ENERGY & FUELS
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2019
·
IF 3.021
Zhen-Yi Du,Bin-Bin Zhang,Ting-Sheng Chen,Yuli Betancur,Wen-Ying Li
Isobutanol derived from biomass can serve as a potential renewable candidate for the production of light olefins and aromatics, which are the building blocks to manufacture fuels and chemicals in the petrochemical industry. Dependent upon the product requirements, the product selectivity toward olefins or aromatics can be tuned by adjusting the reaction conditions and the properties of HZSM-5 catalysts. On bare HZSM-5, mild conditions (low temperature, low space time, and low acidity) favored the production of olefins and harsh conditions (high temperature, high space time, and high acidity) were more likely to produce aromatics. Ga was impregnated onto HZSM-5 to enhance the production of aromatics. Unexpectedly, Ga introduction only induced the intertransformation between olefins and aromatics without significantly impacting the selectivity of low-value paraffins. The exchanged Ga sites functioning together with Brønsted acid were identified as active Ga species and strengthened the direct dehydrogenation of C6–C8 olefins. The in situ-generated water from isobutanol dehydration affected the formation of Ga species. This resulted in different promotional effects of Ga on the transformation of isobutanol and isobutene. The reaction pathways were developed on the basis of the catalyst evaluation results, in tandem with an in situ diffuse reflectance infrared Fourier transform spectroscopy study on the intermediates formed during isobutanol transformation. Selectivity of olefins and aromatics from isobutanol transformation can be tuned by adjusting reaction conditions and properties of HZSM-5 catalysts.
研究领域:
催化化学
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能源化学
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产品关联
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2019
·Vol. 33
·期 3
·e4745
·
IF 3.259
Yibing Xie,Langlang Wang,Ping Ning,Xueqian Wang,Qi Wang,Yingjie Zhang,Mengyu Wang
A series of Ce modified catalysts were prepared using equivalent-volumetric ultrasonic impregnation method for AsH 3 removal. The performance of catalytic oxidation of AsH 3 under dynamic conditions was studied under different synthesis and reaction conditions. Through screening tests, the optimum catalyst was impregnated by 10 wt.% Ce (CH 3 COO) 3 precursor and subsequently calcinated at 550 °C. When the reaction temperature reached 170 °C, the Ce-HZSM-5 catalyst could maintain an oxidation efficiency of over 90% in 82 hrs. Furthermore, the chemical structure and properties of the catalyst and its catalytic oxidation mechanism with AsH 3 were analyzed using SEM-EDS, BET, XRD, XPS, H 2 -TPR and FT-IR. The results showed that Ce mainly existed on the catalyst surface in the forms of Ce 4+ and Ce 3+ . In the reaction process, the chemisorbed oxygen played a key role in the transformation between the two valence states. AsH 3 was firstly oxidized to elemental As with the participation of lattice oxygen. Then, the elemental As was partially blown into the rear part of the adsorption column along with the air flow and subsequently, de-sublimed on the column wall. Herein, the elemental As remained on the surface of Ce-HZSM-5 catalyst, which would further oxidize to As 2 O 3 . For the recovery of As, Ce-HZSM-5 proved to be a promising catalyst in AsH 3 removal. Highlights The CeO x modified HZSM-5 catalyst was used to catalytic oxidation of AsH 3 . The Ce-HZSM-5 catalyst could maintain over 90% oxidation efficiency in 82 hrs. AsH 3 was catalytic oxidized to elemental As and H 2 O on the catalyst surface and the As can be collected. The As adsorbed on the catalyst surface can be oxidized to As 2 O 3 but cannot be further oxidized to As 2 O 5 .
