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Effect of pre-calcination for modified cao-based sorbents on multiple carbonation/calcination cycles

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Chinese Journal of Chemical Engineering 2017年第10期25卷 1412-1421页

作者： Xiaotong Liu Xiaoxun Ma Liu He Shisen Xu School of Chemical Engineering Northwest University Xi'an 710069 China Chemical Engineering Research Center of the Ministry of Education for Advanced Use Technology of Shanbei Energy Xi'an 710069 China Shaanxi Research Center of Engineering Technology for Clean Coal Conversion Xi'an 710069 China International Scientific and Technological Cooperation Base for Clean Utilization of Hydrocarbon Resources Xi'an 710069 China China Huaneng Group Clean Energy Technology Research Institute Beijing 100098 China

In the present work,the effect of pre-calcination on carbonation conversion and cyclic stability of modi fied caobased sorbent was investigated by thermogravimetric analyzer(TGA).The modi fied cao-based sorbents with CaAc_2 as precursor were respectively doped with different elements(Mg,Al,Ce,Zr and La).The speci fic surface area,pore volume and pore size distribution were tested by N_2 isothermal adsorption measurements.The phase compositions of sorbents were characterized by X-ray diffraction(XRD).The results showed that the cyclic stabilities of the sorbents were improved by pre-calcination.The pre-calcination was conducted at 900°C for 5 h in air by the muf fle furnace.With pre-calcination,the cyclic stabilities of sorbents could be as high as 96% after 22 cycles,such as cao-Al,cao-Ce and cao-La.After contact with air,the carbonation conversions of spent sorbents with pre-calcination suddenly increased by about one-sixth due to the change of channel structure by hydration.Both the cyclic stability of sorbent and the durability of reactivation were related to the structural stability of sample,especially the stability of mesopores between 2 nm and 5.5 nm.The present work also provided an easy and low-cost method for reactivating the spent cao-based sorbents.

关键词：循环稳定性 cao 碳酸化煅烧助烧剂碳化转化率结构稳定性预烧

Synergistic Effect of Alkali Metals in Coal and Introduced cao during Steam Gasification

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Journal of Thermal Science 2020年第6期29卷 1627-1637页

作者： LIU Yang YANG Xinfang LEI Fulin XIAO Yunhan Key Laboratory of Advanced Energy and Power Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China Research Center for Clean Energy and Power Chinese Academy of SciencesLianyungangJiangsu 222069China University of Chinese Academy of Sciences Beijing 100049China

The steam gasification kinetics of Zhundong raw coal and the washed coal by deionized water or hydrochloric acid with/without addition of cao were tested by thermogravimetric analyzer(TGA)at medium temperatures(650℃ to 800℃).The cation contents of potassium and sodium in samples were determined by Inductively Coupled Plasma Optical Emission Spectrometer(ICP-OES).The Brunauer-Emmett-Teller(BET)surface area of the samples was tested by N2 adsorption,and the morphologies of the samples were characterized by scanning electron microscopy(SEM).Experimental results showed that the organic sodium was the main catalyst for the gasification of the pyrolysis char,and the gasification rate of the char could be enhanced further with the introduction of cao.The inherent alkali metals in coal and the introduced cao showed a synergistic effect that occurred obviously above 735℃.The char conversion curves with or without cao were fitted by the modified volumetric model(MVM).The calculated results indicated that the addition of cao increased the pre-exponential factor obviously,but made little changes on the activation energy.It was proposed that the synergistic effect was resulted from the co-melting of the sodium and cao,which facilitated the migration of the catalyst ions and the generation of C(O)intermediates for the gasification.

关键词： Zhundong coal alkali metals cao synergistic effect steam gasification

基于贝壳衍生cao的低阶煤催化热解特性及热解机理研究

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煤炭转化 2022年第4期45卷 27-33页

作者：王俊丽吕婧李淑英武彦芳郝晓刚官国清赵建国山西大同大学化学与化工学院山西大同037009 太原理工大学化学化工学院太原030024 日本弘前大学地域战略研究所日本青森030-0813

以贝壳所得cao为催化剂,以内蒙古兴和煤煤样为研究对象,采用固定床及热重分析法研究了催化剂不同混合比例(质量比,下同)对内蒙古兴和煤热解行为的影响,并从化学键角度和煤热解产物的气液相组成的变化探讨了cao作为催化剂时低阶煤的催化... 详细信息

