CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2021
·
IF 3.171
Xing Zhang,Jingfeng Wu,Junhao Chen,Liang Lu,Lingjun Zhu,Shurong Wang
The catalytic cracking of bio-oil is important to produce aromatic hydrocarbons , which can partially replace gasoline or diesel to greatly reduce carbon emissions from transportation. To further promote the formation of aromatic hydrocarbons, this work studied the effects of the preparation method and the acid strength of Ga 2 O 3 /HZSM-5 on catalytic cracking of the bio-oil distilled fraction systematically. The preparation method of Ga 2 O 3 /HZSM-5 had an important effect on its catalytic activity: the Ga 2 O 3 /HZSM-5 prepared by physical mixing showed the low dispersion of active phases and poor pore structure, resulting in its insufficient activity and severe coke deposition; the Ga 2 O 3 /HZSM-5 prepared by precipitation exhibited the higher activity, while many polycyclic aromatic hydrocarbons unfavorable for the subsequent utilization were in the oil phase; the Ga 2 O 3 /HZSM-5 prepared by impregnation showed the highest activity and 35.5% (mass) selectivity of the oil phase, including 80.3% monocyclic aromatic hydrocarbons and 12.0% polycyclic aromatic hydrocarbons. The Brønsted acidity of Ga 2 O 3 /HZSM-5 decreased with Si/Al ratio, leading to the decline in reactant conversion, oil phase selectivity and quality. Meanwhile, the polymerization between monocyclic aromatic hydrocarbons and oxygenates was promoted to produce many polycyclic aromatic hydrocarbons and even coke, causing catalyst deactivation .
研究领域:
能源化学
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2018
·
IF 3.956
Huamei Yang,Koyo Norinaga,Ji Li,Wenyou Zhu,Haijun Wang
This study aimed to experimentally investigate the effect of HZSM-5 on the distribution of volatile products, especially carbon monoxide (CO), C 1 –C 5 hydrocarbons and aromatic hydrocarbons (AHs) during catalytic pyrolysis of lignin and lignin model compounds. Catechol was pyrolyzed using a two-stage tubular reactor (TS-TR) connected to a gas chromatography system over HZSM-5 at 550–950 °C. Forty-three products, including four inorganic gases, twenty C 1 –C 5 hydrocarbons, and nine AHs were quantified using three GC-columns. Results indicated that HZSM-5 accelerated the catechol conversion with a large amount of CO and AHs produced. C 1 –C 5 hydrocarbons were formed during non-catalytic pyrolysis of model compounds, and consumed quickly during HZSM-5 catalytic pyrolysis of catechol. Catalytic pyrolysis of phenol , guaiacol and syringol was carried out at 650 °C in the TS-TR over HZSM-5. HZSM-5 obviously promoted the conversion of lignin model compounds, and largely increased the yield of volatile products especially CO and AHs. Three lignin samples were also catalytically pyrolyzed over HZSM-5 in the TS-TR at 650 °C. HZSM-5 increased the yield of C 2 -C 3 hydrocarbons and AHs, and reduced the yield of oxygenated compounds. HZSM-5 could promote the formation of AHs (lower than 10 wt%) during lignin pyrolysis, but not as obviously as during model compounds pyrolysis (higher than 19 wt%). High yields of char and tar would account for the low catalytic efficiency of HZSM-5 during lignin pyrolysis.
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
ENERGY & FUELS
·
2018
·
IF 3.024
Zihao Zhang,Hao Cheng,Hao Chen,Jing Li,Kequan Chen,Xiuyang Lu,Pingkai Ouyang,Jie Fu
Hierarchical HZSM-5 with tunable acidity, zeolitic crystallinity, and porosity were prepared using different organosilanes and used for the production of aromatics from the catalytic fast pyrolysis (CFP) of rice straw. As the chain length of organosilanes changed, the composition of the products including aromatics and coke varied greatly. Additionally, the introduction of ammonium ions into organosilanes led to a lower yield of aromatics and a higher yield of coke. Transmission electron microscopy, temperature-programmed desorption of NH3, N2 adsorption–desorption (Brunauer–Emmett–Teller), and X-ray diffraction were used to explore the influence of the morphological structure, acidity distribution, textural properties, and crystallinity on the CFP of rice straw. The results indicated that the crystallinity, textural properties, and total acidity had a great influence on the synthesis of aromatics.
