Flame speed and Kst reactivity data for pulverised corn cobs and peanut shells

Power generation using waste material from the processing of agricultural crops can be a viable biomass energy source. However, there is scant data on their burning properties and this work presents flame speed and explosibility data for two agricultural waste materials: corn cobs (CC) and peanut shells (PS). The parameters were measured on the modified 1 m3 dust explosion equipment. Two coarse size fractions of corn cobs and peanut shells of size less than 500 μm were tested using the Leeds 1 m3 vessel and were compared with two pulverized coal samples. This is typical of the size fraction used in pulverized coal power stations and of pulverized biomass currently used in power generation. The explosion parameters minimum explosible concentration (MEC), rate of pressure rise (dP/dt), deflagration index (Kst), peak to initial pressure rise (Pm/Pi), turbulent and laminar flame speeds were determined using a calibrated hemispherical disperser in the 1 m3 vessel. MEC were measured in the range of 0.6–0.85 (based on 0% ignition probability) in terms of burnt equivalence ratio, Oburnt, which were comparable to the coal samples. The measured Kst (25–60 bar m/s) and turbulent flame speeds (∼1.3 m/s) were lower than for coal, which was a reflection of the lower calorific value. These results showed that these crop residues are technically feasible power plant fuels to burn alongside coal or as a renewable biofuel on their own.