon carbide, pumice, silica, zirconia, titanium oxide, or mixtures of these.
• the inert carrier that is conveniently used in the present invention has a surface area of not more than 2 m. /g. and a porosity of 30 to 65%, at least of the pores having a pore diameter in the range of 50 to 1500 microns.
• the catalyst used in the present invention can be prepared for example by adding an aqueous solution of ammonium bichromate and an aqueous solution of copper nitrate to an aqueous solution containing ammonium molybdate, ammonium paratungstate, and ammonium metavanadate, pouring a carrier material into the mixture, heating the mixture to evaporate it to dryness and thereby to deposit the compounds on the carrier, if desired molding it into tablets for instance, and then calcining it at 350-600 C. Any compound which can form a catalytic oxide by calcination such as hydroxides or carbonates can be used as materials for the production of the catalysts.
• the catalytic vapor phase oxidation process of the present invention can be performed by passing a gaseous mixture consisting of 1 to 10% by volume of an unsaturated aldehyde (for example, acrolein, or methacrylein), 5 to 15% by volume of molecular oxygen, 20 to 60% by volume of steam, and 20 to 50% by volume of an inert gas over the catalyst prepared as above described, at a temperature of 200 to 350 C. and a pressure of atmospheric pressure to 10 atmospheres.
• the space velocity is maintained at 500 to 5000 hrr-
• the reaction can be carried out either in a fixed bed or in a fluidized bed.
• the one-pass yield of the unsaturated carboxylic acid can be maintained high without a decrease in the space velocity. While not wishing to be limited by any theory, it is assumed that this is perhaps because the catalytic activity is regulated by the bonding of complete oxides of copper, chromium, and tungsten or acid salts With the Mo-V system, and that it is controlled by the porosity of the carrier.
• Comparative Example2 12 4.6 2.2 0 O 220 1,000 54.6 92.0 50.2 240 2, 000 46. a 93. 0 4s. 1 260 3, 000 40. 0 93. 0 37. 2
• R t cqnverr' s 1 t t iii i 1 i deposited on the alpha-alumina carrier was obtained- Space raging; ai lefn Zrein a ryliiz velocity ture mole acid (mole acid mole One thousand mlllllitfils of the resulting catalyst were Examples (MP1) (0 a) Descent) percent) pecem) packed mto a U-shaped stainless steel tube having a diameter of 25 cm., and the tube was immersed in a molten 4.0 3:323 i883 37 8 3 13 82:3 nitrate bath heated at 220260 C.
• Example 1 A gaseous mixture consisting of 4% of acrolein, 55% of air, and 41% of EXAMPLES 4 6 steam, all by volume, was fed into the tube, and reacted The procedure f Example 1 was repeated except that at a Space Velocity of 1000 to 3000 The results r the composition of the gaseous mixture was changed. obtained are shown in Table 1. The results obtained are given in Table 3.
• Example 1 EXAMPLES 7 TO 9 The procedure of Example 1 was repeated except that The procedure of Example 1 was repeated except that ammonium paratungstate, ammonium bichromate, and a different carrier was used. The results are given in copper nitrate were not used. As a result a catalyst in 00 Table 4.
• Example 1 which a catalytic oxide having a metal element composi- EXAMPLES 10 TO 14 tion Mo V deposited on the alpha-alumina carrier was obtained. Using this catalyst, the reaction was per- The procedure of Example 1 was repeated except that formed under the same conditions as set forth in Example the atomic ratio of metal elements in the catalytic oxide 1. The results obtained are given in Table 1. 79 was varied. The results obtained are given in Table 5.
• EXAMPLE 15 Using the same catalyst and apparatus as used in Example 1, a gaseous mixture consisting of 4% by volume of methacrolein, 51% of air, and 45% of steam was reacted at 340 C. and a space velocity of 2000 hr. The conversion of methacrolein was 70%; the selectivity of methacrylic acid was 75.5%; and the one-pass yield of methacrylic acid was 52.8%.
