本文選題：甲醇　切入點(diǎn)：甲醛　出處：《西北大學(xué)》2017年碩士論文

【摘要】：將聚甲氧基二甲醚用作柴油添加劑使用,與柴油組成混合燃料。使用時(shí)具有環(huán)保及高效性能,可有效節(jié)能減排。本實(shí)驗(yàn)使用低成本原料甲醇、甲醛及低成本催化劑酸性樹(shù)脂進(jìn)行合成研究,旨在為聚甲氧基二甲醚的生產(chǎn)提供一個(gè)新的路線。本文合成實(shí)驗(yàn)使用甲醇、甲醛在酸性樹(shù)脂催化劑上合成聚甲氧基二甲醚。本文的主要工作為催化劑研究和合成工藝條件考察。在催化劑研究中,首先篩選樹(shù)脂催化劑,在催化機(jī)理分析基礎(chǔ)上,在樹(shù)脂引入含有質(zhì)子酸的酸性基團(tuán),并在此基礎(chǔ)上再次引入路易斯酸改性催化劑酸性,同時(shí)考察催化劑再生條件。并對(duì)其合成工藝進(jìn)行優(yōu)化,得到優(yōu)化的工藝條件。首先,討論了甲醇甲醛合成聚甲氧基二甲醚的催化反應(yīng)機(jī)理,是在酸性樹(shù)脂催化下的縮醛化反應(yīng)。本實(shí)驗(yàn)對(duì)部分市售酸性樹(shù)脂進(jìn)行篩選,實(shí)驗(yàn)結(jié)果顯示:聚合反應(yīng)時(shí)強(qiáng)酸性樹(shù)脂D001催化效果較優(yōu)。甲醇轉(zhuǎn)化率為43.5%,產(chǎn)物選擇性為40.8%。其次,以聚苯乙烯白球樹(shù)脂作為底物,對(duì)催化劑進(jìn)行酸化。使用濃硫酸、發(fā)煙硫酸、氨基磺酸、濃磷酸和醋酸對(duì)白球樹(shù)脂進(jìn)行酸化,調(diào)節(jié)催化劑的酸性。結(jié)果表明:發(fā)煙硫酸制備出的強(qiáng)酸性樹(shù)脂具有較高的催化活性。聚合反應(yīng)甲醇轉(zhuǎn)化率為45.8%,產(chǎn)物選擇性為46.3%。在此基礎(chǔ)上對(duì)強(qiáng)酸樹(shù)脂引入路易斯酸進(jìn)行改性,繼續(xù)優(yōu)化其酸性。使用結(jié)果表明:以FeCl3為改性劑時(shí)性能最佳。聚合反應(yīng)甲醇轉(zhuǎn)化率為53.0%,產(chǎn)物選擇性為49.0%。對(duì)強(qiáng)酸樹(shù)脂和路易斯酸改性的催化劑進(jìn)行表征,表明改性催化劑改性基團(tuán)穩(wěn)定的結(jié)合到樹(shù)脂上,改性未影響樹(shù)脂自身結(jié)構(gòu),且改性后其酸強(qiáng)度降低、酸中心數(shù)量增多。使用FeCl3改性催化劑對(duì)PODEn的反應(yīng)工藝條件進(jìn)行了考察。最優(yōu)條件為:反應(yīng)溫度控制在90～96℃范圍內(nèi),壓力1.0MPa,物料比n(CH2O):n(CH3OH)=3:1,重時(shí)空速1.5h-1。聚合反應(yīng)甲醇轉(zhuǎn)化率和產(chǎn)物選擇性分別為57.0%和52.8%。最后對(duì)強(qiáng)酸性樹(shù)脂催化劑失活再生進(jìn)行探索。采用鹽酸對(duì)失活催化劑進(jìn)行再生,通過(guò)催化劑表征,推斷催化劑失活的主要方式是磺酸基團(tuán)中H+的損失,通過(guò)鹽酸再生可得到效果較佳的再生催化劑。
[Abstract]:Poly (methoxy) dimethyl ether was used as diesel additive and mixed with diesel oil.Use with environmental protection and efficient performance, energy saving and emission reduction can be effective.In this experiment, methanol, formaldehyde and low cost catalyst acid resin were used to synthesize polymethoxy dimethyl ether, which provided a new route for the production of poly (methoxy) dimethyl ether.In this paper, methanol and formaldehyde were used to synthesize poly (methoxy) dimethyl ether over acid resin catalyst.The main work of this paper is the study of catalyst and the investigation of synthetic conditions.In the study of catalyst, the resin catalyst was first screened, and the acidic group containing proton acid was introduced into the resin on the basis of the analysis of the catalytic mechanism, and the acid of the Lewis acid modified catalyst was introduced again on this basis.At the same time, the conditions of catalyst regeneration were investigated.The synthetic process was optimized and the optimized process conditions were obtained.Firstly, the catalytic mechanism of synthesis of poly (methoxy) dimethyl ether from methanol and formaldehyde was discussed.The results showed that the catalytic effect of strong acid resin D001 was better in polymerization reaction.The methanol conversion was 43.5 and the selectivity of the product was 40.8.Secondly, the catalyst was acidified with polystyrene white ball resin as substrate.Acid was acidified with concentrated sulfuric acid, fuming sulfuric acid, amino sulfonic acid, concentrated phosphoric acid and acetic acid to regulate the acidity of the catalyst.The results showed that the strong acid resin prepared by fuming sulfuric acid had high catalytic activity.The conversion of methanol was 45.8 and the selectivity of the product was 46.3.On this basis, the strong acid resin was modified with Lewis acid, and its acidity was optimized.The results show that FeCl3 is the best modifier.The methanol conversion of polymerization was 53.0 and the selectivity of the product was 49.0.The strong acid resin and Lewis acid modified catalyst were characterized. The results show that the modified catalyst can bind to the resin stably, and the modified catalyst does not affect the structure of the resin, and the acid strength of the modified catalyst decreases and the number of the acid center increases.The reaction conditions of PODEn were investigated by using FeCl3 modified catalyst.The optimum conditions are as follows: the reaction temperature is controlled in the range of 90 鈩，

本文編號(hào)：1710825