Patent ID: 7002052

Claim:
An integrated process of preparing a C 2-5 alkenyl-substituted aromatic compound and hydrogen from a C 2-5 alkane and a C 6-12 aromatic compound, the process comprising: (a) contacting a C 2-5 alkane and a C 2-5 alkyl-substituted aromatic compound in a dehydrogenation reactor in the presence of a dehydrogenation catalyst under process conditions sufficient to prepare a dehydrogenation effluent stream comprising a C 2-5 alkenyl-substituted aromatic compound, the C 2-5 alkyl-substituted aromatic compound, a C 2-5 alkene, the C 2-5 alkane, and hydrogen; (b) separating the dehydrogenation effluent stream under conditions sufficient to obtain an essentially non-aromatic, gaseous stream comprising the C 2-5 alkene, the C 2-5 alkane, and hydrogen, and an aromatics stream comprising the C 2-5 alkenyl-substituted aromatic compound and the C 2-5 alkyl-substituted aromatic compound, the aromatics recovery being greater than about 90 weight percent; (c) feeding the essentially non-aromatic gaseous stream comprising C 2-5 alkene, C 2-5 alkane, and hydrogen into an alkylation reactor wherein the gaseous stream is contacted with a C 6-12 aromatic compound in the presence of an alkylation catalyst under process conditions sufficient to prepare an alkylation effluent stream comprising the C 2-5 alkyl-substituted aromatic compound, and optionally, poly(C 2-5 alkyl-substituted) aromatic compounds(s), and optionally, unreacted C 6-12 aromatic compound, and a gaseous stream comprising C 2-5 alkane and hydrogen; (d) separating the alkylation effluent stream under conditions sufficient to recover a C 2-5 alkyl-substituted aromatic compound fraction, and optionally, a poly(C 2-5 alkyl-substituted) aromatic compound(s) fraction, and optionally, a C 6-12 aromatic compound fraction; (e) recycling the C 2-5 alkyl-substituted aromatic compound recovered from steps (b) and (d) into the dehydrogenation reactor of step (a); (f) separating the gaseous stream comprising C 2-5 alkane and hydrogen obtained from step (c) under conditions sufficient to obtain an essentially pure stream of hydrogen and an essentially pure stream of C 2-5 alkane; and (g) recycling the C 2-5 alkane from step (f) into the dehydrogenation reactor of step (a).