(621bl) Effects of Composite Iron–Sodium Catalyst on Coal Pyrolysis and Gasification

Effects of composite iron¨Csodium catalyst on
coal pyrolysis and gasification

Qingxi Cao^a,b, Maohong Fan^b,[1],
Drayson Bratt^b, Xin Huang^b, Hui Liu^a

^aHarbin Institute of Technology,
92 West Dazhi Street, Harbin 150001, People's Republic
of China

^bDepartment
of Chemical and Petroleum Engineering, University of Wyoming, 1000 E Univ.
Ave., Laramie WY 82071, United States

Abstract: The objective of this research is to study the effect of an
environmentally-friendly, inexpensive composite catalyst, FeCO₃¨CNa₂CO₃,
on pyrolysis and gasification of a low-sulfur sub-bituminous Wyodak coal from
the Powder River Basin (PRB) of Wyoming. The catalytic effects of the composite
catalysts were evaluated by comparing the produced gas compositions and carbon
conversion kinetics to those achieved from raw coal. All of the evaluation works
are being conducted in a fixed bed gasifier at atmospheric pressure. N₂
is used as the protected gas for pyrolysis while CO₂ is used as the
gasification agent. The composite catalyst is designed to be active during both
pyrolysis and gasification process and it could considerably increase the
carbon conversion rate constants at low temperatures. In addition, compared to
raw coal without use of catalyst, the composite catalyst is expected to be able
to significantly increase the yield of H₂ during coal pyrolysis and
enhance the yield of CO during char gasification. The catalytic effect of the composite
catalyst is also being quantitatively evaluated using shrinking core and random
pore models.