Enhanced hydrogen production via assisted biomass gasification using lithium manganate as a bifunctional material

Abstract

The rising energy demand, among other economic and technological factors, has resulted in an increase in greenhouse gas emissions. Therefore, it is crucial to develop technologies to produce clean energy, such as hydrogen (H₂) generation from biomass sources. In this context, the use of alkaline ceramics has been reported to show promising results for pyrolysis and gasification processes. Thus, the present study aimed to investigate hydrogen production based on the bifunctional activity of lithium manganate (Li₂MnO₃) using glucose and cellulose molecules as biomass models. Furthermore, the effect of the heating rate and biomass : ceramic molar ratio was evaluated. The results for glucose showed that the addition of Li₂MnO₃ during its pyrolysis highly enhanced and shifted H₂ production to lower temperatures through an assisted gasification process, reducing Mn⁴⁺ ions to Mn³⁺ and Mn²⁺. Besides, solid products evidenced carbon capture, which mainly contributed to improving H₂/CO_x ratios. Thereafter, during cellulose evaluation, under optimal glucose : Li₂MnO₃ experimental pyrolytic conditions, the results corroborated the bifunctional application of the ceramic. Thus, further studies on the biomass assisted-gasification process using modified Li–Mn-based ceramics have significance to enhance the H₂ production and purity, while reducing the emission of carbon oxides.