Performance analysis of a biomass gasification power system combined with the molten salt thermal storage for heavy oil thermal recovery and power supply

To reduce fossil fuel consumption and carbon dioxide emissions in traditional heavy oil thermal recovery processes, this paper innovatively proposes integrating biomass gasification, combined cycle, and molten salt thermal energy storage for heavy oil thermal recovery and power supply. During valley period, the main steam from the combined cycle is used for turbine power generation, molten salt heating, and heavy oil thermal recovery. During peak period, the stored high-temperature molten salt is first used to heat feedwater into steam to meet the steam supply requirements for heavy oil thermal recovery. The residual heat of the high-temperature molten salt is then further utilized to heat feedwater, thereby increasing the power generation of the system. Through system integration, not only is the stability of the steam supply for heavy oil thermal recovery enhanced, but the operational flexibility of the entire system is also improved. Based on system simulation, the performance is evaluated, including energy analysis, exergy analysis, and economic analysis. Research results show that the energy efficiency of the integrated system is 34.91 %, the exergy efficiency is 36.41 %, and the equivalent round-trip efficiency of the energy storage system can reach 72.72 %. The low valley regulation rate of the integrated system is increased by 12.93 %, and the peak modulation ratio is increased by 9.40 %. Additionally, the total investment cost of the integrated system is 11065.65 k$, with a dynamic payback period of 2.53 years and a net present value of 57161.88 k$. This paper may provide a new approach for heavy oil extraction.