JOURNAL OF POROUS MATERIALS
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2019
·Vol. 26
·期 6
·1831-1838
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IF 1.947
Mutyala Suresh,Yu Ya-Dong,Jin Wei-Guang,Wang Zhi-Shuo,Zheng Deng-Yue,Ye Chun-Rong,Luo Binbin
Composite material, tetraethylenepentamine (TEPA) incorporated UiO-66 was prepared by impregnation method to study CO 2 capture in a fixed bed reactor, atmospheric pressure. All synthesized adsorbents were characterized using PXRD, N 2 adsorption–desorption isotherms, FT-IR, TGA, SEM, and Elemental analysis. Characterization results have revealed that incorporated TEPA was present within pores of UiO-66. CO 2 adsorption was higher on TEPA incorporated UiO-66 compared to UiO-66. It was due to the chemical interaction between –NH 2 and CO 2 . High CO 2 adsorption capacity 3.70 mmol g −1 was obtained on 30TEPA/UiO-66 at 75 °C, 1 bar. Because of more flexibility and high dispersive nature of TEPA at this temperature. The same CO 2 adsorption capacity was obtained in each adsorption cycle without decomposition of the amine on 30TEPA/UiO-66. Avrami adsorption kinetic model has suggested adsorption of CO 2 on composite material was chemical adsorption and deactivation model suggested an initial rate of adsorption was higher on TEPA incorporated UiO-66.
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
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Fanhui Meng,Lina Wang,Muhammad Asif Nawaz,Qian Wang,Zhiyuan Gong,Zhong Li
Direct conversion of syngas to light hydrocarbons has been intensively studied in recent years; however, the high selectivity of light hydrocarbons is still a challenging task to achieve a high CO conversion. Here, a bifunctional catalyst consisting of a methanol synthesis catalyst (CZA) and a methanol to dimethyl ether (DME) catalyst (Al 2 O 3 ) was employed with a hydrocarbon synthesis catalyst (SAPO-34), for syngas conversion to light hydrocarbons in a dual fixed-bed reactor. The conversion of simulated intermediates CO/CO 2 /DME/N 2 /H 2 with a molar ratio of 9/6/4/5/76, obtained from syngas conversion to DME over CZA and Al 2 O 3 , was studied over SAPO-34 zeolites. It was found that SP34-0.1 with Si/Al ratio of 0.1, exhibited low amount of strong acid (0.60 mmol/g) and high selectivity to light olefins (74.1%), while SP34-0.4 with Si/Al ratio of 0.4 exhibited high amount of strong acid (1.00 mmol/g) leading to high selectivity of light paraffins (88.4%). The in-situ DRIFTS analysis illustrated that DME can be rapidly adsorbed on the hydroxyl site of SAPO-34 and decomposed into the surface methyl species, where SP34-0.4 could produce more dimethylcyclopentenyl cationic species than SP34-0.1. It was suggested that the overall reaction route led to a high selectivity to light olefins (84.2%) with a CO conversion of 61.2% on (CZA + Al 2 O 3 ) catalyst combined with SP34-0.1, while a high selectivity to light paraffins (76.3%) could be achieved by combining with SP34-0.4 at 70.3% CO conversion. Since, the current study interprets that the selectivity of hydrocarbons can be adjusted by regulating the acidity of SAPO-34 to achieve a high CO conversion in the dual fixed-bed reactor scheme.
研究领域:
化学工程
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催化科学
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2014
·
IF 3.019
Jie Zhang,Xingjun Wang,Fuchen Wang,Jie Wang
The hydrogasification of three low rank coals (YX lignite, XD lignite and ZD subbituminous coal) was carried out in a fixed-bed reactor to investigate the effects of hydrogen pressure on the formations of gaseous, liquid and char products. The reactor was typically heated at a rate of 15 °C/min up to 700 °C with a holding time of 60 min under various hydrogen pressures up to 5 MPa. The yields of BTX (i.e., benzene, toluene, and xylene) and naphthalene increased with increasing hydrogen pressure up to 5 MPa for all three coals, but more significant for XD and ZD coals. The compositional analysis of char revealed that the chars produced by the hydrogasification had higher molar ratios of H/C and lower molar ratios of N/C than those produced by the pyrolysis in N 2 atmosphere, whereas the former chars had higher or lower molar ratios of S/C than the latter chars from case to case depending principally on coals. The apparent reaction rate constants of the chars hydrogasification in the isothermal stage as a function of hydrogen pressure were found to follow a power equation of the power exponents varying with coals.
