Process for converting c2-c5 hydrocarbons to gasoline and diesel fuel blendstocks

A method for converting C2-5 alkanes to a broad-range of fuel products constituting higher-value C5-24 hydrocarbon fuels or fuel blendstocks, comprising:

• passing a fresh, C2-5 alkane-rich feedstream through a thermal olefination reactor, the fresh, C2-5 alkane-rich feedstream having any one or more of the C2-5 alkanes and containing at least 90 wt % C2-5 feed alkanes, the thermal olefination reactor operating without a dehydrogenation catalyst and without steam, the thermal olefination reactor converting the C2-5 feed alkanes to product olefins in an effluent olefination stream;
• passing at least a portion of the effluent olefination stream to an oligomerization reactor containing a zeolite catalyst and operating at a temperature, pressure and space velocity to crack, oligomerize and cyclize the product olefins to form an effluent oligomerization stream comprising the fuel products, unconverted C2-4 alkanes and methane;
• separating C2-4 alkanes and methane from the effluent oligomerization stream;
• passing a recycle stream comprising the separated C2-4 alkanes and methane from the effluent oligomerization stream directly back through the thermal olefination reactor, separating C5 alkanes from the effluent oligomerization stream;
• passing a recycle stream comprising the separated C5 alkanes from the effluent oligomerization stream directly back through the thermal olefination reactor,
• the olefination reactor operating at a temperature, pressure and space velocity to convert at least 80 wt % of the C2-5 feed alkanes to product olefins in the effluent olefination stream;
• and
• recovering the fuel products from the effluent oligomerization stream.