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
CHEMISTRY & BIODIVERSITY
·
2024
·Vol. 21
·期 6
·e202400150
·
IF 2.3
Long Ren,Yupu Xu,Wenjun Chen,Changsen Zhang
Experiments were conducted in this study on the co-hydropyrolysis of three components of biomass (cellulose, hemicellulose, and lignin) and HDPE by using SR-Pd/Trap-HZ-5 as catalyst. To control the variable, we use the same experiment conditions in co-hydropyrolysis: Si/Al ratio of 50, Pd load 1 %, catalyst to reactant ratio of 1 : 10, 1 MPa, 400 °C, reaction time 1 h. Use XRD, TEM, BET, and NH 3 -TPD to confirm catalyst successful synthesis; use pine sawdust (PW) co-hydropyrolysis with HDPE to analyse catalytic activity; and use GC/MS to characterize the chemical composition of the bio-oil from the co-hydropyrolysis of biomass components and HDPE. The results show that cellulose has a significant synergistic effect with aromatic hydrocarbon production, whose selectivity was 93.3 %; hemicellulose has a synergistic effect; aromatic selectivity can reach 75.1 %; and a negative synergistic effect between lignin and HDPE was shown as the selectivity of aromatic hydrocarbons decreased from 62.1 % to 15.6 %. Graphical
研究领域:
能源与燃料化学
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催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CATALYSIS
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2014
·
IF 1.552
Shurong Wang,Qinjie Cai,Xiangyu Wang,Li Zhang,Yurong Wang,Zhongyang Luo
Acids and ketones in biomass pyrolysis oil (bio-oil) can be readily cracked to produce hydrocarbons. They can also be enriched in the distilled fraction using molecular distillation techniques. To simulate the actual composition of the distilled fraction, the co-cracking performance of mixtures of hydroxypropanone, cyclopentanone, and acetic acid with ethanol in a fixed-bed reactor over an HZSM-5 catalyst was studied. The influences of reaction temperature and pressure on the reactant conversion, selectivity, and composition of the oil phase were investigated. At a low reaction temperature of 340 °C, the conversions of acetic acid and ethanol were as low as 67.9% and 74.4%, respectively, and the oil phase had a low hydrocarbon content of 59.8%, with large amounts of oxygenated byproducts. Cracking under atmospheric pressure also generated a low-quality oil phase with a very low selectivity of only 10.8%. Increasing the reaction temperature promoted reactant conversion and improved the deoxygenation efficiency, whereas increasing the reaction pressure significantly promoted hydrocarbon production. The optimum conditions for biogasoline production were 400 °C and 2 MPa. Under these conditions, the reactant conversion reached 100% and the oil phase selectivity was 31.5 wt%. This oil phase consisted entirely of hydrocarbons, 91.5 wt% of which were aromatic hydrocarbons , indicating that the HZSM-5 catalyst had high activity for deoxygenation and aromatization reactions during cracking. In addition, characterization of the spent catalysts and stability tests showed that the catalyst was deactivated after a long reaction time. However, the catalytic activity was recovered by catalyst regeneration.
研究领域:
能源生物学
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催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2015
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IF 4.321
Qian Yao,Lujiang Xu,Zheng Han,Ying Zhang
Furfural, an abundant biomass derived compound, was converted into indoles via thermo-catalytic conversion and ammonization with zeolites. The effect of reaction temperature, catalyst, weight hourly space velocity (WHSV) and ammonia to furfural molar ratio on the product distribution was investigated systematically. They all played important roles on indoles production. The maximal carbon yield of indoles (20.79%) was achieved by using HZSM-5 (Si/Al = 25) catalyst at 650 °C with WHSV as 1.0 h −1 and NH 3 to furfural molar ratio as 2. The HZSM-5 (Si/Al = 25) catalyst was recycled for five times and showed slight deactivation. Three possible aldehyde group of furfural conversion pathways were proposed and one possible reaction pathway from furfural to indoles was verified based on the experimental and quantum calculation results, that is, furfural firstly reacted with ammonia to form furfural-imine, and then furfural-imine underwent a cracking reaction to form furan. Thereafter, furan was converted to pyrrole and finally to indoles.
