Investigation on the characteristics of pyrolysates during co-pyrolysis of Zhundong coal and Changji oil shale and its kinetics

Abstract Xinjiang province, China, contains abundant Manasi coal and Changji oil shale resources. While, Manasi coal is rich in AAEMs and Changji oil shale has low oil yield. Therefore, the co-pyrolysis technique of Manasi coal and CJR oil shale is adopted to achieve the purpose of increasing the pyrolysis oil and gas yields. The results revealed that oil and gas yields were improved during co-pyrolysis, and when the proportion of Manasi coal was 5%, the oil and gas yields were increased by 8.20% and 2.65%, respectively. The concentrations of H2 and CH4 in the co-pyrolysis gas were higher than the weighted values. And, the relative content of short-chain aliphatic hydrocarbons increased in the pyrolysis oil of mixed fuels, leading to the conversion from heavy oil to light oil. The prediction model of oil yield during co-pyrolysis was proposed. When the proportion of Manasi coal was 10%, the synergistic index of co-pyrolysis was the highest. In addition, the synergy during co-pyrolysis occurred when the temperature exceeded 455 °C, which originated from the catalytic effect of AAEMs. When the conversion rate exceeded 0.5, the E values of MF1 and MF2 were lower than individual fuels during pyrolysis, and synergistic and catalytic effect occurred.