The coke-oven gas (COG)-to-natural gas (CGtNG) is a promising process of chemical industry. However, the CGtNG suffers from low hydrogen utilization efficiency and natural gas capacity due to the high ratio of hydrogen to carbon of the COG. The CO2 derived from chemical looping hydrogen process can be an effective carbon source to optimize syngas composition for high efficient natural gas production. Therefore, a novel process of COG chemical looping hydrogen assisted COG-to-natural gas (CG(CLH)-CGtNG) is proposed in this paper. The key parameters are optimized for maximizing COG utilization and natural gas production in the novel process. Results show that the novel process could solve the issues of CO2 utilization in the chemical looping hydrogen process and low natural gas production in the CGtNG. At the cost of additional 4.36 t/h COG consumption, the novel process produce about 19% more natural gas and additional 1.39 t/h hydrogen compared with the conventional CGtNG process. The corresponding hydrogen utilization and exergy efficiencies of the novel process are increased from 61.1% to 78.5% in the CGtNG to 82.4% and 87.6% through intensive mass and energy integration, respectively. (C) 2018 Elsevier Ltd. All rights reserved.