AICHE JOURNAL
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2020
·Vol. 66
·期 8
·e16979
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IF 3.519
Piao Cao,Yuan Yuan,Chizhou Huang,Weizhen Sun,Ling Zhao
Seven typical quaternary ammonium ionic liquids, amino acid ionic liquids, and imidazolium ionic liquids were synthesized, characterized, and investigated as co-catalyst for the sulfuric acid catalyzed isobutane alkylation. The results show that the introduction of [OPSIm][HSO 4 ] or [Pr 3 NPS][HSO 4 ] both leads to a better catalytic performance and higher quality of alkylate products. The molecular dynamic simulation indicates that the [OPSIm][HSO 4 ] can promote the dissolution of isobutane molecules at interface, further improving the ratio of isobutane to olefin from 1.02 to 1.18. Differently, the [Pr 3 NPS][HSO 4 ] can significantly increase the interface width from 0.66 to 0.97 nm and reduce the interface tension from 28.49 to 14.62 mN/m, thereby enhancing the reaction area and improving the ion transfer. The [Pro][HSO 4 ] and [Gly][HSO 4 ] result in a worse quality of alkylate products due to no positive effect on the interfacial properties such as interfacial solubility of isobutane.
研究领域:
化学工程
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催化
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Yangyang Xin,Yufeng Hu,Mengchen Li,Kebin Chi,Shang Zhang,Fei Gao,Siqi Jiang,Yichuan Wang,Chunxiao Ren,Guohua Li
Alkylation catalyzed by concentrated sulfuric acid (H2SO4) is an important process for industrial production of excellent high octane gasoline blending components. This process has some vital drawbacks such as extensive side reactions and high consumption of H2SO4 due to the presence of the most notorious impurities including H2O, acid soluble oil (ASO), and esters. In this study, isobutane alkylation was studied with H2SO4 (275 mL) in a batch reactor at −10 to 0 °C and 0.45 MPa, with the corresponding stirrer speed, feed rate, acid/hydrocarbon volume ratio, and isobutane/isobutylene volume ratio being 3000 rpm, 5.0 mL/min, 1.2, and 14.3, respectively. The effects of the acid strength and composition of acid on the alkylate quality were investigated. The composition of used acid was analyzed. The results show that used acid is mainly composed of roughly 89% free H2SO4, 6% H2O, 2% esters, and 3% ASO. The compounds existing in the ASO extracted from used acid were identified, and their concentrations were quantitatively determined. The results show that the most abundant ASO molecules are five-membered or six-membered cyclic homoannular conjugated olefins such as cyclopentadiene (15.67%) and cyclohexadiene (14.12%). The effects of acid strength, H2O, ASO, and esters on alkylation depend strongly on the concentrations of H2SO4 and these impurities. Therefore, their optimal concentrations were determined to achieve advantageous effects on the alkylation. The results are about 93–95% for H2SO4, 2–4% for H2O, 1.5–2.5% for ASO, and 0.4–1% for esters, beyond which an adverse effect will appear. Under the optimal concentrations, the value of the research octane number, the trimethylpentane (TMP)/dimethylhexane ratio, and the contents of C8 and TMP remained steady at high levels of about 92–93, 5.8–6.3, 68–70, and 58–60%, respectively.
