| 摘要 |
1357259 Alkyl aromatic hydrocarbons TEXACO DEVELOPMENT CORP 20 Sept 1972 [11 Nov 1971] 43457/72 Heading C5E Methylated aromatic hydrocarbons are made by (a) catalytically disproportionating toluene feed in the presence of H 2 in reactor 4, (b) fractionating in tower 8 to provide benzene, toluene, C 8 hydrocarbons, and C 9 and heavier hydrocarbon fractions (the latter containing ethylated aromatics) and recycling (via 12) the toluene fraction to (a), (c) catalytically disproportionating the C 8 fraction from (b) in reactor 20 in the presence of H 2 to form benzene, toluene, trimethyl benzenes, tetramethylbenzenes and ethylated aromatics, (d) fractionating in fractionator 26 the product from (c) into a C 6 -C 8 fraction, a C 9 fraction, and a C 10 and heavier fraction which latter is recovered, and recycling the C 6 -C 8 fraction via 30 to fractionator 8, (e) the C 9 fraction recovered from (d) being free from ethylated aromatics and preferably being fractionated to give xylenes, mesitylene, pseudo cumene and hemimellitene, which latter two can be recycled to step (c). The C 9 and heavier fractions of step (b) are withdrawn from fractionator (9) and de-ethylated in de-ethylator 70 to give benzene and methyl benzenes, together with the C 10 fraction from fractionator 26 which has been fractionated again in fractionator 52. The 188-195‹ C. boiling fraction from 52 is cooled to produce durene crystals. The disproportionation catalyst is preferably sulphided Group VIII metal on hydrogen mordenite and alumina. |