研究领域:
化学工程
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能源科学
✓ 已验证
DOI
高影响因子
FUEL
·
2018
·
IF 4.908
Yaqiu Tao,Lulu Tao,Zhigang Pan,Simin Qiu,Xiaodong Shen
Formic acid is a promising hydrogen storage material for its high H 2 capacity, easy transfer and moderate H 2 regeneration conditions. Active carbon supported Mo 2 C with or without Co doping were used as the heterogeneous catalyst in the decomposition of a high concentrated aqueous solution of formic acid up to 50% on a fixed bed reactor. For a given flow rate and reaction temperature, though higher volume of H 2 is produced per unit time, the increase in formic acid’s concentration reduces both H 2 selectivity and formic acid conversion rate. At 250 °C, a stream of 236 mL/min H 2 was generated continuously at a high H 2 selectivity (91%) and formic acid conversion rate (86%), from a 10% formic acid fed at the flow rate of 5 mL/min. High reaction temperature improved the conversion of formic acid feed at little expense of H 2 selectivity. The doping of Co in the Mo 2 C lattice improves the H 2 selectivity to 100% at 100–200 °C. A life time study showed the stability of this system by the remained high H 2 selectivity in formic acid decomposition. This work of using active carbon supported molybdenum carbides and high concentrated aqueous formic acid, opens up a new route for the portable H 2 generator using formic acid as a hydrogen storage material at no environmental risk.
研究领域:
化学工程
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能源科学
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2023
·
IF 5.9
Tianqing Zhou,Chaojian Zhang,Lungang Chen,Yue Yao,Shuxiang Lu,Xiaoyuan Liao
The direct synthesis of 2,5-furandicarboxylic acid (FDCA) from readily renewable fructose, would provide a cost approach without separation of 5-hydroxymethylfurfural (HMF). The method would realize efficient and continuous production, reduced by-products, without cumbersome HMF separation process, and reduced production costs. In this work, we succeeded in converting fructose directly into FDCA over combined Amberlyst-15 and Pd/Al 2 O 3 in fixed bed reactor. We firstly time, compared One-bed two-catalysts (OBTC), and two-bed two-catalysts (TBTC) system. For the individual merits of the Amberlyst-15 and Pd/Al 2 O 3 , the catalytic performance of the combined beds is significantly improved compared with individual one. The high yields of FDCA (48 %) and fructose conversion (100 %) were obtained, respectively. Our one-step continuously method makes the FDCA production much more economical, energy-saved.
研究领域:
化学工程
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可再生资源利用
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·
IF 7.139
Jun Zhang,Yonghong Niu
Biomass gasification produces hydrogen , which is a clean and promising technology. One of the most important aspects of the biomass gasification process is choosing the right catalyst. In this study, 10% La 1-X Ce X FeO 3 /Dolomite (X = 0,0.2,0.4,0.6,0.8) synthesized using the sol-gel method was used as a catalyst in biomass gasification for the production of hydrogen-rich syngas . Gasification tests were carried out in a fixed bed reactor . The effects of an elemental substitution in LaFeO 3 , temperature on the product were examined. Ce-substitution boosted the activity of LaFeO 3 /DOL according to the data. Among the prepared catalysts, La 0.8 Ce 0.2 FeO 3 /DOL performed the best, yielding a greater H 2 production and tar with a higher naphthalene concentration. As the temperature rises, so does the H 2 yield, at 850 °C, the highest H 2 yield is 0.69Nm 3 /Kg. Furthermore, the aromatization of phenols in tar is more likely to occur at high temperatures.
