AICHE JOURNAL
·
2020
·Vol. 66
·期 8
·e16979
·
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
·
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
·
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
MOLECULES
·
2017
·Vol. 22
·期 4
·560
·
IF 2.861
Yating Zhang,Lingbiao Gu,Fei Wang,Lingjun Kong,Guangyong Qin
As a natural and healthy beverage, tea is widely enjoyed; however, the pesticide residues in tea leaves affect the quality and food safety. To develop a highly selective and efficient method for the facile removal of pesticide residues, the subcritical butane extraction (SBE) technique was employed, and three variables involving temperature, time and extraction cycles were studied. The optimum SBE conditions were found to be as follows: extraction temperature 45 °C, extraction time 30 min, number of extraction cycles 1, and in such a condition that the extraction efficiency reached as high as 92%. Further, the catechins, theanine, caffeine and aroma components, which determine the quality of the tea, fluctuated after SBE treatment. Compared with the uncrushed leaves, pesticide residues can more easily be removed from crushed leaves, and the practical extraction efficiency was 97%. These results indicate that SBE is a useful method to efficiently remove the bifenthrin, and as appearance is not relevant in the production process, tea leaves should first be crushed and then extracted in order that residual pesticides are thoroughly removed.Keywords:subcritical butane;pesticide residue;bifenthrin;black tea
研究领域:
食品科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
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
·
催化科学
·
能源化工
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Jun Jiang,Teng Li,Kexin Huang,Guangyu Sun,Jing Zheng,Jinlong Chen,Weiran Yang
As a bio-based platform chemical, it is desirable to convert levulinic acid (LA) to varieties of value-added biochemicals. n-Butane, mainly from nonrenewable fossil resources, is a basic chemical to produce some important chemicals, such as butadiene and ethylene. In this paper, 95.5% yield of n-butane was obtained from LA in one-step over base-treated Pt/C at around 300 °C in 4 h. The reaction pathway was confirmed to be the hydrodeoxygenation of LA to valeric acid (VA) and then the VA decarboxylation to n-butane by kinetic studies. Base-treated Pt/C had better reactivity due to its improved decarboxylation activity. Detailed characterization of the catalyst revealed that the Pt particle size is the key reason for the activity improvement, and further studies showed that Pt nanoparticles with a size of 2–4 nm showed the highest decarboxylation activity. This is the first report on the direct conversion of LA to n-butane.
研究领域:
化学工程
·
可再生资源
·
催化科学
✓ 已验证
DOI
高影响因子
Surfaces and Interfaces
·
2021
·
IF 4.837
Ikram Ullah,T.A. Taha,Asma M. Alenad,Ikram Uddin,Asif Hayat,Ashiq Hayat,Muhammad Sohail,Ahmad Irfan,Javid Khan,Arkom Palamanit
In this study, sulfated zirconia with loading of platinum (Pt) and platinum alumina (PA-Al 2 O 3 ) promoted sulfated zirconia (SZ) catalysts were synthesized by hydro-thermal route. The samples were characterized by XRD, BET, FT-IR, NH 3 -TPD, and TGA. The catalytic efficiency of all the synthesized catalysts was tested on the isomerization of n -butane. The results indicated that the conversion of n -butane (71.04%), selectivity to i -butane (98.96%), and yield of i -butane (70.30%) is significantly high for PA/SZ sample than that of Pt modified SZ and bare SZ. The results of this study suggest that the SZ modified by Pt/Al 2 O 3 (PA) provided better catalytic performance and higher stability (within 25 h of TOS), when compared with SZ, and Pt-modified SZ.
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
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
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
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2015
·
IF 2.679
Cui Wang,Jitai Guo,Kai Cheng,Yao Chen
(Liquid + liquid) equilibrium data for the ternary systems of {water + ethanol + 1,1′-oxybis(butane)} and {water + 2-propanol + 1,1′-oxybis(butane)} at T = (293.15, 298.15, 303.15, 308.15) K have been measured under atmospheric pressure. The experimental results were correlated by using the modified and extended UNIQUAC models. Distribution coefficients and separation factors of ethanol and 2-propanol were calculated and discussed in detail. The temperature influence on liquid-phase regions was analysed.
