APPLIED CATALYSIS A-GENERAL
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2023
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IF 5.5
Cheng Cang Li,Da Jian Li,Shu Tian Yin,Ze Zhen Wang,Chen Lan Liu,Chun Hui Zhou
Glycerol can be converted to allyl alcohol via deoxydehydration using molybdenum-vanadium, rhenium and iron based catalysts. However, the dehydration causes severe coking at strong acid sites on the surface of catalyst. Molybdenum-vanadium oxide supported on calcium oxide-intercalated montmorillonite (MoV-CaMMT) was prepared by oxalate anion intercalation followed by impregnation. MoV-CaMMT displayed the best catalytic performance of 86.5% glycerol conversion and good stability in 5 h. Correlating the results of XRD, XPS and TG analysis, it can be demonstrated that the addition of CaO in the catalyst preparation is conducive to the crystallization and dispersion of vanadium oxides, and reduces the acid strength, while the presence of a few vanadium dioxide and the stable conversion of V 4+ and V 5+ are the reasons for enhancing coking-resistance of MoV-CaMMT. Additionally, NH 3 -TPD analysis proved the coexistence of weak and strong acid sites in MoVO x , which are conducive to the formation of acetol.
研究领域:
催化化学
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材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
Green Energy & Environment
·
2020
·
IF 6.395
Jiadi Liu,Minghuan Liu,Shaoyun Chen,Bingqing Wang,Jin Chen,Da-Peng Yang,Shangzhou Zhang,Wenxiao Du
Developing an environmental-friendly and highly active catalyst in transesterification for biodiesel production is of great importance for a more economic biodisel process. Herein, we reported that waste eggshells were used to adsorb Au(III) in water and convert the Au(III)-polluted eggshells into the functional nanocatalyst-CaO/Au for the transesterification reaction between soybean oil and methanol to the preparation of biodiesel. By coupling of CaO and Au nanoparticles, CaO/Au nanoparticles showed superior catalytic activity for the transesterification reaction between soybean oil and methanol. An optimum performance was observed over CaO/Au nanocomposites in a methanol-oil molar ratio at 12 : 1 with catalyst content of 1.0 wt% at 70 °C for 3 h. Besides, the catalytic activity of CaO/Au nanocatalyst was almost unchanged after recycling for 5 times and the yield of biodiesel still kept at 88.9%. The proof-of concept study provided us a sustainable method for utilization of waste eggshells to remedy the metal ions-polluted wastewater and the synthesis of functional nanocomposite for biodiesel production, show great potential application of waste eggshell in adsorption and catalytic reactions.
研究领域:
环境科学
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催化化学
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhu-yu Li,Le-ran Li,Sheng Li,Ding-can Wang,Qi Niu,Kai Li,Ji Liu,Qiang Lu
Calcium-based thermochemical heat storage (TCHS) is an economical and environmentally friendly technology for efficient heat storage. It can strengthen the flexibility in power systems of renewable energy and promote the recovery and storage of waste heat in energy-intensive industries. However, CaO/CaCO 3 is extremely prone to sintering at operational temperatures. Consequently, a cost-effective approach was proposed to synthesize calcium-based TCHS materials modified by pyroligneous acid (PA) impregnation and co-doping with dual transition metals. The heat storage performance, physicochemical property, and anti-sintering mechanism of synthesized CaO were comparatively examined. The sample prepared with a molar ratio of Ca: Co: Mn = 100:3:7 (PACa-Co3Mn7) exhibited an initial energy storage density of 1.76 MJ/kg, which gradually rose to 1.88 MJ/kg. After 20 cycles, the value decreased by only 4.39 % from its peak, indicating outstanding TCHS performance. Characterization results indicated that the specific surface area and pore volume of PACa-Co3Mn7 were 10.48 m 2 /g and 0.035 cm 3 /g, which were 2.34 and 2.69 times