本文選題：低共熔溶劑 + 季銨鹽��； 參考：《北京化工大學(xué)》2015年碩士論文

【摘要】：酚類物質(zhì)是一種重要的有機(jī)化工原料,其廣泛應(yīng)用于農(nóng)藥、香料、醫(yī)藥、合成纖維、消毒劑、防腐劑、酚醛樹脂等化工產(chǎn)品及中間體的合成,有巨大的市場需求。煤焦油和煤液化油中含有豐富的酚類物質(zhì),從這些油中提取高附加值的酚類物質(zhì)具有重要意義。目前從油中分離酚類化合物主要采用NaOH洗脫法,這也是唯一大規(guī)模工業(yè)化應(yīng)用的方法。其本質(zhì)是堿洗和酸洗過程,需用大量酸堿溶液,并產(chǎn)生需再次處理的含酚廢水。因此有必要尋找一種新型分離方法進(jìn)行油酚混合物的分離。為解決上述問題,本課題組發(fā)現(xiàn)一系列季銨鹽能與油中酚類物質(zhì)形成低共熔溶劑(DES),進(jìn)而從油中萃取酚類物質(zhì)。此法操作簡單,分離率高,萃取劑低廉易得、無毒且可循環(huán)使用,有著誘人的工業(yè)應(yīng)用前景。眾所周知,新工藝的應(yīng)用需要大量熱力學(xué)及動力學(xué)基礎(chǔ)數(shù)據(jù),本文針對低共熔溶劑法分離油酚混合物過程中的相平衡及傳質(zhì)動力學(xué)內(nèi)容展開研究,論文的主要內(nèi)容和結(jié)果如下：1.本文首先對季銨鹽萃取苯酚的相平衡過程進(jìn)行研究,考察溫度及季銨鹽含量對平衡的影響。結(jié)果表明：隨著溫度升高,達(dá)到萃取平衡后,苯酚的分配系數(shù)減小,選擇性降低,不利于油酚分離過程,且達(dá)到分離飽和時所需季銨鹽的量變大,不利于從DES中反萃出季銨鹽。在一定溫度下,季銨鹽的量加到某一值后,平衡時的上下相組成不發(fā)生變化。2.通過對不同比例DES的傅里葉紅外光譜與氫核磁譜圖的分析,進(jìn)一步驗證了低共熔溶劑中氫鍵的存在。3.考察了溫度及苯酚濃度對氯化膽堿、四甲基氯化銨、四乙基氯化銨、1-丁基-3-甲基咪唑氯鹽、1-乙基-3-甲基瞇唑氯鹽五種萃取劑在甲苯中溶解度影響。結(jié)果表明：溶解度均隨著溫度的升高而升高,其中氯化膽堿與四乙基氯化銨的溶解度最小。在25℃下,五種萃取劑在純甲苯中的溶解度均很小,在20-50μg/mL范圍內(nèi)。苯酚濃度對其溶解度影響很大,苯酚濃度越大,萃取劑溶解度越大。4.為了深入了解低共熔法分離油酚混合物過程中的動力學(xué)特征,本文以氯化膽堿與苯酚形成低共熔溶劑,采用恒界面池法測定了苯酚在模擬油/DES界面的傳質(zhì)系數(shù)與萃取速率。分別考察了攪拌速度、溫度、接觸面積、季銨鹽種類及濃度對萃取過程的影響。結(jié)果表明：苯酚的萃取速率隨著攪拌速度的增加而增大。苯酚萃取的傳質(zhì)阻力主要存在于DES相,即苯酚向DES相擴(kuò)散是萃取的速控步驟；萃取速率隨著溫度的升高而升高,在所研究體系中根據(jù)阿倫尼烏斯方程得出苯酚萃取過程的正向表觀活化能為8.9 kJ·mol-1,苯酚的萃取為擴(kuò)散控制過程。界面?zhèn)髻|(zhì)系數(shù)不隨接觸面積和萃取劑濃度的的改變而發(fā)生變化,但萃取通量隨著接觸面積的增大而增大；傳質(zhì)系數(shù)和萃取速率與季銨鹽種類有關(guān),季銨鹽與苯酚形成的DES黏度越小,越有利于傳質(zhì)過程。
[Abstract]:Phenolic compounds are an important organic chemical material. They are widely used in the synthesis of chemical products and intermediates, such as pesticides, spices, medicines, synthetic fibers, disinfectants, preservatives, phenolic resins and other chemical products and intermediates. There are abundant phenolic substances in coal tar and coal liquefaction oil, and high value-added phenolic compounds are extracted from these oils. It is of great significance. NaOH elution is mainly used to separate phenolic compounds from oil, which is the only method of large-scale industrial application. The essence is alkali washing and acid washing process. It is necessary to use a large amount of acid and alkali solution and produce the wastewater that needs to be retreated again. Therefore, it is necessary to find a new separation method for the mixture of petroleum phenol. In order to solve the above problems, we found that a series of quaternary ammonium salts can form a low eutectic solvent (DES) with phenolic compounds in oil, and then extract phenolic compounds from oil. This method is easy to operate, high separation rate, cheap and easy to obtain, nontoxic and recyclable, and has a promising industrial application prospect. It is well known that the application of the new process is well known. The main contents and results of this paper are as follows: 1. firstly, the phase equilibrium process of quaternary ammonium salt extraction of phenol was studied, and the balance of temperature and quaternary ammonium salt content was investigated. The results show that with the increase of temperature, the distribution coefficient of phenol decreases and the