Hydrogen production from organic waste in Bangladesh: Impacts of temperature and steam flow on syngas composition

Abstract

More than 0.13 million tons of waste are generated annually, making conventional methods of treatment including anaerobic digestion, incineration, and landfilling insufficient.Thus, a long-term solution is required.Therefore, this study used a process modeling through Aspen Plus V11 to investigate how variations in waste types and gasification temperatures affect the ability to producing hydrogen. Additionally, the use of a Steam Rankin Cycle has been used to optimize the economy through generation. To explore the potential of various type of waste, proximate and Ultimate analysis have been done experimentally in lab and some of them (Rice Husk, Rice Straw, Sugar-cane Baggage, Cow-dung etc.) have been taken from references. This study presents validation against experimental data using dolomite and olivine as bed materials. The model showed strong agreement with experimental results, accurately predicting hydrogen concentration, CO, and CO₂. A detailed thermodynamic analysis revealed an increase in hydrogen purity from 50.9 % in raw syngas to 100 % after pressure swing adsorption (PSA), accompanied by an exergy reduction from 48.99 MW to 34.68 MW due to separation and thermal losses. Parametric studies demonstrated that gasification temperatures between 750 °C and 800 °C and steam-to-biomass ratios of 0.4–0.5 optimize hydrogen production. Feedstock type significantly influenced performance; rice straw, rice husk, jute stick, and cow dung exhibited higher hydrogen yields compared to food waste. The model predicted a hydrogen production rate of approximately 1020  kg/h per ton of dry feedstock, with an overall system efficiency of 48.5 % based on exergy analysis.