Techno economical assessment of a low-carbon hydrogen production process using residual biomass gasification and carbon capture

Abstract

Aiming to mitigate the environmental impact derived from fossil fuels, we propose an integrated carbon capture-biomass gasification process is proposed to produce low-carbon hydrogen as an alternative energy carrier. The process begins with the pre-treatment of empty fruit bunches (EFB), involving grinding, drying, torrefaction, and pelletization. The resulting EFB pellet is then fed into a dual gasifier, followed by a catalytic cracking of tar and water gas shift reaction to produce syngas, aiming to increase its H2 to CO ratio. Subsequently, we explore two alternatives (DEPG and MEA) for syngas upgrading by removing CO2. Finally, a PSA system is modeled to obtain H2 at 99.9% purity. The pre-treatment stage densifies the biomass from an initial composition (%C 46.47, %H 6.22, %O 42.25) to (%C 54.10, %H 6.09, %O 28.67). The dual gasifier operates at 800�C, using steam as a gasifying agent. The resulting syngas has a volume concentration (%CO 20.0, %CO2 28.2, %H2 42.2, %CH4 5.9). Next stages of the process focus on removing the CO2 and increased H2 through catalytic reactions from the syngas. Thus, the DEPG carbon capture process can decrease the CO2 concentration to 2.9%, increasing the hydrogen to 95.6% in volume. In contrast, the MEA process reduces the concentration of CO2 to 5.2% and increases the concentration of H2 to 93.1%. Moreover, we estimate a levelized costs of hydrogen (LCOH) and carbon capture cost for each method (DEPG and MEA) (LCOC) and CO2 avoided (LCCA). LCOH: 3.05 USD/kg H2, LCOC: 92 and 59 USD/t CO2 and 183 and 119 USD/t CO2, for DEPG and MEA respectively.