• a process for producing unsaturated carboxylic acids which comprises oxidizing unsaturated aldehydes in the vapor phase in the presence of a catalyst comprising a catalytic oxide supported on an inert carrier, said catalytic oxide consisting essentially of the recited metal elements in the atomic ratio Mo:V:Cu:Cr:W of 12:214:16:04:012 with the proviso that Cr+W is not 0, said inert carrier having a surface area not greater than 2 mF/g. and a porosity of 30 to 65%, at least 90% of the pores having a pore diameter in the range of 50 to 1500 microns.
• a process for producing unsaturated carboxylic acids which comprises oxidizing unsaturated aldehydes in the vapor phase at 200 to 350 C. and normal atmospheric pressure to 10 atmospheres in the presence of a catalyst comprising a catalytic oxide supported on an inert carrier, said catalytic oxide consisting essentially of the recited metal elements in the atomic ratio Mo:V:Cu:Cr:W of 12:214:16:0 4:012 with the proviso that Cr-i-W is not 0, said inert carrier having a surface area not greater than 2 m. /g. and a porosity of 30 to 65%, at least 90% of the pores having a pore diameter in the range of 50 to 1500 microns.
• a process for producing acrylic acid which comprises oxidizing acrolein with molecular oxygen in the vapor phase at 200-350 C. and normal atmospheric pressure to 10 atmospheres in the presence of a catalyst comprising a catalytic oxide supported on an inert carrier, said catalytic oxide consisting essentially of the recited metal elements in the atomic ratio Mo:V:Cu:Cr:W of 12:214:16:0-4:0-12 with the proviso that Cr+W is not 0, said inert carrier having a surface area not greater than 2 mF/g. and a porosity of 30 to 65%, at least 90% of the pores having a pore diameter in the range of to 1500 microns.
• a process for producing methacrylic acid which comprises oxidizing methacrolein with molecular oxygen in the vapor phase at 200 to 350 C. and normal atmospheric pressure to 10 atmospheres in the presence of a catalyst comprising a catalytic oxide supported on an inert carrier, said catalytic oxide consisting essentially of the recited metal elements in the atomic ratio Mo:V:Cu:Cr:W of 12:214:16:0-4:0-12 with the proviso that Cr+W is not 0, said inert carrier having a surface area not greater than 2 m. g. and a porosity of 30 to at least of the pores having a pore diameter in the range of 50 to 1500 microns.
• said inert carrier is selected from u-alumina, silicon carbide, pumice, silica, zirconia, titanium oxide or mixtures thereof.
• said inert carrier is selected from a-alumina, silicon carbide, pumice, silica, zirconia, titanium oxide and mixtures thereof.
• said inert carrier is selected from a-alumina, silicon carbide, pumice, silica, zirconia, titanium oxide or mixtures thereof.
• said inert carrier is selected from u-alumina, silicon carbide, pumice, silica, zirconia, titanium oxide or mixtures thereof.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Catalysts (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

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• 1970
  • 1970-10-23 JP JP45092759A patent/JPS4911371B1/ja active Pending
• 1971
  • 1971-10-19 DE DE2152037A patent/DE2152037C3/de not_active Expired
  • 1971-10-19 US US00190661A patent/US3833649A/en not_active Expired - Lifetime
  • 1971-10-21 GB GB4900971A patent/GB1361246A/en not_active Expired
  • 1971-10-21 NL NL717114523A patent/NL149781B/xx not_active IP Right Cessation
  • 1971-10-22 PL PL1971151174A patent/PL78378B1/pl unknown
  • 1971-10-22 CA CA125,897A patent/CA941384A/en not_active Expired
  • 1971-10-22 BE BE774329A patent/BE774329A/xx not_active IP Right Cessation
  • 1971-10-22 FR FR7138017A patent/FR2110044A5/fr not_active Expired
  • 1971-10-22 SU SU1709252A patent/SU436486A3/ru active
  • 1971-10-22 DD DD15850071A patent/DD91810A5/xx unknown
  • 1971-10-24 CS CS7457A patent/CS169826B2/cs unknown

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