發(fā)布時(shí)間：2018-02-04 03:16

  本文關(guān)鍵詞： 生物柴油 脂肪酸 發(fā)酵液 水相反應(yīng) 催化劑 疏水功能化　出處：《青島科技大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：脂肪酸酯是重要的化工產(chǎn)品,迫于化石資源短缺及環(huán)境壓力,以生物基脂肪酸為原料制備脂肪酸酯衍生物已成為國際上的研究熱點(diǎn)。然而,基于生物轉(zhuǎn)化手段的脂肪酸產(chǎn)物濃度僅為5 g/L,遠(yuǎn)低于化學(xué)手段的百克每升級別,產(chǎn)物分離、提純困難、高衍生成本一直是制約生物基脂肪酸酯產(chǎn)業(yè)化的重要因素。本文通過沉淀法,水熱法和溶膠-凝膠法分別合成了表面活性劑-金屬離子(S-M)絡(luò)合材料,磷鎢酸改性的多孔配位聚合物材料(PCP(Cr)-PTA)和負(fù)載磷鎢酸MCM-41分子篩并進(jìn)行疏水功能化處理的改性材料(OTS-PTA-MCM-41),將三種材料運(yùn)用到在水相中催化合成生物柴油的反應(yīng)中,通過材料疏水功能化實(shí)現(xiàn)催化劑對底物分子及溶劑水分子的選擇性通過,探討催化劑用量、反應(yīng)溫度、反應(yīng)時(shí)間和不同醇水比例等反應(yīng)條件對棕櫚酸酯化率的影響,得到了以下實(shí)驗(yàn)結(jié)果。DBS-Sn(IV)在醇相催化棕櫚酸制備生物柴油的最佳反應(yīng)條件為:棕櫚酸甲醇摩爾比為1:25,催化劑加入量50 mg,反應(yīng)溫度70℃,反應(yīng)時(shí)間3 h。此時(shí)的棕櫚酸甲酯的產(chǎn)率高達(dá)97.4%。催化劑在重復(fù)五個(gè)反應(yīng)周期,棕櫚酸產(chǎn)率基本沒有下降。DBS-Sn(IV)催化發(fā)酵液脂中肪酸酯化實(shí)驗(yàn),反應(yīng)溫度為110℃,反應(yīng)時(shí)間3 h,催化劑加入量為100 mg,此時(shí)棕櫚酸甲酯產(chǎn)率為87.4%。同樣的條件,催化發(fā)酵液中的棕櫚酸酯化產(chǎn)率也達(dá)到89.1%。PCP(Cr)-PTA在水相催化棕櫚酸植被生物柴油的最佳反應(yīng)條件為:醇水比1:9,反應(yīng)溫度130℃,反應(yīng)時(shí)間3小時(shí),催化劑的加入量為反應(yīng)物的5%,棕櫚酸甲酯的產(chǎn)率達(dá)到84.7%,催化劑在重復(fù)五個(gè)反應(yīng)周期,棕櫚酸產(chǎn)率基本沒有下降。將PCP(Cr)-PTA運(yùn)用到催化發(fā)酵液脂中肪酸酯化反應(yīng)中,使用上述反應(yīng)條件,棕櫚酸甲酯的產(chǎn)率為80.0%。七種不同孔徑的OTS-PTA-MCM-41催化劑實(shí)現(xiàn)了對底物分子及溶劑水分子遵守N-2規(guī)律的選擇性通過,OTS-PTA-MCM-41(C14)催化發(fā)酵液脂中肪酸酯化,在150℃,反應(yīng)3小時(shí),月桂酸甲酯、肉豆蔻酸甲酯、棕櫚酸甲酯的產(chǎn)率分別為91.1%、87.9%和90.7%。此外,通過催化劑表征并關(guān)聯(lián)反應(yīng)效率、效果,明確最佳雜多酸活性中心三級結(jié)構(gòu)、負(fù)載率、疏水性等關(guān)鍵參數(shù),建立構(gòu)效關(guān)系,指導(dǎo)催化劑優(yōu)化調(diào)變;并在阻斷發(fā)酵液內(nèi)主要雜質(zhì)干擾機(jī)制的前提下,最終實(shí)現(xiàn)發(fā)酵液內(nèi)脂肪酸的原位酯化。
[Abstract]:Fatty acid ester is an important chemical product. Due to the shortage of fossil resources and environmental pressure, the preparation of fatty acid ester derivatives from biological fatty acids has become a hot spot in the world. The concentration of fatty acid products based on bioconversion is only 5 g / L, which is far lower than that of 100 grams per liter by chemical means, so it is difficult to separate and purify the products. High derivatization cost has been an important factor to restrict the industrialization of bio-base fatty acid esters. In this paper, surfactant metal ion S-M complex materials were synthesized by precipitation method, hydrothermal method and sol-gel method, respectively. The porous coordination polymer modified by phosphotungstic acid (MCM-41) and the modified material supported on phosphotungstic acid MCM-41 molecular sieve and treated with hydrophobic functionalization (. OTS-PTA-MCM-41). Three kinds of materials were used to catalyze the synthesis of biodiesel in water phase. The selective passage of catalyst to substrate and solvent water was realized by hydrophobic functionalization. The amount of catalyst and reaction temperature were discussed. The effects of reaction time and ratio of alcohol to water on the esterification rate of palmitic acid were studied. The following results were obtained: 1: 25 molar ratio of palmitic acid to methanol and 50 mg catalyst was used to prepare biodiesel from palmitic acid catalyzed by alcohol in the presence of DBS-SnCIV. the optimum reaction conditions were as follows: 1: 25 molar ratio of palmitic acid to methanol and 50 mg of catalyst. The reaction temperature was 70 鈩，

本文編號：1489161