those of CaO stemmed from the calcination of limestone, respectively. The fruitful pores provided pathways for CO 2 diffusion within the CaO particles or CaCO 3 product layer. The uniformly distributed Co and Mn elements combined to form Ca 3 CoMnO 6 . Ca 3 CoMnO 6 could serve as the inert carrier that mitigated the grain-growth of CaO, thereby stabilizing the pore structure and resisting the sintering of PACa-Co3Mn7. Furthermore, density functional theory (DFT) calculations demonstrated that the free Mn and Co elements efficiently promoted the electrons transfer between CaO and CO 2 , which improved the reactivity of PACa-Co3Mn7. Therefore, CaO modified by PA impregnation and co-doping with dual transition metal is a promising candidate for the TCHS system.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xingbo Wang,Yibo Pan,Weidong Fan,Hao Guo,Hai Zhang
CaO-based sorbents are among the most promising materials for capturing CO 2 from high-temperature flue gas in coal-fired power plants. Fly ash, a solid waste product generated by coal-fired power plants, can be utilized as a calcium source for the in-situ preparation of CaO-based sorbents to capture CO 2 from high-temperature flue gas. Nevertheless, the inherent characteristics of fly ash, such as its low adsorption capacity and poor activity, present challenges in its utilization. Doping is an effective method for enhancing the adsorption capacity and activity of sorbents. In this study, fly ash-CaO sorbents were doped and hydrated with six common chlorides and hydroxides in order to investigate the potential effects of the dopants on the sorbents. The carbonation performance of these sorbents was evaluated in a calcination/carbonation reaction system, and the modified sorbents were characterized using multiple methods to elucidate the underlying mechanisms. The results indicate that the carbonation conversion of the six modified sorbents is in the order of Fe(OH) 3 / Fe(Cl) 3 > KCl > NaCl > KOH>NaOH. The element enhancement of the modified sorbents at the same doping ratio is in the order of Fe 3+ > K + > Na + , and Cl − exhibit better synergistic effects with K + and Na + compared to OH − . Some dopants improve the carbonation reaction kinetics of the sorbents, promoting the overall reaction shift towards the rapid reaction stage. This study provides a promising pathway for the reuse of solid waste fly ash and the development of CaO-based sorbents suitable for rapid reaction scenarios.
研究领域:
能源与环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ENERGY
·
2021
·
IF 9.746
Yunlei Zhao,Bo Jin,Xiao Luo,Zhiwu Liang
Many works have focused on the reactivity and valence transition of Fe-based oxygen carriers in chemical looping partial oxidation reforming process. However, the reforming performance and impacts of operating factors are unclear with the co-feeding of CaO being CO 2 carrier to realize simultaneous CO 2 capture and utilization. In this work, thermodynamic equilibrium calculation, reactivity test and material characterization are carried out to optimize the process characteristics. The impacts of feeding conditions (Fe/Al weight ratio, methane amount, Ca/Fe mole ratio and packing manner) on the reforming reactivity are obtained to reveal the interaction between CaO and Fe 2 O 3 . The gas product distribution indicates that the carbon deposition and oxidation degree is closely related to CH 4 amount. The spatial configuration between CaCO 3 and Fe 2 O 3 reforming is essential to obtain the desirable reforming products. The difference of FeO existence on the theoretical and experimental phase components illustrates that reaction degree is affected by the reduction agent amount. By comparing the methane temperature-programmed reaction of CaCO 3 , Fe 2 O 3 and their mixture, it is suggested that the existence of CaCO 3 is beneficial for accelerating iron-based methane reforming. This study provides a way to improve reaction degree and optimize process characteristic for chemical looping reforming process.
