Continuous Ozonolysis Process To Produce Non-CO Off-Gassing Wood Pellets

Abstract

Prior work on the mechanism of carbon monoxide (CO) formation from stored wood pellets has provided the basis for a continuous process that results in the production of pellets that do not off-gas CO. It had been shown that exposure to ozone eliminated the unsaturated hydrocarbons that autoxidize to produce hydroxyl radicals, which, in turn, react with the hemicellulose to produce CO. To develop a practical process to eliminate the CO formation, a kinetic study of the continuous ozonolysis of wood fiber was conducted using a small materials auger. The reaction was found to follow a pseudo-first-order reaction such that the reduction in CO emissions was linearly proportional to the ozone exposure (concentration × time). The exposure needed to reduce or eliminate the formation of CO from the exposed fiber was around 42 000 ppm min at a flow rate of 0.57 kg/min of fiber or approximately 0.032 g of O3/kg of fiber to be passivated. The volatile organic compounds produced during the ozonolysis of fiber were ana...