Chemical looping co-gasification of wheat straw and lignite with calcium-enhanced iron-based oxygen carrier for syngas production

The use of biomass to partially replace fossil fuels to produce syngas is an effective way to reduce net CO2 emissions. The chemical looping co-gasification of wheat straw and lignite with iron-based oxygen carrier (OC) was studied using a thermogravimetric analyzer (TGA) and a fixed-bed reactor. TGA results provided evidence of interaction between the wheat straw and lignite at a mass ratio of 1:1. Further, the effects of temperature, oxygen carrier/mixed feedstocks (OC/MF) ratio, steam/mixed feedstocks (S/MF) ratio, and CaO /mixed feedstocks (CaO/MF) ratio in the fixed-bed reactor were investigated. The results showed that the optimal product distribution was achieved under the conditions of 950 °C, OC/MF = 1, S/MF = 4, and CaO/OC = 0.75. The H2/CO ratio of the syngas was in the range of 1.84–1.93. This work provides a new strategy for preparing syngas with high yield and low greenhouse gas emissions.