Catalyst for production of butadiene, process for producing the catalyst, and process for producing butadiene using the catalyst

Abstract

A catalyst for producing butadiene using n-butene as a raw material, a process for producing the same and a process for producing butadiene using the catalyst are provided, and specifically, a catalyst for producing butadiene by gas-phase contact oxidative dehydrogenation of n-butene, which is capable of stably producing butadiene in a high yield from the beginning of the reaction, a process for producing the same and a process for producing butadiene, in which the catalyst is a shaped catalyst containing a complex metal oxide having molybdenum as an essential ingredient, wherein the pore volume of macropores is 80% or more, more preferably 90% or more, based on the total pore volume, are provided.

Claims

1. A shaped catalyst of a complex metal oxide having molybdenum as an essential ingredient, which is a shaped catalyst used in production of butadiene by a gas-phase contact oxidative dehydrogenation reaction of n-butene in the presence of molecular oxygen, wherein pore volume of macropores of the shaped catalyst is 80% or more based on a total pore volume, wherein the shaped catalyst is a spherical coat-shaped catalyst in which the complex metal oxide is supported on an inert spherical support.

2. The shaped catalyst according to claim 1, wherein the pore volume of macropores of the shaped catalyst is 90% or more based on the total pore volume.

3. The shaped catalyst according to claim 1, wherein the total pore volume is 0.1 ml/g or more and 0.4 ml/g or less.

4. The shaped catalyst according to claim 1, wherein the complex metal oxide has a composition represented by the following formula (1):
Mo.sub.aBi.sub.bNi.sub.cCo.sub.dFe.sub.fX.sub.gY.sub.hO.sub.xFormula (1) wherein Mo, Bi, Ni, Co, Fe and O represents molybdenum, bismuth, nickel, cobalt, iron and oxygen, respectively; X represents at least one element selected from the group consisting of tungsten, antimony, tin, zinc, chromium, manganese, magnesium, silicon, aluminum, cerium, tellurium, boron, germanium, zirconium and titanium; Y represents at least one element selected from the group consisting of potassium, rubidium, calcium, barium, thallium and cesium; a, b, c, d, f, g, h and x represents numbers of atoms of molybdenum, bismuth, nickel, cobalt, iron, X, Y and oxygen, respectively, and a=12, b=0.1 to 7, c+d=0.5 to 20, f =0.5 to 8, g=0 to 2, h=0.005 to 2, and x=a value determined depending on oxidation states of individual elements.

5. The shaped catalyst according to claim 1, wherein powder of the complex metal oxide is supported by a tumbling granulation method.

6. A process for producing the coat-shaped catalyst according to claim 1, wherein powder of the complex metal oxide is supported by a tumbling granulation method.

7. A process for producing butadiene by using the shaped catalyst according to claim 1 and subjecting n-butene to gas-phase contact oxidative dehydrogenation in the presence of molecular oxygen.

8. The process for producing butadiene according to claim 7, wherein a change between T within one hour from start of reaction and T after two hours is 20 C. or less.

9. The process for producing butadiene according to claim 7, wherein a shaped catalyst of a complex metal oxide having molybdenum as an essential ingredient, which is a shaped catalyst used in production of butadiene by a gas-phase contact oxidative dehydrogenation reaction of n-butene in the presence of molecular oxygen, wherein pore volume of macropores of the shaped catalyst is 80% or more based on a total pore volume, is used, and a change between T within one hour from start of reaction and T after two hours is 10 C. or less.

Description

EXAMPLES

(1) The following will more specifically describe the present invention with reference to Examples but the invention should not be construed as being limited to these Examples. The conversion of n-butene, selectivity for butadiene and yield of butadiene in Examples are each defined as follows.
Conversion of n-butene=(Number of moles of reacted n-butene)/(Number of moles of supplied n-butene)100
Selectivity for butadiene=(Number of moles of formed butadiene)/(Number of moles of reacted n-butene)100
Yield of butadiene=(Conversion of n-butene/100)(Selectivity for butadiene/100)100

