【摘要】：生物柴油作為一種可再生的環(huán)保燃料,可用以替代傳統(tǒng)的化石燃料,在能源、資源日益枯竭的今天,其對(duì)社會(huì)的可持續(xù)發(fā)展具有重要意義。傳統(tǒng)的生物柴油制備過程中,原料油的高酸值問題一直是亟待解決的問題之一。原料油的酸值高,生物柴油制備過程就會(huì)變得復(fù)雜,且對(duì)產(chǎn)品生物柴油的品質(zhì)有較大影響。本文以酸值較高的地溝油為原料,研究了從原料脫酸,到酯交換反應(yīng),再到粗產(chǎn)品精制的整個(gè)生產(chǎn)工藝,并對(duì)副產(chǎn)物甘油的精制工藝進(jìn)行了探討。主要研究內(nèi)容如下:(1)本文采用“萃取-堿煉聯(lián)合法”對(duì)地溝油進(jìn)行脫酸處理。得到萃取脫酸的最佳工藝條件:以95%乙醇為萃取劑,萃取液液比1:2.0(w/w),萃取次數(shù)2次,萃取時(shí)間每次10min,萃取溫度30℃,在此條件下可將原料地溝油的酸值由40.35mg KOH/g降至2.36mg KOH/g;再用堿煉法將地溝油的酸值降低至0.28mg KOH/g。(2)以KOH為催化劑催化酯交換過程的進(jìn)行。得到酯交換過程的最佳條件:反應(yīng)操作時(shí)間60min,反應(yīng)操作溫度60℃,甲醇用量18%(w/w),催化劑用量0.7%(w/w)。在該條件下,油脂的轉(zhuǎn)化率可達(dá)97.53%,粗生物柴油層產(chǎn)率達(dá)98.36%。(3)分別探討了“酸洗-水洗法”和“鹽析-酸洗-水洗法”對(duì)生物柴油除雜過程的影響,并對(duì)兩種方法的處理結(jié)果進(jìn)行了比較。得到最佳的“酸洗-水洗法”工藝條件:1次酸洗2次水洗,用水20%,用酸0.1%,溫度60℃。在所得條件下,除雜后的產(chǎn)品的酸值為0.36mg KOH/g,總甘油含量為0.34%,油品回收率為98.54%。后在“酸洗-水洗法”的基礎(chǔ)上,增加一步鹽析過程,得到最佳的鹽析條件為:NaCl溶液濃度10%,NaCl溶液用量15%(w/w),鹽析溫度60℃。在“鹽析-酸洗-水洗法”的最佳操作條件下,生物柴油的酸值降至0.24mg KOH/g,總甘油含量降至0.25%,油品回收率為98.12%。(4)分別用活性炭和過氧化氫對(duì)生物柴油進(jìn)行兩次脫色。得到最佳的活性炭脫色工藝條件為:脫色操作溫度60℃,脫色操作時(shí)間2h,活性炭用量3%(w/w)。在該最佳條件下,油品的脫色率可達(dá)70.65%,油品的回收率達(dá)98.84%。得到過氧化氫二次脫色最佳工藝條件為:H_2O_2用量15%(w/w),脫色操作溫度60℃,脫色操作時(shí)間5h,H_2O_2濃度15%,在該最佳工藝條件下,油品的脫色率為15.89%,油品的回收率為99.12%。經(jīng)兩次脫色處理后,油品的總脫色率可達(dá)到76.28%,油品的回收率為97.97%,同時(shí),生物柴油中的總甘油含量可降至0.12%,游離甘油含量為0.012%。(5)對(duì)副產(chǎn)物甘油的精制工藝進(jìn)行了研究。得到最佳粗甘油除雜工藝參數(shù)為:操作溫度50℃,甲醇用量50%(w/w),操作時(shí)間40min,溶液pH值在4左右,在所得最佳工藝條件下,甘油的含量由61.08%提升至88.04%,甘油的回收率為87.34%。甘油脫色的最佳工藝條件為:脫色溫度60℃,脫色時(shí)間2h,活性炭用量3%(w/w)。,甲醇用量50%(w/w)。在所得最佳脫色工藝下,甘油含量進(jìn)一步提升至95.41%,最終回收率達(dá)85.47%。
[Abstract]:Biodiesel, as a renewable environmental protection fuel, can be used to replace traditional fossil fuels. Nowadays, energy and resources are increasingly exhausted, which is of great significance to the sustainable development of society. In the traditional preparation process of biodiesel, the problem of high acid value of feedstock oil has always been one of the problems to be solved urgently. When the acid value of raw oil is high, the preparation process of biodiesel will become complex, and it will have a great influence on the quality of biodiesel. Using furrow oil with high acid value as raw material, the whole production process from deacification of raw material to transesterification reaction to refining of crude product was studied, and the refining process of by-product glycerol was discussed. The main research contents are as follows: (1) in this paper, the extraction-alkali refining method was used to deacify the furrow oil. The optimum extraction conditions were as follows: 95% ethanol as extractant, extraction liquid-liquid ratio 1 鈮，

本文編號(hào)：2494899