本文選題：金屬鎳　切入點(diǎn)：相轉(zhuǎn)化　出處：《天津工業(yè)大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：氫氣是重要的石油化工原料,作為清潔能源能有效緩解由于溫室氣體排放造成的環(huán)境污染。傳統(tǒng)金屬鈀及其合金膜在氫氣分離應(yīng)用中存在著成本高、不耐高溫、極易氫脆等缺點(diǎn),金屬鎳膜克服了傳統(tǒng)鈀膜這些缺點(diǎn),對于重整氣分離氫有很大應(yīng)用前景。本文運(yùn)用干濕紡絲法制備了金屬鎳中空纖維膜前驅(qū)體,并探索了紡絲條件對膜厚度的影響,進(jìn)一步通過燒結(jié)技術(shù)得到致密的金屬鎳中空纖維膜。結(jié)合機(jī)械強(qiáng)度、XRD、SEM等表征手段對所得到的金屬鎳中空纖維膜進(jìn)行表征,并對金屬鎳中空纖維膜進(jìn)行了透氫測試。首先成功制備了金屬鎳中空纖維膜前驅(qū)體,實(shí)驗(yàn)結(jié)果表明在含氫氣混合氣的氣氛下,經(jīng)過1400℃左右燒結(jié)3小時(shí),能夠得到所需的致密的金屬鎳中空纖維膜。透氫測試在溫度高達(dá)1000℃下進(jìn)行,原料氣是含氫的混合氣,氮?dú)庾鳛榇祾邭狻錃鉂B透經(jīng)過致密金屬鎳中空纖維膜的控速步驟主要是通過氫原子擴(kuò)散控制。金屬鎳膜的厚度在256μm,在1000℃下氫氣的滲透通量能夠達(dá)到7.66× 10-3 mol m~(-2) s~(-1),并且達(dá)到100%的氫氣選擇性。金屬鎳膜在含CO_2、CO、水蒸氣的氣氛下表現(xiàn)高的氫氣選擇穩(wěn)定性,顯示其在高溫下烴重整制氫中潛在的應(yīng)用。然后通過控制芯液流速和空氣距這兩個(gè)紡絲條件制備出了不同厚度的金屬鎳中空纖維膜。實(shí)驗(yàn)表明在紡絲的過程中留有一定的空氣距有利于形成具有更高機(jī)械強(qiáng)度的中空纖維膜。金屬鎳中空纖維膜的透氫通過西韋特方程進(jìn)行描述,這表明可以通過進(jìn)一步減小膜的厚度來減小擴(kuò)散的阻力來提高膜的透量。通過順流模式切換到逆流模式中空纖維膜的透氫速率能提高4-8%。金屬鎳中空纖維膜在不同操作條件下的透氫結(jié)果可以通過數(shù)學(xué)模型的計(jì)算進(jìn)行預(yù)測。
[Abstract]:Hydrogen is an important petrochemical raw material. As a clean energy, it can effectively alleviate the environmental pollution caused by greenhouse gas emissions. Traditional palladium and its alloy membrane have high cost and high temperature resistance in hydrogen separation. Metal nickel membrane overcomes these shortcomings of traditional palladium membrane and has great application prospect for hydrogen separation by reforming gas. In this paper, nickel hollow fiber membrane precursor was prepared by dry and wet spinning method. The influence of spinning conditions on the membrane thickness was explored, and the dense nickel hollow fiber membrane was obtained by sintering technology. The metal nickel hollow fiber membrane was characterized by means of mechanical strength and XRDX SEM. Firstly, the metal nickel hollow fiber membrane precursor was successfully prepared. The experimental results showed that the precursor was sintered at 1400 鈩，

本文編號(hào)：1604178