Bio-energy with carbon capture and storage via alkaline thermal Treatment: Production of high purity H2 from wet wheat straw grass with CO2 capture

Abstract Biomass has a unique potential for “negative emissions” of CO2 if carbon capture and storage are integrated into the biomass conversion. While a large body of research has explored biomass conversion, challenges such as low energy density and high moisture content persist. This study proposes and investigates a novel single-step reaction scheme called Alkaline Thermal Treatment (ATT) to convert a real biomass feedstock (e.g. wet wheat straw grass) into high purity H2 in the presence of alkali (e.g., NaOH) at a moderate temperature of 500 °C and ambient pressure. Importantly, negligible CO and a very low percentage of CO2 (0.3%) were detected in the product gas stream, thus rendering gas products from the ATT reaction usable in various applications including fuel cells without further gas purification steps. The solid residue contained a very high percentage of carbonate, confirming the in-situ carbon capture effect.