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
·
2022
·
IF 8.035
Yangyang Xin,Yufeng Hu,Yichuan Wang,Siqi Jiang,Mengchen Li,Kebin Chi,Shang Zhang,Fei Gao,Chunxiao Ren,Shuai Zhang,Chenglong Ma
For alkylation catalyzed by H 2 SO 4 , the promotion of solubility of isobutane in H 2 SO 4 is of major importance to the enhancement of quality of alkylates. ASO (acid-soluble oils or conjunct polymers or red oil) are the potential co-catalyst to improve the solubility of isobutane and to optimize the interfacial characteristics of acid/hydrocarbon dispersions. On the basis of the calculation results of COSMO-RS method, we found that the solubility of isobutane in H 2 SO 4 was obviously increased upon the addition of most ASO molecules. Moreover, a better dissolution of isobutane in H 2 SO 4 can be achieved by adding the hydrocarbons like paraffins and cycloparaffins into H 2 SO 4 . On the basis of these findings, two cycloparaffins were selected and used as the co-catalyst (the co-catalysts A and B) to improve the performance of the H 2 SO 4 catalyst. The alkylation results showed that these cycloparaffins enhanced the quality of alkylates. In particular, upon the addition of the co-catalyst B, the RON (research octane number) value, the TMP/DMH (trimethylpentane/dimethylhexane) ratio, and the contents of C8 and TMP (trimethylpentane) were increased significantly from 92.67 and 6.51, 68.25% and 59.10% to 94.38 and 6.97, 74.81% and 65.34%, and the consumption of the H 2 SO 4 catalyst was reduced by 38%.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Ying-Bin Jiang,Feng-Li Yu,Bing Yuan,Cong-Xia Xie,Shi-Tao Yu
In this study, the solubility of isobutane in different types of polyethers was evaluated. Macroscopic and microscopic simulations of molecular bonding of isobutane to polyethers such as PEG200 and PPG200 were performed. The solubility of isobutane in different polyethers with different degrees of polymerization was investigated. The solubility of isooctane—the main alkylated gasoline product—in different polyethers was also determined. Based on the solubility ratios of isobutane and isooctane in the same polyether, PEG200 was selected as a component of a deep eutectic solvent (DES), which was then used for catalyzing the alkylation of isobutane and isobutene to prepare alkylated gasoline. Owing to the good solubility of isobutane in polyether, a three-component Brønsted–Lewis acidic DES catalyst, InCl 3 /PEG200/TfOH, could be used to prepare high-quality alkylated gasoline (conversion rate: 89.12%, C8 selectivity: 82.83%) at a low alkane-to-alkene ratio (5:1). Moreover, owing to its poor solubility to isooctane, the DES catalyst could be easily separated from alkylated gasoline. This DES catalyst retains its high catalytic activity over seven cycles.
研究领域:
化学工程
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催化科学
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能源化工
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2021
·
IF 3.171
Shuo Li,Jianlin Cao,Xiang Feng,Yupeng Du,De Chen,Chaohe Yang,Wenhua Wang,Wanzhong Ren
Elucidating the confinement effect harbours tremendous significance for isobutane alkylation with C 4 olefin . Herein, the confinement effect over zeolite catalysts was elucidated by combining DFT calculations, experiments (using the novel Beta zeolite exposing only external surfaces (Beta-E) and conventional Beta-I zeolite with both external and internal surfaces) and multi-techniques ( e . g ., TGA-DTG, HRTEM, SEM and XRD). It is found that the main active sites for C 4 alkylation reaction are located on internal surface rather than external surface. On the external surface, the hydride transfer reaction does not occur because the H-shared intermediate cannot be formed without the confinement effect. Moreover, the external surface has stronger selectivity for C 4 olefin adsorption than isobutane, leading to enhanced oligomerization reactions. Therefore, the suitable micropore with confinement effect is essential for zeolite-catalyzed C 4 alkylation. The atomic-scale insights of this work are of great referential importance to the design of highly effective zeolite 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
FUEL
·
2020
·
IF 5.578
Hongyan Wang,Song Ma,Zhimao Zhou,Minjie Li,Hui Wang
The alkylation process of iso butane with butene is important in the petroleum industry. Ionic liquids (ILs) are considered as attractive alternative catalysts for iso butane alkylation besides strong liquid acids (H 2 SO 4 or HF) and solid superacids. In this study, ILs based on amides-aluminum chloride (AlCl 3 ) were synthesized and characterized, which exhibited both Lewis and Brønsted acidities. These deep eutectic ILs were found to be efficient catalysts for iso butane alkylation. The influences of the amide substrate, AlCl 3 /amide molar ratio, and metal additive on Lewis and Brønsted acidities were observed together with the synergetic effect of Lewis and Brønsted acid sites in the catalytic process. CuCl modified Urea-1.6AlCl 3 showed the best catalytic performance. The butene conversion was about 99.9% and C8 selectivity reached 57.6% under optimized reaction conditions (temperature of 15 °C, stirring rate of 1500 rpm, hydrocarbon feeding rate of 300 mL/h, iso butane/olefin molar ratio of 15:1, and reaction time of 15 min). In addition, Urea-1.6AlCl 3 -0.13CuCl could be recycled and reused for at least 20 times without obvious loss in catalytic activity.
