Light alkanes to transportation fuel

A system for converting a feed stream comprising pentanes to produce a liquid transportation fuel or a component thereof, comprising:

• a. a first reactor comprising a first catalyst bed that contains a first catalyst comprising a zeolite, wherein the first reactor is operable to receive a hydrocarbon feed stream a hydrocarbon feed stream comprising at least 50 wt. % pentanes and less than 10 wt. % hydrocarbons that contain either from one to four or at least seven carbon atoms and to facilitate contact between the hydrocarbon feed stream and the first catalyst, wherein the first reactor is further operable to maintain the first catalyst bed at a first temperature and a first pressure that facilitates the catalytic conversion of the hydrocarbon feed stream by the first catalyst to produce a first effluent comprising olefins containing from two to five carbon atoms, monocyclic aromatics and unconverted alkanes containing from two to five carbon atoms;
• b. a second reactor comprising a second catalyst bed that contains a second catalyst comprising a zeolite, wherein the second reactor is operable to receive the first effluent and to facilitate contact between the first effluent and the second catalyst, wherein the second reactor is further operable to maintain the second catalyst bed at a second temperature that is at least 25° C. lower than the first temperature and a pressure that is at least 50 psig (3.45 Bar) higher than the first pressure to facilitate the catalytic conversion of the first effluent by the second catalyst to produce a second effluent comprising monocyclic aromatics and olefins containing from two to five carbon atoms at a molar ratio that is in the range from 0.75 to 1.25, wherein the second catalyst has a distinct chemical composition from the first catalyst;
• wherein the second temperature is at least 25° C. lower than the first temperature;
• c. a third reactor comprising a third reaction zone that contains an alkylation catalyst, wherein the third reactor is operable to receive the second effluent and facilitate contact between the second effluent and the alkylation catalyst in the third reaction zone, wherein the third reactor is operable to maintain the third reaction zone at a temperature and a pressure that facilitates alkylation of the monocyclic aromatics in the second effluent with the C2-C4 olefins from second effluent to produce an alkylation effluent comprising an increased quantity of mono-alkylated aromatics containing eight or nine carbon atoms relative to the quantity of mono-alkylated aromatics containing eight or nine carbon atoms in the second effluent;
• d. a first separator operable to separate and partially condense the alkylation effluent to produce a heavy fraction and a light fraction, wherein the heavy fraction comprises monocyclic aromatics and unreacted alkanes containing at least five carbon atoms, wherein the light fraction comprises hydrogen and at least 80 wt. % olefins and alkanes containing four or fewer carbon atoms;
• e. a second separator operable to separate a benzene stream from the heavy fraction to produce an aromatics product comprising mono-alkylated aromatics and residual benzene that meets specifications for a component of a liquid transportation fuel, wherien the system further comprises a first conduit operable to convey the benzene stream to be combined with the second effluent;
• f. a third separator operable to separate hydrogen from the light fraction to produce a diluent stream comprising C1-C4 olefins and alkanes, wherein the system further comprises a second conduit operable to convey the recycle stream to be combined with the feed stream.