Design and thermodynamic analysis of a novel structure utilizing coke oven gas for LNG and power cogeneration.

Coke oven gas is a by-product of the process of producing coke from coal and contains valuable compounds such as hydrogen and methane. In this study, an improved process was proposed for co-generation of power and LNG from COG with low CO 2 emissions and high energy and exergy efficiency. This proposed process includes: LNG Recovery Unit, Organic Rankin Cycle, and the power plant. The results of simulation showed that the exergy and energy efficiencies for this proposed process are 77.9% and 70.29%, respectively, which are considerably higher than other studies. It is found that the total exergy destruction of the proposed process is 4272.95 kW, and the power plant with 3118.1 kW exergy destruction has the largest share in total exergy destruction. Additionally, outcomes showed that ORC recovered 1205 kW of waste heat from compressor exhaust gases and produced 167.4 kW of power. Environmental analysis shows indirect carbon emissions for the proposed process is zero. The CO 2 emissions for the total energy and electric power generation were 0.0034 k g C O 2 / M J and 406 g C O 2 / k W h e l , respectively which are lower than coal or natural gas power plants. • A novel structure was proposed to produce power and LNG from Coke oven gas. • This proposed process includes LNG Recovery Unit, Organic Rankin Cycle and the power plant. • Using ORC made cooling utility consumption reach its minimum value. • The proposed process has low carbon dioxide emission. • The energy and exergy efficiencies are 70.29% and 77.9%. [ABSTRACT FROM AUTHOR]