- Email: [email protected]
A growing interest in isobutane dehydrogenation
298
Catalysts for the Conversion Methanol to Hydrocarbons
of
M. Tachibana, of Teikoku Kako Ltd (Japanese Kokai Tokkyo Koho, JP 82-7477), has found that dihydroaluminium tripolyphosphoric acid can be used for the conversion of methanol to hydrocarbons at temperatures between 2500 and 440°C. For example, with 40 q of the catalyst and u;i,q -a flow of-95% of methanol (4 cm h- 1. a conversion of 98.4% was‘obtained'with the following product distribution: CH4, 6.6%; C2H6, 2.6%; C2H4, 21.4%; C3H8, 6.3%; C3H6, 43.5%;'CqH8, 16.4%; C5HI0, 3.2%; together with traces of dimethyl ether, CO and C02. The catalyst is reported to have a long life-time and its activity is unchanged by air. K. Wada and Y. Kobayashi, of Mitsubishi Chemical Industries Ltd (Japanese Kokai Tokkyo Koho,JP 82-24315) have found that crystalline compounds of the zirconium phosphate system (Zr(R-P03)2, where R is an alkyl, ally1 or allyloxy group) are also effective for the production of hydrocarbons from methanol or dimethylether at pressures between one and 50 atm., temperatures from 350-4500C and LHSVs of O.l-lOh-1. For example, zirconium oxychloride (32.2 g) was dissolved in 46 wt % HF solution (130 g) and added to a solutio of C6H5PO(OH)2 (158 g) inwater (500 cm 9 ) and reacted for 3 days at 60°C. The white crystals of Zr(C6H5PO3)2 produced were tabletted and calcined at 400°C for 6h. A sample of 8 cm3 of this catalyst, having a' surface area of 27-35 m2g-I, was used for the cpnversion of methanol (1.84gb) in NE (4.2 dm3 h-I). The conversion of me hanol was 53.9% with a selectivity to hydrocarbons of 26.3% (balance dimethvlether) between i7-37% of the hydrocarbons was ethylene and 23-38% was propylene.
Fischer-Tropsch Catalvsts
Synthesis
using Fe-ZSM-5
A paper published in Colloids and Surfaces IJ.M. Stencel et al.. 4 (19821, 33I)desc;ibes adetailed characterisatibn of a series of catalysts,prepared by the deposition of Fe3(CO)I2 on a ZSM-5 highsilica zeolite,using techniques such as XPS, SIMS and ISS. The paper shows how these techniques give information on the distribution of the iron in the zeolite:
at low loadings (less than _ 1 wt %), the iron species are incorporated in the zeolite structure; at higher loadings (1.6 - 7.9 wt % Fe), weakly interacting iron crystallites of approximately constant size are formed; at even higher loadinqs (up to 20 wt % iron), larqer crystailites are found. Earlier work (V.U.S. Rao et al., ACS Fuel Chemistry Oiv.Symp., 25 (1980) 119) had reported that such catalysts produce from a 1:l mixture of CO and Hy a liauid hvdrocarbon product of which 95% is in the &-Cl1 gasoline range with an octane number-of 94 and that the addition of cobalt to the catalyst (V.lJS.Raoand R.J. Gormley, Hydrocarbon Processing, 59 (1980) 139) causes dramatic changes in the product selectivity and suppression of the water-gas shift reaction. Preliminary catalytic experiments carried out by Rao on reduced (4500C) catalysts prepared from Fe3(CO)I2 (16 wt. % Fe) are reported bv Stencel and his coworkers. Both the uncalcined material and one calcined at 500°C were effective catalysts for the hydrogenation of CO, the calcined catalyst giving a higher proportion of liquid hydrocarbons(particularlv olefins) and less methane than the uncalcined material. The difference is thought to be due to differences in the physical and chemical properties of the interacting species. A Growing Interest Dehydrogenation
in Isobutane
The increasing consumption of MTB (methyl tertiarybutyl ether (CH3)3COCH3) has initiated a growing interest in the dehydrogenation of isobutane. Analogously to the dehydrogenation of n-butane, two types of catalysts can be applied: alkalized Cr203-Al20 (with or without MgO as promo ?or) or noble metals (Pd,Pt,Rh or Irl modified bv Sn and supported on A1203 or ZnO-Ai and containino alkali metals. The bia problem in i&butane dehydrogenationd is the formation of coke and the isomerisation to n-butane. Recently, however, UOP Inc., who have world-wide acceptance as experts in this field, announced (Hydrocarbon Processing, April 1982) a second generation of noble metal carrier catalysts which have a depressed activity for isomerisation and coking. The new catalysts also exhibit good regeneration properties.
