Coking dry gas-derived hydrogen for H2/CO ratio tuning of syngas in petroleum coke/biomass chemical looping gasification to olefins

To achieve energy saving and carbon reduction in olefins production from petroleum coke, this study proposes and constructs three integrated processes featuring synergistic multi‑dimensional utilization of resources. A coking dry gas-to-hydrogen unit is introduced as an independent module to adjust the H 2 /CO ratio of the petroleum coke-derived syngas and to couple with the methanol-to-olefins process. Initially, this study constructs two systems of coupling coking dry gas steam reforming or chemical looping hydrogen with petroleum coke chemical looping gasification for olefins production. Then, a system of coupling coking dry gas chemical looping hydrogen with petroleum coke-biomass chemical looping gasification for olefins production is further designed to improve the conversion of petroleum coke. The techno-economic performance of the three coupled systems is evaluated. Under the coking dry gas fuel mode, the coking dry gas chemical looping hydrogen coupled with petroleum coke-biomass chemical looping co-gasification for olefins production system achieves an energy efficiency of 53.33% and a carbon utilization efficiency of 48.25%. These values are 1.40 and 4.82 percentage points higher in energy efficiency and 0.63 and 4.09 percentage points higher in carbon utilization efficiency than those of the other two systems. The integrated system achieves a levelized cost of olefins of 905 US $/t and a payback period of 5.9 years.