Influence Of Co-Pyrolysis And Catalysis Of Biomass With Waste Tires On The Liquid Properties

The liquid from biomass pyrolysis is mainly comprised of many oxygen-containing organic compounds, for instance, phenol, methylphenol, C₁₀-C₁₆ hydrocarbons, and aromatic hydrocarbons. There are still many difficulties in acting as fuel for the liquid from biomass pyrolysis containing higher amount of oxygen, strong eroding property for the engine, igniting delay, storing instability etc though oxy-fuel maybe be a green fuel for motor vehicles in the future. In addition, the liquid from waste tiers pyrolysis contains higher PAHs that is limited for fuel. These problems are brought due to the element composition of raw materials, which contain higher ratio of hydrogen and oxygen for biomass and contain higher amount of carbon for waste tires. And these problems cannot be overcome by their alone pyrolysis either biomass or waste tires in order to meet the requirements as a dynamic fuel. Co-pyrolyzing for biomass with waste tires that change their mixture ratio by means of adjusting proportion of materials perhaps improves the liquid property as a fuel, further enhances the using value of biomass and waste tires. Co-pyrolysis increases the gas yield, reduces the liquid and solid yields;The existence of catalysis may increase gas yield also, reduce liquid yield, butchange the range of gas and liquid yield correlating to the molecular sieveaperture. Observing the variation for limonene, PAHs and oxygen content in theliquid, the experiment demonstrates that the limonene and PAHs contents arelower than that of calculated value obtained through individual pyrolysis, andoxygen content is higher than that of calculated value through individualpyrolysis. Through co-pyrolyzing for the mixture of biomass and waste tires,synergetic effect for some components may take place. Analysis for theco-pyrolysis oil from the point of view about fuel oil quality indicates thatco-pyrolysis can overcome the shortcomings of lower heat value from the liquidof pyrolysis biomass. When the materials ratio is suitable, the heat value ofliquid from co-pyrolysis nears to diesel oil's. Catalysis can influence the heatvalue of liquid. Comparing with diesel oil, the viscidity and density of liquidfrom co-pyrolysis of biomass with waste tires are higher. The catalysis canremarkably reduce the viscidity and density of liquid from co-pyrolysis ofbiomass with waste tires. Although the existence of HZSM-5, MCM-41,SBA-15 all can reduce the viscidity and density of the liquid, these are higherthan that of diesel. Molecular weight distribution of liquid from single-pyrolysisbiomass and waste tires is different. Co-pyrolysis liquid make for adjustingmolecular weight distribution of liquid that nears to that of diesel or gas oil. So,it can improve the liquid quality through co-pyrolysis. TG analysis of pyrolysis oil indicates that the volatility of co-pyrolysis oil is better than diesel, but the low boil point fraction and high boil point fraction are still higher than that of diesel, in which SBA-15 exhibits more obvious role in reducing high boil point fractions than MCM-41. In conclusion, the co-pyrolysis oil quality is better than the single-pyrolysis oil. However, some differences still exist for the properties of co-pyrolysis oil as diesel or gas oil.