生物油典型含氧化合物在分子蒸馏过程中的分离特性研究  

Separation Characteristics of Typical Oxygenate Components of Biomass Pyrolysis Oil in Molecular Distillation

作　　者：刘翊希 戴贡鑫 张兴 王凯歌[1] 王树荣[1] LIU Yixi;DAI Gongxin;ZHANG Xing;WANG Kaige;WANG Shurong(State Key Laboratory of Clean Energy Utilization,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学能源清洁利用国家重点实验室,浙江杭州310027

出　　处：《林产化学与工业》2020年第4期9-16,共8页Chemistry and Industry of Forest Products

基　　金：国家自然科学基金创新研究群体项目(51621005)。

摘　　要：对棉花秆热解得到的生物油进行了一系列不同蒸发面温度和压力条件下的分子蒸馏实验,探究蒸馏产物的宏观特性以及典型含氧化合物在不同蒸馏条件下的分离特性。研究发现:馏出组分具有较高的氢碳比和氧含量,残余组分具有较高热值和碳含量,但n(H)∶n(C)接近1∶1。引入分离因子(αi,n)对典型含氧化合物的蒸出能力进行半定量评估,结果表明:乙酸、1,1-二甲氧基丙烷、2,5-二甲氧基四氢呋喃等小分子化合物在实验条件下极易被蒸出,3-甲基-1,2-环戊二酮的蒸出能力受实验中蒸馏条件的影响较高;大分子化合物中,单酚类化合物的蒸出能力突出,其中愈创木酚在1500 Pa下的蒸出能力最强,苯酚受温度变化影响较小;二酚的蒸出能力远低于单酚,其中苯二酚在2500 Pa/50℃下蒸出能力极差,但进一步降低压力可大幅提升其蒸出性能;长链酯类和糖类化合物的蒸出能力受蒸馏温度和压力变化的影响较小。In order to investigate the separation characteristics of typical oxygenate components of biomass pyrolysis oil in both macro-and micro-level,a series of molecular distillation experiments were conducted under different evaporation temperature and operation pressure using cotton stalk pyrolysis oil as raw material.It showed that the distilled fractions had higher H/C molar ratios and contained higher oxygen content than the residual fractions,while the residual fractions contained higher carbon contents with higher heating value and their H/C molar ratios was close to 1.The separation factor(αi,n)was defined based on previous study and was used to evaluate the separation characteristics of typical compounds in micro-level.It showed that compounds with light molecular weights such as acetic acid,1,1-dimethoxy-propane,tetrahydro-2,5-dimethoxy-furan were very easy to be distilled under all experiment conditions,while the distillation of 3-methyl-1,2-cyclopentanedione was highly affected by the temperature and pressure in the experiment.It also indicated that monophenol compounds such as guaiacol,syringol and phenol could be distilled more easily than other compounds with large molecular weight,among which guaiacol was the easiest one to be distilled under 1500 Pa and the phenol was less affected by temperature changes.It was much harder to distill diphenol than monophenol,among them,benzenediol showed comparatively poor distillation characteristics under the conditions of 2500 Pa/50℃especially.However,further lower the operation pressure could facilitate the evaporation of benzenediol largely.The changes of evaporation temperature and operation pressure had less effect on distillation of long-chain esters and carbohydrates than other compounds with large molecular weight.

关 键 词：生物质 生物油 分子蒸馏 分离特性 分离因子 

分 类 号：TQ35[化学工程] TK6[动力工程及工程热物理—生物能]