Process for the production of renewable distillate-range hydrocarbons

A renewable diesel fuel prepared by

• (a) dehydrating bio-based alcohols, with the bio-based alcohols comprising isobutanol, to form an olefin stream and a water stream wherein the dehydration process is conducted at selected process conditions sufficient to achieve conversion of the bio-based alcohols that is 95% or more and wherein an amount of oxygenates in the olefin stream is less than 1 wt %;
• (b) separating the olefin stream from the water stream;
• (c) contacting the olefin stream with a halometallate ionic liquid catalyst, the halometallate ionic liquid catalyst comprising an organic cation and a halometallate anion, in an oligomerization reactor under oligomerization conditions to form a mixture comprising the halometallate ionic liquid catalyst and an oligomer product, wherein the oligomer product comprises about 39-52 mol % tri-substituted olefins and 34-49 mol % tetra-substituted olefins, and with at least 50 wt % of the oligomer product has boiling point distribution of from 150 C to 400 C;
• (d) separating the oligomer product from the halometallate ionic liquid catalyst;
• and
• (e) fractionating the oligomer product into various fractions and recovering a diesel fuel fraction stream, which comprises from 50 to 90 mol % of tri-substituted and tetra-substituted olefins and has a branching index in the range of 56-68.