【作者】 王志强；

【导师】 张玉明；

【作者基本信息】 中国石油大学(北京) ， 化工过程机械， 2022， 硕士

【摘要】 秸秆是一种资源丰富、分布广泛的典型农业生物质,具有可再生、环境友好的特点,通过生物质水热炭化（Hydrothermal carbonization,HTC）技术开发利用秸秆生物质资源能够缓解能源危机与环境问题,是最具应用潜力的工艺。然而研究者们对于秸秆类生物质的催化水热炭化制备功能化碳材料以及催化剂作用机理的研究还较少。本文主要选取了柠檬酸（CA）、氢氧化钠（Na OH）、氯化锌（Zn Cl₂）和硫酸亚铁铵（（NH₄）₂Fe（SO₄）₂）作为玉米秸秆生物质水热炭化过程中的催化剂,并结合纤维素、木质素、葡萄糖等模型化合物的水热炭化揭示催化作用机理。通过活化进一步改善玉米秸秆水热炭的物理结构与化学性质,以探究高吸附性能碳材料的制备路径。随着反应强度的增加,秸秆水热炭化固相产物的含碳量从49.04wt.%增加到58.46wt.%,热值从19.43MJ/kg增加至24.18MJ/kg。在最优水热条件下加入催化剂进行HTC反应,发现催化剂能促进生物质的水解反应,使改性水热炭产率呈不同程度的降低。氯化锌的加入使水热炭的比表面积从12.14m²/g增加至17.98m²/g,硫酸亚铁铵使水热炭具有更强的N-H红外吸收峰,氯化锌使水热炭具有更强C=O、C=C红外吸收峰,Na OH使水热炭有更强的C-O红外吸收峰。在水热炭化过程中,CA促进真实生物质中的纤维素和木质素组分水解为低聚物,并与水解产物葡萄糖发生反应,增加了水热炭的芳香度和含氧官能团。Zn Cl₂主要促进真实生物质中纤维素组分水解成d-葡萄糖,并促进葡萄糖的二次成炭反应。Na OH抑制真实生物质中纤维素组分炭化成球,并促进木质素组分水解成酚类化合物,将生物质转化为生物油。（NH₄）₂Fe（SO₄）₂与真实生物质中木质素组分以及由纤维素组分水解成的葡萄糖发生氮掺杂反应,增加秸秆水热炭中的胺基官能团。通过对秸秆水热炭进行活化处理进一步调控水热炭的性质,经Zn Cl₂改性的水热炭活化后具有最大的比表面积1532.9m²/g,对CO₂有最大吸附量136.7cm³/g,经CA改性的水热炭活化后对Cr（Ⅵ）有最大的单位吸附量88.9mg/g。Zn Cl₂改性炭对Cr（Ⅵ）的最大的单位吸附量是23.51mg/L,动力学和热力学拟合结果表明,水热炭对Cr（Ⅵ）的吸附主要是单分子层的化学吸附过程。更多还原

【Abstract】 Straw is a sort of usual agricultural biomass with abundant sources and large distribution,which is renewable and environmentally friendly.Biomass hydrothermal carbonization technology is used to develop and make use of straw biomass resources to alleviate energy crisis and environmental problems,which is the most manageable technological know-how for application.However,few researchers have studied the catalytic hydrothermal carbonization of straw biomass to produce functional carbon substances and the mechanism of catalyst action.In this paper,citric acid(CA),Na OH,Zn Cl2 and(NH4)2Fe(SO4)2 are selected as catalysts for the HTC of maize straw biomass,and the catalytic mechanism is printed via combining the hydrothermal carbonization of model compounds such as cellulose,lignin and glucose.The physical shape and chemical houses of maize straw hydrothermal carbon has been similarly expanded with the aid of activation to discover the training path of carbon materials with excessive adsorption properties.With the expand of response intensity,the carbon content of the stable phase merchandise increased from 49.04 wt.% to 58.46 wt.%,and the calorific price expanded from 19.43MJ/kg to 24.18MJ/kg.It was once observed that the catalyst can promote the hydrolysis response of biomass and reduce the yield of modified hydrothermal carbon in exclusive stages by using adding the catalyst to the HTC response beneath the top of the line hydrothermal conditions.The unique surface area of hydrothermal carbons was expanded from 12.14m2/g to 17.98m2/g by Zn Cl2.The hydrothermal carbons had improved N-H infrared absorption peaks by means of(NH4)2Fe(SO4)2.The hydrothermal carbon had stronger C=O and C=C infrared absorption peaks due to the motion of Zn Cl2,and the hydrothermal carbon had enhanced C-O infrared absorption peaks due to the action of Na OH.In the HTC process,cellulose and lignin factors in actual biomass were hydrolyzed into oligomers with the aid of CA.Glucose reacted with CA to extend the aromaticity and oxygen-containing practical groups of hydrothermal charcoal.Cellulose factors in actual biomass had been hydrolyzed to D-glucose with the aid of Zn Cl2,and the secondary carbonization response of glucose was promoted.Na OH inhibited the carbonization of cellulose aspects in actual biomass into pellets and promoted the hydrolysis of lignin components into phenolic compounds,converting biomass into bio-oil.(NH4)2Fe(SO4)2 was doped with the lignin component of real biomass and glucose hydrolyzed from cellulose aspect to increase the amine useful agencies in straw hydrothermal charcoal.The properties of straw hydrothermal charcoal had been similarly regulated by way of activation treatment.The activated hydrothermal carbon modified by Zn Cl2 had a most specific surface vicinity of 1532.9m2/g and a most adsorption capacity of136.7cm3/g for CO2.The most adsorption capacity for Cr(Ⅵ)was 88.9mg/g after activated by way of CA modified hydrothermal carbon.The most adsorption capacity of Zn Cl2 modified carbon on Cr(Ⅵ)was 23.51mg/L.The kinetic and thermodynamic fitting effects exhibit that the adsorption of Cr(Ⅵ)on hydrothermal carbons was on the whole a monomolecular chemisorption process.更多还原