International Journal of Hydrogen Energy, Vol.45, No.15, 9098-9112, 2020
Gasification of low-melting hydrocarbon material in the airflow heated by hydrogen combustion
The airflow heated by combustion of hydrogen-oxygen mixture to a temperature ranging from 300 to 1500 K is used for the gasification of a low-melting hydrocarbon material - polypropylene (PP) in a flow-type reactor. The yield of PP gasification products is shown to increase with the airflow temperature. At temperatures up to 1200 K, the yield of PP gasification products attains 19.7 g/s and the ratio of the mass flow rates of air and PP gasification products attains 19.7 g/s and the ratio of the mass flow rates of air and PP gasification products attains a value of 1.8. The presence of oxygen in the airflow allows increasing the yield of the gasification products due to the subsequent combustion of PP which ensures the gasification process at low airflow temperatures. Only short-time ignition with help of hydrogen-oxygen mixture combustion is required at the airflow temperature of 300 K. At these conditions, the yield of PP gasification products attains a value of 8.5 g/s and the ratio of the mass flow rates of air and PP gasification products is 5.0. An analytical model is proposed for calculating the characteristics of the PP gasification process with PP combustion taken into account. The results of calculations agree with the experimental data within an accuracy of 2%-4%. Further estimates indicate that the minimum possible ratio of the mass flow rates of air and PP gasification products can attain 0.34 with an increase in the airflow temperature to 3000 K. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.