轻馏分生物油催化酯化脱水提质研究

为了得到稳定的含氧液体燃料及较好分离糖类及其衍生物,以Amberlyst-36离子交换树脂为催化剂在100℃下对粗生物油进行酯化脱水提质工艺优化,考察了反应时间、催化剂用量以及正丁醇和生物油质量比(醇油比)对提质的影响,得到最佳提质条件为醇油比1.5∶1.0、15%的催化剂用量、反应时间4 h,此条件下提质油酸值从72.23 mg/g降为3.98 mg/g,水分从53.06%降为3.34%,热值由8.75 MJ/kg升高至31.50 MJ/kg。GC-MS分析显示生物油中不稳定酸、醛、酮转化为稳定含氧化合物,稳定目标产物酯、醇、醚GC含量占74.70%。接着进行老化实验,保存3个月,粗生物油黏度从3.21 mm2/s增加到48.24 mm2/s,极不稳定,提质油理化性质显著提高并保持稳定。最后将20.00 g提质油、30.00 g蒸馏水和30.00 g二氯甲烷进行充分混合,萃取分液,可以基本将糖类及其衍生物从提质油中分离出来,得到粗糖质量为1.24 g,糖类物质总GC含量为87.92%,其中丁基-β-D-吡喃葡萄糖苷占到75.28%。

Upgrading of Light Fraction in Bio-oil by Catalytic Esterification and Water Removal

Stable oxygenated liquid fuel and sugars derivatives were obtained by esterification and water removal of crude bio -oil over Amberlyst-36 ion-exchange resin .The effects of reaction time , catalyst dosage and alcohol-oil ratio were investigated .The results showed that the optimum upgrading conditions were alcohol -oil ratio 1.5∶1.0, 15%catalyst dosage and 4 h.Under these operation factors, the acid number of upgraded bio-oil reduced from 72.23 mg/g to 3.98 mg/g, water content decreased from 53.06 %to 3.34 %, heating value increased from 8.75 MJ/kg to 31.50 MJ/kg.The GC-MS analysis showed that the labile acids, aldehydes and ketones of crude bio-oil could transform to stable oxygenated compounds , and the GC content of stable compounds (esters, alcohols and ethers) reached up to 74.70%.Crude bio-oil and upgrading bio-oil were kept for 3 months to compare the changes of characteristics .The results showed that crude bio-oil was extremely unstable and viscosity increased from 3.21 mm2/s to 48.24 mm2/s.In contrast, upgrading bio-oil was relatively stable and the physicochemical properties were improved significantly.Moreover, 20.00 g upgrading bio-oil, 30.00 g distilled water and 30.00 g dichloromethane were mixed adequately for separation of sugar derivatives .It was found that sugar derivatives could almost completely separate from upgrading bio-oil.The mass of crude sugars was 1.24 g and the total GC content of sugar derivatives was 87.92 %, in whichβ-D-glucopyranoside , butyl accounted for 75.28 %.