本文選題：太陽能熱化學(xué) + 天然氣基化學(xué)鏈燃燒�。� 參考：《中國科學(xué)院大學(xué)(中國科學(xué)院工程熱物理研究所)》2017年碩士論文

【摘要】：太陽能與天然氣互補(bǔ)的熱化學(xué)燃料轉(zhuǎn)化及發(fā)電系統(tǒng)與不同熱力循環(huán)相結(jié)合,可以實(shí)現(xiàn)太陽能的高效利用,減少化石能源消耗量和CO2排放量。但是,目前天然氣基化學(xué)鏈燃燒還原反應(yīng)需要較高的驅(qū)動(dòng)溫度,中低聚光比的槽式聚光集熱系統(tǒng)不能滿足還原反應(yīng)溫度的需求;采用高聚光比的太陽能聚光集熱形式,如塔式太陽能聚光集熱系統(tǒng)驅(qū)動(dòng)化學(xué)鏈還原反應(yīng)的發(fā)生,存在太陽熱能與反應(yīng)所需熱品位差過大,使得太陽熱能的品位提升潛力較小,且塔式聚光集熱系統(tǒng)存在結(jié)構(gòu)復(fù)雜、材料要求高及成本較高等不足,一定程度上限制了太陽能與天然氣互補(bǔ)的熱化學(xué)燃料轉(zhuǎn)化及發(fā)電系統(tǒng)的應(yīng)用。基于鈣鈦礦型氧化物獨(dú)特的結(jié)構(gòu)特點(diǎn)和優(yōu)異的性能,本文提出用鈣鈦礦型氧化物替代常規(guī)氧化物作為化學(xué)鏈燃燒的氧載體,重點(diǎn)在鈣鈦礦型氧化物的A、B位元素選擇上開展了研究,通過改變A、B位的元素,摻雜和改變材料的制備方法等途徑,進(jìn)行一系列實(shí)驗(yàn)驗(yàn)證工作,以尋找適用于中低溫太陽能的最佳氧載體材料。本文研究了天然氣基的化學(xué)鏈燃燒,采用溶膠-凝膠法制備了 A位分別是La、Sr、Ba的鈣鈦礦型氧化物,通過對材料的物化表征和反應(yīng)性能的研究,初步判斷La是一種較為合適的A位元素。采用燃燒法和溶膠-凝膠法制備了相應(yīng)的材料,通過對比兩種制備方法所得材料的微觀形貌、制備周期、反應(yīng)活性等參數(shù),初步確定燃燒法是一種較為理想的材料制備方法。采用燃燒法制備了 La系的Ni基鈣鈦礦型氧化物,用XRD、SEM、BET等分析手段對材料進(jìn)行物化表征,并在熱重中研究了材料的反應(yīng)性能,初步確定鈣鈦礦型氧化物L(fēng)aNiO3是一種有潛力的適用于中低溫太陽能的氧載體。為了進(jìn)一步降低還原反應(yīng)溫度、提高低溫下的釋氧量等,通過對氧化物L(fēng)aNi03的B位進(jìn)行摻雜以改善材料的性能。結(jié)果表明,氧化物L(fēng)aCu0.1Ni0.9O3可以在350℃的溫度下與CH4發(fā)生還原反應(yīng),反應(yīng)速率較快,lmol氧載體在還原反應(yīng)過程中可以釋放0.42mol氧氣,具有較強(qiáng)的低溫釋氧能力,且具有良好的循環(huán)再生性和穩(wěn)定性,在30次循環(huán)氧化還原反應(yīng)中始終保持較高的反應(yīng)性,30次循環(huán)反應(yīng)之后氧載體表面燒結(jié)現(xiàn)象不明顯,仍保持良好的孔隙結(jié)構(gòu),表明LaCu0.1Ni0.9O3是一種可用于中溫太陽能驅(qū)動(dòng)的天然氣基化學(xué)鏈燃燒的氧載體。本論文基于鈣鈦礦型氧化物優(yōu)異的特性,探索中溫太陽能驅(qū)動(dòng)的天然氣基鈣鈦礦化學(xué)鏈燃燒新方法,尋找出了一種可以和低聚光比的槽式聚光系統(tǒng)的集熱溫度相匹配的天然氣基化學(xué)鏈燃燒系統(tǒng)的新材料。
[Abstract]:Solar energy and natural gas complementary thermochemical fuel conversion and power generation system combined with different thermal cycles can achieve the efficient use of solar energy and reduce fossil energy consumption and CO2 emissions. However, at present, the reduction reaction of natural gas based chemical chain combustion needs higher driving temperature, and the trough condensing heat collecting system with low and low concentration ratio can not meet the demand of reduction reaction temperature, and the solar energy concentrator with high concentration ratio can not meet the demand of reduction reaction temperature. For example, if the reduction reaction of chemical chain driven by tower solar energy collector system occurs, the difference between solar thermal energy and the heat grade required for the reaction is too large, which makes the potential of improving solar thermal energy small, and the structure of tower solar energy collector system is complex. The shortage of high material requirement and high cost limits the application of thermochemical fuel conversion and power generation system which is complementary to solar energy and natural gas to some extent. Based on the unique structure and excellent properties of perovskite-type oxides, this paper proposes to use perovskite-type oxides instead of conventional oxides as oxygen carriers for chemical chain combustion. The emphasis is on the selection of elements at the Agna B site of perovskite oxides. A series of experimental verification work has been carried out by changing the elements of the AZB site, doping and changing the preparation methods of the materials, etc. In order to find the best oxygen carrier material suitable for medium and low temperature solar energy. In this paper, the chemical chain combustion of natural gas was studied. Perovskite oxides at position A were prepared by sol-gel method. It is preliminarily judged that La is a more suitable element at position A. The corresponding materials were prepared by combustion method and sol-gel method. By comparing the microstructure, preparation period, reaction activity and other parameters of the two preparation methods, it was preliminarily determined that the combustion method is an ideal method for the preparation of materials. Ni-based perovskite oxides of La system were prepared by combustion method. The physical and chemical properties of the materials were characterized by XRDX SEMT-BET, and the reaction properties of the materials were studied by thermogravimetry. It is preliminarily confirmed that perovskite oxide La NiO3 is a potential oxygen carrier suitable for medium and low temperature solar energy. In order to further reduce the temperature of the reduction reaction and increase the oxygen release at low temperature, the B site of the oxide Lani03 was doped to improve the properties of the material. The results show that the oxide LaCu0.1Ni0.9O3 can be reduced to Ch _ 4 at 350 鈩，

本文編號：2059013