Example 1

(2) <Catalyst>

(3) While heating and stirring 3,000 parts by weight of distilled water, 423.8 parts by weight of ammonium molybdate and 1.64 parts by weight of potassium nitrate were dissolved therein to obtain an aqueous solution (A1). Separately, 302.7 parts by weight of cobalt nitrate, 162.9 parts by weight of nickel nitrate, and 145.4 parts by weight of ferric nitrate were dissolved in 1,000 parts by weight of distilled water to prepare an aqueous solution (B1), and 164.9 parts by weight of bismuth nitrate was dissolved in 200 parts by weight of distilled water, which had been acidified by adding 42 parts by weight of conc. nitric acid, to prepare an aqueous solution (C1). Then, (B1) and (C1) were sequentially mixed into the above aqueous solution (A1) with vigorous stirring and the formed suspension was dried by means of a spray dryer and calcinated at 440 C. for 6 hours to obtain a pre-calcinated powder (D1). The composition ratio of the catalyst-active ingredient excluding oxygen at this time was as follows: Mo=12, Bi=1.7, Ni=2.8, Fe=1.8, Co=5.2 and K=0.15 in terms of atomic ratio.

(4) Thereafter, using a powder obtained by mixing 5 parts by weight of crystalline cellulose into 100 parts by weight of the pre-calcinated powder and an inert support (a spherical material containing alumina and silica as main ingredients and having a diameter of 4.5 mm), the weight of the support and the weight of the pre-calcinated powder for use in shaping were adjusted so that the support amount became a ratio of 50% by weight. Using a 20% by weight aqueous glycerin solution as a binder, a coat-shaped catalyst (E1) was obtained by supporting and shaping into a spherical shape having a diameter of 5.2 mm by means of a tumbling granulator.

(5) For the support shaping, a cylindrical shaping machine having a diameter of 23 cm was used and the number of rotations of the base plate was controlled to 260 rpm. The relative centrifugal acceleration on this occasion was 8.7G.

(6) The coat-shaped catalyst (E1) was calcinated at a calcination temperature of 530 C. for 4 hours under an air atmosphere to obtain a catalyst (F1).

(7) <Catalyst Analysis>

(8) The total pore volume of the above catalyst (F1) was 0.24 ml/g and the ratio of the pore volume of macropores was 99%.

(9) <Dehydrogenation Reaction Test>

(10) A silica-alumina sphere having a diameter of 5.2 mm and the above catalyst (F1) each were sequentially packed in 30 cm and 8 cm into a stainless steel-made reaction tube having an inner diameter of 22.2 mm, in which a thermocouple to measure the catalyst layer temperature was installed at the axis of the tube, from the raw material gas inlet of the reaction tube. The temperature of the reaction bath was set at 320 C. A mixed gas having a molar ratio of n-butene:air:water=1:10:5, in which the supply amount was set to become a space velocity of 1440 h.sup.1, was introduced into the reaction tube to carry out a dehydrogenation reaction. In addition, as the n-butene, a 1-butene gas of 99% purity was used. Then, the outlet gas after the elapse of two hours from the start of the reaction was analyzed by means of a gas chromatography. The conversion of n-butene, selectivity for butadiene, and yield of butadiene are shown in Table 1. Further, T immediately after the start of the reaction and T after the elapse of two hours are also shown in Table 1.

(11) From Table 1, even after the elapse of two hours from the start of the reaction, it was seen that the conversion of n-butene was 99.3% and the yield of butadiene was 89.0% and thus a high conversion and a high yield were achieved. It was also seen that T immediately after the start of the reaction was 42.8 C. and T after the elapse of two hours was 39.2 C. and thus a large temperature change was not observed and T was stable from the beginning of the reaction.

(12) From the above results, it can be seen that butadiene can be obtained from n-butene in a high conversion and a high yield for a long period of time, and a stable operation can be performed from the beginning of the reaction.

(13) TABLE-US-00001 TABLE 1 Reaction time Conversion of Selectivity for Yield of T (hr) n-butene (%) butadiene (%) butadiene (%) ( C.) At the start of 42.8 reaction 2 99.3 89.6 89 39.2

Comparative Example 1

(14) <Catalyst>

(15) A mixed powder was obtained by mixing 100 parts by weight of the pre-calcinated powder (D1) with 10 parts by weight of crystalline cellulose and 10 parts by weight of YB-155 (a shaping aid for extrusion) manufactured by Yuken Industry Co., Ltd. To the mixed powder was mixed 100 parts by weight of AEROSIL OX50 manufactured by Nippon Aerosil Co., Ltd., and the whole was extruded so as to be a ring shape to obtain an extrusion-shaped catalyst (E2). The outer diameter/inner diameter/length (mm) of the resulting shaped catalyst (E2) was 5.4/3.6/5.0.

