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1、天津大學(xué)碩士學(xué)位論文從棉籽油脫臭餾出物中提取維生素E姓名:雷鵬申請(qǐng)學(xué)位級(jí)別:碩士專業(yè):化學(xué)工程指導(dǎo)教師:郭翠梨20090601摘要本文旨在探索以棉籽油脫臭餾出物為原料提取天然維生素E的工藝方法,確定了以酯化、吸附為主要單元操作的工藝流程。研究了以濃硫酸和強(qiáng)酸性陽(yáng)離子交換樹(shù)脂為催化劑進(jìn)行甲酯化的操作條件和采用吸附樹(shù)脂進(jìn)行吸附的操作條件對(duì)分離維生素E的影響。主要結(jié)論如下:甲酯化反應(yīng)采用濃硫酸作催化劑時(shí),較適宜的操作條件是:反應(yīng)時(shí)間1小時(shí),反應(yīng)溫度60℃,醇料比(甲醇體積與餾出物質(zhì)量之比)3:1,濃硫酸用量2
2、%。在此條件下反應(yīng)后樣品的酸價(jià)由原料的71.09mgKOH/g降到0.50mgKOH/g甲酯化反應(yīng)采用強(qiáng)酸性陽(yáng)離子樹(shù)脂作催化劑時(shí),較適宜的操作條件是:反應(yīng)溫度68℃、催化劑用量55%、醇料比3:1、反應(yīng)時(shí)間5h。在此反應(yīng)條件下,原料的酸價(jià)可以降到1.03mgKOH/g。通過(guò)靜態(tài)吸附試驗(yàn)確定Al吸附樹(shù)脂對(duì)維生素E吸附的特性與溶液中維生素E的初始濃度、吸附溫度相關(guān):在乙醇對(duì)酯化物的溶解范圍內(nèi)和高于20℃的前提下,較高的維生素E濃度和較低的溫度有利于Al吸附樹(shù)脂對(duì)維生素E的吸附,吸附模型可用Freundlic
3、h吸附等溫方程來(lái)進(jìn)行擬合。通過(guò)固定床吸附試驗(yàn)確定了以5%(體積分?jǐn)?shù))乙酸一乙醇溶液為解吸劑。吸附操作條件為:床層高度500mill、直徑25mm,吸附溫度25℃,流速lBV/h,上柱液中維生素E濃度4.49mg/mL;解吸操作條件:溫度25℃、流速1BVha。在此條件下通過(guò)固定床吸附分離,可將維生素E的純度從原料中的8%提高到75%以上,回收率83%以上。關(guān)鍵詞:維生素E脫臭餾出物酯化吸附分離ABSTRACTThepurposeofthispaperistostudytechnicsofseparati
4、ngvitaminEfromCottonseedOilDeodorizerDistillate(CODD).Thispaperstudyoperationconditionofesterification(usesulfuricacidandstronglyacidiccationexchanger-sulfonicacidfunctionalityrespectively)andadsorptiontoseparatevitaminEfromCODD.Mainresultsareasfollows:W
5、henusesulfuricacidascatalyzer,thebestconditionofesterificationisthatreactiontimeis1hour,temperatureis60℃,proportionofmethanolandrawmaterialis3:1,massofsulfuricacidis2wWo.Onthiscondition,acidityofCODDcanreduceto0.50mgKOH/gfrom71.09mgKOH/gbyesterification.
6、Whenusestronglyacidiccationexchanger—sulfonicacidfunctionalityascatalyzer,thebestconditionofesterificationisthattemperatureis68℃,massofcatalyzeris55wt%,proportionofmethanolandrawmaterialis3:1,timeis5hours.Onthiscondition,acidityofCODDcallreduceto1.03mgKO
7、H/gfrom71.09mgKOH/gbyesterification.ThepropertyofadsorptionofA1adsorbentresincorrelatetoconcentrationofvitaminEandtemperature.HighconcentrationofvitaminEandlowtemperaturearepositivetoadsorption.ThemodeofadsorptioncanbesimulatedwithFreundlichequation.Thro
8、ughimmovablebedadsorptionexperiment,weselect5v01%aceticacid—ethanolsolutionasdesorbent.Theabsorptionconditionisthatthesizeofresinbedis500x25mm,temperatureis25℃,velocityofflowis1BV/h,initialconcentrationofvitaminEis4.49mg/m