| CPC C10G 3/46 (2013.01) [C10G 3/50 (2013.01); C11B 3/006 (2013.01); C11C 1/04 (2013.01); C11C 1/10 (2013.01); C11C 3/12 (2013.01); C10G 2300/1011 (2013.01); C10G 2300/202 (2013.01); C10G 2300/4006 (2013.01); C10G 2300/4081 (2013.01); C10G 2300/708 (2013.01); C10G 2400/04 (2013.01)] | 20 Claims |

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1. A system for producing a renewable fuel comprising C10-C18 alkanes, the system comprising:
a first reaction chamber configured to:
receive a primary feedstock and up to 50% water under counter-current flow conditions, the primary feedstock comprising biologically-derived triglycerides and catalyst poisons;
hydrolyze the primary feedstock for at least an hour to form a hydrolysis effluent comprising (i) an aqueous solution comprising glycerol and a first portion of the catalyst poisons and (ii) an intermediate feedstock comprising free fatty acids and a second portion of the catalyst poisons, wherein the first reaction chamber is maintained at a temperature between 250° C. and 270° C. and a pressure between 700 psig and 900 psig; and
separate the intermediate feedstock and the aqueous solution;
a distillation column configured to:
receive the intermediate feedstock; and
distill the intermediate feedstock at an absolute pressure under 700 mm Hg to obtain a purified intermediate feedstock comprising free fatty acids and a bottom stream containing unreacted triglycerides, diglyceride, monoglyceride, free fatty acids, and at least a portion of the second portion of the catalyst poisons;
a second reaction chamber comprising a metallic catalyst and configured to hydrotreat the purified intermediate feedstock by contacting the purified intermediate feedstock with hydrogen to produce the renewable fuel comprising C10-C18 alkanes, wherein the hydrotreating is carried out at a temperature between 200° C. and 350° C. and a pressure between 300 and 1000 psig;
a purification unit configured to:
remove the at least the portion of the second portion of the catalyst poisons from the bottom stream to form a recycle stream containing unreacted triglycerides, diglyceride, monoglyceride, and free fatty acids; and
direct the recycle stream to the first reaction chamber.
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