改性生物质热解油的组成及特性

RESEARCH ON THE COMPOSITIONS AND PROPERTIES OF UPGRADED PYROLYSIS OIL

针对影响生物质热解油性质的主要官能团,以苄基氯为改性剂,在相转移催化剂的作用下,将热解油中的羧酸基团和酚羟基转化为酯类、醚类化合物。由于亲水基团转化为疏水性基团,改性后的生物油与原料油相比,具有明显的疏水性质,显著降低了含水量(由33.00%降至0.83%);由于影响pH值的羧基转化为酯基,pH值由2.82提升至5.72;基团的转化还降低了含氧量,提高了热值(由14.3MJ/kg提升至31.7MJ/kg)。经过GC-MS、FT-IR分析,原油中羧酸和酚类化合物大部分转化为相应的酯化产物和醚化产物。结合分析结果,探讨了改性过程的反应机理及副反应机理。

Using benzyl chloride and bio-oil as raw materials,upgraded bio-oil was obtained by converting phenolic hydroxyl and carboxyl group into ether and ester under phase transform catalyst,and became water insoluble as the hydro-philic radicals were changed into hydrophobic radicals.Therefore,water content was reduced from 33.00% to 0.83%.The gross calorific value increased from 14.3 to 31.7MJ/kg because oxygen content decreased after upgrading process.Acidity of upgraded bio-oil was also alleviated from 2.82 to 5.72 due to converting carboxyl group into ester.The results of GC-MS and FT-IR analysis showed that the organic acids and phenolic compounds were converted into corresponding esters and ethers.