研究领域:
化学工程
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石油化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Mingzu Liu,Xiuxiu Zhao,Zefeng Ma,Bing Yuan,Fengli Yu,Congxia Xie,Shitao Yu
As a naturally rigid polycyclic biomass platform compound without oxygen, α-pinene has always been expected to develop high-energy–density fuel with both good combustion performance and cryogenic properties by increasing carbon number in a high atom economical way. The present work has explored the screening of alkylation blocks for α-pinene over H 3 PW 12 O 40 (HPW). Here, a novel pinene-based blended fuel was prepared through cross-alkylation of α-pinene with mixed isobutane/isobutene, the common low-cost feedstock of alkylated gasoline. The reaction conditions including feed composition, reaction time, catalyst dosage, and reaction temperature were optimized. The mechanism of the hybrid alkylation process was further computationally speculated and experimentally verified. Produced liquid hydrocarbon products after hydrogenation and vacuum distillation possessed higher net heat of combustion and flash point than those of pinane, and lower freezing point and viscosity than those of dimers fuel from pinene. These favorable performances indicate that alkylated pinanes have promising potential as high-energy aviation fuel.
研究领域:
化学工程
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2021
·
IF 3.995
Ruizhen Zhang,Jie Wang,Lina Han,Jiancheng Wang,Liangfu Zhao
HZSM-5 molecular sieves are efficient catalysts in the aromatization of light hydrocarbons and the fabrication of HZSM-5-based core–shell composites has become an important strategy to improve their catalytic performance due to the simultaneous modification of the acidity and pore structures in the catalyst. In this paper, HZSM-5/SAPO-5 (CSZP and CSZC) were synthesized via a two-stage crystallization process using PDDA and CTAB as modifiers of HZSM-5, respectively. The structure, acidity, and the weight of carbon deposition of the resulting molecular sieves catalysts were characterized using various methods and their catalytic behavior in isobutane aromatization investigated. The results show that CSZP exhibits a perfect core–shell structure with a uniform and thin shell composed of nano-SAPO-5, while CSZC has an irregular coat configuration with HZSM-5 covered by a rough and thick shell consisting of flaky micro-SAPO-5 crystals. The introduction of SAPO-5 via an in-situ synthesis decreases the Brønsted acidity of the catalysts to different extents and provides a large number of intergranular mesopores due to the stacking of SAPO-5 on the surface of HZSM-5, which is favorable toward improving the BTEX selectivity (benzene, toluene, ethylbenzene, and xylene) and catalytic stability over CSZP and CSZC. Meanwhile, CSZP has more competitive advantages than CSZC in promoting the mass transfer efficiency due to its significantly thinner shell than CSZC, which combined with its moderate acidity and appropriate mesopore structure result in its excellent selectivity and stability during the aromatization of isobutane.
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
Molecular Catalysis
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2022
·
IF 5.089
Mingxun Han,Fanji Liu,Xiangxiang Li,Xiqing Zhang,Yiren Lu,Yanjun Lin,Lihong Zhang
A series of manganese-based catalysts supported on γ-Al 2 O 3 with low loading amount of manganese from 0.5% to 2.0% were prepared by incipient impregnating method. All catalysts were tested on non-oxidative dehydrogenation of isobutane at 600 °C. In order to explore physicochemical properties of all catalysts, various characterizations including XRD, H 2 -TPR, XPS, UV-vis, NH 3 -TPD and TG were carried out on manganese-based catalysts. The experimental results indicated that MnO x species were highly dispersed on γ-Al 2 O 3 support, and both Mn 2+ and Mn 3+ ions are main active species for isobutane dehydrogenation. The reduced catalyst 1.5%Mn/ γ -Al 2 O 3 exhibited the most optimal dehydrogenation performance among all catalysts, reaching at isobutane conversion of 36% and isobutene selectivity of 79%. The main reasons for the excellent activity and selectivity of 1.5%Mn/ γ -Al 2 O 3 were related to the high proportion of low valence manganese ions including Mn 2+ and Mn 3+ as well as the high concentration of medium strong acid sites and weak strong acid strength.
