Isomerization and catalytic activation of pentane-enriched hydrocarbon mixtures

A method for converting a feed stream comprising pentanes to produce a blend component of liquid transportation fuel, the method comprising:

• a) providing a hydrocarbon feed stream comprising at least 50 wt. % pentanes, including both n-pentane and isopentane;
• b) at least partially separating the hydrocarbon feed stream in a separator to produce:
• a first fraction that comprises at least 80% of the isopentane present in the hydrocarbon feed stream (on a molar basis), and that further comprises at least 90% of hydrocarbons present in the hydrocarbon feed stream (on a molar basis) that are characterized by a vapor pressure equal to or greater than the vapor pressure of isopentane, and
• a second fraction that comprises at least 80% of the n-pentane content of the hydrocarbon feed stream (on a molar basis) and at least 90% of hydrocarbons from the hydrocarbon feed stream that contain six or more carbons (on a molar basis);
• Step c):
• contacting the first fraction with an activation catalyst at a temperature and a pressure that facilitates catalytic activation of at least a portion of the first fraction by the activation catalyst to produce an activation effluent comprising olefins containing from two to five carbon atoms, monocyclic aromatics and unconverted hydrocarbons containing from two to five carbon atoms;
• Step d):
• removing a first portion of the second fraction as the blend component of liquid transportation fuel;
• e) contacting a second portion the second fraction with at least one isomerization catalyst in an isomerization reactor that is maintained at a temperature and a pressure that facilitates the isomerization of at least a portion of n-pentane in the second fraction to produce isopentane, thereby producing an isomerization effluent characterized by an increased ratio of isopentane to n-pentane (on a wt. % basis) relative to the isopentane to n-pentane ratio of the hydrocarbon feed stream;
• f) combining the isomerization effluent with the hydrocarbon feed stream of a).