Environmental Engineering Reference
In-Depth Information
Process and Reactor Level Simulations
of Coal-Direct Chemical-looping
Combustion
Ramesh K. Agarwal, Subhodeep Banerjee, Xiao Zhang,
Zheming Zhang and Ling Zhou
Abstract Reducing carbon emissions from fossil-fueled power plants has been an
active area of research in recent years. One technology that appears to be very
promising for high-ef
ciency low-cost carbon capture is chemical-looping combus-
tion (CLC) (Leion et al.
2009a
). CLC involves combustion of fuels (either gas or solid)
by heterogeneous chemical reactions with an oxygen carrier, usually a particulate
metal oxide. Because of the absence of air in the fuel reactor, the combustion products
are not diluted by other gases (e.g., N
2
), resulting in high purity of CO
2
available at the
fuel reactor outlet. Also, the net energy release from a CLC process is theoretically
identical to that from conventional combustion of the fuel (Abad et al.
2012
; Lin-
derholm et al.
2013
; Mattisson et al.
2009a
). Research by Lyngfelt et al. (
2001
) has
shown that the energy cost of solid circulation, which is the only energy cost of
separation, is a very small percentage (approximately 0.3 %) of the total energy
released by the combustion process compared to other pre-combustion technologies
such as the oxy-fuel combustion in which the oxygen separation process consumes
nearly 15 % of the electricity generation (Hong et al.
2009a
,
b
). Therefore, CLC holds
signi
cant promise as a next-generation combustion technology due to its potential to
allow zero CO
2
emission with little effect on the ef
ciency of the power plant.
Keywords CLC process model
CLOU process model
Bituminous coal and
anthracitic coal
Multiphase
fl
ow
Hydrodynamic characteristics
Cold
fl
ow
simulations
1 Introduction
In recent years, the use of coal for CLC process has gained increasing interest since
coal is likely to maintain its dominant role in the power generation sector in the
foreseeable future. Additionally, other solid fuels such as biomass also hold
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