以贝壳所得cao为催化剂,以内蒙古兴和煤煤样为研究对象,采用固定床及热重分析法研究了催化剂不同混合比例(质量比,下同)对内蒙古兴和煤热解行为的影响,并从化学键角度和煤热解产物的气液相组成的变化探讨了cao作为催化剂时低阶煤的催化热解机理。结果表明:在球磨混合方式下,低阶煤与cao基催化剂质量比为2∶1时,焦油产率明显升高,从原来的18.17%增至22.04%,而热解气体产率明显下降,从原来的15.18%降至10.50%。气体产物组分分析结果表明气体产物中H_(2)含量显著提升,从原来的27.47 mL/g增至33.36 mL/g;液体产物组分分析结果表明催化热解焦油中的轻质组分含量明显高于原煤热解焦油中的轻质组分含量,进一步增大催化剂用量,焦油中轻质组分含量变化不显著;热解机理分析结果表明催化剂的加入显著改变了CO_(2)的析出历程,进而影响了煤的失重历程,另外,催化剂的加入使得煤大分子结构中化学键的裂解温度降低,反应更加容易进行,其中催化剂的加入对煤中芳香环的缩聚生成H_(2)的反应影响较大。

关键词：低阶煤催化热解 cao 贝壳热解机理

Influence of NaCl-CaCl_2 on Decomposing REPO_4 with cao

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Journal of Rare Earths 2007年第6期25卷 779-782页

作者：孙树臣吴志颖边雪高波吴文远涂赣峰 School of Materials & Metallurgy Northeastern University

The influence of NaCl-CaCl2 on thermal decomposition of REPO4（RE： Ce, La, Nd, Th） with cao was studied. The heat decomposing process of REPO4 was tested with TG-DTA experiments. The results showed that the decomposition temperature of REPO4 with cao was reduced because of adding NaCl-CaCl2 mixture （NaCl：CaCl2 = 1：1 ）. The influence of the addition of NaCl-CaCl2, roasting temperature and roasting time on decomposition ratio of REPO4 with cao was studied. The results showed that the decomposition ratio of REPO4with cao was 79% when the addition percentage of NaCl-CaCl2 was 10%, the roasting temperature was 750℃, and the roasting time was 1 h.

关键词： NaCl-CaCl2 cao REPO4 decomposition ratio rare earths

Behavior of cao and Calcium in pure Magnesium

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Rare Metals 2006年第Z2期25卷 150-154页

作者： HA Seong-Ho LEE Jin-Kyu JO Hyung-Ho JUNG Seung-Boo KIM Shae K. Department of Advanced Material Engineering Sungkyunkwan University 300 Chunchun-dong Jangan-gu Suwon Gyunggi-do 440-746 KoreaAdvanced Material Division Korea Institute of Industrial Technology 7-47 Songdo-dong Yeonsu-gu Incheon 406-840 Korea Advanced Material Division Korea Institute of Industrial Technology 7-47 Songdo-dong Yeonsu-gu Incheon 406-840 Korea Department of Advanced Material Engineering Sungkyunkwan University 300 Chunchun-dong Jangan-gu Suwon Gyunggi-do 440-746 Korea

Mg alloys exhibit a number of good properties such as low density, good castability and high specific strength. However, molten Mg and Mg alloys are ignited without the melt protective gases during melting and casting process due to their high reactivity. The purpose of this study is to investigate effects of Ca and cao on pure Mg through microstructure observation, ignition test and phase analysis. With increasing Ca and cao contents, the ignition resistance of Ca or cao added pure Mg is increased and the grains are refined. As results of XRD and EDS, cao is reduced to Ca in cao added pure Mg. Mg2Ca phase is formed even in 0.1 wt.%cao added pure Mg by reduction mechanism, while Mg2Ca phase is formed over 1.35 wt.% Ca added pure Mg.

关键词： Mg cao ignition resistance Mg2Ca phase

Vanadium extraction and dephosphorization from V-bearing hot metal with fluxes containing cao

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Journal of Central South University 2015年第8期22卷 2887-2893页

作者：王艳南宋文臣李宏 State Key Laboratory of Advanced Metallurgy (University of Science and Technology Beijing) School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

Extracting vanadium and removing phosphorus simultaneously by adding cao containing materials to V-bearing hot metal were investigated under the condition of simulating the process of vanadium extraction with insufficiently supplying oxygen in converter. Through preliminary experiments, 3 h and 1375 °C were chosen as the optimum holding time and reaction temperature for formal experiments, respectively. The results of the formal experiments suggest that making basic slag can extract vanadium and remove phosphorus simultaneously. The vanadium extraction rate(ηV) and phosphorus removal rate(ηP) both increase with an increase in the basicity of the original slag materials and the Fe2O3 contents. The vanadium distribution ratio)(V L′is about an order of magnitude greater than the phosphorus distribution ratio),(P L′but the latter is more sensitive to slag basicity than the former. The phosphorus distribution ratio is beyond 6 when the basicity of the original slag materials is beyond 1, which indicates a much better performance of phosphorus removal compared to the phosphorus removal in the current process. Therefore, it is very feasible to properly raise slag basicity to remove phosphorus with consideration of the grade of vanadium slag. The relations between ηV and ηP, and between L′V and L′P are linear under the experimental conditions.

