【摘要】：環(huán)境污染及化石能源的有限儲(chǔ)量,使得尋找無(wú)污染、可再生的清潔能源成為日益緊迫的任務(wù)。太陽(yáng)能以其儲(chǔ)量豐富、環(huán)境友好等特點(diǎn)有望成為化石能源的理想替代能源。但太陽(yáng)能能量密度較低,不穩(wěn)定等問(wèn)題成為目前制約太陽(yáng)能快速發(fā)展的瓶頸。因此,將太陽(yáng)能轉(zhuǎn)化為氫能等容易儲(chǔ)存、能量密度高、清潔環(huán)保的二次能源成為能源領(lǐng)域研究的熱點(diǎn)之一�；谶x擇性膜分離的太陽(yáng)能熱化學(xué)方法通過(guò)選擇性地分離產(chǎn)物,促使反應(yīng)向正向進(jìn)行,提高反應(yīng)物轉(zhuǎn)化率并降低太陽(yáng)能燃料的制取溫度。本學(xué)位論文依托國(guó)家自然科學(xué)基金、國(guó)家重點(diǎn)研發(fā)計(jì)劃等科研課題,基于能的品位概念,探索太陽(yáng)能到化學(xué)能的低溫高效轉(zhuǎn)換方法。對(duì)基于選擇性膜分離的太陽(yáng)能熱化學(xué)利用過(guò)程的轉(zhuǎn)化機(jī)理、能量品位提升規(guī)律以及能量效率趨勢(shì)進(jìn)行綜合研究,并進(jìn)行實(shí)驗(yàn)驗(yàn)證。本文的主要內(nèi)容及結(jié)論如下:(一)針對(duì)選擇性膜分離的高溫太陽(yáng)能熱化學(xué)分解水或二氧化碳制取氫氣或一氧化碳過(guò)程進(jìn)行熱力學(xué)分析和模擬研究。提出基于真空泵輔助的透氧膜反應(yīng)器系統(tǒng)和基于甲烷輔助的透氧膜反應(yīng)器系統(tǒng)的能量效率變化趨勢(shì),其中基于真空泵輔助的透氧膜反應(yīng)器系統(tǒng)能量利用效率為2.9%;基于甲烷輔助的透氧膜反應(yīng)器系統(tǒng)太陽(yáng)能至化學(xué)能轉(zhuǎn)換效率可達(dá)63%。該部分理論分析為基于選擇性膜分離的高溫太陽(yáng)能熱化學(xué)實(shí)際應(yīng)用奠定理論基礎(chǔ)。(二)對(duì)上述傳統(tǒng)膜反應(yīng)器進(jìn)行改進(jìn),提出交替式透氫膜透氧膜反應(yīng)器,可以在較低溫度下大幅提高太陽(yáng)能熱化學(xué)分解水的轉(zhuǎn)化率和能量利用效率,例如在1500℃時(shí),水蒸氣轉(zhuǎn)化率從"等溫法"熱化學(xué)循環(huán)的1.26%提升至99.99%,太陽(yáng)能至化學(xué)能轉(zhuǎn)換效率從2.9%提升至42.6%。新型等溫交替透氫透氧系統(tǒng)為太陽(yáng)能分解水制氫的應(yīng)用提供有價(jià)值的研究和應(yīng)用方向。(三)針對(duì)太陽(yáng)能分解水溫度高、聚光成本高的缺點(diǎn),將傳統(tǒng)甲烷重整反應(yīng)與選擇性膜分離結(jié)合,提出基于透氫膜和透二氧化碳膜的新型中低溫太陽(yáng)能甲烷重整系統(tǒng)。系統(tǒng)可以在300-400℃實(shí)現(xiàn)甲烷的完全轉(zhuǎn)化(工業(yè)甲烷重整反應(yīng)需要在800-1000℃才能達(dá)到甲烷的完全轉(zhuǎn)化),大幅度提高能量利用效率,并可能帶來(lái)太陽(yáng)能燃料成本的顯著降低。最后,從催化劑制備、反應(yīng)器設(shè)計(jì)、實(shí)驗(yàn)臺(tái)搭建、系統(tǒng)流程設(shè)計(jì)等方面對(duì)該模型進(jìn)行實(shí)驗(yàn)研究。實(shí)驗(yàn)結(jié)果表明,通過(guò)交替填充催化劑和氫氧化鈣模擬交替分離氫氣和二氧化碳的甲烷重整實(shí)驗(yàn)在400℃時(shí)具有88.02%的甲烷轉(zhuǎn)化率。實(shí)驗(yàn)驗(yàn)證本文提出模型的可行性,為未來(lái)甲烷重整和槽式太陽(yáng)能集熱器結(jié)合奠定基礎(chǔ)。
[Abstract]:Environmental pollution and the limited reserves of fossil energy make it an increasingly urgent task to find clean and renewable energy sources without pollution. Solar energy is expected to be an ideal alternative to fossil energy because of its rich reserves and environmental friendliness. However, the low energy density and instability of solar energy become the bottleneck of solar energy development. Therefore, converting solar energy into hydrogen energy, such as easy storage, high energy density, clean and environmentally friendly secondary energy has become one of the research hot spots in the field of energy. The solar thermochemical method based on selective membrane separation promotes the reaction forward by selectively separating the products, increases the conversion of the reactants and lowers the preparation temperature of solar fuel. This dissertation is based on the National Natural Science Foundation and the National key R & D projects. Based on the concept of energy grade, this thesis explores the low-temperature and high-efficiency conversion method from solar energy to chemical energy. The conversion mechanism, energy grade enhancement law and energy efficiency trend of solar thermochemical utilization process based on selective membrane separation were studied and verified by experiments. The main contents and conclusions of this paper are as follows: (1) Thermodynamic analysis and simulation study on the thermochemical decomposition of water or the production of hydrogen or carbon monoxide from high temperature solar energy by selective membrane separation is carried out. The energy efficiency change trend of oxygen permeable membrane reactor system based on vacuum pump and methane assisted oxygen permeable membrane reactor system is presented. The energy utilization efficiency of the oxygen-permeable membrane reactor system based on vacuum pump is 2.9, and the conversion efficiency from solar energy to chemical energy of the oxygen-permeable membrane reactor system based on methane is 63. The theoretical analysis provides a theoretical basis for the practical application of high temperature solar thermochemistry based on selective membrane separation. (2) to improve the traditional membrane reactor mentioned above, an alternative hydrogen permeable membrane reactor is proposed, which can greatly improve the conversion rate and energy utilization efficiency of solar thermochemical decomposition water at low temperature, for example, at 1500 鈩，

本文編號(hào)：2225643