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
Molecular Catalysis
·
2021
·
IF 5.062
Jiameng Wang,Zhen Song,Mingxun Han,Xiangxiang Li,Lihong Zhang
A series of Al 2 O 3 supported Mo-based Mo/Al-X ( X = 1, 2, 3, 4) catalysts were prepared by incipient-wetness impregnation method. The Mo/Al-X catalysts were evaluated in the isobutane direct dehydrogenation reaction at 600 °C, and the physicochemical properties of Mo/Al-X catalysts were investigated by using XRD, BET, SEM, H 2 -TPR, NH 3 -TPD, TEM , XPS and TG-DTG techniques. The results indicated that the MoO x species were highly dispersed, and Mo 4+ ions were the main active species for the reaction of isobutane direct dehydrogenation to isobutene. The Mo/Al-1 catalyst displayed the hollow microspheric structure with mesoporous shell and big pore window. And Mo/Al-1 catalyst with the lowest S BET value of 167 m 2 •g −1 exhibited optimal catalytic performance, achieving superior and stable isobutane conversion of 30.5% and isobutene selectivity of 84.6%, respectively. Excellent catalytic performance, anti-sintering and carbon-resistance ability of Mo/Al-1 catalyst are attributed to the low specific surface area, small particle size, high Mo 4+ /Mo 6+ molar ratio, strong Mo species and support interaction, and high concentration and strength of weak and medium-strong acid sites.
研究领域:
化学工程
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2014
·
IF 2.733
Hao Ma,Rui Zhang,Xianghai Meng,Zhichang Liu,Haiyan Liu,Chunming Xu,Rentan Chen,Peter A. A. Klusener,Jan de With
Composite ionic liquid (CIL) prepared from triethylamine hydrochloride, anhydrous aluminum(III) chloride, and cuprous chloride is a new catalyst for isobutane alkylation. This composite ionic liquid alkylation (CILA) technology yields an alkylate with favorable product distribution. CILA is a promising replacement for sulfuric acid and hydrofluoric acid alkylation technologies. However, some solids are formed during alkylation, and solid amount increases with time on stream. In a number of separation steps, the used CIL was divided into liquid and solid. Nuclear magnetic resonance, X-ray diffraction, X-ray photoelectron spectroscopy, and elemental analyses were applied to characterize these fractions. The content of acid-soluble oil (ASO) in solid was also investigated. The results showed that the solid was mainly cuprous chloride and contained about 1 wt % ASO. The loss of aluminum chloride and detachment of CuCl as a form of solid from CIL resulted in the decrease of CIL acidity and product selectivity.
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
Molecular Catalysis
·
2021
·
IF 5.062
Zhen Song,Jiameng Wang,Xiqing Zhang,Fanji Liu,Lihong Zhang
A series of MgF 2 -modified hydrotalcite-like (HT) derivatives supported Pt-In catalysts PtInHTR-X (X = NH 4 F, NaF and KF, R = reduced catalyst) were prepared by combination of hydrothermal method, alkali-etching and impregnation strategy and applied to direct dehydrogenation of isobutane to isobutene. The catalysts and precursors were characterized by XRD, SEM, TEM, XPS, TG, O 2 -TPO and low temperature N 2 adsorption-desorption isotherms. The formation of MgF 2 phase as dopant to modify the catalyst can influence the pore structure and even the surface acid properties of catalysts. Especially, compared with the three catalysts, PtInHTR-KF catalyst had better stability of isobutene selectivity of over 95% after 9 h reaction, and PtInHTR-NH 4 F and PtInHTR-NaF catalysts exhibited more stable isobutane activity of 60%. One of the reasons for this catalytic performance is that small particles of MgF 2 and unsaturated MgF 2 can provide weak acidic sites which can inhibit coke deposition. And it was found the improved catalytic performance was also related to the appropriate In 3+ /In 0 ratio, well-dispersed Pt species and the excellent anti-sintering ability of catalysts modified MgF 2 .
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
危险品化学品经营许可证（带存储）