研究领域:
能源科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2016
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IF 2.835
Pengfei Zhao,Ji Sun,Yimin Li,Ke Wang,Zeguang Yin,Zhongyun Zhou,Zhen Su
A facile carbon template method was employed to modify the microstructure of calcined organometallic calcium compounds (i.e., calcium acetate, calcium citrate, and calcium gluconate) for high-temperature CO2 capture. The effects of the decomposition atmosphere, carbon source, and pyrolysis temperature on the physical and chemical properties as well as the cyclic CO2 capture performance were determined using various morphological characterization techniques and detailed thermogravimetric analysis. During pyrolysis in an inert atmosphere, in situ carbon formed from organometallic calcium compounds, which served as a template for controlling the sintering of CaCO3, and the subsequent carbon burnoff in air promoted the fabrication of porous CaO. Among the three organometallic calcium compounds, the pyrolysis process of calcium gluconate exhibited the earliest carbonization and the template with the highest organic carbon content and the slowest decomposition of CaCO3. Therefore, the most favorable structure (i.e., the smallest crystal size, largest specific surface area, and largest pore volume of CaO) was obtained from calcium gluconate, which was responsible for the fastest adsorption rate, highest capacity, and best stability. Moreover, this superior performance was maintained when the pyrolysis temperature was approximately 600–800 °C.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2020
·
IF 5.578
Muhammad Irfan,Aimin Li,Lei Zhang,Guozhao Ji,Yuan Gao
Catalytic gasification, coupled with in-situ CO 2 capture over Ni-CaO catalyst, is considered to be an effective approach for H 2 -rich and tar-free syngas production. However, the poor stability of Ni-CaO based catalyst raises a question regarding its large scale application. In this study, HfO 2 was used as a stabilizer and promoter for the Ni-CaO catalyst system. The stability of catalyst was evaluated through cyclic carbonation-calcination test with a thermogravimetric analyzer. The results showed that HfO 2 incorporated catalysts performed better stability towards cyclic CO 2 capture. The effect of different HfO 2 additions in catalyst, catalyst to municipal solid waste (C/MSW) ratio, gasification temperature, and moisture content (MC) of MSW was investigated on syngas composition, H 2 yield, dry gas yield (DGY) and product distribution (syngas, tar and char). The results indicated that H 2 yield was improved from 212 mL/g (without catalyst) to 442 mL/g with Ni-CaO (NC) catalyst and further improved with the application of HfO 2 promoted catalysts (Ni-CaO-HfO 2 ). The catalyst with 20% HfO 2 (NCH-20) exhibited maximum H 2 yield of 597 mL/g. Moreover, a significant reduction in tar content from 8.79 wt% (without catalyst), 3.19 wt% (with Ni-CaO) to 2.81 wt% (with NCH-20) was also recorded with HfO 2 promoted catalysts.
研究领域:
化学工程
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环境科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2020
·
IF 3.573
Ying-Bo Zhu,Jia Guo,Yu-Long Ma,Yuan-Yuan Li
The production of high-value-added chemicals from the degradation of real lignin still has been an unresolved issue. In this study, a two-step strategy was proposed to obtain n-hexanol from alkali lignin, and high conversion of alkali lignin and selectivity of n-hexanol were achieved. The deoxygenation performance of the synthesized Ni-HZSM-5 catalyst, modified by Ca, was efficiently improved. At first, through the deoxygenation of alkali lignin via Ni/CaO-HZSM-5, the C–O bonds of the material were broken effectively and 44% degree of deoxygenation (DOD) was obtained. Second, n-hexanol was selectively produced over the Ni/HZSM-5 catalyst from the liquid product obtained by the first step. The efficiency of deoxygenation (DOD) was attained at 71%, and the heat value increased to 51.6 MJ/kg from 19.9 MJ/kg after the two-step strategy. This strategy showed a high catalytic effect to produce n-hexanol from alkali lignin using Ni/CaO-HZSM-5 and Ni/HZSM-5 catalysts and revealed a superior advantage in the hydrodeoxygenation of real lignin to form high additional value chemicals.
