Assessment on steam gasification of municipal solid waste against biomass substrates

• Steam gasification as an alternative for MSW treatment was studied.
• A previously developed numerical model for MSW gasification was used.
• Results were validated with data gathered from the literature.
• Results were compared with previously studied biomass substrates.
• Environment and economic assessment based on the results was conducted.

Waste management is becoming one of the main concerns of our time. Not only does it takes up one of the largest portions of municipal budgets but it also entails extensive land use and pollution to the environment using current treatment methods. Steam gasification of Portuguese municipal solid wastes was studied using a previously developed computational fluid dynamics (CFD) model, and experimental and numerical results were found to be in agreement. To assess the potential of Portuguese wastes, these results were compared to those obtained from previously investigated Portuguese biomass substrates and steam-to-biomass ratio was used to characterize and understand the effects of steam in the gasification process. The properties of syngas produced from municipal solid waste and from biomass substrates were compared and results demonstrated that wastes present the lowest carbon conversion, gas yield and cold gas efficiency with the highest tar content. Nevertheless, the pre-existing collection and transportation infrastructure that is currently available for municipal waste does not exist for the compared biomass resources which makes it an interesting process. In addition a detailed economic study was carried out to estimate the environmental and economic benefits of installing the described system. The hydrogen production cost was also estimated and compared with alternative methods.