本文選題：低共熔溶劑　切入點(diǎn)：酯化　出處：《遼寧科技大學(xué)》2015年碩士論文

【摘要】：隨著社會(huì)經(jīng)濟(jì)的快速發(fā)展,能源短缺與環(huán)境污染問(wèn)題日益嚴(yán)重,生物柴油是一種可替代化石燃料的生物燃料,引起了廣泛的關(guān)注。使用高酸值油脂作為生物柴油二步法(先預(yù)酯化反應(yīng)降酸,再轉(zhuǎn)酯化反應(yīng))的生產(chǎn)原料,在成本控制和環(huán)境污染控制方面具有明顯優(yōu)勢(shì)。傳統(tǒng)預(yù)酯化反應(yīng)采用濃硫酸作催化劑,存在腐蝕設(shè)備、催化劑不能重復(fù)使用,需水洗除酸且廢液不易處理等問(wèn)題。固體催化劑可以避免液體酸分離困難和有毒廢棄物的產(chǎn)生,但固體酸的高成本和高反應(yīng)條件,制約了其發(fā)展。基于以上原因,國(guó)內(nèi)外均已開(kāi)始研究應(yīng)用低共熔溶劑作為催化劑降低生物柴油生產(chǎn)成本,減少環(huán)境污染。本文通過(guò)自制氯化膽堿/甲基磺酸的新型低共熔溶劑(DES),催化高酸值原料油和地溝油中游離脂肪酸的甲酯化反應(yīng)。探討了氯化膽堿/甲基磺酸不同摩爾比對(duì)酯化率的影響,以及物理性質(zhì)的變化;并對(duì)自制DES的催化能力、催化活性和穩(wěn)定性進(jìn)行了探討;利用了響應(yīng)面法得到此DES在酯化反應(yīng)中的最優(yōu)條件,并在最優(yōu)條件下,將不同酸值的地溝油、原料油合成生物柴油,并進(jìn)行氣相色譜分析,得出生物柴油中甲酯的組成,為DES從制備到生物柴油合成的工業(yè)化生產(chǎn)提供可行性的參考。本研究得到了如下結(jié)論:(1)在氯化膽堿/甲基磺酸摩爾比為1:2時(shí)合成的DES催化能力最強(qiáng),同時(shí)不同摩爾比對(duì)DES的密度、PH值、導(dǎo)電性都有很大的影響。隨著摩爾比的增大,這三個(gè)物理參數(shù)均增大。(2)為了探討自制DES的活性及催化能力時(shí),用DES催化不同酸值的原料油,并與工業(yè)上常用的催化劑和固體催化劑進(jìn)行了比較,并對(duì)DES進(jìn)行回收重利用,最終發(fā)現(xiàn)DES是這些催化劑中催化能力最強(qiáng)的,并且對(duì)于高低酸值都有很好的催化效果,當(dāng)DES重復(fù)使用6次后,酯化率變化非常小,這打破了液體酸不能重復(fù)利用的缺點(diǎn)。(3)響應(yīng)面法得到在氯化膽堿/甲基磺酸的摩爾比為1:2時(shí),DES催化酯化反應(yīng)的最優(yōu)條件:反應(yīng)溫度:70℃、反應(yīng)時(shí)間為75min,催化劑用量為3%,醇酸比為18%,此時(shí)酯化率為99%,酸值降低到1 mg KOH/g一下,完全滿(mǎn)足工業(yè)上的需要。在最優(yōu)條件下,地溝油可以達(dá)到生產(chǎn)生物柴油的標(biāo)準(zhǔn),并且在實(shí)驗(yàn)中得到了較好的效果,符合工業(yè)上的生產(chǎn)要求,降低了工業(yè)成本。
[Abstract]:With the rapid development of social economy, the problem of energy shortage and environmental pollution is becoming more and more serious. Biodiesel is a kind of biofuel that can replace fossil fuel. High acid value oil is used as the raw material for the production of biodiesel in two steps (reducing acid first by preesterification, then transesterification). It has obvious advantages in cost control and environmental pollution control. Traditional pre-esterification reaction uses concentrated sulfuric acid as catalyst, and corrosion equipment exists, the catalyst can not be reused. The solid catalyst can avoid the difficult separation of liquid acid and the generation of toxic waste, but the high cost and high reaction conditions of solid acid restrict its development. The application of low eutectic solvent as catalyst to reduce the production cost of biodiesel has been studied both at home and abroad. In this paper, a new low eutectic solvent of choline chloride / methanesulfonic acid was developed to catalyze the methyl esterification of free fatty acids in high acid value feedstock oil and gutter oil. The difference between choline chloride and methyl sulfonic acid was discussed. The effect of molar ratio on esterification, The catalytic ability, catalytic activity and stability of self-made DES were discussed. The optimum conditions of DES in esterification reaction were obtained by using the response surface method, and the gutter oil with different acid values was obtained under the optimal conditions. Biodiesel was synthesized from raw oil and analyzed by gas chromatography. The composition of methyl ester in biodiesel was obtained. In this study, we obtained the following conclusion: 1) the catalytic activity of DES was strongest at 1:2 when the molar ratio of choline chloride to methyl sulfonic acid was 1:2, which provided a feasible reference for the industrial production of DES from preparation to biosynthesis of biodiesel. At the same time, the density and PH value and electrical conductivity of DES were greatly influenced by different molar ratios. With the increase of molar ratio, these three physical parameters all increased. (2) in order to study the activity and catalytic ability of DES, DES was used to catalyze feedstock with different acid values. Compared with industrial catalysts and solid catalysts, the DES was recycled and reused. Finally, it was found that DES was the most effective catalyst and had good catalytic effect for high or low acid value. When DES was reused for 6 times, the esterification rate changed very little. This breaks down the disadvantage that liquid acid can't be reused.) response surface method is used to get the optimum condition for esterification of acetylcholine chloride / methyl sulfonic acid at 1:2: reaction temperature: 70 鈩，

本文編號(hào)：1693075