Catalytic activation and alkylation of isopentane-enriched mixtures

A method for converting a feedstock comprising pentanes to produce a liquid transportation fuel, comprising:

• a) providing a hydrocarbon feed stream comprising at least 50 wt. % pentanes, including both n-pentane and isopentane, wherein the hydrocarbon feed stream further comprises less than 10 wt.% of hydrocarbons containing four or fewer carbons;
• b) at least partially separating various constituents in the hydrocarbon feed stream according to each constituent's vapor pressure, to produce:
• i) first fraction comprising at least 80% of the isopentane present in the feed stream, and at least 90% of hydrocarbons present in the feed stream that are characterized by a vapor pressure equal to or greater than the vapor pressure of isopentane;
• ii) a second fraction that comprises at least 80% of the n-pentane present in the feed stream and at least 90% of any hydrocarbons containing six or more carbons that were in the feed stream;
• c) contacting the first fraction with a first activation catalyst at conditions comprising a first temperature and first pressure that facilitate conversion of at least a portion of the first fraction by the first activation catalyst to a first effluent comprising C2-C5 olefins and aromatics;
• d) contacting at least a portion of the second fraction with a second activation catalyst at a second temperature and second pressure that facilitate conversion of at least a portion of the second fraction by the second catalyst to produce a second effluent comprising C2-C5 olefins and aromatics, wherein the first temperature is lower than the second temperature;
• e) combining at least a portion of the first effluent and the second effluent to produce a mixed effluent and contacting at least a portion of the mixed effluent with an alkylation catalyst at conditions of temperature and pressure that facilitate the conversion of the mixed effluent to produce an alkylation effluent comprising an increased wt. % of mono-alkylated aromatics relative to the mixed effluent, wherein the mono-alkylated aromatics contain from seven to nine carbon atoms and wherein the contacting converts a portion of the mixed effluent to a liquid hydrocarbon product that comprises the liquid transportation fuel.