A zeolite membrane composite includes a porous support and a zeolite membrane formed on at least one surface of the porous support. The zeolite membrane of the zeolite membrane composite is formed of an X-MOR-type zeolite, where X includes at least one type of transition metal ion.

A separation method includes a separation step of using a zeolite membrane composite to separate a branched diolefin from a branched hydrocarbon mixture containing the branched diolefin and at least one branched hydrocarbon in which the number of carbon-carbon double bonds is 1 or less and that is of an equivalent carbon number n to the branched diolefin. The zeolite membrane composite used in this step is a zeolite membrane composite that includes a porous support and a FAU-type zeolite membrane formed on at least one surface of the porous support, and in which the FAU-type zeolite membrane is a silylated FAU-type zeolite membrane including a silyl group at the surface thereof.

A separation method includes a separation step of using a zeolite membrane composite to separate a branched diolefin from a branched hydrocarbon mixture containing the branched diolefin and at least one branched hydrocarbon in which the number of carbon-carbon double bonds is 1 or less and that is of an equivalent carbon number n to the branched diolefin. The zeolite membrane composite used in this step is a zeolite membrane composite that includes a porous support and a FAU-type zeolite membrane formed on at least one surface of the porous support, and in which the FAU-type zeolite membrane is a silylated FAU-type zeolite membrane including a silyl group at the surface thereof.

Systems and methods for recovering cyclopentadiene and/or isoprene from a mixture comprising C.sub.5 hydrocarbons are disclosed. A C.sub.5 mixture comprising cyclopentadiene and/or isoprene is flowed into a dimerization unit to form dimers. The dimers are then separated from the unreacted C.sub.5 hydrocarbons. The separated dimers are monomerized to form a stream comprising cyclopentadiene and/or isoprene, which is subsequently separated to form a first product stream comprising primarily isoprene and a second product stream comprising primarily cyclopentadiene.

Systems and methods for recovering cyclopentadiene and/or isoprene from a mixture comprising C.sub.5 hydrocarbons are disclosed. A C.sub.5 mixture comprising cyclopentadiene and/or isoprene is flowed into a dimerization unit to form dimers. The dimers are then separated from the unreacted C.sub.5 hydrocarbons. The separated dimers are monomerized to form a stream comprising cyclopentadiene and/or isoprene, which is subsequently separated to form a first product stream comprising primarily isoprene and a second product stream comprising primarily cyclopentadiene.

Provided is a method of producing a conjugated diene, including a step of dehydrating a γ,δ-unsaturated alcohol in the presence of a solid acid catalyst having a Hammett acidity function (H.sub.0) of −12.2 or less.

Provided is a method of producing a conjugated diene, including a step of dehydrating a γ,δ-unsaturated alcohol in the presence of a solid acid catalyst having a Hammett acidity function (H.sub.0) of −12.2 or less.

Provided is a method of producing a conjugated diene, including a step of dehydrating a γ,δ-unsaturated alcohol in the presence of a solid acid catalyst having a Hammett acidity function (H.sub.0) of −12.2 or less.

Provided is a technique of producing isoprene from 3-methyl-1,3-butanediol or 1,3-butadiene from 1,3-butanediol by using a single catalyst. A catalyst produces a conjugated diene containing zirconium oxide and calcium oxide in order to produce isoprene by removing two water molecules from one 3-methyl-1,3-butanediol molecule or produce 1,3-butadiene by removing two water molecules from one 1,3-butanediol molecule. Furthermore, a method for producing a conjugated diene includes a step of obtaining a fluid containing a conjugated diene that is isoprene or 1,3-butadiene by bringing a fluid containing 3-methyl-1,3-butanediol or a fluid containing 1,3-butanediol into contact with the catalyst for producing a conjugated diene as a single catalyst so as to cause a dehydration reaction to proceed.

Provided is a technique of producing isoprene from 3-methyl-1,3-butanediol or 1,3-butadiene from 1,3-butanediol by using a single catalyst. A catalyst produces a conjugated diene containing zirconium oxide and calcium oxide in order to produce isoprene by removing two water molecules from one 3-methyl-1,3-butanediol molecule or produce 1,3-butadiene by removing two water molecules from one 1,3-butanediol molecule. Furthermore, a method for producing a conjugated diene includes a step of obtaining a fluid containing a conjugated diene that is isoprene or 1,3-butadiene by bringing a fluid containing 3-methyl-1,3-butanediol or a fluid containing 1,3-butanediol into contact with the catalyst for producing a conjugated diene as a single catalyst so as to cause a dehydration reaction to proceed.