Changing and Transferring Property of Chlorine in Co-pyrolysis of Waste Plastics and Coal

The co-pyrolysis process of coal and waste plastics was studied. Changing and transferring property of chlorine in the process was investigated. There was synergistic effect between coal and waste plastics when chlorine was released, which resulted in increase of chlorine in tar and decrease in coke. The effect of waste plastics' amount on chlorine releasing property varied with the amount of waste plastics in the sample and the time of constant temperature at the same final co-pyrolysis temperature (such as 950 degrees C). Using the distributional function of chlorine, the distribution of chlorine in coke, tar and gas was studied. The results indicated that the distribution of chlorine in the co-pyrolysis process could be controlled to a certian extent by controlling the percentage of waste plastics and the time of constant temperature. The amount of chlorine redistributed in coke decreases with the increase of constant temperature time and increased with the increase of the percentage of waste plastics. On the contrary, the chlorine in tar increased with the increase of the constant temperature time and the percentage of waste plastics. And the chlorine redistributed in gas increased with the increase of the constant temperature time, but it decreased when the percentage of waste plastics increased. Additionally, the mathematical model of chlorine changing and transferring rule was established.