(16) The extrusion-shaped catalyst (E2) was calcinated under the same conditions as in Example 1 to obtain a catalyst (F2).

(17) <Catalyst Analysis>

(18) The total pore volume of the above catalyst (F2) was 0.42 ml/g and the ratio of the pore volume of macropores was 78%.

(19) <Dehydrogenation Reaction Test>

(20) A dehydrogenation reaction test was carried out in the same manner as Example 1 except that the catalyst (F2) was used. Then, the outlet gas after the elapse of two hours from the start of the reaction was analyzed by means of a gas chromatography. The results of the reaction are shown in Table 2 in the same manner as Example 1.

(21) From Table 2, it can be seen that T is 97.4 C. at the beginning of the reaction and is 50 C. or more higher than that in Example 1 and thus particularly large heat generation occurs. Even after two hours from the start of the reaction, T is 10 C. or more higher than that in Example 1. Therefore, since the catalyst is exposed to higher temperature, the case is disadvantageous in catalyst life. T immediately after the start of the reaction and T after the elapse of two hours are 97.4 C. and 55.8 C., respectively and a large temperature change is observed immediately after the reaction, so that it is surmised that the operation in plant is very difficult.

(22) Moreover, it was seen that the yield of butadiene after the elapse of two hours was 2.5% lower than that in Example 1. This is because a successive reaction proceeds to increase CO and CO.sub.2 and the selectivity for butadiene is decreased. Since the amount of the active ingredient of the catalyst is equal in Comparative Example 1 and Example 1, it is surmised that a difference in the ratio of macropores to mesopores in the pore volume remarkably influences the degree of the successive reaction. When the successive reaction increases, the heat of reaction owing to the reaction becomes large and as a result, T becomes larger.

(23) Therefore, by using a catalyst having a large ratio of pore volume of macropores of the invention, T could be suppressed and the yield of butadiene could be enhanced.

(24) TABLE-US-00002 TABLE 2 Reaction time Conversion of Selectivity for Yield of T (hr) n-butene (%) butadiene (%) butadiene (%) ( C.) At the start of 97.4 reaction 2 99.3 87.1 86.5 55.8

Comparative Example 2

(25) <Catalyst>

(26) A mixed powder was obtained by mixing 100 parts by weight of the pre-calcinated powder (D1) with 5 parts by weight of crystalline cellulose and 5 parts by weight of YB-155 (a shaping aid for extrusion) manufactured by Yuken Industry Co., Ltd. To the mixed powder was mixed 20 parts by weight of AEROSIL 200 manufactured by Nippon Aerosil Co., Ltd., and the whole was extruded so as to be a ring shape to obtain an extrusion-shaped catalyst (E3). The outer diameter/inner diameter/length (mm) of the resulting shaped catalyst (E3) was 5.4/3.6/5.0.

(27) The extrusion-shaped catalyst (E3) was calcinated under the same conditions as in Example 1 to obtain a catalyst (F3).

(28) <Catalyst Analysis>

(29) The total pore volume of the above catalyst (F3) was 0.47 ml/g and the ratio of the pore volume of macropores was 79%.

(30) <Dehydrogenation Reaction Test>

(31) The catalyst (F3) and an inactive substance were mixed so that the amount of the active ingredient per unit volume became equal to that in Example 1 and Comparative Example 1 and the same volume as in Example 1 and Comparative Example 1 was packed. As the inert material, a silica-alumina sphere having a diameter of 5.2 mm was used. Except for the above, a dehydrogenation reaction test was carried out in the same manner as Example 1. Then, the outlet gas after the elapse of two hours from the start of the reaction was analyzed by means of a gas chromatography. The results of the reaction are shown in Table 3.

(32) From the result of Table 3, the heat generation at the reaction could be suppressed by diluting the catalyst with the inert material but the conversion of n-butene decreased by 5.2% after the elapse of two hours from the start of the reaction although the amount of the active ingredient was equal to that in Example 1. Therefore, effects equal to those exhibited by the catalyst of the invention cannot be exhibited by simply diluting the catalyst with the inert material.

