A
system and method for
biomass pyrolysis utilizing
chemical looping combustion of a produced
char to capture
carbon dioxide is disclosed. The
system includes a
biomass pyrolysis reactor, a
char combustor, and oxidation reactor and a separator for separating
carbon dioxide from
flue gas produced by the
char combustion. The
pyrolysis reactor pyrolyzes
biomass in the presence of reduced
metal oxide sorbents producing char and
pyrolysis oil vapor. The char is separated and combusted in the char
combustor, in the presence of oxidized
metal oxide sorbents, into a gaseous
stream of
carbon dioxide and
water vapor. The carbon dioxide and water are separated so that a
stream of carbon dioxide may be captured. The oxidation reactor oxidizes, in the presence of air, a portion of reduced
metal oxide sorbents into oxidized metal oxide sorbents that are looped back to the char
combustor to provide
oxygen for
combustion. A second portion of the reduced metal oxide sorbents is recycled from the char combustor to the pyrolysis reactor to provide heat to drive the pyrolysis.
Pyrolysis oil upgrading catalyst particles may be used in addition to the metal oxide sorbents as
heat energy carrier particles to improve the quality of the
pyrolysis oil vapors produced in the pyrolysis reactor. Also, the metal oxide sorbents may have metals incorporated therein which serve to
upgrade the pyrolysis vapors produced during pyrolysis. Non-limiting examples of such metals include Ni, Mo, Co, Cr, W, Rh, Ir, Re, and Ru.