Enrichment of hydrogen in product gas from a pilot-scale rice husk updraft gasification system

Abstract

An updraft gasifier was employed to treat 3 kg of dried rice husk per batch with different types of gasifying agents such as air, steam/air, and air with dolomite catalyst addition at various operating conditions. The H2 content, low heating value, and H2/CO ratio in syngas were compared to determine the most effective solution to enhance the H2 production from rice husk gasification. The presence of dolomite in air gasification produced the highest H2 content in the product gas, up to 15.4 mol%, followed by 7.08 and 3.6 mol% when steam/air and air standalone were used as gasifying agents, respectively. The higher low heating value of syngas 5.1 MJ/Nm3 was observed in catalytic air gasification compared to 3.6 MJ/Nm3 when steam was added. The optimal operation condition was reported at an airflow rate of 3 m3/h and a catalyst mixing ratio of 15 %.

Keywords

• Rice husk
• Enriched hydrogen syngas
• Dolomite
• Updraft gasifier