(33) TABLE-US-00003 TABLE 3 Conversion Reaction time of n-butene Selectivity for Yield of T (hr) (%) butadiene (%) butadiene (%) ( C.) At the start of 37.1 reaction 2 94.1 89 83.7 30.7

Example 2

(34) <Catalyst>

(35) While heating and stirring 3,000 parts by weight of distilled water, 750 parts by weight of ammonium molybdate and 13.8 parts by weight of cesium nitrate were dissolved therein to obtain an aqueous solution (A4). Separately, 695.5 parts by weight of cobalt nitrate, 103 parts by weight of nickel nitrate, and 286 parts by weight of ferric nitrate were dissolved in 1,000 parts by weight of distilled water to prepare an aqueous solution (B4), and 291.8 parts by weight of bismuth nitrate was dissolved in 300 parts by weight of distilled water, which had been acidified by adding 73 parts by weight of conc. nitric acid, to prepare an aqueous solution (C4). Then, (B4) and (C4) were sequentially mixed into the above aqueous solution (A4) with vigorous stirring and the formed suspension was dried by means of a spray dryer and calcinated at 460 C. for 5 hours to obtain a pre-calcinated powder (D4). The composition ratio of the catalyst-active ingredient excluding oxygen at this time was as follows: Mo=12, Bi=1.7, Ni=1.0, Fe=2.0, Co=6.8 and Cs=0.20 in terms of atomic ratio.

(36) Thereafter, using a powder obtained by mixing 5 parts by weight of crystalline cellulose into 100 parts by weight of the pre-calcinated powder and an inert support (a spherical material containing alumina and silica as main ingredients and having a diameter of 4.0 mm), the weight of the support and the weight of the pre-calcinated powder for use in shaping were adjusted so that the support amount became a ratio of 50% by weight. Using a 20% by weight aqueous glycerin solution as a binder, a coat-shaped catalyst (E4) was obtained by supporting and shaping into a spherical shape having a diameter of 4.4 mm.

(37) For the support shaping, a cylindrical shaping machine having a diameter of 23 cm was used and the number of rotations of the base plate was controlled to 260 rpm. The relative centrifugal acceleration at this time was 8.7G.

(38) The coat-shaped catalyst (E4) was calcinated at 520 C. for 4 hours to obtain a catalyst (F4).

(39) <Catalyst Analysis>

(40) The total pore volume of the above catalyst (F4) was 0.25 ml/g and the ratio of the pore volume of macropores was 100%.

(41) <Dehydrogenation Reaction Test>

(42) A dehydrogenation reaction test was carried out in the same manner as Example 1 except that the catalyst (F4) was used and the reaction temperature was 330 C. Then, the outlet gas after the elapse of two hours from the start of the reaction was analyzed by means of a gas chromatography. The results of the reaction are shown in Table 4 in the same manner as Example 1.

(43) From the results of Table 4, even in the catalyst (F4) having a composition different from that of the catalyst (F1), after the elapse of two hours from the start of the reaction, it was seen that the conversion of n-butene was 98.9% and the yield of butadiene was 91.0% and thus a high conversion and a high yield were achieved.

(44) Moreover, T at the beginning of the reaction was 26.7 C. and it is seen that the heat generation is a little. T after the elapse of two hours from the start of the reaction is 27.6 C.

(45) Therefore, similarly to Example 1, it was seen that a large temperature change was not observed and the temperature was stable from the beginning of the reaction.

(46) TABLE-US-00004 TABLE 4 Yield of Reaction time Conversion of Selectivity for butadiene T (hr) n-butene (%) butadiene (%) (%) ( C.) At the start of 26.7 reaction 2 98.9 92.0 91.0 27.6

(47) From the above results, a catalyst wherein the ratio of the pore volume of macropores is 80% or more can suppress a heat generation behavior and be stably used, can be used at a high conversion of n-butene even at a little T, and can maintain a high yield of butadiene, so that the catalyst is industrially very useful.

(48) While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

(49) The present application is based on Japanese Patent Application No. 2012-098259 filed on Apr. 23, 2012, and the contents are incorporated herein by reference. Also, all the references cited herein are incorporated as a whole.

INDUSTRIAL APPLICABILITY

(50) The catalyst of the present invention is used in a process for stably producing butadiene from n-butene from the beginning of the reaction.