研究领域:
生物化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2023
·
IF 2.8
Zhang Yakun,Xu Lin,Wang Wen,Wu Qing,Zhang Yi
The efficient conversion of ethane has attracted more and more attention because of the shale gas revolution. The coupling of ethane dehydrogenation (EDH) and benzene alkylation over the 1.5Pt/HZSM-5 realize high activity close to the thermodynamic equilibrium of EDH at 500 ℃ and 0.9 bar ethane partial pressure. Meanwhile, the coupled reaction shows long-term stability during 22 h with a slightly decreased ethane conversion of 0.03% per hour and as high as 42% selectivity of ethylbenzene. Based on various characterization, including XRD, HR-TEM, NH 3 -TPD, Py-IR, TGA, it is confirmed that the coupling reaction could convert ethylene, formed by EDH over Pt sites, to ethylbenzene via benzene alkylation over Brönsted acidic sites (BAS) subsequently, and suppressing the sintering of Pt species and coke deposition induced by aromatization and deep dehydrogenation, resulting in high activity and long-time steady state. Graphical Abstract
研究领域:
化学工程
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Baocheng Qiu,Yakun Zhang,Yi Liu,Yi Zhang
The efficient conversion of ethane has become more attractive recently because of the shale gas revolution. Platinum-based catalyst is the most active for direct dehydrogenation of ethane to ethylene, but it always suffers deactivation due to coke deposition and sintering of supported Pt. We have successfully synthesized a Pt-embedded inside HZSM-5 crystal catalyst (Pt@HZSM-5) by hydrothermal synthesis using Pt/SiO 2 as only silicone source, to realize excellent stability during the dehydrogenation of ethane (EDH) to ethylene. Based on various characterization results, including in-situ synchrotron XANES and EXAFS, in situ XPS, operando DRIFTS, as well as 27 Al MAS NMR, the stable Pt species with high electron density on Pt@HZSM-5 avoids the deep dehydrogenation of ethane to form coke, and the surrounding environment of Pt active phase, including newly formed HZSM-5 frameworks and its acidity, contributes to suppressing the aromatization of the formed ethylene. As synergic effects, the Pt@HZSM-5 catalyst realizes excellent stability during 50 h EDH reaction without any regenerations with relatively high ethane conversion under the serve reaction conditions (90% ethane in feed gas, 0.1 MPa, 550 °C). However, the conventional Pt/HZSM-5 catalyst exhibits dynamic transformation of Pt chemical state, particle size, and its surrounding environment, resulting in rapid deactivation induced by much more carbon deposition and aromatization of the formed ethylene.
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
BIORESOURCE TECHNOLOGY
·
2019
·
IF 6.669
Xin Zhang,Ziguo Yuan,Qian Yao,Ying Zhang,Yao Fu
In this work, corn cob was used as raw material to selectively produce acetonitrile via catalytic fast pyrolysis (CFP) in ammonia over Ga/HZSM-5 catalyst. A series of catalysts with different catalyst carriers (including HZSM-5, USY, MCM-41, HY, and γ-Al 2 O 3 ) and active metals (including Fe, Co, Ni, Cu, Zn, Cr, Ca, Mg and Ga) were prepared and screened. The reaction conditions, such as temperature, ammonia flow rate and residence time were changed to investigate the effect on the product distribution and acetonitrile production. The results indicated that with the desired catalyst (2% Ga/HZSM-5) and optimal reaction conditions (Temperature 700 °C; ammonia flow rate 80 ml/min; residence time 2.4 s), the highest carbon yield of acetonitrile from corn cob with a value of 18.4% could be obtained, and the carbon selectivity in bio-oil was 83.5%. This study provides an economical and environmental-friendly method for the direct production of acetonitrile from abundant biomass.
研究领域:
能源与环境科学
·
生物质转化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
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2022
·
IF 5.723
Guoqiang Hou,Tingjun Fu,Xin Li,Qian Ma,Zhong Li
HZSM-5 catalysts with abundant silanol nests were fabricated by removing framework Al, which effectively promoted the selective alkylation of toluene with methanol by inhibiting the deep alkylation of aromatics to heavy aromatics and the conversion of methanol to light hydrocarbons. Correspondingly, the alkylation efficiency reached 65.3% at a toluene conversion of 31.3% over dealuminated HZSM-5, higher than the 55.2% efficiency and 28.0% conversion of parent zeolites, respectively. In situ DRIFTS and single-factor experimental clarified that toluene adsorption was enhanced and methanol to hydrocarbons was inhibited with the presence of silanol nests. Additionally, by increasing the crystal size of HZSM-5 with silanol nests from 2 to 5 µm, para-xylene selectivity was increased from 36.1% to 65.5% because of the enhanced diffusion barrier . The finding of the positive effect of the silanol nests on toluene alkylation can provide a solid fundamental basis for the rational design of catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2018
