To resolve problems surrounding simultaneous CO2 conversion and COG (coke oven gas) utilization, a novel system combining a dual-gas of CGG (coal gasified gas) and COG with the technology of CO2 recycling into a single gasifier and reforming unit is proposed. 3E performance (energy, environmental, and economic) analysis showed that this novel system renders unnecessary the traditional water gas shift process, and realizes the conversion and utilization of CH4 and CO2 that would otherwise be directly discharged into the air. Under a weak carbon mitigation policy, the economics of co-producing low-carbon fuels and electricity from a dual-gas of CGG and COG are promising. The "dual-gas" technology is a potentially viable option for clean coal and its efficient use in the co-production of low-carbon fuels and electricity in areas possessing COG, natural gas or other unconventional natural gas resources. (C) 2014 Elsevier Ltd. All rights reserved.