研究领域:
能源科学
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催化化学
✓ 已验证
DOI
高影响因子
ENERGY & FUELS
·
2018
·
IF 3.024
Hai-bo Zhao,Wen-ting Xu,Qiang Song,Jian-kun Zhuo,Qiang Yao
The migration of K during biomass thermal conversion can cause severe ash-related problems. K2CO3 and KCl are two important inorganic forms of K that appear during biomass thermal conversion. In this study, a fixed-bed reactor was used to investigate the effect of H2O vapor and SiO2 on the migration characteristics of these two inorganic K species. The results showed that K is released through the decomposition of pure K2CO3 during pyrolysis. K release from K2CO3 at 800 °C was not obvious, and the release rate increased significantly with temperature but mainly depended on the decomposition rate of K2CO3. The presence of H2O vapor can promote K release by reacting with K2CO3 and forming volatile KOH. When SiO2 was present, a rapid reaction occurred between SiO2 and K2CO3, and this reaction inhibited the release of K significantly. The reaction rate increased significantly with temperature, and H2O vapor promoted the reaction of SiO2 and K2CO3. In a pyrolysis atmosphere, KCl can be released by direct evaporation and cannot react with SiO2; by contrast, KCl can react with SiO2 to form insoluble K silicates in the presence of steam. With increasing temperature, the release rate of KCl increased faster than the K-silicate formation rate, resulting in a decrease in the proportion of insoluble K silicates generated. The results obtained in this work provide a basis for understanding the migration of inorganic K during biomass thermal conversion.
研究领域:
能源化学
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燃烧学
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热力学
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无机化学
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环境工程
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材料科学
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化学工程
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2019
·Vol. 11
·期 8
·2179-2186
·
IF 4.495
Hualei Hu,Danxin Hu,Haitao Jin,Pilan Zhang,Guozheng Li,Hao Zhou,Yong Yang,Chunlin Chen,Jian Zhang,Lei Wang
Graphical In the reaction zone : Benefiting from the presence of the secondary porosity and the appropriately acidity, the hierarchically structured ZSM-5 (HSZ) catalysts exhibited the excellent catalytic performance for the conversion of 2,5-bis(hydroxymethyl)furan (BHMF) to 2,5-bis(ethoxymethyl)furan (BEMF) in a continuous fixed bed reactor. The highest yield of BEMF (90.46 %) was obtained over the HSZ-150 catalyst under the reaction condition of 140 °C, 2.0 MPa of H 2 , and 0.3 h −1 of WHSV. The selective conversion of 2,5-bis(hydroxymethyl)furan (BHMF) to 2,5-bis(ethoxymethyl)furan (BEMF) was investigated in a fixed bed reactor over several heterogeneous solid acid catalysts, including Amberlyst-15, ZSM-5, Mordenite, and a series of hierarchically structured ZSM-5 zeolites (HSZ). The HSZ catalysts exhibited superior catalytic performance to other three commercial catalysts. The highest yield of BEMF (90.46 %) was obtained over the HSZ-150 catalyst under the reaction condition of 140 °C, 2.0 MPa of H 2 , and 0.3 h −1 of WHSV. Moreover, the HSZ-150 catalyst displayed an extremely good stability in the etherification reaction, maintaining more than 80 % yield of BEMF for about 80 h. The outstanding catalytic performance of the HSZ-150 catalyst could be ascribed to that the presence of mesopores enhanced the etherification activity by alleviating the diffusion limitation, and the appropriate acidity improved the BEMF selectivity via suppressing the side reactions.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 47
·26554-26562
·
IF 2.936
Liying Guo,Lili Deng,Xianchao Jin,Yirong Wang,Haozhi Wang
In this study, functionalized composite catalysts, namely, ILs (ILX/(ZnBr2)2), with hydroxyl, carboxyl and amino groups immobilized on a molecular sieve (MCM-22) support were synthesized with the help of a silane coupling agent, 3-chloropropyltriethoxysilane (CPTES). Cycloaddition of CO2 and propylene oxide (PO) was carried out in a fixed bed reactor. The results show that MCM-22-CPTES-[AeMIM][Zn2Br5] demonstrates the best catalytic properties for this reaction. A high selectivity and yield of propylene carbonate (PC) could be reached at 130 °C under a CO2 pressure of 2.0 MPa, with a LHSV of 0.75 h−1 and a molar ratio of CO2/PO of 3 : 1. The yield stabilized at 61.6% after 50 h in the fixed bed reactor.
