Design, energy efficiency, and CO2 emissions analysis of a power generation process of coking dry gas reforming coupled with solid oxide fuel cell and organic Rankine cycle

Coking dry gas is a kind of refinery dry gas, which is rich in H2 and light hydrocarbon resources, but it's often used as fuel, resulting in inefficient utilization of dry gas resources and a large amount of air pollutants emissions. Solid oxide fuel cell can efficiently convert the chemical energy of hydrogen into electricity. Therefore, this work establishes a model of a power generation process of coking dry gas reforming coupled with the solid oxide fuel cell and organic Rankine cycle. Process simulation is used to analyze the influence of key operating parameters on the system output performance. The obtained results indicate that the net electrical efficiency of the proposed system is increased from 45.45 % of the coking dry gas direct combustion for power generation system to 56.89 %. In terms of environmental impact, the CO2 emissions of the new system is 373.31 kg/MWh, 20.12 % lower than that of the direct combustion process. Besides, the effect of air excess ratio on system performance is evaluated and the net electrical efficiency of the proposed system increases to 63.73 % as the air excess ratio decreases from 2.0 to 1.1. The above results show that the proposed hybrid power system can provide an effective way for efficient and clean utilization of coking dry gas.