【摘要】： 在能源危機的沖擊下,世界各國都在加速新能源的開發(fā)和利用,燃料乙醇作為一種高效,清潔的可再生能源得到廣泛關(guān)注。隨著膜分離技術(shù)的發(fā)展,滲透汽化法作為一種高效、節(jié)能膜分離技術(shù)受到廣泛的關(guān)注。而優(yōu)先透醇滲透汽化膜被認為是未來制取燃料乙醇的關(guān)鍵技術(shù)之一。目前對于優(yōu)先透醇膜的研究仍然以板式膜為主,但是中空纖維滲透汽化膜組件具有裝填密度高、自支撐結(jié)構(gòu),成本低等優(yōu)勢,具有較大的潛在應(yīng)用價值。 鑒于此,本文以聚砜超濾膜為基膜,通過動態(tài)加壓復(fù)合聚二甲基硅氧烷(PDMS)試制內(nèi)皮層式中空纖維PDMS/PS優(yōu)先透醇滲透汽化膜。實驗首先對不同成膜方式下的滲透汽化透醇性能進行比較,得出倒向動態(tài)復(fù)合法可以獲得較好的分離效果。在此基礎(chǔ)上,考察了動態(tài)過濾時間,PDMS聚合物濃度,交聯(lián)劑TEOS濃度等因素對PDMS/PS復(fù)合膜的滲透汽化透醇性能的影響。得出制備的適宜條件為：動態(tài)過濾時間60min；聚合物PDMS濃度22.8wt%；交聯(lián)劑TEOS濃度1.5wt%。對復(fù)合前后中空纖維膜的內(nèi)表面進行電鏡,原子力顯微鏡,接觸角的分析表征,證實了致密分離層的形成。在50℃時,該復(fù)合膜對8wt.%乙醇／水體系的分離因子可達6.4,滲透通量約265 g/m2.h。進一步測定了復(fù)合膜對不同醇／水體系滲透汽化透醇性能,發(fā)現(xiàn)在相同的復(fù)合條件下,該復(fù)合膜對異丙醇／水體系的分離因子可達10.1,滲透通量為(50℃)。 本文還進一步在PDMS溶液中加入改性后的沸石分子篩,動態(tài)加壓法制備了內(nèi)皮層中空纖維PDMS-Silicalite/PS優(yōu)先透醇滲透汽化膜。實驗考察了分子篩添加量,超聲時間等因素對PDMS-Silicalite/PS復(fù)合膜的滲透汽化透醇性能的影響。得出在硅鋁比為500條件下,超聲10h,分子篩添加量為0.15wt.%,時對8wt.%的乙醇／水體系分離因子能達到10.0,滲透通量為1076g/m2.h。實驗還比較了不同硅鋁比對PDMS-Silicalite/PS復(fù)合膜的滲透汽化透醇性能的影響,得出：硅鋁比越高,滲透汽化分離性能越好。對分子篩改性前后進行紅外光譜等的表征證實了改性后分子篩分子結(jié)構(gòu)的變化,對復(fù)合前后中空纖維膜的內(nèi)表面進行電鏡,原子力顯微鏡,接觸角的分析,證實了疏水致密雜化分離層的形成。
[Abstract]:Under the impact of energy crisis, every country in the world is speeding up the development and utilization of new energy. Fuel ethanol, as a kind of efficient and clean renewable energy, has received extensive attention. With the development of membrane separation technology, pervaporation as a kind of high efficiency and energy-saving membrane separation technology has received extensive attention. The preferential pervaporation membrane is considered as one of the key technologies for the preparation of fuel ethanol in the future. At present, the research on preferential permeable alcohol membrane is still focused on the plate membrane, but the hollow fiber pervaporation membrane module has the advantages of high filling density, self-supporting structure and low cost, so it has great potential application value. In view of this, the endothelial layer hollow fiber PDMS/PS was preferentially permeated into alcohol pervaporation membrane by using polysulfone ultrafiltration membrane as the base membrane and dynamic pressure composite polydimethylsiloxane (PDMS). In this experiment, the pervaporation of alcohol pervaporation under different membrane formation methods was compared, and it was concluded that the reverse dynamic composite method could obtain a better separation effect. On this basis, the effects of dynamic filtration time, polymer concentration and crosslinking agent TEOS concentration on the pervaporation and alcohol permeability of PDMS/PS composite membrane were investigated. The optimum conditions were obtained as follows: the dynamic filtration time was 60 min, the concentration of polymer PDMS was 22.8wt, the concentration of crosslinking agent TEOS was 1.5wt. The formation of dense separation layer was confirmed by electron microscope atomic force microscope and contact angle analysis on the inner surface of hollow fiber membrane before and after composite. At 50 鈩，

本文編號：2257902