Integrated CO2-hydrothermal carbonization and high temperature steam gasification of bamboo feedstock: A comprehensive experimental study

Abstract

This study investigated an integrated CO2-hydrothermal carbonization (CO2-HTC) and steam gasification of bamboo feedstock, an abundant biomass in Vietnam. Bamboo underwent CO2-HTC at 240 °C under 100% CO2 atmosphere with a biomass-to-water ratio of 1:4 and a residence time of 60 min. The resulting hydrochar served as feedstock for steam gasification at 900 °C under an atmosphere of 40% H2O and 60% N2. A parallel experiment using raw bamboo provided a basis for comparison. Results indicate notable enhancements in fixed carbon content, bulk density, and higher heating value of bamboo subsequent to CO2-HTC. The CO2-HTC bamboo displayed a higher maximum decomposition rate. Its char also showed quicker conversion, enhancing gasification efficiency. A syngas richer in both H2 and CO by 2% was also produced with CO2-HTC bamboo compared to the raw bamboo. The observed improvements in gasification performance suggest promising avenues for the more effective and sustainable utilization of bamboo in energy production.