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 Å 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 Å 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.+.

In some embodiments, a process for producing a cyclic olefin includes introducing a polymer to a metathesis catalyst in a reaction vessel under reaction conditions. The process includes obtaining a cyclic olefin product comprising the cyclic olefin. In some embodiments, a process for producing a cyclic olefin includes introducing an article comprising a polymer to a metathesis catalyst in a reaction vessel under reaction conditions. The process includes obtaining a cyclic olefin product comprising the cyclic olefin.

In some embodiments, a process for producing a cyclic olefin includes introducing a polymer to a metathesis catalyst in a reaction vessel under reaction conditions. The process includes obtaining a cyclic olefin product comprising the cyclic olefin. In some embodiments, a process for producing a cyclic olefin includes introducing an article comprising a polymer to a metathesis catalyst in a reaction vessel under reaction conditions. The process includes obtaining a cyclic olefin product comprising the cyclic olefin.

A method for synthesizing polyolefin materials with a controlled degree of branching includes the following steps: polymerizing cyclic olefin monomers under catalyst conditions. The cyclic olefin monomer is shown in formula I, where n≥0, n is an integer. By changing monomers and reaction parameters such as reaction temperature, solvent type, catalyst concentration, monomer concentration and reaction time, the degree of branching, the molecular weight and molecular weight distribution of polyolefin can be controlled. Compared with the existing process, the present invention is a new polymerization process, which can prepare the hyperbranched polyolefin with precise and controllable branching structure. The polyolefin material prepared according to the present invention has advantages of a controlled degree of branching, low viscosity and good fluidity, which has broad application in coating, lubricant, polymer and process flow improvement technologies.

A method for synthesizing polyolefin materials with a controlled degree of branching includes the following steps: polymerizing cyclic olefin monomers under catalyst conditions. The cyclic olefin monomer is shown in formula I, where n≥0, n is an integer. By changing monomers and reaction parameters such as reaction temperature, solvent type, catalyst concentration, monomer concentration and reaction time, the degree of branching, the molecular weight and molecular weight distribution of polyolefin can be controlled. Compared with the existing process, the present invention is a new polymerization process, which can prepare the hyperbranched polyolefin with precise and controllable branching structure. The polyolefin material prepared according to the present invention has advantages of a controlled degree of branching, low viscosity and good fluidity, which has broad application in coating, lubricant, polymer and process flow improvement technologies.

A method for making hydrogenated cyclooctatetraene dimers including cyclo-dimerizing butadiene to form 1,5-cyclooctadiene in the presence of at least one first catalyst, dehydrogenating 1,5-cyclooctadiene to 1,3,5,7-cyclooctatetraene, dimerizing 1,3,5,7-cyclooctatetraene to a C.sub.16 multicyclic hydrocarbon cyclooctatetraene dimer, and hydrogenating multicyclic hydrocarbon cyclooctatetraene dimer to form hydrogenated cyclooctatetraene dimers.

A method for making hydrogenated cyclooctatetraene dimers including cyclo-dimerizing butadiene to form 1,5-cyclooctadiene in the presence of at least one first catalyst, dehydrogenating 1,5-cyclooctadiene to 1,3,5,7-cyclooctatetraene, dimerizing 1,3,5,7-cyclooctatetraene to a C.sub.16 multicyclic hydrocarbon cyclooctatetraene dimer, and hydrogenating multicyclic hydrocarbon cyclooctatetraene dimer to form hydrogenated cyclooctatetraene dimers.

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 Å 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.++.

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.