Improved hydrogen production through steel slag-based heat recirculating system integrated with catalytic lignocellulosic biomass

The efficient hydrogen production from lignocellulosic biomass greatly alleviates environmental pollution and optimizes energy structure. To improve the thermal conversion efficiency of biomass, a novel porous media combustion system was proposed by combining the industrial solid waste of steel slag and pretreated wood. The effects of steel slag parameters on biomass combustion characteristics were investigated under different operating conditions. And the alkali with different metal types and ionic concentrations was utilized to enhance the combustion efficiency of biomass. Results indicated that the addition of steel slag significantly increased the combustion temperature and syngas production. And the maximum hydrogen was obtained when steel slag was located downstream. With the increasing of steel slag content, the mole fraction of hydrogen increased first and then decreased. Furthermore, the inlet velocity greatly increased the combustion temperature and reaction rate. Compared to the None group, the addition of caustic solutions reduced the combustion temperature and obviously shortened the preheating time. And the hydrogen was improved with the maximum values of 14.8% and 12.9% after Na2CO3 and K2CO3 solutions pretreatment, which also achieved the maximum H2/CO of 1.07 and 1.02. The corresponding results provided theoretical guidance for the efficient utilization of biomass and green hydrogen production.