研究领域:
化学工程
·
物理化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Mingyuan Shao,Chaoquan Hu,Jiahan Sun,Shuanghao Xu,Maoqiao Xiang,Qingshan Zhu
This study investigated the dehydrogenation of butane over TiO2-based catalysts prepared by a co-precipitation method. The catalysts were characterized in detail using various surface techniques, such as XRD, XPS, SEM, and pyridine-FTIR. Their performances toward butane dehydrogenation showed that the product distribution was considerably affected by the reaction temperature and the composition of the catalysts. Two different selectivity regions were observed for most of the catalysts. A higher butene selectivity over butadiene was obtained at relatively low temperatures, while an opposite trend was observed at high temperatures. In situ DRIFT measurements did not find an obvious change in the reaction pathway for butane dehydrogenation over the TiO2-based catalysts. The variation in selectivity with temperature can be well correlated with the different types of oxygen species on the 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
CHEMOSPHERE
·
2023
·
IF 8.8
Jiaxuan Wang,Zhengxuan Ji,Peiru Fan,Jiaqi Duan,Jiaqing Xiong,Zhe Liu,Yushi Hou,Na Wang
Perfluorobutane sulfonic acid (PFBS) is a kind of anthropogenic recalcitrant contaminant that has posed a threat to drinking water safety and brought widespread public health concerns. Nanofiltration (NF) is an effective way to remove PFBS from drinking water, while the removal is influenced by coexisting ions. To investigate the effects and intrinsic mechanisms of coexisting ions on the rejection of PFBS, poly(piperazineamide) NF membrane was utilized in this work. Results showed that most cations and anions in the feedwater could effectively improve PFBS rejection and simultaneously reduce NF membrane permeability. In most cases, the decrease in NF membrane permeability corresponded to an increase in the valence of cations or anions. When cations (Na + , K + , Ca 2+ , and Mg 2+ ) were present, the rejection of PFBS was effectively improved from 79% to more than 91.07%. Under these conditions, electrostatic exclusion was the dominant NF rejection mechanism. This was also the leading mechanism for 0.1 mmol/L Fe 3+ coexisted condition. As the concentration of Fe 3+ increased to 0.5–1 mmol/L, intensified hydrolyzation would accelerate the formation of the cake layers. The differences in the cake layer characteristics led to the different rejection trends of PFBS. For anions (SO 4 2− and PO 4 3− ), both sieving effects and electrostatic exclusion were enhanced. As anionic concentration raised, the NF rejection of PFBS increased to above 90.15%. By contrast, the effect of Cl − on PFBS rejection was also affected by coexisting cations in the solution. The dominant NF rejection mechanism was electrostatic exclusion. Accordingly, it is suggested that the usage of negatively charged NF membranes could facilitate the efficient separation of PFBS under ionic coexisting conditions, thereby ensuring the safety of drinking water.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 18
·10072-10080
·
IF 3.049
Xin Niu,Liguo Wang,Junya Cao,Yan Cao,Peng He,Junya Zhou,Huiquan Li
A novel approach for the synthesis of epoxybutane via decarboxylation of butenyl carbonate derived from butanediol was developed for the first time. For the carbonylation of butanediol with dimethyl carbonate, NaAlO2 has exhibited excellent catalytic activity under mild reaction conditions. The yield of butenyl carbonate reached as high as 96.2%. NaAlO2 provides suitable acid–base active sites to promote the transesterification reaction of butanediol and dimethyl carbonate. For the following step of decarboxylation of butenyl carbonate, ionic liquid 1-butyl-3-methylimidazolium bromide could effectively catalyze the decarboxylation process both in batch or continuous processes. Moreover, the catalytic mechanism for the crucial step of decarboxylation of butenyl carbonate over 1-butyl-3-methylimidazolium bromide was explored using DFT calculations. The results showed that the electrostatic and hydrogen-bond effects of 1-butyl-3-methylimidazolium bromide played a crucial role for the generation of epoxybutane. Briefly, the Br anion of the ionic liquid attacks the methylene of the ring and the H of the ionic liquid cation attacks the carbonyl oxygen, which facilitated the five-ring opening and subsequent decarboxylation to form BO. This study not only provided a new and green synthetic route for producing epoxybutane, but also contributed to the effective utilization of butanediol, which is inevitably produced as by-product in the process of coal to ethylene glycol, suggesting a promising application in the clean manufacture of epoxybutane with inexpensive cost.
研究领域:
化学工程
·
绿色化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）