Abstract:
Rising energy demand drives increased fossil fuel consumption, exacerbating global warming.
Unsustainable fossil fuel use exceeds dangerous CO2 levels. Since the 1800s, burning fossil
fuels released over 1,100 Gt CO2. Hydrogen fuel has the potential to reduce annual CO2
emissions by 6 gigatons. Biomass-based hydrogen generation is a favorable technique,
contributing to decarbonization. In this study, numerical investigations of the integrated
biohydrogen production process through gasification using sugarcane bagasse as a biomass
source have been presented. Aspen Plus/ Hysys Adsorption software was used for the
simulation and analysis of various processes involved in hydrogen production. Literature
contains descriptions of different components of biohydrogen production processes for various
biomasses. However, there is a lack of comprehensive research that explores the entire
biohydrogen production process with the specific goal of obtaining pure hydrogen from a
particular biomass. Moreover, there is a lack of scholarly studies that specifically investigate
this topic within the context of Pakistan. The purpose of this study is to address this research
gap by providing an integrated analysis of biohydrogen production, specifically focusing on
utilizing the most suitable biomass found in Pakistan as the raw material. The steam-blown
circulating fluidized bed gasifier was fed with biomass residue to obtain the product gas.
Sensitivity analysis of the gasification process revealed that increasing the temperature and
steam-to-biomass ratio positively affect hydrogen production, while an increase in gasifier
pressure has a negative effect on hydrogen production. The product gas was then introduced as
an inlet to the hydrogen enrichment process, where it was processed to remove hydrocarbon
content and underwent water gas shift reaction to obtain the hydrogen rich synthesis gas
containing 61.7% hydrogen by volume. Parametric analyses of the enrichment process showed
that the lower inlet temperature of the water gas shift reactor and higher steam flow rate favours
the hydrogen enrichment process. Finally, the synthesis gas was passed through the pressure
swing adsorber yielding hydrogen with a purity exceeding 99%. Parametric analysis of the
purification process disclosed that higher adsorber pressure and lower syngas flow rate result in
delayed breakthrough points. Overall, sugarcane bagasse possesses significant potential for
hydrogen production in Pakistan.
