催化加氢改性生物质油轻质组分

Upgradation of Light Fraction of Biomass Oil via Catalytic Hydrogenation

以稻壳为原料热解得到的生物质原油是一种成分复杂、物理化学性能不稳定的混合物,只有经过物理或化学改性的生物质燃料才可以在现代柴油机中应用。采用减压蒸馏的方式分离出生物质油轻质组分,在4个温度(150、250、350和150/350℃)和压力2MPa条件下,以MoS2为催化剂,在间歇反应釜中进行催化加氢改性。从改性油产率、加氢前后油品性能及nH/nC的变化来判断不同温度条件下MoS2对生物质油轻质油的催化加氢效果。结果表明,随着反应温度的升高,改性油产率逐渐降低,150℃下所得改性油产率为80.3%,而350℃下产率仅为65.4%,但此时的改性油具有较高的nH/nC(3.80),150/350℃两段式反应条件在脱氧方面更具优势。催化加氢机理归结为化合物中含有的不饱和化学键(CC和CO)容易在MoS2催化剂条件下发生加氢或加氢脱氧反应。

The crude biomass oil obtained from rice husks was a complicated mixture with the unstable physic-chemical properties. Only these biomass oils, which were modified, can be used in diesel engine. The refined biomass oil was prepared by the vacuum distillation approach from the crude biomass oil. The refined biomass-oil was upgraded via the catalytic hydrodeoxygenation over MoS2 under different temperatures （150, 250, 350 and 150/350℃） and 2 MPa. The yields of upgraded oils were calculated, and the properties and nil^no of oils were also analyzed, which were used to evaluate the upgrading performance. The experimental results showed that the yield of upgraded oil decreased with the temperature rising. The yield of upgraded oil was 80.3% at 150℃, while at 350℃, the yield （65.4%） was lower, but the rate of n./nc（3.8） was higher. The two- stage reaction at 150/350℃ turned out the better catalytic deoxygenation than those of the one-stage temperature condition. The catalytic hydrodeoxgenation mechanism over MoS2could be clarified via the unsaturated functional bonds （C=C and C =O sites） of the components in the refined oil that were easily attacked by the hydrogen during the proper temperature and pressure.