【摘要】：木質(zhì)素是自然界中最豐富的芳香類化合物,也是制漿造紙和木質(zhì)纖維素生物煉制過程的主要副產(chǎn)物。熱解是將木質(zhì)素資源化、能源化利用的一個(gè)有效途徑。但由于分離方法不同,所得的木質(zhì)素產(chǎn)品具有不同的熱解特性。本文通過有機(jī)酸處理、堿處理和氧化處理從甘蔗渣中分離得到5種木質(zhì)素,即乙酸木質(zhì)素(AAL)、Acetosolv木質(zhì)素(As L)、Milox木質(zhì)素(ML)、過氧乙酸木質(zhì)素(PAAL)和堿木質(zhì)素(AL)。采用差示掃描量熱(DSC)和熱重分析(TGA)對(duì)5種木質(zhì)素的熱解性質(zhì)進(jìn)行了研究。發(fā)現(xiàn)5種木質(zhì)素的熱解過程均可分為水分脫除、玻璃化轉(zhuǎn)變、熱解和緩慢結(jié)焦4個(gè)階段。采用非等溫的Coats-Redfern積分法對(duì)熱重?cái)?shù)據(jù)進(jìn)行動(dòng)力學(xué)擬合。結(jié)果表明,PAAL在200~700℃范圍內(nèi)的熱解為二級(jí)動(dòng)力學(xué)反應(yīng),另外4種木質(zhì)素則在250~700℃范圍內(nèi)為二級(jí)動(dòng)力學(xué)反應(yīng)。5種木質(zhì)素的熱解表觀活化能分別為AAL 33.33kJ/mol、As L 36.36kJ/mol、ML 31.10kJ/mol、PAAL24.74kJ/mol以及AL 36.93 kJ/mol。
[Abstract]:Lignin is one of the most abundant aromatic compounds in nature, and it is also the main by-product of pulping, papermaking and lignocellulosic biological refining process. Pyrolysis is an effective way to utilize lignin as resource and energy. However, due to the different separation methods, the lignin product has different pyrolysis properties. In this paper, five kinds of lignin were isolated from bagasse by organic acid treatment, alkali treatment and oxidation treatment, that is, acetic acid lignin, (AAL), Acetosolv lignin, (As L), Milox lignin (ML),. Peroxyacetate lignin (PAAL) and Alkali lignin (AL). The pyrolysis properties of lignin were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). It was found that the pyrolysis process of lignin could be divided into four stages: water removal, glass transition, pyrolysis and slow coking. The thermogravimetric data were fitted by non isothermal Coats-Redfern integration method. The results show that the pyrolysis of PAAL at 200 鈩，

本文編號(hào)：2298848