研究领域:
化学工程
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材料科学
·
能源转化
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Yang Shen,Chunjiang Liu,Cunhao Cui,Hairong Ren,Mingming Gu,Haoran Liu,Zhongyue Zhou,Fei Qi
Lignin catalytic pyrolysis presents a promising and sustainable approach to producing aromatic molecules. Herein, we investigated the effect of modified zeolite with copper (Cu/HZSM-5) catalyst on efficiently pyrolyzed kraft lignin into aromatic hydrocarbons (AHs) production, especially mononuclear aromatic hydrocarbons (MAHs). Time-of-flight mass spectrometry (TOF-MS) was employed to compare the volatile product profiles of lignin during catalytic pyrolysis. The highest yield of MAHs reached 70.59 mg/g based on dry lignin at 550 °C, accounting for 70.23% among lignin pyrolysis products, compared to the pristine HZSM-5 zeolite catalytic system with MAHs yield of only 54.31 mg/g and of 40.34% in products. At 550 °C and 60 s residence time, the 5% Cu/HZSM-5 catalyst demonstrated the best performance compared to all other catalysts in terms of selectively producing MAHs. The results are ascribed to the enhancement of decarboxylation and aromatization processes by the doping of copper. This work demonstrates a cost-effective pathway that potentially converts kraft lignin into aromatic hydrocarbon production at a phenomenally high selectivity, providing a concept for industrial application toward biomass utilization and high value-added production.
研究领域:
生物质能
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催化化学
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可再生资源
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
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2017
·Vol. 7
·期 12
·383
·
IF 3.082
Nana Li,Yadong Bi,Xiaoqiang Xia,Hui Chen,Jianli Hu
The hierarchical HZSM-5 zeolite was prepared successfully by a simple NaOH treatment method. The concentration of NaOH solution was carefully tuned to optimal the zeolite acidity and pore structure. Under NaOH treatment conditions, a large number of mesopores, which interconnected with the retained micropores, were created to facilitate mass transfer performance. There are very good correlations between the decline of the relative zeolite crystallinity and the loss of micropores volume. The Ni nanoclusters were uniformly confined in the mesopores of hierarchical HZSM-5 by the excessive impregnation method. The direct deoxygenation in N2and hydrodeoxygenation in H2of the methyl laurate were compared respectively over the Ni/HZSM-5 catalysts. In the N2atmosphere, the deoxygenation rate of the methyl laurate on the Ni/HZSM-5 catalyst is relatively slow. In the presence of H2, the synergistic effect between the hydrogenation function of the metal and the acid function of the zeolite supports can make the deoxygenation level more obvious. The yield of hydrocarbon products gradually reached the maximum with the appropriate treatment concentration of 1M NaOH, which could be attributed to the improved mass transfer in the hierarchical HZSM-5 supports.
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
ENERGY CONVERSION AND MANAGEMENT
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2020
·
IF 8.208
Changsong Hu,Huiyan Zhang,Shiliang Wu,Rui Xiao
This article is intended to deepen the understanding of molecular shape selectivity of HZSM-5 in catalytic conversion of biomass pyrolysis vapors through the study of catalyst effective pore size. Ex-situ catalytic fast pyrolysis (CFP) of biomass over HZSM-5 with varied catalyst loadings were carried out using a continuous feeding two-stage fluidized-bed/fixed-bed combination reactor. Results showed that in addition to the shape selective reactions inside catalyst channels, cracking and aggregating reactions occur at the external surface of HZSM-5. The catalytic activity of HZSM-5 external surface for some heavy compounds was observed to be relatively low. On the basis of the molecular dimension information provided by quantum chemical calculations, it was found that HZSM-5 has an effective pore size which is significantly larger than its static pore size at CFP temperature. Catalytic alkylation of naphthalene with methanol over HZSM-5, HZSM-5@silicalite-1, HSAPO-34, HM, Hβ, HUSY and HMCM-41 were further compared to determine the effective pore size of HZSM-5. It is proposed that the effective pore size of HZSM-5 at CFP temperature is between the critical molecular diameters of 2,3- and 1,6-dimethylnaphthalene (between 7.520 and 7.961 Å).
