Enhancement of synthesis gas production using gasification-plasma hybrid system

The gasification of a high density polyethylene (HDPE) was conducted by a hybrid gasification system which is divided into a gasification reactor and a plasma reactor. HDPE pellets were injected into the gasification reactor at the feeding rate of 22 g/min. In the gasification reactor, HDPE were converted into gas phase with the help of oxygen and steam additives. Nitrogen thermal plasma was operated at 3 kW in the plasma reactor to enhance syngas production by gas reforming and thermal cracking. Produced gases from each reactor were analyzed to examine chemical reactions in each stage. A high yield of syngas was achieved in virtue of enhanced gasification reactions in the thermal plasma reactor, while the gasification reactor was operated at the durable condition of atmospheric pressure and low temperature of about 900 K. In the gasification, CH4 was produced from the decomposition of raw material and methanation reaction. In the plasma reactor, however, the amount of CH4 was decreased obviously due to the oxidation, reforming and decomposition of hydrocarbon. Therefore, the yield of syngas was improved from 17.66 g/min to 28.46 g/min in HDPE gasification with oxygen additive and from 17.89 g/min to 25.80 g/min with oxygen and steam additives, respectively.