Process analysis of an oxygen lean oxy-fuel power plant with co-production
Journal article, 2009
This paper investigates new possibilities and synergy effects for an oxy-fuel fired polygeneration scheme
(transportation fuel and electricity) with carbon capture and co-firing of biomass. The proposed process
has the potential to make the oxy-fuel process more effective through a sub-stoichiometric combustion
in-between normal combustion and gasification, which lowers the need for oxygen within the process.
The sub-stoichiometric combustion yields production of synthesis gas, which is utilised in an integrated
synthesis to dimethyl ether (DME). The process is kept CO2 neutral through co-combustion of biomass in
the process. The proposed scheme is simulated with a computer model with a previous study of an oxyfuel
power plant as a reference process. The degree of sub-stoichiometric combustion, or amount of synthesis
gas produced, is optimised with respect to the overall efficiency. The maximal efficiency was found
at a stoichiometric ratio just below 0.6 with the efficiency for the electricity producing oxy-fuel process of
0.35 and a DME process efficiency of 0.63. It can be concluded that the proposed oxygen lean combustion
process constitutes a way to improve the oxy-fuel carbon capture processes with an efficient production
of DME in a polygeneration process.