改性沸石分子篩催化脫水乳酸甲酯的反應(yīng)

生物工程論文編號:SW069  論文字?jǐn)?shù):12542,頁數(shù):27

目錄

中文摘要…………………………………………………………………………………………2      
英文摘要…………………………………………………………………………………………3
目錄………………………………………………………………………………………………4
 緒論…………………………………………………………………………………………6
1.1 丙烯酸的合成路線……………………………………………………………………7
1.2路線選擇………………………………………………………………………………16
1.3反應(yīng)機(jī)理………………………………………………………………………………17
實(shí)驗(yàn)部分……………………………………………………………………………………18
2.1實(shí)驗(yàn)儀器與原料………………………………………………………………………18
2.2 催化劑的制備……………………………………………………………………… 18
2.3 乳酸甲酯脫水制備丙烯酸甲酯和丙烯酸的反應(yīng)………………………………… 18
2.4 產(chǎn)品分析方法……………………………………………………………………… 19
3. 結(jié)果與討論…………………………………………………………………………………19
 3.1原料摻水量對反應(yīng)和催化3的影響………………………………………………… 19
 3.2溫度對反應(yīng)和催化劑的影響…………………………………………………………20
 3.3載氣N2對反應(yīng)和催化劑的影響……………………………………………………… 21
 3.4進(jìn)料速度對反應(yīng)和催化劑的影響……………………………………………………22
 3.5含水原料對催化劑穩(wěn)定性的影響……………………………………………………23
總結(jié)與展望…………………………………………………………………………………24
致謝…………………………………………………………………………………………… 25
參考文獻(xiàn)……………………………………………………………………………………… 26

摘要： 通過生物基路線制備丙烯酸及酯具有潛在的經(jīng)濟(jì)效益，同時(shí)對化石資源的綠色替代具有重要意義。考察了X，Y，ZSM-5等沸石分子篩經(jīng)過鉀、鈣、鈷等金屬離子交換改性后，在乳酸甲酯脫水制備生物基丙烯酸甲酯過程中的催化性能。試驗(yàn)結(jié)果表明K離子改性Y沸石分子篩對產(chǎn)物的選擇性高，而ZSM-5類具有較高的轉(zhuǎn)化率，但是選擇性低。分析結(jié)果說明：Y分子篩催化劑的高選擇性與其特有的骨架結(jié)構(gòu)相關(guān)。沸石分子篩催化劑需要通過金屬離子的交換才能調(diào)整到適當(dāng)?shù)乃釅A性實(shí)現(xiàn)最佳催化的效果。在上述結(jié)論的基礎(chǔ)上，以鉀離子改性的NaY分子篩為催化劑，對反應(yīng)溫度，反應(yīng)空速等反應(yīng)條件進(jìn)行了優(yōu)化，得到了較高的丙烯酸甲酯得率。
 關(guān)鍵詞：丙烯酸甲酯；乳酸甲酯；分子篩；離子交換

Dehydration of methyl lactate catalyzed by modified zeolites

Abstract:  Acrylates, important organic intermediates, were needed in increasingly huge amounts. However, the pressing supply situation of petroleum challenged the conventional petrobased process of acrylate production and made the biobased process potentially feasible in economy.
This paper investigated the catalytic performances of zeolites X, Y and ZSM-5 after ion exchange treatment in the dehydration of methyl lactate to methyl acrylate. The ion exchanged Y had much higher selectivity compared to ion exchanged ZSM-5, though the modified ZSM-5 had higher activity. The relatively high selectivity of zeolite Y might have correlation with its big-pore structure. Zeolite NaY was exchanged with K+ to tune the acidity of NaY. This modified zeolite showed best performance among other modified zeolite catalysts. The reaction temperature, LHSV and other conditions were optimized for the potassium exchanged zeolite NaY, and the yield of methyl acrylate was elevated.
 Key words: methyl acrylate; methyl lactate; molecular sieve; ion exchange