酒糟炭基固体酸的制备及其催化性能研究

发布时间：2018-04-03 23:57

  本文选题：酒糟　切入点：磺化炭基固体酸　出处：《合肥工业大学》2017年硕士论文

【摘要】：在石油化工和精细化工中,酸催化剂占有非常重要的地位。液体酸具有较高的催化活性因而广泛地应用于工业生产中,但其缺点是污染环境、腐蚀设备、产物难纯化和催化剂难循环利用等。为克服液体酸的缺点,人们把固体酸引入到酸催化中,但当前研究的固体酸也存在制备成本高和催化活性低的不足。因此研究成本低廉且高效的生物炭固体酸催化剂成为近年来催化剂研究的热点。本文以酒糟为原料,研究了酒糟炭基磺酸化固体酸和酒糟炭负载型磷钨酸催化剂的制备方法,并利用 XRD、FT-IR、XPS、TG、31PMASNMR、NH3-TPD、N2 吸附-脱附、元素分析和酸量滴定对制备的催化剂的组成、结构和表面酸性进行表征;通过乙酸和正丁酯的酯化反应为探针反应对制备的催化剂的催化活性和稳定性进行检测,并利用气相色谱、红外光谱和折光率来研究催化剂的选择性;同时还研究了酒糟炭基磺酸化固体酸在乳酸丁酯合成中的应用。主要结果如下:(1)通过响应面试验设计得出一步炭化磺化法制备酒糟炭基磺酸化固体酸的最优制备条件:硫酸浓度为85 wt%、制备温度为20℃和制备时间为1.4 h;在此条件下制备的催化剂,酸密度为1.73 mmol/g,在探针反应中催化乙酸转化率达到97.6 %;催化剂催化活性随使用次数增加逐渐降低,可通过85 wt%硫酸进行再生。催化剂对乳酸正丁酯的催化合成同样具有较高的活性和选择性。(2)以酒糟炭为载体,采用浸渍法制备了一系列负载型磷钨酸催化剂。磷钨酸的负载量为50 wt%时,催化剂的催化活性较好。催化剂的比表面积为415 m2/g,磷钨酸以Keggin型结构均匀的分散在酒糟炭表面和孔道内。负载型磷钨酸催化剂适宜的酯化反应条件:催化剂用量为0.008 g/g,醇酸比为1.4,反应时间为2.0 h。在此条件下,乙酸的转化率为97.4%,重复使用5次,乙酸的转化率仍达到91.3%。
[Abstract]:Acid catalyst plays an important role in petrochemical industry and fine chemical industry.Liquid acids are widely used in industrial production because of their high catalytic activity, but their shortcomings are pollution of the environment, corrosion of equipment, difficult purification of products and difficult to recycle the catalyst, etc.In order to overcome the shortcomings of liquid acids, solid acids are introduced into acid catalysis. However, the current research on solid acids also has the disadvantages of high preparation cost and low catalytic activity.Therefore, the research of low cost and high efficiency biocarboxylic acid catalysts has become a hot topic in recent years.In this paper, the preparation methods of solid carbon-based sulfonic acid and carbon-supported phosphotungstic acid catalyst for distiller's grains were studied, and the composition of the catalysts prepared by XRDX FT-IRT, XPST TGN 31PMASN MRN NH 3-TPDN N 2 adsorption and desorption, elemental analysis and acid titration were studied.The structure and surface acidity were characterized. The catalytic activity and stability of the prepared catalysts were determined by the esterification of acetic acid and n-butyl ester as probes, and the catalytic activity and stability of the prepared catalysts were determined by gas chromatography.The selectivity of the catalyst was studied by infrared spectroscopy and refraction, and the application of solid carbon-based sulfonic acid in the synthesis of butyl lactate was also studied.The main results are as follows: (1) the optimum conditions for the preparation of solid carbon-based sulfonic acid from distillers' grains by one step carbonization sulfonation method were obtained by response surface test: the concentration of sulfuric acid was 85 wt, the preparation temperature was 20 鈩，

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