MATERIALS CHEMISTRY AND PHYSICS
·
2021
·
IF 4.094
He Li,Yongsheng Liu,Wenbo Li,Yansong Liu,Qingfeng Zeng
In order to aid dissolution of ceramic cores, calcium oxide was added to alumina to fabricate composite ceramics cores via 3D printing . The effect of sintering temperature and addition of calcia (5 wt%) on the microstructure and properties of the sintered ceramics were investigated. CaAl 12 O 19 formed via a chemical reaction between alumina and calcium oxide at high temperature, and CaAl 12 O 19 could be clearly seen in scanning electron microscope (SEM) images, energy dispersive X-ray spectroscopy (EDS) measurements, and X-ray diffraction (XRD) measurements. The sintered composite ceramics had porous structure and uniform elemental distribution. The sintered ceramics exhibit greater shrinkage, bulk density, and flexural strength when the sintering temperature is higher. The CaAl 12 O 19 grains provide connections between alumina grains, which ensures the sintered ceramics have greater strength and less deformation compared to un-sintered ceramics.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY
·
2017
·
IF 4.52
J. Yan,C.Y. Zhao,Z.H. Pan
Cyclic stability is a key factor in the design of thermochemical heat storage systems . Because carbon dioxide (CO 2 ) may react with heat storage materials and lead to a decrease in energy storage efficiency, the effect of CO 2 on Ca(OH) 2 /CaO and Mg(OH) 2 /MgO systems is investigated in this study. The experimental results show that CO 2 reacts with CaO in the water vapor that appears during the heat release process. Therefore, in the design of Ca(OH) 2 /CaO systems, CO 2 should be cleared from the system. The results from Mg(OH) 2 /MgO systems show that CO 2 only slightly reacts with MgO and Mg(OH) 2 during heat storage and release processes. This study indicates that carbonic acid (H 2 CO 3 ) could easily react with CaO/Ca(OH) 2 to form CaCO 3 during heat release processes. Generally, the remaining CO 2 reduces the reversibility of Ca(OH) 2 /CaO systems but has only a slight influence on Mg(OH) 2 /MgO systems. In addition, the experimental results show that carbonate shell does not exist in rehydration for both of the CaO/MgO samples, but the influence of CO 2 on the entire process increases after each cycle.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Guangyao Zhao,Zhehui Zhao,Sixing Zhang,Jiakang Yao,Na Cheng,Zhen Li,Yu Han,Xiaotao Zhang
Thermochemical energy storage technology based on the Ca(OH)₂/CaO dehydration-hydration reaction is considered as a promising strategy for addressing the transient storage of renewable energy due to high thermal storage density, long cycle characteristics, and safety. However, this technology suffers from drawbacks like agglomeration and sintering at high temperatures, along with poor cycling stability. In this study, the "dynamic" doping of Ca(OH)₂ with C₃N₄ was introduced to optimize the microstructure of particles, which enhanced the thermal performance, elevated conversion rate, and improved cycling stability, without reducing thermal storage density. In-depth characterizations revealed that C₃N₄ transformed Ca(OH)₂ from a flake-like structure to uniform spherical particles, approximately 10 μm in size. In particular, when the doping amount reached 30 wt%, the thermal storage density increased by 11.10% in contrast to Pure Ca(OH)₂, the peak reaction temperature decreased by 13.98°C, and the conversion rate improved to 91.22%. Simultaneously, the material exhibited excellent anti-caking properties, maintaining a thermal storage density of 776.46 J/g after 20 cycles, representing a 27% augmentation compared to the unmodified sample. The microscale effect of the material was retained. In summary, this outcome showcases outstanding comprehensive properties, taking thermochemical energy storage materials further into practical scenarios.