·
IF 3.468
Yunwu Zheng,Lei Tao,Xiaoqing Yang,Yuanbo Huang,Can Liu,Zhifeng Zheng
The present study aims to improve the yields and selectivity of aromatic hydrocarbons in the catalytic pyrolysis of biomass by the addition of low-density polyethylene (LDPE), which has a higher hydrogen-carbon ratio than biomass. We have investigated the thermal decomposition behavior and kinetics, as well as the product distribution, of the co-pyrolysis of biomass (cellulose and pine sawdust) and plastic (LDPE) both with and without a catalyst (HZSM-5) using thermogravimetric analysis (TGA) and analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Our results, based on the weight loss difference (△ W ), show that there is a positive and synergistic interaction between the biomass and LDPE. After the addition of LDPE, the synergistic reactions inhibited catalyst coking effectively and decreased the formation of solid residues. In addition, the ZSM-5 catalyst improved the reaction activity and reduced the activation energy, although the reaction mechanism is not changed. At the same time, the Flynn-Wall-Ozawa (FWO) method was used to fit the kinetic data for both non-catalytic and catalytic co-pyrolysis of biomass and LDPE, and the activation energies ( E a ) of the cellulose + LDPE + catalyst and pine + LDPE + catalyst systems were found to be 168.81 and 185.87 kJ/mol, respectively. The co-pyrolysis of biomass and LDPE effectively improved the yield and selectivity of aromatics and increased the selectivity for benzene, toluene, xylene, and ethylbenzene (BTXE). The addition of LDPE can effectively improve the selectivity for naphthalene family products (methylnaphthalene and 2-methylnaphthalene) in the catalytic pyrolysis of biomass and decrease the content of aromatic hydrocarbons larger than C10.
研究领域:
能源科学
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化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS SURVEYS FROM ASIA
·
2018
·Vol. 22
·期 3
·129-135
·
IF 3.081
Zhang Di,Zhao Yun-Peng,Fan Xing,Liu Zhong-Qiu,Wang Rui-Yu,Wei Xian-Yong
A series of Ni/HZSM-5 catalysts with different Ni-loadings and Si/Al ratios were prepared by incipient wetness impregnation and employed for catalytic hydrogenation of levulinic acid (LA) to gamma-valerolactone (GVL). Their physicochemical properties were characterized by X-ray diffraction, nitrogen adsorption–desorption, X-ray photoelectron spectrometer, temperature-programmed desorption of ammonia,transmission electron microscopy, temperature-programmed reduction of hydrogen, and pyridine-adsorbed infrared spectroscopy. The diffraction peaks assigned to Ni phase were not observed, implying that nickel particles were small and had a high dispersion on the supports. The catalysts with a strong acidity and the appropriate ratio of Brönsted (B) acid sites to Lewis (L) acid sites (B/L = 4.9) show an excellent activity and selectivity for the hydrogenation of LA to GVL. High conversion of LA and selectivity towards GVL were achieved over 5 wt% Ni/HZSM-5-50. The maximum GVL yield of 100% over 5 wt% Ni/HZSM-5-50 was obtained under the optimized reaction conditions of 210 °C, 2 h, and 3 MPa initial hydrogen pressure.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2022
·
IF 4.654
Jun Zhang,Zhen Wu,Yafei Wu,Xiaoling Liu,Xun Li,Yu Zhang,Haian Xia,Fei Wang
Catalytic cracking of fatty acid methyl esters (biodiesel) is an attractive alternative to petroleum processing to produce valuable and versatile aromatics over the Zn-modified HZSM-5(25) catalysts. The catalysts with a Zn loading amount of 0–2.6 wt % were prepared and characterized. The introduction of Zn species presented great effects on the textural property and acidity of the parent HZSM-5(25) zeolite, and the chemical state of Zn species was heavily dependent on the amount of Zn loading. The strong Brönsted acid sites on the 0.5% Zn/HZSM-5(25) catalyst were exchanged by Zn species and formed new Zn-Lewis acid sites, which were identified as [ZnOH]+ and Zn2+ species. These Zn species greatly enhanced the dehydrogenation activation of alkanes to form more alkenes. Besides, they also promoted the further dehydrogenation reactions during aromatization of alkenes, thus improving the formation of H2 (>4 wt %) and increasing the production of aromatics (>40 wt %). The dominant components in the organic liquid product were monocyclic aromatics including benzene, toluene, and xylenes. Moreover, the 0.5% Zn/HZSM-5(25) catalyst exhibited an excellent stability, adaptability, and regeneration.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）