在小型流化床反应器中,对CaO伴随生物质快速热裂解制油过程中的直接脱氧效果进行了研究。当反应温度为520℃、载气流量8 000 L/h时,在纯白松粉末和CaO伴随条件下分别制出了生物油样品。实验结果表明,当采用纯白松与CaO/白松质量比分别为1、2、4时,生物油样品中有机组分的含氧量依次为39.38%、39.15%、39.04%和32.29%;在CaO/白松质量比为4时,生物油有机组分含氧量的下降幅度达18.0%(相对变化)。GC-MS分析结果表明,CaO加入后左旋葡聚糖和甲酸、乙酸等高含氧量物质相对含量明显下降,证实了CaO伴随生物质热裂解过程中"富氧中间体"固氧路径的存在;与此同时,糠醛类等主要来源于脱水反应的产物相对含量上升,说明CaO的加入也促进了脱水反应的发生。
Direct deoxygenation effect of CaO on bio-oil from biomass pyrolysis was studied in a fluidized bed experimental apparatus.Bio-oil was produced at reaction temperature of 520℃ and carrier-gas flow-rate of 8000L/h using white pine alone and white pine accompanied with CaO,respectively.The result shows that the oxygen contents of the organic components in the bio-oils are 39.38%,39.15%,39.04% and 32.29% for white pine alone and white pines with 1,2,4 times of CaO added,respectively.With 4 times CaO added,the oxygen content of the organic components decreases by 18.0%(relative variation).Detailed GC-MS analysis indicates that the relative contents of high-oxygen containing levoglucosan,formic acid,acetic acid,etc.are greatly reduced with CaO-adding,implying the existence of the oxygen-capture path of "high-oxygen containing intermediates" in biomass pyrolysis process.Furthermore,the species of furfural is derived from dehydration reactions,and the increase in the relative content demonstrates that CaO-adding can also catalyze the dehydration reactions.