METHODS FOR BIOMASS TORREFACTION WITH CARBON DIOXIDE CAPTURE

摘要

An environmental friendly, continuous biomass torrefaction system is disclosed herein. This torrefaction system captures carbon dioxide (CO2) from the combustion gases generated in the process. A portion of the captured CO2 is recycled and used as the inert gas for torrefying biomass and cooling the torrefied biomass. The rest of the captured CO2 is stored.

主权项

1. A torrefaction process for biomass, the process comprising
a) Preheating raw biomass in a dryer wherein the biomass loses its moisture; b) Torrefying the preheated biomass in a torrefaction reactor, wherein volatiles so generated are routed to a combustor and torrefied biomass is transmitted to a heat exchanger; c) Cooling the torrefied biomass in said heat exchanger, wherein recycled carbon dioxide (CO2) is heated up by directly contacting the torrefied biomass; d) Burning said volatiles from step b together with added fuel in said combustor to provide heat for said torrefaction process, wherein the combustion gases (mainly carbon dioxide and water) are routed to said dryer through a heat exchanger; and e) Cooling said combustion gases coming out of said dryer in a condenser, wherein water is condensed and disposed, and part of cooled CO2 is captured and stored, and part of cooled CO2 is recycled and used as an inert gas for torrefying biomass in said torrefaction reactor.