CaO伴随纤维素快速热裂解的落体试验研究

Falling-body Experiment on Fast Cellulose Pyrolysis Accompanied by CaO

采用自由落体-辐射加热的试验方法,对CaO伴随生物质快速热裂解制油的脱氧效果进行了研究.利用气相色谱/质谱联用仪(GC-MS)对油样进行分析,结果表明:纤维素一次裂解的主要产物是左旋葡聚糖(LG);纯纤维素以及33%和56%CaO伴随纤维素裂解油中LG的质量百分含量分别为59.1%、35.8%和25.1%;LG作为热解油中含氧量最高的成分,其质量百分含量随CaO的加入急剧下降,说明CaO的加入可降低热解油的含氧量.计算结果表明:33%和56%CaO伴随纤维素热裂解时,可分别降低油品含氧量约10%和12.5%,说明CaO可直接固定纤维素热裂解平行反应中CO2或类似中间基团,形成有利于葡萄糖单体分裂、重整路线进行的"化学汇"结果.

Deoxygenization effect of CaO on bio-oil from biomass pyrolysis was studied by a series of freely falling body-radiation heating experiments. GC-MS analysis results on bio-oil samples show that the prima- ry pyrolysis product of cellulose is levoglucosan （LG）. In the bio-oil product respectively obtained from pyrolysis of pure cellulose, cellulose with addition of 33% and 56% CaO, the corresponding LG mass percentage is 59. 1%, 35. 8% and 25. 1%. With addition of CaO, mass percentage of LG, which contains highest oxygen content in bio-oil, reduces sharply. That means CaO plays an important role in bio-oil deoxygenization. Calculation results show that during cellulose pyrolysis with addition of 33% and 56% CaO, the oxygen content can be reduced respectively by 10% and 12.5%, demonstrating that CaO can fix CO2 or similar intermediate products, which makes pyrolysis parallel reactions towards the direction of glucose decomposing and reforming.