THE ROLE OF VOLATILE COMPONENTS IN THE PROCESS OF THERMAL DESTRUCTION AND IGNITION OF THE SUNFLOWER HUSK BIOMASS

Abstract

The final composition of volatile components in the process of oxidative pyrolysis depends on the temperature level of the process. The gas output increases with the growth of hydrogen, methane and heavy hydrocarbons concentration in the process of pyrolysis in the range of 200-500°C. In this case, there is a noticeable decrease in undesirable impurities in the output of carbon dioxide and nitrogen in the fuel gas. The obtained data on the dynamics of thermal decomposition of biomass under heating conditions reflect the complex dependence of the yield of total gas individual components both on time and on the temperature of the process. The more volatiles contained in the source fuel, (the other things being equal) the faster the gas mixture ignites, and the more intensely it burns out. The composition and temperature of the gas mixture affects the pressure drop and auto-ignition temperature in the pyrolysis chamber. It was found that the lowest self-ignition temperature of a gas mixture is 490°C. A series of experiments to determine the critical condition for self-ignition at a constant temperature of 490°C and various initial pressures of the mixture (100-300 kPa) was carried out. It was found that the transition from a smooth increase in pressure of 90 kPa to an explosive one (up to 300-400 kPa) depends on the composition and temperature of the gas mixture. Therefore, the composition of the gas and its ignition temperature can be controlled by adjusting the mode of pressure increase in the reactor.