本文選題：吸附分離 + 理想吸附溶液理論�。� 參考：《浙江師范大學》2015年碩士論文

【摘要】：現(xiàn)代化工業(yè)社會過多使用化石燃料,釋放大量的C02等溫室氣體,嚴重危害地球生態(tài)平衡,而吸附分離技術是目前捕集C02最有效的方法之一。多孔芳香骨架材料(Porous aromatic frameworks, PAFs)則由于其巨大的比表面積、良好的物理化學穩(wěn)定性、孔容和孔徑可調控性及永久的微孔性等優(yōu)良特性,使得此類材料在氣體吸附分離等領域有著廣泛的應用前景。本文選用PAF-1材料作為前驅體對其進行碳化后處理,并初步研究碳化材料對C02的吸附分離性能,文章主要圍繞以下三個方面進行研究：1.首先參考文獻合成四溴代四苯甲烷并以其為聚合反應單體,利用金屬Ni催化的厄爾曼偶聯(lián)反應合成具有金剛石結構的PAF-1材料。然后,采用KOH作為活化劑,通過高溫處理以實現(xiàn)PAF-1的碳化,并考察活化溫度對碳化材料結構的影響。利用XRD、SEM、TGA和N2吸脫附等表征手段對所得材料進行結構表征,結果表明,所制備的PAF-1材料具有較高的BET比表面積(3921 m2/g),最可幾孔徑分布在約1.4 nm處。碳化后所得材料BET比表面積均有所下降,孔徑變小,孔徑分布結果顯示其同時具有0.5-0.8 nm和1.2 nm兩種尺寸的孔。在實驗考察溫度范圍內,碳化材料的BET比表面積、總孔容及微孔孔容都隨著碳化溫度的升高而升高,其中以800℃為最佳碳化溫度。2.選取碳化溫度為800℃的碳化材料(K-PAF-1-800)作為吸附劑,利用靜態(tài)體積法分別測定了CO2、CH4和N2在25℃、37℃和50℃下的單組分氣體吸附等溫線,并選用Toth模型對實驗數(shù)據(jù)進行擬合。結果表明,該模型可以很好地描述實驗測得的吸附等溫線。此外,采用Clausius-Clapeyron方程計算獲得等量吸附熱隨吸附量的變化曲線,獲得了吸附熱力學參數(shù)。當吸附量較低時,CO2、CH4和N2的等量吸附熱隨著吸附量的升高有所增加,但隨著吸附量的進一步升高,等量吸附熱反而呈下降趨勢,這與K-PAF-1-800同時具有兩種尺寸的孔有關,當吸附量較低時,吸附主要發(fā)生在小孔孔道中,隨著吸附量的增加,吸附質分子之間的作用力增加,從而導致等量吸附熱隨著吸附量的升高而增加；當吸附質在小孔孔道中充填滿后,吸附質分子只能在大孔孔道中吸附,由于吸附質分子與大孔孔道間的作用力較弱,從而導致等量吸附熱隨著吸附量的升高而降低。3.基于三種吸附質分子在K-PAF-1-800上的吸附強度不同,采用穿透柱技術測定了CO2/N2和CO2/CH4雙組分混合氣體在K-PAF-1-800上的吸附分離行為。實驗結果表明,我們所研究的K-PAF-1-800材料對CO2/N2和CO2/CH4兩種不同的混合體系均表現(xiàn)出良好的吸附分離性能。此外,利用理想吸附溶液理論(ideal adsorbed solution theory, IAST)對雙組分混合氣體的吸附分離性能進行了預測,預測結果與穿透柱實驗結果基本相符。
[Abstract]:In modern industrial society, excessive use of fossil fuels, release of a large amount of CO2 and other greenhouse gases, seriously endangers the ecological balance of the earth. Adsorption and separation technology is one of the most effective methods to capture CO2 at present.The porous aromatic frames (PAFs) have excellent properties such as large specific surface area, good physical and chemical stability, pore volume and pore size control, and permanent micropore properties.This kind of material has a wide application prospect in gas adsorption separation and other fields.In this paper, PAF-1 was chosen as the precursor for carbonization and post-treatment, and the adsorption and separation properties of CO2 were preliminarily studied. The study focused on the following three aspects: 1.Firstly, tetrabromotetraphenylmethane was synthesized with reference to the literature and used as polymerization monomer to synthesize PAF-1 material with diamond structure by Erman coupling reaction catalyzed by metal Ni.Then, KOH was used as activator to realize the carbonization of PAF-1 by high temperature treatment, and the effect of activation temperature on the structure of carbonized materials was investigated.The structure of the PAF-1 was characterized by XRD-SEMGA and N2 adsorption and desorption. The results showed that the prepared PAF-1 material had a high BET specific surface area of 3921 m2 / g ~ (-1) and the most suitable pore size was about 1.4 nm.After carbonization, the BET surface area decreased and the pore size became smaller. The pore size distribution showed that the pore size was 0.5-0.8 nm and 1.2nm at the same time.The BET surface area, total pore volume and micropore volume of carbonized materials increased with the increase of carbonation temperature, and the optimum carbonization temperature was 800 鈩，

本文編號：1739034