Process for converting C2—C5 hydrocarbons to gasoline and diesel fuel blendstocks

A method for converting C2-5 alkanes in a feedstream to a range of C5-24 fuel products, comprising:

• olefinating the alkanes in a fresh, C2-5 alkane-rich feedstream in a thermal olefination reactor operating at a temperature, pressure and space velocity to convert the C2-5 alkanes to product olefins without the use of a dehydrogenation catalyst and without the use of steam, the alkane-rich feedstream containing at least 90 wt % C2-5 feed alkanes;
• converting the product olefins into the fuel products by contacting the product olefins with a zeolite catalyst in an oligomerizing reactor 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;
• passing a recycle stream comprising unconverted C2-4 alkanes and methane from the effluent oligomerization stream back through the thermal olefination reactor to provide the effluent olefination stream with at least 80 wt % of the feed C2-5 alkanes having been converted to C2-5 olefins;
• and
• recovering the fuel products from the effluent oligomerization stream.

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 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 having an effluent olefination stream comprising C2-5 product olefins and C2-5 alkanes;
• passing the effluent olefination stream through an oligomerization reactor, the oligomerization reactor containing a zeolite catalyst and operating at a temperature, pressure and space velocity to crack, oligomerize and cyclize product olefins in the effluent olefination stream to form an effluent oligomerization stream comprising the fuel products, unconverted C2-5 alkanes and methane;
• separating unconverted C2-4 alkanes and methane from the effluent oligomerization stream and recycling the separated unconverted C2-4 alkanes and methane from the effluent oligomerization stream back through the thermal olefination reactor, the fresh, C2-5 alkane-rich feedstream and the recycled, separated C2-4 alkanes together comprising a total alkane feed to the olefination reactor, the thermal olefination reactor operating at a temperature, pressure and space velocity to produce the effluent olefination stream in which at least 80 wt. % of the C2-5 feed alkanes have been converted to product C2-5 olefins;
• and
• recovering the fuel products from the effluent oligomerization stream.

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 containing at least 90 wt. % C2-5 feed alkanes, the thermal olefination reactor operating without a dehydrogenation catalyst and without steam, the 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 and methane;
• passing a recycle stream comprising methane from the effluent oligomerization stream back through the oligomerization reactor, the olefination reactor operating at a temperature, pressure and space velocity to convert at least 80 wt. % of the feed C2-5 alkanes to product olefins in the effluent olefination stream;
• and
• recovering the fuel products from the effluent oligomerization stream.

A method for converting C2-5 alkanes in a feedstream to a range of C5-24 fuel products, comprising:

• olefinating the alkanes in a fresh, C2-5 alkane-rich feedstream in a thermal olefination reactor operating at a temperature, pressure and space velocity to convert the C2-5 alkanes to product olefins without the use of a dehydrogenation catalyst and without the use of steam, the alkane-rich feedstream containing at least 90 wt. % C2-5 feed alkanes;
• converting the product olefins into the fuel products by contacting the product olefins with a zeolite catalyst in an oligomerizing reactor 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 and methane;
• passing a recycle stream comprising methane from the effluent oligomerization stream back through the oligomerization reactor, the thermal olefination reactor converting at least 80 wt. % of the feed C2-5 alkanes to C2-5 olefins;
• and
• recovering the fuel products from the effluent oligomerization stream.

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 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 having an effluent olefination stream comprising C2-5 product olefins and C2-5 alkanes;
• passing the effluent olefination stream through an oligomerization reactor, the oligomerization reactor containing a zeolite catalyst and operating at a temperature, pressure and space velocity to crack, oligomerize and cyclize product olefins in the effluent olefination stream to form an effluent oligomerization stream comprising the fuel products, unconverted C2-5 alkanes and methane;
• separating C2-4 alkanes and methane from the effluent oligomerization stream and recycling methane from the effluent oligomerization stream back through the oligomerization reactor, the fresh, C2-5 alkane-rich feedstream and the recycled, separated C2-4 alkanes together comprising a total alkane feed to the olefination reactor, the thermal olefination reactor operating at a temperature, pressure and space velocity to produce the effluent olefination stream in which at least 80 wt. % of the C2-5 feed alkanes have been converted to product C2-5 olefins;
• and
• recovering the fuel products from the effluent oligomerization stream.