Gasification of Municipal Solid Waste

Gasification has been developed as an alternative method for producing cleaner energy. However, over 1,400 unit of operating gasifiers are using coal as energy source, while only 200 unit of gasifiers are using biomass and waste as feedstock (Higman in State of the Gasification Industry: Worldwide Gasification and Syngas Databases 2016 Update, 2016.). Feedstock used for gasification process became a main concern to ensure the process produce clean energy from renewable source. Gasification for treating municipal solid waste (MSW) considered as a promising method to solve environmental and energy production problems as it eliminates MSW and generates clean energy at the same time. The gasification process converts MSW into syngas mixture consist of carbon monoxide (CO), hydrogen (H2) and carbon dioxide (CO2), methane, and water vapour (Mondal in International Journal of Hydrogen Energy 47 20064–20075, 2022; Wiyono et al., in Case Studies in Thermal Engineering 20 1–11, 2020), that can be used as fuel for a gas turbine (Mazzoni et al., in Energy 196, 2020). Gasification process needs medium or gasifiying agent to sustain the process, such as oxygen or air and steam. MSW gasification in the presence of air can generate syngas contained 12% of H2 with lower heating value (LHV) ranged between 2 and 6 MJ/Nm3 (Couto et al., 2015) and syngas contains about 19% of H2 (Ozturk & Dincer in International Journal of Hydrogen Energy 46 6251–6261, 2021). While steam gasification can increase H2 gas in syngas mixture significantly up to 55% with higher calorific value of about 13 MJ/Nm3 (Wang et al., in International Journal of Hydrogen Energy 37 6503–6510, 2012). However, there are some challenges in treating MSW using gasification process which are regarding undesirable CO2 production and tar formation. Both problems related to improvement of syngas quality and can be solved by catalyst use.