發(fā)布時(shí)間：2018-03-25 14:37

  本文選題：蓖麻油　切入點(diǎn)：脫水　出處：《安徽理工大學(xué)》2017年碩士論文

【摘要】：蓖麻油可用于合成許多工業(yè)制品,這些工業(yè)制品在諸多領(lǐng)域有著廣泛的應(yīng)用。因此,加大對(duì)蓖麻油深加工的發(fā)展力度是必然的趨勢(shì)。目前,蓖麻油脫水這一條工業(yè)鏈已日漸成熟,但是還存在許多問題。由于蓖麻油需要在較高的溫度下進(jìn)行脫水反應(yīng),在反應(yīng)過程中,易發(fā)生熱聚合、熱裂解等副反應(yīng),使得蓖麻油脫水程度不高。為了提高蓖麻油脫水反應(yīng)效率,本文將NaHSO4負(fù)載于MCM-41中制得NaHSO4/MCM-41催化劑,并通過改變催化劑制備方法和對(duì)催化劑的物理性能進(jìn)行改性,提高催化劑的催化效率。將NaHSO4負(fù)載于MCM-41上制得NaHSO4/MCM-41催化劑。通過對(duì)催化劑進(jìn)行XRD、N2吸附脫附、NH3-TPD、FT-IR、TG、吡啶紅外分析研究催化劑的物理化學(xué)性質(zhì)。分析結(jié)果表明:MCM-41的六方介孔結(jié)構(gòu)沒有改變,而且NaHS04成功的負(fù)載到MCM-41上。實(shí)驗(yàn)結(jié)果表明:NaHSO4/MCM-41的催化效果比NaHSO4的催化效果好。在最優(yōu)工藝條件下:反應(yīng)時(shí)間70 min、NaHSO4負(fù)載量25 wt%、反應(yīng)溫度240℃、催化劑用量4 wt%,催化產(chǎn)物的碘值和羥值分別為134.2 g(I2)/100g 和 17.3 mg(KOH)/g。以不同浸漬順序合成了十二烷基三乙氧基硅烷(DTEOS)改性的NaHSO4/MCM-41催化劑(硅烷化催化劑)并將其應(yīng)用于蓖麻油脫水反應(yīng)中。通過 XRD、N2 吸附脫附、SEM、TEM、紅外、XPS、29Si MAS NMR、接觸角、NH3-TPD和吡啶紅外等表征分析催化劑的物理化學(xué)性能。分析結(jié)果表明:硅烷化提高催化劑的疏水性;硅烷化催化劑的不同的浸漬步驟對(duì)催化劑的NaHSO4的分散度、比表面積、酸位分布和疏水性能均有很大的影響。評(píng)價(jià)結(jié)果表明:硅烷化催化劑的催化活性均高于NaHSO4/MCM-41的催化活性;在硅烷化催化劑中,同時(shí)浸漬DTEOS和NaHSO4的催化劑作用后得到的產(chǎn)物具有最高的碘值和最低的羥值。以超臨界浸漬法制備了 NaHSO4/MCM-41-SUP催化劑作為蓖麻油脫水的催化劑,并以常規(guī)浸漬法制備的NaHSO4/MCM-41-IMG催化劑作為對(duì)照。結(jié)果證實(shí):NaHSO4/MCM-41-SUP的催化效果和重復(fù)使用性能比NaHSO4/MCM-41-IMG好。采用XRD、N2吸附脫附、NH3-TPD、吡啶紅外、紅外、TG和CHNS元素分析來測(cè)試催化劑的物理化學(xué)性能。根據(jù)表征結(jié)果,超臨界二氧化碳浸漬方法有利于提高NaHSO4的分散度、增加NaHSO4和MCM-41間的作用位點(diǎn)、增強(qiáng)催化劑的熱穩(wěn)定性并且提高催化劑的中酸位和Bransted酸位的量。因此,NaHSO4/MCM-41-SUP中NaHSO4的浸出量和積碳量會(huì)降低,從而它的失活速率會(huì)降低。此外該催化劑的重復(fù)使用性能很好。經(jīng)過六次使用后,NaHSO4/MCM-41-IMG作用后得到的產(chǎn)物的碘值從135.2 g(I2)/100g降為114.2 g(I2)/100g,羥值從 14.7 mg(KOH)/g 增為 59.1 mg(KOH)/g(NaHSO4/MCM-41-IMG中積碳量和S元素浸出量分別為11.5 wt%和51.8%),而NaHSO4/MCM-41-SUP作用后得到的產(chǎn)物的碘值從137.5 g(I2)/100g降為134.5 g(I2)/100g,羥值從13.1 mg(KOH)/g 增為 16.5 mg(KOH)/g(NaHSO4/MCM-41-SUP 中積碳量和 S 元素浸出量分別為4.7 wt%和10.9%)。
[Abstract]:Castor oil can be used to synthesize many industrial products, which are widely used in many fields. Therefore, it is an inevitable trend to increase the development of castor oil deep processing. The industrial chain of castor oil dehydration has matured gradually, but there are still many problems. Since castor oil needs dehydration reaction at a higher temperature, it is easy to take place in the process of thermal polymerization, pyrolysis and other side reactions. The degree of dehydration of castor oil is not high. In order to improve the efficiency of dehydration reaction of castor oil, the NaHSO4/MCM-41 catalyst was prepared by loading NaHSO4 in MCM-41, and the physical properties of the catalyst were modified by changing the preparation method of the catalyst. The catalytic efficiency of the catalyst was improved. The NaHSO4/MCM-41 catalyst was prepared by loading NaHSO4 on MCM-41. The physical and chemical properties of the catalyst were studied by the adsorption and desorption of NH _ 3-TPD-FT-IRT _ (TG) on the catalyst. The results showed that the hexagonal mesoporous structure of the catalyst was not changed, the results showed that the hexagonal mesoporous structure of the catalyst was not changed. Moreover, NaHS04 was successfully loaded on MCM-41. The experimental results showed that the catalytic effect of w / NaHSO _ 4 / MCM-41 was better than that of NaHSO4. Under the optimum conditions, the reaction time was 70 min, the loading amount of NaHSO _ 4 was 25 wt, and the reaction temperature was 240 鈩，

本文編號(hào)：1663575