研究领域:
储能技术
·
材料科学
·
热能工程
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Shuo Wang,Xuan Meng,Jing Zhang,Xiangyang Zhang,Sitan Wang,Li Shi,Naiwang Liu
Calcium cyanamide was synthesized by the twice calcination of calcium oxide and urea which was different from the traditional calcium carbide method. Including reaction time, reaction temperature, and reaction molar ratio, the more suitable reactions were explored, which improved the utilization of urea and yield of calcium cyanamide. The phenomenon of visco-wall during the reaction process was alleviated by adding sodium chloride, and this effect was explained at the micro level. The chemical bond and weight change of the main byproducts and intermediate products in the reaction process were characterized systematically. A reaction model between urea and calcium oxide was constructed based on density functional theory (DFT), which complemented the reaction conditions and characterization results. Finally, the reaction mechanism between urea and calcium oxide was proposed.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Yunfei Xue,Xiaogang Gu,Shuguang Lu,Zhouwei Miao,Mark L. Brusseau,Minhui Xu,Xiaori Fu,Xiang Zhang,Zhaofu Qiu,Qian Sui
The ability of Fe(II)-activated calcium peroxide (CaO 2 ) to remove benzene is examined with a series of batch experiments. The results showed that benzene concentrations were reduced by 20–100% within 30 min. The magnitude of removal was dependent on the CaO 2 /Fe(II)/Benzene molar ratio, with much greater destruction observed for ratios of 4/4/1 or greater. An empirical equation was developed to quantify the destruction rate dependence on reagent composition. The presence of oxidative hydroxyl radicals (HO ) and reductive radicals (primarily O 2 − ) was identified by probe compound testing and electron paramagnetic resonance (EPR) tests. The results of the EPR tests indicated that the application of CaO 2 /Fe(II) enabled the radical intensity to remain steady for a relatively long time. The effect of initial solution pH was also investigated, and CaO 2 /Fe(II) enabled benzene removal over a wide pH range of 3.0–9.0. The results of radical scavenging tests showed that benzene removal occurred primarily by HO oxidation in the CaO 2 /Fe(II) system, although reductive radicals also contributed. The intermediates in benzene destruction were identified to be phenol and biphenyl. The results indicate that Fe(II)-activated CaO 2 is a feasible approach for treatment of benzene in contaminated groundwater remediation.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Weiqiang Song,Lantao Yang,Xi Ma,Gaoqiang Liang
CaO and MgO were used to neutralize aluminum dihydric tripolyphosphate (ADTP) by co-grinding, and the effects of CaO and MgO on anticorrosive performance of ADTP on mild steel were studied. The efficiency of the resulting multicomponent pigments as corrosion inhibitors for mild steel boards in 3.5% w/w NaCl solution was determined by electrochemical measurements. The results showed that the anticorrosive performance depended on the component of the pigments and the feeding order of ADTP, CaO, and MgO in grinding. ADTP/MgO/CaO displayed more high performance than others, which was attributed to the relatively integrated passivating film constructed on the surface of the test board. And the anticorrosion of waterborne epoxy coatings was effective and persistent.
