This work presents the experimental studies of acacia woodchip gasification in a downdraft gasifier with two stages air supply. The effects of oxygen concentration in gasified agent on the temperature of gasifier, the syngas composition, the lower heating value and tar content in the producer gas are investigated. Results indicate that oxygenenriched air rate not only favors to reduce tar component but also improves the heating value of the producer gas. | Vietnam Journal of Chemistry, International Edition, 55(4): 465-469, 2017 DOI: The effect of combustion temperature to low-tar gas production using oxygen-enriched air Dinh Quoc Viet1,4, Nguyen Van Vinh1, Nguyen Tien Cuong3, Pham Hoang Luong2, Van Dinh Son Tho2* 1 2 School of Chemical Engineering Vietnam Japan International Institute of Science for Technology 3 School of Heat Engineering and Refrigeration, Hanoi University of Science and Technology 4 Faculty of Chemistry, Quy Nhon University Received 7 November 2016; Accepted for publication 28 August 2017 Abstract Tar content in producer gas from biomass gasification is a serious problem for fuel gas utilization in downstream applications. This work presents the experimental studies of acacia woodchip gasification in a downdraft gasifier with two stages air supply. The effects of oxygen concentration in gasified agent on the temperature of gasifier, the syngas composition, the lower heating value and tar content in the producer gas are investigated. Results indicate that oxygenenriched air rate not only favors to reduce tar component but also improves the heating value of the producer gas. When increasing oxygen concentration from 21 vol.% to 42 vol.% in the gasified agent, the tar content of the producer gas decreases from mg/Nm3 to 30 mg/Nm3, hydrogen concentration increases from to vol.%, CO concentration increases from vol.% to vol.%, CH 4 concentration increases from to vol.% and the low heating value increases from MJ/m3 to MJ/m3, respectively. On the other hand, the carbon conversion efficiency, gasification efficiency and gas yield of the gasifier are also presented in this approach. Keywords. Downdraft gasification, acacia woodchip, tar content, oxygen-enriched air. 1. INTRODUCTION Global climate change due to CO2 emissions is currently debated around the world. This issue have become a major concern and has encouraged .
