Next Generation Oxy-Fired Systems: Potential for Energy Efficiency Improvement Through Pressurization

Abstract

Oxy-fired combustion has been identified as a key technology needed for greenhouse gas mitigation because it is capable of producing a concentrated CO2 stream suitable for sequestration. This technology as applied to pulverized coal systems has recently been brought to a near-commercial status with several key world-wide demonstrations. A barrier to its adoption has been the large additional auxiliary power required for oxygen production and CO2 compression which results in low overall system efficiency. There have been various strategies proposed to address these efficiency issues. A very promising concept is the use of pressurized combustion in order to increase the system efficiency. The use of pressure increases the power requirement of the air separation system. However, pressurization increases the boiler and steam side efficiencies while decreasing the power requirement for the CO2 compression system. The use of pressure will also affect the performance and size of each piece of equipment within the system. This paper describes the efficiency benefit of using pressure as compared with a baseline ambient pressure oxy-fired system and a typical air-fired system. The technical aspects of various system layouts are presented, the overall efficiency is evaluated and the merits of specific configurations are discussed. Design issues of equipment associated with the fuel supply, furnace, ash removal, heat transfer and flame moderation systems are presented.

Membranes for Environmentally Friendly Energy Processes

“…Their ITM oxygen unit can attribute a 48% less capital cost and a 68% energy saving compared to cryogenic ASU. Moreover, pressurized oxyfuel combustion systems could be another potential solution to achieve a high purity CO 2 in flue gas and reduce the energy penalties, which provides a better performance over conventional atmospheric oxyfuel combustion power cycles [ 73 , 74 ]. CANMET Energy Technology Centre and ThermoEnergy Corp. have conducted the techno-economic evaluations on the pressurized oxyfuel combustion systems [ 75 , 76 , 77 ].…”

Numerical study of hydrogen effects on pressurized methane‐oxy combustion in counter‐flow diffusion flame

“…The use of a pressurized oxy-fuel combustion (POFC) system, operating at elevated pressures, has been proposed to overcome this efficiency penalty of the oxy-fuel combustion system. The POFC system has several benefits [20][21][22] such as (a) the increased latent heat recovery at high pressures, (b) reduction of the physical energy consumption for CO 2 compression before the CCS (carbon capture and storage) process, (c) the minimized system scale, (d) the enhanced convective and radiative heat transfer, and (e) the absence of air infiltration in the system.…”