Keywords: pyrolysis biomass oil, thermal oxidation stability, GC-MS, chain reaction, rice husks, gas flux, oxidation time, temperature, copper foil, biomass oxidation, renewable energy
On the thermal oxidation stability of pyrolysis biomass oil
The rice husk-based biomass-oil is composed of complex organic compounds and water, and its oxidation stability has a direct influence on its physico-chemical property and application. The advanced oxidation experiments were carried out through the flowing of air and oxygen respectively. The influences of four factors, including gas flux, oxidation time, temperature and copper foil, on the oxidation process of rice husk-based biomass-oil, by measuring the pH value variation and the weight of deposit before and after oxidation were studied. The results showed that the pH value of biomass-oil decreased slowly with the increases of the gas flux and operation time. The presence of copper in the oil made the sediment weight increase after oxidation. Based on the GC-MS analyses of the compositions of biomass-oil before and after oxidation, it was found that the acetic acid was the main component in the oxidised biomass-oil, which was attributed to the pH value decrease of biomass-oil after oxidation. At the same time the content of phenolic compound was also increased compared with that before oxidation. It was also proposed a chain-reaction-based mechanism for the biomass oxidation.