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2019
·
IF 5.128
Kejia He,Qiang Song,Zhennan Yan,Na Zheng,Qiang Yao
Alkaline injection is an effective way to control the emission of high concentration SO 3 caused by the use of high-sulfur coal and selective catalytic reduction (SCR), but its performance is affected by the competitive absorption of SO 2 . A fixed-bed reactor was used to study the competitive absorption of SO 3 and SO 2 by Ca(OH) 2 . The dynamic absorption curves in different atmospheres were obtained, the intermediate products were characterized, and the competitive absorption mechanism was discussed. The absorption of SO 3 and SO 2 consists of the chemical kinetics-controlled and product layer diffusion-controlled stages. In the chemical kinetics-controlled stage, the SO 3 and SO 2 removal efficiencies were around 90% and 55% at first and then decreased; the SO 3 selectivity was around 0.1 at first and then increased. In the product layer diffusion-controlled stage, the SO 3 removal efficiency gradually decreased but kept greater than 10%, while the SO 2 removal efficiency deceased to zero; the SO 3 selectivity continued to increase and reached 0.31 at most when SO 2 absorption ceased. There existed significant competition between SO 3 and SO 2 absorption. The increasing SO 3 concentration promoted the SO 3 absorption and the increasing SO 2 concentration decreased it. The absorption of SO 3 increased the intensity of the SO 4 2 - band, decrease the intensity of the SO 3 2 - band, and made the product layer more compact. The possibility of SO 3 reacting with the components (CaSO 3 , CaSO 4 and CaCO 3 ) on the reacted Ca(OH) 2 surface was analyzed. Ionic diffusion was proposed as the main mechanism of the continuous SO 3 absorption after the formation of a dense product layer.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2022
·
IF 3.428
Yunwen Liao,Si Chen,Qian Zheng,Bingyuan Huang,Juan Zhang,Hongquan Fu,Hejun Gao
The bifunctional biochar(N/CaO/BC) was prepared by a simple high temperature calcination using melamine and biomass material of sugarcane bagasse and agricultural wastes eggshell. Its structure and properties were analyzed by SEM, XRD, BET, and XPS. The adsorption capacity was evaluated in the phosphorus solutions. The effect of initial pH, concentration and temperature on adsorption were investigated. Nano-CaO were disperse evenly on the surface of Biochar, resulting a special specific surface area and porous structures. It has a rich nitrogen and CaO and the adsorption capacity could obtain 251.16 mg P/g at 300 K over a broad range of pH. The electrostatic force caused by C = NH + and precipitation reaction caused by CaO are the main driving forces of phosphorus removal and it exhibited a good P adsorption selectivity. P-rich N/CaO/BC contain P, N, C, Ca elements, which could provide nutrients to the soil and promotes the growth of crops. The dual-functionalization strategy of biochar provides a new way for the reuse of waste biomass and a new method for P utilization as resource in agricultural production.
研究领域:
环境科学
·
农业科学
✓ 已验证
产品关联
DOI
高影响因子
CEMENT & CONCRETE COMPOSITES
·
2020
·
IF 6.257
Woo Sung Yum,Jung-Il Suh,Dongho Jeon,Jae Eun Oh
This study investigated the effect of calcium formate (CF) on the strength development and microstructure of the CaO-activated ground granulated blast furnace slag (GGBFS) system. The main activator (i.e., CaO) was fixed at 4 wt%, and the GGBFS was replaced with CF at 0, 1, 3, and 5 wt%. The use of CF significantly increased the strength of the binder system by inducing (1) more dissolution of GGBFS, (2) greater C–S–H formation although when CF was used over a certain limit (i.e., 3 wt%), the formation of C–S–H began to be disturbed, and most importantly, (3) an increase in C2AH8 formation. In this study, although the greater formation of C2AH8 was the main cause of the strength enhancement, the C2AH8 phase also likely increased porosity and reduced strength as it was metastable; thus, strength increasing effect and reducing effect likely offset each other; thus, with increasing CF dosage, when the former was more dominant, the strength was enhanced (e.g., up to 3 wt%), but when the latter was larger, the strength enhancement decreased (e.g., at 5 wt%).
研究领域:
材料科学
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2024
·Vol. 9
·期 10
·e202304987
·
IF 1.9
Bing Li,Yue Yu,Bingjiang Jia,Ziqing Huang,Jingyi Liu,Bolin Guo,Qing Zhang
Graphical Ca(OH) 2 shows an excellent activity for the production of lactic acid from glucose in the presence of H 2 . Under the condition, H 2 can also inhibit the decomposition of lactic acid. Strong alkalinity of the catalyst facilitates the occurrences of the intermediates such as dihydroxyacetone or glyceraldehydes, and then improves glucose conversion to lactic acid. Catalytic conversion of glucose to lactic acid is a green promising strategy for the effective utilization of biomass-derived carbohydrates to generate valuable chemicals. The generation of lactic acid would also be distinguishing in different reaction atmospheres. In this work, we firstly investigated the decomposition of lactic acid and glucose transformation to lactic acid in H 2 . No obvious decomposition of lactic acid was observed in H 2 . The activity testing results showed that glucose could be completely converted over the selected hydroxides, while the formation of lactic acid was closely related to the alkalinity of hydroxide. The yield of lactic acid was remarkably obtained to be 87 % over Ca(OH) 2 at 220 °C for 3 h. Stronger alkalinity of the catalyst would facilitate glucose isomerization to fructose, and then easily be transformed into dihydroxyacetone or glyceraldehyde intermediates through reverse aldol condensation, which is beneficial to the generation of lactic acid.
