Abstract:
This research aimed to study the hydrogen production from CO2 gasification of two types of biochar: bamboo char and palm kernel char, in conjunction with a catalytic water gas shift reaction. The experiments were carried out using a two-stage fix-bed reactor, where the upper section operated at 900 °C for gasification, while the lower section facilitated water gas shift reactions at temperatures of 300, 500, and 700 °C, respectively. Calcium carbonate (CaCO3) was employed as a source of carbon dioxide for the CO2 gasification. A NiCu/Al2O3 catalyst, along with calcium oxide (CaO), was used in the lower section for promoting the water-gas shift reaction. The results indicated that using calcium oxide (CaO) adsorbent with the catalyst at a water gas shift temperature of 700 °C achieved the highest hydrogen production and concentration, compared to using only either the catalyst or calcium oxide. This suggests a combined effect of the CaO adsorbent, which captures carbon dioxide, and the catalyst, which enhances the water-gas shift reaction. Furthermore, the results of gas products from the two biochars derived from different types of biomass revealed no significant differences, as they exhibited similar carbon and elemental contents. Additionally, increasing the amounts of calcium carbonate or calcium oxide adsorbent led to further improvements in hydrogen yield and concentration.