Co-Pyrolysis of Rice Husk and Chicken Manure

Abstract The increase in the production scale of chicken causes an increment in the produced manure. Chicken manure is considered an excellent soil amendment due to the high nitrogen and phosphorous content. However, the high production of manure exceeds the soil requirements. Rice husk is a by-product of rice production. Approximately one hundred forty million tons of rice husk is produced per year worldwide. There are several ways to manage rice husk such as animal bedding, direct combustion, or as a soil fertilizer. The husk's ashes are suitable for construction or as reinforcing material due to the high silica content. However, rice husk has a low volatile matter and high silica content, which makes processes like direct combustion inefficient. Thermochemical processes (such as pyrolysis and gasification) are effective ways to manage waste. The present study investigates the co-pyrolysis of chicken manure and rice husk. The experiments were conducted in a non-isothermal gravimetrical analyzer using nitrogen at a flowrate of 100 ml/min at three different heating rates (5, 10, and 15 °C/min). The degradation of individual biomass and biomass blends is investigated. The kinetic parameters are calculated using the Friedman method. Results show a positive synergetic effect for mixing ratios greater than 20% rice husk. The mixing ratio of 40% of rice husk manifested the best performance among all blends. This mixture showed the minimum energy of activation (90.2 kJ/mol). Also, the 40% rice husk mixing ratio showed maximum conversion when compared with chicken manure's conversion.