Multi-stage biomass conversion

摘要

A multi-stage process and system for converting solid particulate biomass in a riser reactor having at least two different reaction zones. A lower reaction zone is configured to optimize pyrolysis of the biomass into pyrolysis products, while an upper reaction zone is configured to efficiently crack the pyrolysis products. The relative residence times and/or temperatures of the upper and lower reaction zones can be controlled to optimize product quality and yield.

主权项

1. A biomass conversion process comprising:
(a) pyrolyzing solid particulate biomass in a lower reaction zone of a riser reactor to thereby produce an initial pyrolysis product; (b) combining a thermal modification medium with said initial pyrolysis product to thereby form a thermally-modified product mixture, wherein said thermal modification medium has a substantially different temperature than the temperature of said initial pyrolysis product; and (c) cracking at least a portion of said thermally-modified product mixture in an upper reaction zone of said riser reactor to thereby produce a cracked pyrolysis product, wherein the vapor component residence time in said upper reaction zone is at least 50 percent greater than the vapor component residence time in said lower reaction zone.