The invention relates to a process for preparing 4-vinylcyclohexene, which
comprises the steps (A) providing an n-butane-containing feed gas
stream, (B) feeding the n-butane-containing feed gas stream into at least
one dehydrogenation zone and dehydrogenating n-butane to butadiene to
give a product stream comprising butadiene, n-butane, possibly 1-butene
and 2-butene and possibly water vapor and other secondary constituents,
(C) feeding the product stream from dehydrogenation, if appropriate after
separating off water vapor and secondary constituents, into a
dimerization zone and catalytically dimerizing butadiene to give a
product stream comprising 4-vinylcyclohexene, n-butane and possibly
1-butene, 2-butene and unreacted butadiene, and (D) separating off
4-vinylcyclohexene from the product stream from the dimerization and
recirculating n-butane and possibly 1-butene, 2-butene and unreacted
butadiene to the dehydrogenation zone.