Catalytic pyrolysis for upgrading silver grass (Miscanthus sinensis) and carbon dioxide into flammable gases

This study proposes a sustainable hydrogen production platform using a fast-growing and inedible biomass waste, silver grass (Miscanthus sinensis). Pyrolysis of silver grass waste (SGW) was investigated using CO₂ as a co-feedstock, focusing on the distribution of hydrogen in different products. When the catalyst was absent, hydrogen element distribution to H₂ gas during pyrolysis of SGW at 800 °C reached 10 wt%. During pyrolysis with the Ni/SiO₂ catalyst, 60.3 wt% of hydrogen was converted into H₂ gas, and 7.3 wt% of hydrogen was distributed in gaseous hydrocarbons at 600 °C. Owing to the addition of CO₂, CO production was promoted by the catalytic conversion of CO₂ and volatile matter. Notably, CO₂ has been proven to be a useful reactant for producing value-added CO. Thus, catalytic pyrolysis in the presence of CO₂ can be considered as a renewable approach to produce flammable gases with the mitigation of CO₂ emissions.