介孔分子筛反应精馏催化改性生物质裂解油

A novel method of upgrading bio-oil by reactive rectification

采用反应精馏的方法,以含锆介孔分子筛(SO42-/Zr-MCM-41)为酸性催化剂,对生物质热解油进行了催化改性。通过XRD、N2吸附脱附及FT-IR表征了介孔分子筛的孔结构和表面基团。对生物油改性的较佳反应条件进行了考察,较佳的催化剂用量为生物油质量的4%,生物油、乙醇及过氧化氢水溶液(30%)的质量比为1∶0.5∶0.4,回流比1∶6。在上述条件下,轻油收率21.4%(以生物油计)。改性所得两种改性油与原料油相比,含水量由33%分别降至0.5%和5.0%,黏度由18.5mm2/s分别降至0.46mm2/s和3.65mm2/s(30℃),pH值由2.82分别提升至7.06和5.35,热值由14.3MJ/kg分别提升至21.5MJ/kg和24.5MJ/kg。经过GPC、FT-IR和1H NMR分析,轻油主要成分是原料油中的轻组分所转化的酯类化合物,重油主要是原料油中难挥发的成分。

Zirconium-containing mesoporous molecular sieve SO4^2-/Zr-MCM-41 was synthesized and used as a catalyst in upgrading bio-oil through reactive rectification. The suitable operation conditions for bio-oil upgrading were obtained as follows ： catalyst usage based on bio-oil = 4% ; reflux ratio = 1 ： 6 ; mass feed ratio of bio-oil ： ethanol ： hydrogen peroxide （aqueous solution 30% ） = 1 ： 0.5 ： 0.4. The yield of light oil was up to 21.4%. Under these conditions, two kinds of upgraded bio-oils （light oil and heavy oil） were obtained; their densities were reduced from the original 1.16 kg/m^3 to 0.91 kg/m^3 and 0.95 kg/m^3, water content from 33% to 0. 5% and 5.0% , whereas, the gross calorific value increased from the original 14.3 MJ/kg to 21.5 MJ/kg and 24.5 MJ/kg, and the pH value from 2.82 to 7.06 and 5.35, respectively. The volatile organic acids were converted into esters under the action of the solid acid catalyst SO4^2-/Zr-MCM-41 , whereas, the heavy oil was composed of nonvolatile components in the original bio-oil.