研究领域:
生物化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Shijia Pan,Wenxuan Jiang,Lu Tian,Xiang Li,Jiaxin Wang,Yawen Wang,Zhen Li,He Guo
The simultaneous presence of antibiotics and phosphate (P) in wastewater will threaten human health and ecological security. The purpose of this study is to study the simultaneous removal of oxytetracycline (OTC) and P in water by O 3 /CaO 2 advanced oxidation process. With enhancing CaO 2 dosage, the degradation efficiency of OTC first improved and then declined, whereas the removal efficiency of P kept increasing. Increasing the amount of O 3 increased the removal efficiency of OTC, but had little effect on the removal efficiency of P. With 0.80 g/L CaO 2 and 0.50 g/h O 3 , the removal efficiency of OTC and P reached 98.0 % and 90.5 % respectively. The lower OTC concentration was beneficial to OTC degradation and P precipitation. The P concentration has no effect on OTC degradation, but it would affect itself precipitation. Alkaline environment was conducive to OTC degradation and P removal. ·OH, ·O 2 − , 1 O 2 made major contribution to the degradation of OTC, which was verified by ESR technique and free radical capture experiment. During the degradation of OTC and P removal, TOC and COD values decreased, while pH and conductivity showed a downward trend. Based on UV–Vis spectrum, 3D EEMF spectrum and LC-MS analysis, two main degradation pathways of OTC were proposed. Toxicity analysis of intermediates showed that their toxicity was significantly lower than that of OTC. The O 3 /CaO 2 system can be considered as an efficient and prospective method for the simultaneous removal of OTC and P in water.
研究领域:
环境科学
·
水处理工程
·
生物学
✓ 已验证
产品关联
DOI
高影响因子
PROCEEDINGS OF THE COMBUSTION INSTITUTE
·
2014
·
IF 3.828
Huan Liu,Qiang Zhang,Hongyun Hu,Peng Liu,Xiaowei Hu,Aijun Li,Hong Yao
Thermal disposal of sewage sludge is likely to cause serious nitrogen related environmental pollution since it contains considerable amounts of nitrogen, the species of which are quite different from those in coal. Considering that lime (CaO) is a widely applied chemical conditioner for sewage sludge dewatering, this study investigated the catalytic role of conditioner CaO in nitrogen transformation during sewage sludge pyrolysis in a drop-tube/fixed-bed furnace at 873 K, 1073 K and 1273 K, respectively. Model compounds were also used to further clarify the mechanisms involved. According to the results, conditioner CaO increased the fraction of more stable protein-N as well as amine-N. The solid phase reactions produced CaC x N y , thus enhancing the nitrogen retention in char. Correspondingly, decreased relative ratio of nitrates-N/nitrites-N and oxygenated organics in sludge conditioning contributed to less NO emission. Meanwhile, conditioner CaO promoted the conversion of HCN to NH 3 , as well as the deamination of proteins, amine, and other N-containing compounds in tar and char, leading to increased NH 3 generation. Subsequently, CaC x , the decomposition product of CaC x N y , captured NH 3 , driving down the final production of NH 3 . In addition, Ca(OH) 2 hindered the transformation of nitrile-N in char to HCN, decreasing HCN generation. CaO reacted with HCN, further reducing its releasing amount. CaC x N y derived from different sources decomposed to produce a very large amount of N 2 . These indicate that reusing conditioner CaO is a promising strategy for reducing the productions of NO x precursors efficiently and increasing the formation of non-polluting N 2 dramatically.
研究领域:
环境科学
·
能源与燃料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）