【摘要】：隨著石油資源的不斷枯竭及環(huán)境污染的日趨加劇,生物油作為新型環(huán)保的可再生能源受到各國的重點(diǎn)關(guān)注。然而,由生物質(zhì)裂解而得到的生物油因含有大量含氧化合物,包括醇類、酮類、酸類和酚類等,氧含量高達(dá)50%以上,導(dǎo)致生物油的熱值低、儲(chǔ)存和熱穩(wěn)定性差、腐蝕性強(qiáng),阻礙了其廣泛應(yīng)用,因此可以通過對(duì)生物油進(jìn)行催化加氫脫氧,改善其品質(zhì)。采用非晶態(tài)雷尼鎳催化劑,在高壓反應(yīng)釜內(nèi)對(duì)二丙酮醇、糠醛、苯酚和愈創(chuàng)木酚等生物油含氧化合物進(jìn)行低溫催化加氫實(shí)驗(yàn),研究和推測了模型化合物催化加氫特性及反應(yīng)機(jī)理。實(shí)驗(yàn)結(jié)果表明:溫度是影響催化加氫活性的最主要因素,溫度過高容易導(dǎo)致催化劑晶化而降低催化活性;在反應(yīng)溫度180℃、壓力3 MPa、反應(yīng)時(shí)間4 h以及催化劑量8wt.%時(shí),模型化合物的轉(zhuǎn)化率和飽和醇的選擇性分別達(dá)到100.00%和97.74%以上;在此反應(yīng)條件催化真實(shí)生物油的體系中,飽和醇的收率達(dá)到44.00%,pH從4.08升至5.13;通過對(duì)模型反應(yīng)機(jī)理的探討,得出模型主要通過兩種加氫方式進(jìn)行:即不同化合物分別以其O上的孤對(duì)電子選擇性地與催化劑上的兩種活潑態(tài)H(弱吸附的Ni-H、游離的原子態(tài)氫)進(jìn)行加氫反應(yīng),完成催化加氫過程。通過化學(xué)還原法制備了以KBH4為還原劑的Ni-B催化劑,考察了添加助劑Co和載體γ-Al2O3對(duì)制備Ni-B催化劑及其催化性能的影響,并采用X射線衍射儀(XRD)、比表面積(BET)和掃描電子顯微鏡(SEM)對(duì)催化劑的形貌進(jìn)行表征。由表征結(jié)果分析可知:所制備的催化劑均為非晶態(tài)催化劑,催化劑的熱穩(wěn)定性順序?yàn)镹i-Co-B/γ-Al2O3-20%Ni-Co-B-5/5Ni-B-3.5;與Ni-B-3.5和Ni-Co-B-8/2相比,Ni-Co-B/γ-Al2O3-20%催化劑的顆粒更加細(xì)微、分散更加均勻;負(fù)載γ-Al2O3之后的催化劑比表面積更大,有利于提高催化劑的活性。以糠醛、二丙酮醇和愈創(chuàng)木酚的催化加氫為探針反應(yīng)考察了Ni-B系催化劑Ni/Co摩爾比、金屬負(fù)載量等制備條件以及反應(yīng)溫度、壓力、時(shí)間對(duì)催化劑性能的影響。使用Ni-Co-B-5/5為催化劑時(shí),150℃、4MPa、反應(yīng)4 h,糠醛和二丙酮醇的轉(zhuǎn)化率分別為100.00%和98.45%,產(chǎn)物中戊醇和四氫呋喃的量分別為10.65%和14.91%,催化劑開始具有加氫脫氧效果;而使用Ni-Co-B/γ-Al2O3-20%時(shí),反應(yīng)溫度210℃,壓力4 MPa,反應(yīng)時(shí)間4 h的情況下,糠醛、二丙酮醇和愈創(chuàng)木酚的轉(zhuǎn)化率分別為100.00%、100.00%和76.82%,產(chǎn)物戊醇、四氫呋喃和環(huán)己烷的選擇性分別為10.51%、20.12%和11.06%。
[Abstract]:With the continuous depletion of petroleum resources and the worsening of environmental pollution, bio-oil as a new type of renewable energy environment has been the focus of attention. However, the bio-oil obtained from biomass pyrolysis contains a large number of oxygen-containing compounds, including alcohols, ketones, acids and phenols, and the oxygen content is as high as 50%, which results in low calorific value, poor storage and thermal stability, and strong corrosion. Therefore, it can improve the quality of bio-oil by catalytic hydrogenation deoxidation. The hydrogenation of oxygen compounds in bio-oil such as diacetone alcohol furfural phenol and guaiacol was carried out in a autoclave with amorphous Raney nickel catalyst at low temperature. The catalytic hydrogenation characteristics and reaction mechanism of the model compounds were studied and speculated. The experimental results show that temperature is the most important factor affecting the catalytic hydrogenation activity, and too high temperature can lead to the crystallization of the catalyst and decrease the catalytic activity, and when the reaction temperature is 180 鈩，

本文編號(hào)：2194480