关键词：提钒工艺含钒铁水脱磷渣 cao 炉渣碱度实验条件磷分配比 Fe2O3

Effect of cao composition on oxidation and burning behaviors of AM50 Mg alloy

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Transactions of Nonferrous Metals Society of China 2011年第A1期21卷 23-27页

作者： Jin-Kyu LEE Shae K.KIM Advanced Material Division Korea Institute of Industrial Technology 7-47 Songdo-Dong Yeonsu-Gu Incheon 406-840 Korea

Oxidation and burning behaviors were studied for cao added AM50 Mg composites which were manufactured by conventional melting and casting processes without SF6 protective gas. cao added AM50 Mg composites show the stable oxidation resistance, while AM50 Mg alloys show the poor oxidation resistance. The effects of cao addition on the burning resistance under ambient, nitrogen and dry air atmospheres were examined for cao added AM50 Mg composites. With increasing cao addition, the burning temperature increases under ambient, nitrogen and dry air atmospheres. The burning temperatures of small test specimen under all conditions greatly increase even by 0.3% cao (mass fraction) addition into AM50 Mg alloys.

关键词： AM50镁合金燃烧行为复合氧化 cao 镁复合材料组成抗氧化性环境温度

Synthesis of porous cao microsphere and its application in catalyzing transesterification reaction for biodiesel

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中国有色金属学会会刊：英文版 2009年第S3期19卷 674-677页

作者：白海鑫沈晓真刘小花刘圣勇 College of Sciences Henan Agricultural University College of Mechanical and ElectricalEngineering Henan Agricultural University College of Mechanical and Electrical Engineering Henan AgriculturalUniversity College of Mechanical and Electrical Engineering Henan Agricultural University

It is hoped to develop a simple and low cost route for preparing the cao with a novel morphology which can present high catalytic activity in catalyzing transesterification reaction for biodiesel. The porous cao microsphere was synthesized by calcining spherical CaCO3 precursor which was prepared easily by mixing CaCl2 with Na2CO3. The as-prepared cao microsphere was characterized by scanning electronic microscopy(SEM), powder X-ray diffractometry(XRD) and N2 adsorption experiment. The results reveal that the synthesized cao is regular microsphere with many pores in its exterior and interior. The cao microsphere is applied in catalyzing the transesterification reaction of soybean oil for biodiesel and presents excellent catalytic ability with a transesterification yield of 98.72%. This catalyst could have potential applications in other fields in view of its well-defined morphology, simply synthetic route and low cost.

关键词： porous cao microsphere transesterification catalysis biodiesel

Influence of cao and HZSM-5 on oxygen migration in Chlorella vulgaris polysaccharide pyrolysis

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Carbon Resources Conversion 2019年第2期2卷 111-116页

作者： Xiuli Zhang Chunhu Li Anhong Tian Qingjie Guo Kelei Huang Key Laboratory of Clean Chemical Processing of Shandong Province College of Chemical EngineeringQingdao University of Science and TechnologyQingdaoShandong 266042People’s Republic of China Key Laboratory of Marine Chemistry Theory and Engineering Technology of Ministry of Education College of Chemistry and Chemical EngineeringOcean University of ChinaQingdao 266100ShandongPeople’s Republic of China

With polysaccharides of Chlorella pyrenoidosa as the raw material,the effects of cao and HZSM-5 on the yield of bio-oil and the oxygen content in each phase in the pyrolysis of Chlorella vulgaris polysaccharides(CVP),which occurred in a tube furnace at 600℃,were comprehensively investigated.The reaction path of deoxidation was also analyzed by TG,GC and GC-MS.The GC-MS analysis of liquids showed that liquids from the pyrolysis of chlorella polysaccharides included a range of light oxygenated compounds(e.g.,furans,ketones and phenols),and the oxygen content of furan compounds decreased significantly with cao and HZSM-5.Compared with the direct pyrolysis of polysaccharides(CVP),the catalytic pyrolysis contributed to the decrease in the oxygen content of organic components by 7.32%and 5.76%.The GC analysis showed that there was a remarkable downtrend in the release of oxygen-containing gas(CO and CO_(2)),and the emission of CO_(2) decreased from 53.11%to 32.92%.The results of the thermogravimetric analysis indicated that the reaction paths of deoxidation in the pyrolysis process of polysaccharides(CVP)with cao and HZSM-5 varied from those of the direct pyrolysis process:the catalytic pyrolysis with HZSM-5 promoted the conversion of carbohydrate from furans to aromatics over strong acid sites,which was consistent with previous studies;cao not only acted as a catalyst but also participated in the reaction to change the reaction paths.All results and findings can help to further understand the thermochemical utilization of CPP for bio-oil.

关键词： Chlorella vulgaris polysaccharides cao HZSM-5 Pyrolysis Organic compounds Deoxidation Reaction paths