A parametric study on hydrogen production by fluidized bed co-gasification of biomass and waste plastics

This paper presents a parametric study on hydrogen production potential from biomass and waste plastics via fluidized bed co-gasification technique by using different gasifying agents such as steam, air and CO2. In this regard, a new Aspen Plus model representing this process was developed. For this purpose, first, a comparative feedstock selection between several materials was performed, ultimately identifying the cotton husk (CH) and high-density polyethylene (HDPE) mixture as the most promising choice. Secondly, the study focused on steam co-gasification of CH with HDPE to assess the impact of various factors, including plastic content in feedstock, temperature, steam to feedstock ratio (S/F), and the introduction of gasifying agents, namely air and CO2, next to steam. The analysis mainly examined the influence of these parameters on the composition of syngas, calorific value, and the hydrogen production. Accordingly, it was determined that an increase in plastic content and S/F ratio resulted in higher hydrogen concentration in the syngas, and the maximum quantity of H2 with 1189.3 Nm3/ton feed was produced at 900 °C. In addition, co-utilization of air or CO2 with steam as a gasifying agent deteriorated the system performance regarding H2 yield. Thus, it is expected that the model developed will contribute to the researchers, investors, engineers and policy maker working on the gasification technology for hydrogen production.