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
JOURNAL OF SOLID STATE CHEMISTRY
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2019
·
IF 2.291
Yu Sang,Hansheng Li
The objective of this work is to investigate the catalytic effect of a series of modified HZSM-5 zeolites on n-decane cracking at 500 °C and atmospheric pressure. The zeolite catalysts were prepared with phosphorus and/or mesopore modification by excessive impregnation and/or hydrothermal treatment , and were characterized with various methods including SEM, TEM , XRD , FTIR, N 2 adsorption-desorption measurement and NH 3 -TPD. Results show that the addition of phosphorus adjusted the distribution and strength of acid sites in the zeolite crystals. The introduced mesoporous structure improved the diffusion of reactants and products in zeolite pores during n-decane cracking. With appropriate acid amounts and distribution, as well as short channels and high specific surface area, the modified HZSM-5 nanoparticles exhibited higher catalytic activity, better light olefins selectivity and longer lifetime, compared with the original HZSM-5 zeolite. The phosphorus modified HZSM-5 zeolites coupling with MCM-41 matrix was proved to be a promising catalyst for the thermal cracking of n-decane.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2021
·Vol. 16
·期 3
·384-396
·
IF 4.204
Liu Xiangyu,Pan Yanling,Zhang Peng,Wang Yilin,Xu Guohao,Su Zhaojie,Zhu Xuedong,Yang Fan
Alkylation of benzene to value-added, high octane number and low toxic toluene and xylenes provides a way to lower benzene content in gasoline pool, and is hence a method to promote fuel quality. On the other hand, CO 2 accumulation in the atmosphere causes global warming and requires effective route for its valorization. Utilization of CO 2 as a carbon source for benzene alkylation could achieve both goals. Herein, alkylation of benzene with CO 2 and H 2 was realized by a series of low-cost bifunctional catalysts containing zinc/titanium oxides (Zn/Ti oxides) and HZSM-5 molecular sieves in a fixed-bed reactor. By regulating and controlling oxygen vacancies of Zn/Ti oxides and the acidities of HZSM-5, benzene conversion and CO 2 conversion reached 28.7% and 29.9% respectively, along with a total selectivity of toluene and xylene higher than 90%. In this process, more than 25% CO 2 was effectively utilized and incorporated into the target products. Moreover, the mechanism of the reaction was analyzed and the course was simultaneously traced. CO 2 was transformed into methanol firstly, and then methanol reacted with benzene generating toluene and xylene. The innovation provides a new method for upgrading of fuels and upcycling the emissions of CO 2 , which is of great environmental and economic benefits.
研究领域:
化学工程
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环境科学
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催化科学
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Yingyang Song,Junyu Lang,Qingrui Zeng,Jinping Cheng,Mingce Long
Monoethanolamine (MEA)-based carbon dioxide absorption is one of the effective carbon capture, utilization, and storage (CCUS) technologies but is significantly restricted by the high energy consumption in the regeneration of rich amine solution. Solid acid catalysts have the potential to reduce energy consumption, while the exploration of highly active catalysts with abundant Bro̷nsted and Lewis acid sites remains needing. We developed an efficient solid acid catalyst, niobium-modified HZSM-5 (Nb/HZ), to facilitate CO2 desorption from the CO2-captured MEA solutions. The Nb/HZ catalysts with various niobium loadings were synthesized by using an impregnation method. HZSM-5 retained its pore structure and large surface area after niobium incorporation. The catalyst with 4% Nb (4.0-Nb/HZ) has the highest activity and stability, with 61% increase in the desorption rate, 50% increase in the desorbed CO2 amount, and 37% reduction of relative heat duty. According to theoretic calculations and experimental analyses, the Nb/HZ catalyst provides abundant Bro̷nsted and Lewis acid sites to facilitate carbamate adsorption, proton transfer, and carbamate breakdown, thus reducing the activation energy for CO2 desorption. This work provides a valuable solid acid catalyst for amine-based CO2 capture and also brings insights for the development of a novel solid acid for diverse catalysis.
