A novel partial gasification
combined cycle (PGCC) system integrating
coal partial gasification, oxy-fuel combustion, combined cycle, and
CO
2
separation is proposed. The coal–CO
2
partial gasification technology is introduced in the coal gasification unit, and the oxy-fuel
combustion technology is employed in the char combustion unit and
gas turbine (GT) unit. The thermodynamic and economic analysis of
the proposed system is carried out, showing that both energy and exergy
efficiency have an increasing/decreasing tendency when the recycled
flue gas (RFG) ratio of char combustion and GT increase. When the
RFG ratios of char combustion and GT are 0.43 and 0.34, energy and
exergy efficiencies reach maximum values of 48.18 and 45.11%, respectively.
The energy efficiency of the PGCC-Oxy system is higher than that of
the integrated gasification combined cycle (IGCC)-Oxy system by approximately
3%. It can be concluded from the economic analysis that the total
investment on the PGCC-Oxy system is 3272.71 million RMB, and the
internal rate of return (IRR) and payback time is 8.07% and 12.38
years, respectively.