Technoeconomic and life-cycle assessment of biomass-to-hydrogen conversion via a compact fluidized bed calcium looping gasifier.

As the global greenhouse effect intensifies, there is an urgent need for green energy to replace traditional fossil fuels in industries like chemicals and energy. This work explores the potential of biomass, a carbon-negative energy source, to reduce the greenhouse effect through sorption-enhanced biomass gasification. The objective of the study is to evaluate the technoeconomic and environmental performance of a biomass-to-hydrogen (BTH) process utilizing a compact fluidized bed gasifier, in comparison with an alkaline water electrolysis (AWE) system. A sensitivity analysis was conducted on the key technical factors influencing the cost of hydrogen production via electrolysis, aiming to identify the critical factors driving the cost difference between electrolysis-based and biomass-based hydrogen production systems. The hydrogen production capacity of the system is 20,000 Nm3/hr. The results of the technoeconomic analysis indicate that the BTH system results in lower hydrogen production costs, 2.93 $/kg for zero CO2 revenue for negative carbon emissions, potentially decreasing to 1.8 $/kg with CO2 revenue at 60 $/t, compared to AWE's 2.94 $/kg. Moreover, BTH achieves significantly better greenhouse gas (GHG) emission reduction, with life cycle emissions of 3.25 kg CO2eq/kg H2 for zero emissions and -17.75 kg CO2eq/kg H2 for negative emissions, compared with AWE's 1.1 to 4.6 kg CO2eq/kg H2. Our research demonstrates the superior potential of BTH systems over PTH systems in reducing greenhouse gas emissions, highlighting their promise in advancing hydrogen energy production towards more sustainable and efficient practices.