Oxidative pyrolysis of plywood waste: Effect of oxygen concentration and other parameters on product yield and composition

Introducing a small amount of oxygen into the inert carrier gas will not only cause partial oxidation reaction, but also significantly change the composition and distribution of biomass pyrolysis products. The oxygen concentration greatly affects the balance between oxidation reaction and pyrolysis reaction. Therefore, it is very important to clarify the influence of oxygen concentration and other reaction conditions on oxidative pyrolysis. The results showed that the pyrolysis products yields remain constant when the oxygen concentration in the carrier gas ranges from 0 to 3 vol%; however, between 3 to 10 vol%, oxygen reacts with biochar to generate noncondensable gas and release heat, and the mass yield of bio-oil slightly declines. Compared with N2 atmosphere, the temperature corresponding to the maximum weight loss peak of pyrolysis under 10 vol% oxygen concentration shifts from 352.5 degrees C to 292.1 degrees C. With 10 vol% oxygen in the carrier gas, most of the oxygen transfers to non-condensable gas (6.8 vol%) and water (3.2 vol%). The proportion of 0-140 Da (acids, ketones, furans, BTX) in bio-oil decreases significantly. The biochar more porous structure and oxygen-containing functional groups. The study revealed the complex interactions among various parameters in oxidative pyrolysis.