A method for making a fuel includes reacting a conjugated diene or a mixture of conjugated dienes with a catalyst selected from the group consisting of a low valent iron catalyst stabilized with a pyridineimine ligand, an iron precatalyst coordinated to the pyridineimine ligand that is activated with a reducing agent, a low oxidation state Fe complex stabilized with a pyridineimine ligand and a coordinating ligand, and combinations thereof, thereby forming a substituted cyclooctadiene. The substituted cyclooctadiene is then hydrogenated, thereby forming cyclooctane fuel.

A method for making a fuel includes reacting a conjugated diene or a mixture of conjugated dienes with a catalyst selected from the group consisting of a low valent iron catalyst stabilized with a pyridineimine ligand, an iron precatalyst coordinated to the pyridineimine ligand that is activated with a reducing agent, a low oxidation state Fe complex stabilized with a pyridineimine ligand and a coordinating ligand, and combinations thereof, thereby forming a substituted cyclooctadiene. The substituted cyclooctadiene is then hydrogenated, thereby forming cyclooctane fuel.

A method for producing p-xylene, comprising: a dimerization step of bringing a first raw material comprising isobutene into contact with a dimerization catalyst to generate C8 components comprising diisobutylene; a cyclization step of bringing a second raw material comprising the C8 components into contact with a dehydrogenation catalyst comprising Pt in the presence of water to obtain a reaction product comprising p-xylene; and a collection step of collecting p-xylene from the reaction product.

A method for producing p-xylene, comprising: a dimerization step of bringing a first raw material comprising isobutene into contact with a dimerization catalyst to generate C8 components comprising diisobutylene; a cyclization step of bringing a second raw material comprising the C8 components into contact with a dehydrogenation catalyst comprising Pt in the presence of water to obtain a reaction product comprising p-xylene; and a collection step of collecting p-xylene from the reaction product.

A hydrocarbon production method for producing hydrocarbons from a hydrocarbon mixture includes: a first extractive distillation step of performing extractive distillation of an extractive distillation target to obtain a fraction (A) in which isoprene and piperylene are enriched and a fraction (B) in which a linear hydrocarbon and a branched hydrocarbon are enriched; a first distillation step of obtaining a fraction (C) in which isoprene is enriched and a fraction (D) in which piperylene is enriched from the fraction (A); a dehydrogenation step of performing dehydrogenation or oxidative dehydrogenation of either or both of the linear hydrocarbon and the branched hydrocarbon contained in the fraction (B) to obtain a dehydrogenated product; and a recovery step of supplying the dehydrogenated product to an extractive distillation column or a distillation column and obtaining isoprene and/or piperylene from the dehydrogenated product.

A hydrocarbon production method for producing hydrocarbons from a hydrocarbon mixture includes: a first extractive distillation step of performing extractive distillation of an extractive distillation target to obtain a fraction (A) in which isoprene and piperylene are enriched and a fraction (B) in which a linear hydrocarbon and a branched hydrocarbon are enriched; a first distillation step of obtaining a fraction (C) in which isoprene is enriched and a fraction (D) in which piperylene is enriched from the fraction (A); a dehydrogenation step of performing dehydrogenation or oxidative dehydrogenation of either or both of the linear hydrocarbon and the branched hydrocarbon contained in the fraction (B) to obtain a dehydrogenated product; and a recovery step of supplying the dehydrogenated product to an extractive distillation column or a distillation column and obtaining isoprene and/or piperylene from the dehydrogenated product.

Described herein are compositions having an eight-membered monocyclic unsaturated hydrocarbon, methods and system to separate the eight-membered monocyclic unsaturated hydrocarbon at from a hydrocarbon mixture including additional nonlinear unsaturated C.sub.8H.sub.2m hydrocarbons with 4?m?8, by contacting the hydrocarbon mixture with a 10-ring pore molecular sieve having a sieving channel with a 10-ring sieving aperture with a minimum crystallographic free diameter greater than 3 ? and a ratio of the maximum crystallographic free diameter to the minimum crystallographic free diameter between 1 and 2, the molecular sieve having a T1/T2 ratio?20:1 wherein T1 is an element independently selected from Si and Ge, and T2 is an element independently selected from Al, B and Ga, the 10-ring pore molecular sieve further having a counterion selected from NH.sub.4.sup.+, Li.sup.+, Na.sup.+, K.sup.+ and Ca.sup.++.

Described herein are compositions having an eight-membered monocyclic unsaturated hydrocarbon, methods and system to separate the eight-membered monocyclic unsaturated hydrocarbon at from a hydrocarbon mixture including additional nonlinear unsaturated C.sub.8H.sub.2m hydrocarbons with 4?m?8, by contacting the hydrocarbon mixture with a 10-ring pore molecular sieve having a sieving channel with a 10-ring sieving aperture with a minimum crystallographic free diameter greater than 3 ? and a ratio of the maximum crystallographic free diameter to the minimum crystallographic free diameter between 1 and 2, the molecular sieve having a T1/T2 ratio?20:1 wherein T1 is an element independently selected from Si and Ge, and T2 is an element independently selected from Al, B and Ga, the 10-ring pore molecular sieve further having a counterion selected from NH.sub.4.sup.+, Na.sup.+, K.sup.+ and Ca.sup.++.

Described herein are compositions having an eight-membered monocyclic unsaturated hydrocarbon, methods and system to separate the eight-membered monocyclic unsaturated hydrocarbon at from a hydrocarbon mixture including additional nonlinear unsaturated C.sub.8H.sub.2m hydrocarbons with 4?m?8, by contacting the hydrocarbon mixture with a 10-ring pore molecular sieve having a sieving channel with a 10-ring sieving aperture with a minimum crystallographic free diameter greater than 3 ? and a ratio of the maximum crystallographic free diameter to the minimum crystallographic free diameter between 1 and 2, the molecular sieve having a T1/T2 ratio?20:1 wherein T1 is an element independently selected from Si and Ge, and T2 is an element independently selected from Al, B and Ga, the 10-ring pore molecular sieve further having a counterion selected from NH.sub.4.sup.+, Na.sup.+, K.sup.+ and Ca.sup.++.

A method for preparing paraxylene by biomass conversion includes the following steps: (1) contacting a biomass starting material with a hydrogenation catalyst for reaction in a multiphase system formed by an organic solvent, an inorganic salt and water, in the presence of hydrogen as a hydrogen source, and separating the resulting product to obtain an organic phase comprising 2,5-hexanedione; and (2) contacting the organic phase comprising 2,5-hexanedione obtained in the step (1) and ethylene with a molecular sieve catalyst for reaction to obtain paraxylene. The molecular sieve catalyst is at least one selected from the group consisting of aluminophosphate molecular sieves and SCM-14 molecular sieves.