Optimizing the operating conditions for hydrogen-rich syngas production in a plasma co-gasification process of municipal solid waste and coal using Aspen Plus

Abstract

The plasma gasification process is one of the newest and most innovative approaches to meet the needs of waste management but requires assessment and research on operational conditions prior to installation. In this work, a model based on Gibbs free energy minimization was developed and implemented in Aspen Plus®. A combination of municipal solid waste (MSW) and coal has been used as feedstocks. The model's performance was compared with the results of the literature and found to be in good agreement. The effect of various parameters such as temperature, equivalence ratio, MSW/coal blending ratio, and steam-to-feedstock ratio on the composition of syngas and hydrogen production were assessed. Very interesting results were obtained concerning the mixture of the feedstocks that maximize the hydrogen production besides that using steam as a gasifying agent allows higher hydrogen production than using air. When using high amounts of coal in the feedstock mixture, low steam ratios are preferred. When using high amounts of MSW in the feedstock mixture high steam ratios are preferred. The use of pure oxygen as the gasifying agent increases the hydrogen percentage but requires an air separation unit to be included in the process. The results obtained in this study are particularly relevant for countries with coal reserves.