【作者】 林冠烽；

【导师】 蒋剑春；

【作者基本信息】 中国林业科学研究院 ， 林产化学加工工程， 2013， 博士

【摘要】 基于物理法制备成型颗粒活性炭需要使用粘结剂，生产能耗高、成本高、操作繁杂；化学法颗粒活性炭难于同时满足高吸附性和高强度的问题。论文提出以植物原料中纤维素、木质素和半纤维素的模型物为实验参照物，采用比表面积分析仪、X-射线衍射仪、红外光谱仪和气相色谱-质谱联用仪等分析磷酸法颗粒活性炭自成型过程中木质组分结构的演变机制，揭示了磷酸法颗粒活性炭的自成型机理，探明了自成型过程中起塑化和粘结作用的主要成分及来源，可望解决化学法自成型颗粒活性炭生产过程中存在的问题，为生产高强度高吸附性能的化学法颗粒活性炭提供理论基础与技术支撑。论文的主要研究内容和结果如下：以杉木屑为原料，采用磷酸活化法在不添加粘结剂的条件下制备自成型颗粒活性炭。研究结果表明，捏合热处理后，磷酸的催化作用促进了木质原料发生结构重排，引进了含磷官能团和C＝C＝C键。捏合时间较短时，磷酸对木质原料主要起水解和润胀作用。捏合时间较长时，木质原料主要发生脱水和聚合反应。捏合热处理过程中，在酸催化、机械力和热力的作用下，木质原料发生水解降解，形成具有粘结剂、抗氧化剂共同作用的体系，促使木质原料在不另外添加粘结性物质的条件下实现自成型。自成型过程中，起粘结作用的主要成分是糠醛均聚或缩聚形成的呋喃类树脂。浸渍比的增大，有利于颗粒活性炭孔隙结构的发达，但不利于强度的提高。木质颗粒活性炭在自成型过程中生成的粘结剂并未堵塞活性炭的孔隙，自成型过程可以制得孔隙结构发达的活性炭产品。以微晶纤维素为原料，采用磷酸活化法在不添加粘结剂的条件下制备自成型纤维素基颗粒活性炭。研究结果表明，捏合热处理后，纤维素的游离羟基、氢键、CH基团和C-O基团的含量增加，并引入了含磷官能团、C＝C＝C键、C＝C键和C＝O键。捏合时间较短时，磷酸主要对纤维素的无定形区和结晶区起水解和润胀作用。捏合时间较长时，磷酸主要起脱水和热分解的作用。在捏合热处理过程中，纤维素大分子在酸催化、热力和机械力作用下，发生水解降解，形成粘结剂、塑化剂和抗氧化剂共同作用的体系，促使纤维素原料在不另外添加粘结性物质的条件下实现自成型。纤维素自成型过程中，起粘结作用的主要成分是糠醛均聚或缩聚形成的呋喃类树脂，起塑化作用的主要成分为4-甲基苯酚。浸渍比的增大，有利于纤维素基颗粒活性炭吸附性能的提高和孔隙结构的发达，但不利于强度的提高。以半纤维素的模型物——木聚糖为原料，采用磷酸活化法在不添加粘结剂的条件下制备自成型半纤维素基颗粒活性炭。研究结果表明，在捏合热处理过程中，半纤维素在酸催化、热力和机械力的作用下，发生水解降解，形成粘结剂、有机合成中间体和抗氧化剂共同作用的体系，促使半纤维素原料在不另外添加粘结性物质的条件下实现自成型。半纤维素自成型过程中，起粘结作用的主要成分是糠醛均聚或缩聚形成的呋喃类树脂。炭活化温度的升高不利于半纤维素基颗粒活性炭吸附性能的提高和孔隙结构的发达，但有利于强度的提高。在纤维素/木质素和纤维素/半纤维素的混合物制备自成型颗粒活性炭过程中，随着木质素和半纤维素比例的提高，颗粒活性炭的强度呈先升后降的趋势。在捏合加热过程中，纤维素与半纤维素的水解降解产物间发生了协同效应，形成更多具有粘结性能的物质，使其强度高于纤维素和半纤维素单独制备的颗粒活性炭。不同比例的纤维素、半纤维素和木质素的混合物制备颗粒活性炭的过程中，纤维素比例的提高有利于强度的增加，木质素和半纤维素比例的增加不利于强度的提高。在杉木屑与模型物混合制备自成型颗粒活性炭的过程中，随着纤维素比例的提高，强度呈上升趋势。随着木质素和半纤维素比例的提高，强度呈下降趋势。与杉木屑制得的颗粒活性炭相比，添加纤维素和木质素有利于强度的提高，颗粒活性炭强度增大的因素主要来源于纤维素和木质素。捏合产物中糠醛含量的增加有利于颗粒活性炭强度的提高，糠醛含量太高反而不利于强度的提高。对自成型木质颗粒活性炭在甲烷存储和醋酸乙烯催化剂载体活性炭方面的应用进行研究。结果表明，随着浸渍比的升高，颗粒活性炭的甲烷吸附量呈先升后降的趋势，单位体积的甲烷吸附量呈下降的趋势。随着炭活化温度的升高，颗粒活性炭的表观密度、强度和醋酸锌吸附量呈不断上升的趋势，醋酸吸附值呈不断下降趋势。控制好自成型颗粒活性炭的生产工艺，可以制得符合国标产品指标的醋酸乙烯催化剂载体活性炭。更多还原

