Experiments and analysis of propagation front under gasification regimes in a packed bed

• Experimental analysis on propagation rate under gasification conditions
• Flame front propagation rate initially increases as the air mass flux increase.
• Further increase in air mass flux results in decrease in propagation rate.
• Bed movement increases with the increase in air mass flux.
• Physical properties of fuel have an impact on propagation front movement.

The paper analyses the results of experiments on the propagation rate in a fuel bed under gasification conditions in a co-current reactor configuration. Experiments using wood chips with different values of moisture content have been conducted under gasification conditions. The influence of air mass flux on the propagation rate, peak temperature and gas quality is investigated. It is observed from the experiments that the flame front propagation rate initially increases as the air mass flux increased, reaching a peak propagation rate, and further increase in the air mass flux results in a decrease in the propagation rate. However, the bed movement increases with the increase in air mass flux. The experimental results provide an understanding on influence of the fuel properties on propagation front. The surface area per unit volume of the particles in the packed bed plays an important role in the propagation rate. It has been argued that the flaming pyrolysis contributes towards the flame propagation as opposed to the overall combustion process in a packed bed. The calorific value of the producer gas generated is nearly the same over the entire range of air mass flux for bone-dry and 10% moist wood.