This paper proposes a novel multi-functional energy system (MES), which co-generates coke, hydrogen, and power, through the use of coal and coke oven gas (COG). In this system, a new type of coke oven, firing coal instead of COG as heating resource for coking, is adopted. In this method, the coal is substituted for COG and can be considered as transforming it into coal gas indirectly only by burning instead of gasification. The COG rich in H2 is sent to a pressure swing adsorption (PSA) unit to separate about 80% of hydrogen firstly, and then the PSA purge gas is fed to a combined cycle as fuel. The new system combines the chemical processes and power generation system, along with the integration of chemical conversion and thermal energy utilization. In this manner, both chemical energy of fuel and thermal energy can be used more effectively. With the same inputs of fuel and the same output of coking heat, the new system can product about 65% more hydrogen than that of individual systems. As a result, the thermal efficiency of the new system is about 70%, and the exergy efficiency is about 66%. Compared with conventional systems, the primary energy saving ratio can reach as high as 12.5%. Based on the graphical exergy analyses, we disclose that the integration of synthetic utilization of COG and coal plays a significant role in decreasing the exergy destruction of the MES system. The promising results obtained may lead to a clean coal technology that will utilize COG and coal more efficiently and economically.

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