The present invention concerns a process for oligomerizing an olefin feedstock to form an oligomerization product, and a method of controlling such an oligomerization process. The process comprises oligomerizing propylene to form a C.sub.n olefin, including contacting a feed stream comprising propylene and a recycle fraction with a solid phosphoric acid oligomerization catalyst under effective oligomerization conditions in an oligomerization reactor to produce an oligomerization effluent; and fractionating the oligomerization effluent to obtain a product fraction and the recycle fraction, the product fraction comprising the C.sub.n olefin and the recycle fraction comprising a C.sub.n-3 olefin; wherein the recycle fraction comprises at least 80 wt % of the C.sub.n-3 olefin, based on the weight of the recycle fraction; and wherein n is 9, or 12.

The present invention concerns a process for oligomerizing an olefin feedstock to form an oligomerization product, and a method of controlling such an oligomerization process. The process comprises oligomerizing propylene to form a C.sub.n olefin, including contacting a feed stream comprising propylene and a recycle fraction with a solid phosphoric acid oligomerization catalyst under effective oligomerization conditions in an oligomerization reactor to produce an oligomerization effluent; and fractionating the oligomerization effluent to obtain a product fraction and the recycle fraction, the product fraction comprising the C.sub.n olefin and the recycle fraction comprising a C.sub.n-3 olefin; wherein the recycle fraction comprises at least 80 wt % of the C.sub.n-3 olefin, based on the weight of the recycle fraction; and wherein n is 9, or 12.

An oligomerization catalyst, oligomer products, methods for making and using same. The catalyst can include a supported nickel phosphate compound. The catalyst is stable at oligomerization temperatures of 500° C. or higher and particularly useful for making oligomer products containing C4 to C26 olefins having a boiling point in the range of 170° C. to 360° C.

An oligomerization catalyst, oligomer products, methods for making and using same. The catalyst can include a supported nickel phosphate compound. The catalyst is stable at oligomerization temperatures of 500° C. or higher and particularly useful for making oligomer products containing C4 to C26 olefins having a boiling point in the range of 170° C. to 360° C.

An oligomerization catalyst, oligomer products, methods for making and using same. The catalyst can include a supported nickel phosphate compound. The catalyst is stable at oligomerization temperatures of 500° C. or higher and particularly useful for making oligomer products containing C4 to C26 olefins having a boiling point in the range of 170° C. to 360° C.

An oligomerization catalyst, oligomer products, methods for making and using same. The catalyst can include a supported nickel phosphate compound. The catalyst is stable at oligomerization temperatures of 500° C. or higher and particularly useful for making oligomer products containing C4 to C26 olefins having a boiling point in the range of 170° C. to 360° C.

An oligomerization catalyst, oligomer products, methods for making and using same. The catalyst can include a supported nickel phosphate compound. The catalyst is stable at oligomerization temperatures of 500° C. or higher and particularly useful for making oligomer products containing C4 to C26 olefins having a boiling point in the range of 170° C. to 360° C.

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 hydrogen 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 hydrogen to obtain a reaction product comprising p-xylene; and a collection step of collecting p-xylene from the reaction product.

An oligomerization catalyst, oligomer products, methods for making and using same. The catalyst can include a supported nickel phosphate compound. The catalyst is stable at oligomerization temperatures of 500 C. or higher and particularly useful for making oligomer products containing C4 to C26 olefins having a boiling point in the range of 170 C. to 360 C.