分级冷凝生物油组分富集与组分稳定性研究

利用GC-MS分别检测分级冷凝装置和常规冷凝装置制备的核桃壳生物油,对比常规冷凝生物油与分级冷凝多品级生物油有机组分的相对峰面积,发现分级冷凝对组分富集有较大影响,其中,乙酸在第四级生物油内相对峰面积从5.38%上升至9.44%;愈创木酚在第二级内从3.46%上升至6.23%;紫丁香醇在第一级内从1.48%上升至4.44%;异丁香酚在第一级内从5.52%上升至17.84%。经过75 d、15℃恒温恒湿储存后分级冷凝生物油水分增加,分别增加了1.58%、1.88%、1.80%、2.43%;脂肪类有机物峰面积减小;酚类有机物峰面积增大。第一、二级生物油内小分子有机物含量较少,老化反应强度较低;第三、四级生物油内小分子有机物含量较多,老化反应强度较高。根据GC-MS检测结果将有机物分类,统计各类有机物在储存前后的含量变化,分析储存过程中各类有机物发生的老化反应种类以及反应强度。     

微拟球藻热解及其催化热解制备生物油研究

在氮气气氛下对微拟球藻直接热解及其在H-ZSM-5上的催化热解实验进行了研究。在573K～773K考察了热解温度对热解油产物分布的影响。与木质纤维素生物质的热解相比,微拟球藻的热解不仅温度更低,而且油的收率更高。催化剂H-ZSM-5在热解中起到了脱极性官能团和芳构化的作用,使得热解油中的芳香族化合物含量增多,极性化合物含量减少。与木质纤维素生物质相比,微拟球藻热解获得的油热值更高,适合进一步加工为燃油。     

Thermochemistry analyses for transformation of C6 glucose compound into C9, C12 and C15 alkanes using density functional theory

The hydrolysis of cellulose fraction of biomass yields C6 glucose which further can be transformed into long-chain hydrocarbons by C–C coupling. In this study, C6 glucose is transformed into three chain alkanes, namely, C9, C12 and C15 using C–C coupling reactions under the gas and aqueous phase milieus. The geometry optimisation and vibrational frequency calculations are carried out at well-known hybrid-GGA functional, B3LYP with the basis set of 6-31+g(d,p) under the density functional theory framework. The single point energetics are calculated at M05-2X/6-311+g(3df,2p) level of theory. All thermochemical properties are calculated over a wide range of temperature between 300 and 900 K at an interval of 100 K. The thermochemistry suggested that the aqueous phase behaviour is suitable for the hydrolysis of sugar into long-chain alkanes compared to gas-phase environment. The hydrodeoxygenation reactions under each reaction pathway are found as most favourable reactions in both phases; however, aqueous phase dominates over gas phase in all discussed thermodynamic parameters.