乙酸自热重整制氢的钙促进镍基催化剂的研究

发布时间：2018-07-05 02:14

本文选题：生物质油 + 乙酸自热重整　；参考：《成都理工大学》2017年硕士论文

【摘要】：氢能是一种清洁能源,被视为传统化石能源的替代能源之一,并可通过醇类、生物质以及纤维素等可再生原料制取。其中,生物质来源广泛、廉价易得,吸引了广泛的关注。然而,生物质能量密度较低,但经热裂解后可转化为具有较高能量密度的生物质油—一种碳中性的制氢原料。本文选择生物质油典型组分乙酸作为研究对象,同时在重整过程中引入氧气,实现了乙酸自热重整制取氢气,并开发设计出生物质油催化重整制氢的高效催化剂。针对镍基催化剂所面临的氧化、烧结以及积炭等问题,本文制备了La_(2-x)Ca_xNiO_(4±δ)钙钛矿结构以及Ca_xNi_yAl_zO_δ类水滑石结构(LDHs)催化剂,并通过一系列表征手段探讨了助剂钙以及制备方法对于催化剂结构和性能的影响。采用溶胶凝胶法制备了La_(2-x)Ca_xNiO_(4±δ)催化剂。活性测试结果表明:La_2NiO_(4±δ)和Ca_2NiO_(3±δ)催化剂在乙酸自热重整反应过程中稳定性较差;Ca促进的LaCaNiO_(4±δ)催化剂展现出高活性和稳定性。在30 h的稳定性测试中,LaCaNiO_(4±δ)催化剂的乙酸转化率保持在100%,氢气产率达到了2.80 mol-H_2/mol-AC。表征结果表明:用溶胶凝胶法制备出了具有钙钛矿结构、分散性好以及粒径小的LaCaNiO_(4±δ)催化剂;La被Ca部分取代后提高了催化剂的比表面积、镍粒子的稳定性,同时具有较强的抗积炭能力。采用共沉淀法制备了Ca_xNi_yAl_zO_δ-LDHs催化剂,并与Ni_xAl_yO_δ以及浸渍法制备的Ni_x/Ca_yAl_zO_δ催化剂进行了比较。表征结果表明:用共沉淀法制备出了以CaAl-LDHs为前驱体的Ca_(2.55)Ni_(0.45)AlO_(4.5)催化剂;焙烧后,碱性载体CaO有助于抑制积炭,同时Ca_(12)Al_(14)O_(33)提高了镍粒子的稳定性;在ATR反应过程中,该催化剂具有较好的抗氧化性、稳定性以及抗积炭能力。活性测试结果显示Ca_(2.55)Ni_(0.45)AlO_(4.5)催化剂的乙酸转化率保持在100%,氢气产率稳定在2.75mol-H_2/mol-AC。
[Abstract]:Hydrogen energy is a kind of clean energy, which is regarded as one of the alternative energy sources of traditional fossil energy, and can be made from renewable raw materials such as alcohols, biomass and cellulose. Among them, biomass has a wide range of sources, cheap and easy to obtain, attracting wide attention. However, biomass energy density is relatively low, but after pyrolysis, it can be converted into biomass oil with high energy density, which is a carbon-neutral raw material for hydrogen production. In this paper, acetic acid, a typical component of biomass oil, was selected as the research object, and oxygen was introduced into the reforming process to produce hydrogen by self-heating reforming of acetic acid, and an efficient catalyst for hydrogen production by catalytic reforming of biomass oil was developed. In this paper, La2-x CaxNiO4 卤未 perovskite structure and CaxNiyAlzO未 hydrotalcite structure (LDHs) catalysts have been prepared to solve the problems of oxidation, sintering and coke deposition in nickel based catalysts. Through a series of characterization methods, the effects of the auxiliary calcium and the preparation method on the structure and performance of the catalyst were discussed. La2-x CaxNiO4 卤未 catalyst was prepared by sol-gel method. The results of activity test showed that the LaCaNiO4 卤未 and CaS _ 2NiO _ (3 卤未) catalysts exhibited high activity and stability during the autothermal reforming of acetic acid with poor stability and Ca promoted LaCaNiO4 卤未 catalyst. In the 30 h stability test, the acetic acid conversion of LaCaNiO4 卤未 catalyst was kept at 100 and the hydrogen yield reached 2.80 mol-Hstack 2 / mol-AC. The results showed that LaCaNiO _ (4 卤未) catalyst with perovskite structure, good dispersion and small particle size was prepared by sol-gel method, and La _ (4 卤未) catalyst was partially replaced by Ca, which improved the specific surface area of the catalyst and the stability of nickel particles. At the same time, it has strong resistance to carbon deposition. Castax NixNixAlzO未 -LDHs catalysts were prepared by coprecipitation method, and compared with NixAlyO未 and Nix / CayAlzO未 catalysts prepared by impregnation method. The results showed that Ca2.55 Ni0.45 AlO4.5 catalyst was prepared by co-precipitation method, and Ca2.55Ni0.45AlO4.5 catalyst was prepared by coprecipitation method, and Cao can help to inhibit coke deposition, while Ca12Al14O33 can improve the stability of nickel particles during ATR reaction. The catalyst has good oxidation resistance, stability and resistance to carbon deposition. The results of activity test showed that the acetic acid conversion of Ca2.55 Ni0.45 AlO4.5 catalyst was kept at 100 and the hydrogen yield was stable at 2.75mol-H2pmol-AC.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TQ116.2

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