Flash Distillation of Bio-Oils for Simultaneous Production of Hydrocarbons and Green Coke

Abstract

Fast pyrolysis bio-oils from biomass can potentially integrate with petroleum refinery infrastructure for production of renewable fuels and chemicals. Besides hydrodeoxygenation, few feasible options exist for entry points. When considering advanced pyrolysis techniques such as catalytic and/or tail-gas reactive pyrolysis (TGRP), distillation for using both light and heavy ends becomes possible. Our goal was to demonstrate and optimize continuous production of liquid organic distillates and residual solids coke, both in appreciable yields for downstream conversion into renewable products. We fabricated a flash drum for continuous one-step distillations of four oils of varying oxygen content (ranging from 5 to 32 wt %). While a mesh demisting screen enhanced separation, removal of the screen ultimately improved overall yields. The flash drum proceeded to distill lower-oxygen oils (∼10 wt %) with 80 wt % time-on-stream yields over several hours; steady state was reached within 30–40 min. Bio-oils with moder...