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
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xitong Yang,Ruifeng Zhou,Guowei Liu,Sajjad Hussain,Qiuye Li
Catalytic regeneration has become one of the most promising technologies to solve the high energy consumption problem of CO 2 capture in organic amine solutions. As the most mainstream type of catalyst, the instability of acidic catalysts in alkaline solutions attracts increasing attention from researchers. Herein, we proposed a composite catalyst of MnOOH loaded HZSM-5 to weaken the adsorption of alkaline substances and improve the catalytic stability of the catalytic material. The optimized catalytic effect is obtained when the mass ratio of MnOOH is 20% The CO 2 desorption efficiency is increased by 68.2%, and the energy consumption is reduced by 31.8% when the dosage of the catalyst is only dosage of 0.2 wt% amine solution. Through materials characterization and DFT calculations, it was found that the surface O and hydroxyl groups on MnOOH are the key factors for proton cycling, and HZSM-5 has an important impact on improving proton transfer rate. This work provides a valuable approach to solving the stability problem of acidic catalysts.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2016
·Vol. 33
·期 7
·2097-2106
·
IF 1.408
Bai Ting,Zhang Xin,Liu Xiling,Chen Tengfei,Fan Wentao
A series of HZSM-5 catalysts were synthesized by different methods. The physicochemical properties of the HZSM-5 catalysts were characterized by XRD, SEM, N2 isothermal adsorption-desorption, NH3-TPD, Py-IR and TGA, respectively. The results indicated that different preparation conditions lead to different morphologies, textures and the distribution of acid sites. The nanosized HZSM-5 catalysts exhibited better catalytic reactivity and coke capacity than the micro-sized HZSM-5 because nanosized HZSM-5 had larger specific surface area, higher pore volume, more exposed channels and more accessible acid sites. The large particles of NZ-3 in a reasonable range and the smooth surface were conducive to product diffusion; therefore, NZ-3 exhibited higher specific propylene yield and stability than the other nanosized catalysts. The moderate density and distribution of acid sites on NZ-3 also favored the formation of propylene.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2024
·
IF 5.8
Yanlong Jia,Mengyan Wang,Bolun Li,Jiang Liu,Xueping Song,Min Wu,Yongjun Yin
To solve the long-term environmental pollution caused by black liquor and waste plastics, and achieve high-value utilization, the method about co-pyrolysis of black liquid solid and waste plastics (Polypropylene, Polyethylene) catalyzed by Mo-Ni/HZSM-5 to prepare high-quality bio-oil is studied. The results found that hydrocarbons increased from 14.92% to 42.03% as Polyethylene was co-pyrolyzed with BLS, and hydrocarbons increased from 14.92% to 41.75% as Polypropylene was co-pyrolyzed with BLS, adding plastics can significantly improve the hydrocarbons yield of black liquor. Mo-Ni/HZSM-5 acts as a hydro deoxidizer in the pyrolysis of black liquid and waste plastics, the total hydrocarbons of black liquid solid, black liquid solid& Polypropylene, black liquid solid & Polyethylene increased by 6%, 78%, and 45%, respectively. An appropriate increase of pyrolysis temperature can promote the co-pyrolysis of BLS with PP, and BLS with PE, and can increase the yield of hydrocarbons. Compared with black liquor’s pyrolysis, the yield of hydrocarbons can be increased by 59.65% and 24.52% as Polyethylene or Polypropylene is adapted to pyrolysis with black liquid solid, respectively, the high-quality bio-oil is obtained because of a large number of hydrocarbons and high hydrogen content.
研究领域:
环境科学
·
能源工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）