【Abstract】 Based on the preparation of GAC by physical activation needs using a binder, and thisprocess is high energy consumption, high cost and complicated operation. On the other hand, itis difficult for GAC prepared from chemical activation to meet high adsorption andhigh-strength simultaneously. The dissertation used model compound of cellulose, lignin andhemi-cellulose as experimental materials, analyzed the evolution of the lignocellulosiccomponent in the process of self-form by automatic specific surface area analyzer, fouriertransform infrared spectroscopy, X-ray diffractometer, thermogravimetric analysis and gaschromatography-mass spectrometry instrument, revealed the self-form mechanism of GACprepared from phosphoric acid activation, and proved the main ingredient and sources of theplasticizing and cohesive compound in the self-form process. The objective of this dissertationis to solve the problem of the preparation of GAC by chemical activation and provide atheoretical basis and methods. The main research contents and results were as follows:GAC was prepared from fir wood powder by phosphoric acid activation without additionany binder. The results showed that phosphoric acid catalysis would promote therearrangements of the structure of lignocellulosic materials and introducephosphorus-containing functional group and C＝C＝C bond in the process of heat kneading.When heat kneading time was shorter, the main effects of phosphoric acid were hydrolysis anddilation. On the other hand, when heat kneading time was longer, the main reactions oflignocellulosic materials were dehydration and polymerization. In the process of heat kneading,with the effects of acid catalysis, mechanical strength and heat, lignocellulosic materials werehydrolysis degradation and formation of the system combined a binder and antioxidant, whichprompted the self-form of lignocellulosic materials in the condition without adding extraadhesive. In the process of self-form, the main ingredient of binder is furan resin which is fromthe homo or polycondensation of furfural. The increase of impregnation ratio benefited thedevelopment of pore structure in GAC, but not the intensity of GAC. The binder formed in the process of self-form did not clog the porosity of GAC, and the self-form process could producethe GAC with development porosity.GAC was prepared from cellulose by phosphoric acid activation without addition anybinder. The results showed that free hydroxyl groups, hydrogen content, CH groups and COgroups of cellulose were increased and phosphorus-containing functional groups, C＝C＝Cbond, C＝C bond and the C＝O bond were introduced in the process of heat kneading. Whenheat kneading time was shorter, the main effects of phosphoric acid were to hydrolyze anddilate the amorphous and crystalline regions in cellulose. When heat kneading time was longer,the main effects of phosphoric acid were dehydration and polymerization. In the process ofheat kneading, with the effects of acid catalysis, mechanical strength and heat, cellulose washydrolysis degradation and formation of the system combined a binder, plasticizer andantioxidant, which prompted the self-form of cellulose in the condition without adding extraadhesive, and then produced GAC. In the process of self-form, the main ingredient of binder isfuran resin which is from the homo or polycondensation of furfural, and the main ingredient ofplasticizer is4-methylphenol. The increase of impregnation ratio benefited the development ofpore structure in GAC, but not the intensity of GAC.Xylan was used as the main model of hemi-cellulose to prepare hemi-cellulose-basedgranular activated carbon by phosphoric acid activation without addition any binder. Theresults showed that with the effects of acid catalysis, mechanical strength and heat in theprocess of heat kneading, hemi-cellulose was hydrolysis degradation and formation of thesystem combined a binder, synthesis intermediates and antioxidant, which prompted theself-form of hemi-cellulose in the condition without adding extra adhesive, and then producedGAC. In the process of self-form, the main ingredient of binder is furan resin which is from thehomo or polycondensation of furfural. The increase of carbonization/activation temperaturebenefited the development of pore structure in GAC, but not the intensity of GAC.During preparation of GAC from the mixture of cellulose/lignin and the mixture ofcellulose/hemi-cellulose, the intensity of GAC increased firstly and then decreased with the increase of the proportion of lignin and hemi-cellulose. In the process of heat kneading, thesynergistic reaction took place between the hydrolysis degradation product of cellulose andhemi-cellulose, and produced more adhesive substance, so the intensity of GAC prepared fromthe mixture of cellulose/hemi-cellulose was stronger than the GAC prepared from cellulose andhemi-cellulose alone. During preparation of GAC from cellulose/hemi-cellulose/lignin mixture,the intensity of GAC increased with the increase of cellulosic proportion. However, theincrease of the proportion of lignin and hemi-cellulose was not good for intensity increase.During the preparation of GAC from the mixture of fir wood powder and wooden modelcompound, the intensity of GAC increased with the increase of cellulosic proportion, and theincrease of the proportion of hemi-cellulose and lignin showed an opposite trend. Whencompared with the GAC prepared from fir wood powder, the addition of cellulose and ligninbenefited the increase of GAC intensity. The factor for the increase of GAC intensity derivedfrom cellulose and lignin. The increase of furfural content benefited GAC intensity increase,but the intensity would decrease when the content of furfural was too high.The application of GAC in the field of methane adsorption and vinyl acetate catalystcarrier was studied. The results showed that the amount of methane adsorption increased firstlyand then decreased with the increase of impregnation ratio, and the unit volume of methaneadsorption decreased with the increase of impregnation ratio.The apparent density, intensity and adsorption value of zinc acetate of GAC increasedwith rising carbonization/activation temperature， but the adsorption of acetate showed theopposite trend. Controlled the preparation technology of self-form GAC, it would produce thevinyl acetate catalyst carrier conformed the national standard.更多还原