selectivity decreases, which is not conducive to the separation process of phenol, and the quantitative change of quaternary ammonium salt needed when the separation is saturated is not favorable to the stripping of quaternary ammonium salt from DES. At a certain temperature, the amount of quaternary ammonium salt is added to a certain value and the balance is in the upper and lower levels. The phase composition did not change.2. through the analysis of Fourier transform infrared spectra and hydrogen magnetic spectra of different proportions of DES, the existence of hydrogen bonds in the low eutectic solvent.3. was further verified by the investigation of the temperature and the concentration of phenol to choline, four methyl ammonium chloride, four ethyl ammonium chloride, 1- butyl -3- methyl imidazolium chloride, 1- ethyl -3- methyl methazolium chloride. The solubility of five kinds of extractants in toluene shows that the solubility increases with the increase of temperature, and the solubility of choline chloride and four ethyl ammonium chloride is the smallest. At 25, the solubility of five extractants in pure toluene is very small, in the range of 20-50 mu g/mL. The concentration of phenol has a great influence on its solubility and the concentration of phenol is strong. The greater the degree of degree, the greater the solubility of the extractant.4. in order to understand the kinetic characteristics of the mixture of oil and phenol in the low eutectic process. In this paper, the mass transfer coefficient and extraction rate of phenol in the simulated oil /DES interface were determined by the formation of the low eutectic solvent of choline and phenol. The stirring speed, temperature and contact were investigated respectively. The effect of the area and the type and concentration of quaternary ammonium salt on the extraction process. The results show that the extraction rate of phenol increases with the increase of stirring speed. The mass transfer resistance of phenol is mainly in the DES phase, that is, the diffusion of phenol to DES phase is the speed control step of extraction; the extraction rate increases with the increase of temperature, and is based on the study system. The Arrhenius equation shows that the positive apparent activation energy of the phenol extraction process is 8.9 kJ. Mol-1, the extraction of phenol is the diffusion control process. The interfacial mass transfer coefficient does not change with the change of the contact area and the concentration of the extractant, but the extraction flux increases with the increase of the contact area; the mass transfer coefficient and extraction rate and quaternary ammonium salt The smaller the DES viscosity of quaternary ammonium salt and phenol, the better the mass transfer process.
【學(xué)位授予單位】：北京化工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TQ028.32

【參考文獻(xiàn)】

相關(guān)期刊論文 前3條

1 楊竹仙,杜慧芳,周祖銘;N,N-二(1-甲基-庚基)乙酰胺萃取苯酚的動力學(xué)研究[J];環(huán)境化學(xué);1998年03期

2 韋露;樊友軍;;低共熔溶劑及其應(yīng)用研究進(jìn)展[J];化學(xué)通報;2011年04期

3 賈永忠;賈麗;;煤焦油中酚的提取利用[J];當(dāng)代化工;2008年02期

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本文編號：2052020