Catalysts for the Conversion Methanol to Hydrocarbons
of
M. Tachibana, of Teikoku Kako Ltd (Japanese Kokai Tokkyo Koho, JP 82-7477), has found that dihydroaluminium tripolyphosphoric acid can be used for the conversion of methanol to hydrocarbons at temperatures between 2500 and 440°C. For example, with 40 q of the catalyst and u;i,q -a flow of-95% of methanol (4 cm h- 1. a conversion of 98.4% was‘obtained'with the following product distribution: CH4, 6.6%; C2H6, 2.6%; C2H4, 21.4%; C3H8, 6.3%; C3H6, 43.5%;'CqH8, 16.4%; C5HI0, 3.2%; together with traces of dimethyl ether, CO and C02. The catalyst is reported to have a long life-time and its activity is unchanged by air. K. Wada and Y. Kobayashi, of Mitsubishi Chemical Industries Ltd (Japanese Kokai Tokkyo Koho,JP 82-24315) have found that crystalline compounds of the zirconium phosphate system (Zr(R-P03)2, where R is an alkyl, ally1 or allyloxy group) are also effective for the production of hydrocarbons from methanol or dimethylether at pressures between one and 50 atm., temperatures from 350-4500C and LHSVs of O.l-lOh-1. For example, zirconium oxychloride (32.2 g) was dissolved in 46 wt % HF solution (130 g) and added to a solutio of C6H5PO(OH)2 (158 g) inwater (500 cm 9 ) and reacted for 3 days at 60°C. The white crystals of Zr(C6H5PO3)2 produced were tabletted and calcined at 400°C for 6h. A sample of 8 cm3 of this catalyst, having a' surface area of 27-35 m2g-I, was used for the cpnversion of methanol (1.84gb) in NE (4.2 dm3 h-I). The conversion of me hanol was 53.9% with a selectivity to hydrocarbons of 26.3% (balance dimethvlether) between i7-37% of the hydrocarbons was ethylene and 23-38% was propylene.
Fischer-Tropsch Catalvsts
Synthesis
using Fe-ZSM-5
A paper published in Colloids and Surfaces IJ.M. Stencel et al.. 4 (19821, 33I)desc;ibes adetailed characterisatibn of a series of catalysts,prepared by the deposition of Fe3(CO)I2 on a ZSM-5 highsilica zeolite,using techniques such as XPS, SIMS and ISS. The paper shows how these techniques give information on the distribution of the iron in the zeolite:
at low loadings (less than _ 1 wt %), the iron species are incorporated in the zeolite structure; at higher loadings (1.6 - 7.9 wt % Fe), weakly interacting iron crystallites of approximately constant size are formed; at even higher loadinqs (up to 20 wt % iron), larqer crystailites are found. Earlier work (V.U.S. Rao et al., ACS Fuel Chemistry Oiv.Symp., 25 (1980) 119) had reported that such catalysts produce from a 1:l mixture of CO and Hy a liauid hvdrocarbon product of which 95% is in the &-Cl1 gasoline range with an octane number-of 94 and that the addition of cobalt to the catalyst (V.lJS.Raoand R.J. Gormley, Hydrocarbon Processing, 59 (1980) 139) causes dramatic changes in the product selectivity and suppression of the water-gas shift reaction. Preliminary catalytic experiments carried out by Rao on reduced (4500C) catalysts prepared from Fe3(CO)I2 (16 wt. % Fe) are reported bv Stencel and his coworkers. Both the uncalcined material and one calcined at 500°C were effective catalysts for the hydrogenation of CO, the calcined catalyst giving a higher proportion of liquid hydrocarbons(particularlv olefins) and less methane than the uncalcined material. The difference is thought to be due to differences in the physical and chemical properties of the interacting species. A Growing Interest Dehydrogenation
in Isobutane
The increasing consumption of MTB (methyl tertiarybutyl ether (CH3)3COCH3) has initiated a growing interest in the dehydrogenation of isobutane. Analogously to the dehydrogenation of n-butane, two types of catalysts can be applied: alkalized Cr203-Al20 (with or without MgO as promo ?or) or noble metals (Pd,Pt,Rh or Irl modified bv Sn and supported on A1203 or ZnO-Ai and containino alkali metals. The bia problem in i&butane dehydrogenationd is the formation of coke and the isomerisation to n-butane. Recently, however, UOP Inc., who have world-wide acceptance as experts in this field, announced (Hydrocarbon Processing, April 1982) a second generation of noble metal carrier catalysts which have a depressed activity for isomerisation and coking. The new catalysts also exhibit good regeneration properties.