研究领域:
化学工程
·
可再生资源利用
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2021
·
IF 5.645
Zongyuan Zhu,Yanbing Liu,Wenjie Cong,Xubo Zhao,Jidon Janaun,Tao Wei,Zhen Fang
A heterogeneous CaO/Ag nano catalyst was developed and applied for biodiesel production from transesterification of soybean oil. The silver performed synergistic effects with CaO on promoting biodiesel production. The CaO/Ag nano catalysts exhibited abundant strong basic sites with larger BET surface area (7.02 vs 2.05 m 2 /g), pore diameter (58.84 vs 37.08 nm) and pore volume (0.070 vs 0.016 cm 3 /g), which significantly reduced mass transfer resistance of triglycerides during transesterification and improved the mass transfer constants. Response surface methodology was applied to investigate the influence reaction parameters and optimize biodiesel yield. A maximized biodiesel yield of 90.95 ± 2.56 % was achieved using methanol:oil molar ratio of 13, CaO/Ag loading of 5%, reaction time of 90 min and reaction temperature of 72℃. The optimized biodiesel yield for CaO catalyzed transesterification was 88.40 ± 3.34 %, using similar reaction conditions but with 180 min of reaction time. Both nano catalysts were consecutively reused for five times. Kinetic and thermodynamic studies of CaO and CaO/Ag catalyzed transesterification were performed and compared. Economic evaluation of biodiesel production using CaO and CaO/Ag was performed and compared to provide insights for heterogeneous catalyst application for biodiesel production on industrial scale.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Jyoti Gupta,Konstantinos Papadikis,Elena Yu. Konysheva,Yi Lin,Ivan V. Kozhevnikov,Jingjing Li
The impact of CaO on oakwood pyrolysis was explored by the Py-GC/MS at 500 °C. Ca(OH) 2 presents on the CaO surface, indicating its partial hydration (noted as CaO OH ). CaO OH promoted the ketonisation of carboxylic acids to aliphatic ketones, furfural to cyclopentanone/2-cyclopentenone, facilitated the elimination of the methoxy-phenolic compounds. The catalyst loading did not show any significant effect on the formation of acetone, while a noticeable reduction in the phenolics was revealed. Increasing catalyst loading almost eliminated CO 2 , acids, furans, aldehydes, ether groups, whilst the fractions of alcohols, esters, sugars, and alkoxybenzene decreased noticeably. The use of partially hydrated CaO OH in the CFP can create conditions where by-products generated during the ketonisation and phenolics upgrading reactions (CO 2 , H 2 O, CO) interact through the adsorption enhance water-gas-shift reaction and through coking reactions with formation of H 2 used for hydrogenation during multistep conversion of furfural to cyclopentanone in a vapour phase.
研究领域:
能源化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
POWDER TECHNOLOGY
·
2023
·
IF 5.2
Yuxiang Cheng,Zhongjie Shen,Feng Lv,Dayang Wan,Yongchuan Gao,Yiru Yang,Haifeng Lu,Zhenghua Dai,Haifeng Liu
During the Ca(OH) 2 /CaO thermochemical energy storage process, the cyclability of reactions and the consolidation properties of powder storage are important issues to consider. In this study, experiments were conducted to assess the evolution of reaction conversion, particle size and penetration resistance of Ca(OH) 2 /CaO powder fixed bed. The results revealed that the final conversions of both the hydration and dehydration reactions stabilized between 70 and 80%. The particle size distributions of Ca(OH) 2 increased initially and then decreased with the increasing cycle number and degree of dehydration. The dehydration conversion was the dominant factor for changing Ca(OH) 2 bed penetration resistance force. The particle size and penetration resistance of the CaO bed remained stable during long-term storage at high temperatures. The theoretical analysis of the inter-particle forces agreed with the trend of the experimental results, with particle size and moisture content being the main factors affecting cohesion.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
WASTE MANAGEMENT
·
2023
·
IF 8.1
Danni Li,Rui Shan,Jing Gu,Yuyuan Zhang,Xianhai Zeng,Lu Lin,Haoran Yuan,Yong Chen
To relieve the secondary contamination of heavy metals (HMs), the synergistic effect of co-pyrolysis of textile dyeing sludge (DS)/litchi shell (LS) and CaO on the migration of HMs was demonstrated in this study. The proportions of Cu, Zn, Cr, Mn, and Ni in the F4 fraction increased to 75%, 55%, 100%, 50%, and 62% at the suitable CaO dosages. When 10% CaO was added, the RI value of DLC-10% was reduced to 7.89, indicating low environmental risk. The characterizations of the physicochemical properties of biochar provided support for the HMs immobilization mechanism. HMs combined with inorganic minerals or functional groups to form new stable HMs crystalline minerals and complexes to achieve immobilization of HMs. The pH value and pore structure also play an important role in improving the immobilization performance of HMs. In conclusion, the results provided a new direction for the subsequent harmless treatment of HMs-enriched waste.
研究领域:
环境科学
·
废弃物处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）