研究领域:
化学工程
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催化材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2014
·Vol. 21
·期 21
·12563-12568
·
IF 2.757
Shen Shuguang,Li Meina,Li Binbin,Zhao Zhijun
In order to find an effective method for treating urea wastewater, the experiments on the hydrolysis of urea in wastewater were conducted in a fixed bed reactor with different aluminas (α-Al 2 O 3 , γ-Al 2 O 3 , and η-Al 2 O 3 ) as catalysts respectively in contrast with inert ceramic particle. The results indicate that the three alumina catalysts show obvious catalytic activity for urea hydrolysis at 125 °C. The order of activity is η-Al 2 O 3 > γ-Al 2 O 3 > α-Al 2 O 3 , and the activity difference increases with increasing temperature. According to the characterization results, surface acidity has little impact on the activity of catalyst. However, it was found that surface basicity of alumina catalyst plays an important role in catalytic hydrolysis of urea, and the activity of catalyst may be also influenced by the basic strength. With η-Al 2 O 3 as catalyst, the urea concentration in wastewater is reduced to 4.96 mg/L at a temperature of 165 °C. Moreover, the η-Al 2 O 3 shows a good stability for urea hydrolysis. The hydrolysis of urea over η-Al 2 O 3 catalyst can evidently reduce the reaction temperature and is promising to replace industrial thermal hydrolysis process.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
·
2015
·
IF 3.615
Miao Jiang,Li Yan,Yunjie Ding,Qi Sun,Jia Liu,Hejun Zhu,Ronghe Lin,Fengshou Xiao,Zheng Jiang,Jingyue Liu
The heterogenization of homogeneous catalysts is of critical importance for both fundamental research and practical applications. The key obstacle to industrial applications of heterogenized homogeneous catalysts is the long-term stability of the immobilized molecular complexes. We unambiguously demonstrate in this report that the vinyl-functionalized PPh 3 polymers supported single Rh sites (Rh/POL–PPh 3 ) catalyst provided not only excellent catalytic activity but also ultrahigh stability for fixed-bed olefins hydroformylation , which is one of the most important industrial homogeneous catalytic processes for the synthesis of aldehydes and alcohols. HAADF-STEM and EXAFS results indicated that the Rh atoms were present in single Rh sites which were strongly coordinated with the exposed phosphorous atoms of the POL–PPh 3 support. The Rh/POL-PPh 3 catalyst provided high activity and selectivity because it maintained the catalytic functionalities similar to the homogeneous HRh(CO)(PPh 3 ) 3 complex, as demonstrated both by 31 P MAS NMR and in situ FT-IR experiments. Thus a reaction mechanism, similar to that over the homogeneous HRh(CO)(PPh 3 ) 3 complex, was proposed for olefin hydroformylation over the novel Rh/POL–PPh 3 catalyst.
研究领域:
催化化学
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材料科学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Yichuan Li,Guofu Zhu,Yu Wang,Yongming Chai,Chenguang Liu,Shengbao He
Oriented molecular sieve membranes prepared on the surface of a specifically shaped substrate have been applied in the separation and catalysis process, but there is no report on the directional growth of molecular sieve membranes on the surface of spherical substrates. Here, a simple in situ crystallization method was employed to successfully prepare a single layer of b-oriented continuous titanium silicalite-1 (TS-1) molecular sieve membrane on the surface of 2-mm alumina beads. First, a titania intermediate layer was loaded on the surface of beads by the dipping method, and the surface was then modified with the TBOT modification solution. The ratio of the precursor solution was n(TEOS):n(TBOT):n(TPAOH):n(H 2 O) = 1:0.010:0.15:40 and was crystallized at 180 °C for 72 h to prepare the membrane. The content of the templating agent and water affected the size of TS-1 crystal grains and membrane crosslinking—both in turn influenced the continuity and orientation of the molecular sieve membrane. Spherical membrane catalyst was applied to catalyze the epoxidation of chloropropene in a fixed bed reactor, and the conversion of hydrogen peroxide and selectivity of epichlorohydrin attained 87.4% and 93.2%, respectively. This work provides a foundation for the design of novel TS-1 immobilized catalyst.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）