ORGANIC PROCESS RESEARCH & DEVELOPMENT
·
2016
·
IF 2.922
Yiying Zhang,Dongxiang Zhang,Kai Dong,Penghao Lv,Siping Pang,Chenghui Sun
The kinetics of the nitration reaction of 2,6,8,12-tetraacetyl-4,10-dinitro-2,4,6,8,10,12-hexaazaisowurtzitane (TADN) in HNO3–H2SO4 nitrating agent has been studied. The reaction network of the nitration reaction is constructed according to analysis of the experimental results. A kinetics model is introduced and the kinetics parameters are estimated by data fitting. Statistical analysis verifies that the kinetics model is in good agreement with the experimental data. Therefore, the reaction kinetics model can be applied to process analysis and scale-up of nitration of TADN to 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (HNIW).
研究领域:
化学动力学
·
有机化学
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2024
·
IF 3.7
Renjie Deng,Yiming She,Botao Cao,Lele Huang,Junjie Zhu,Huajie Liu,Haishuai Cui,Yao Tian,Fangfang Zhao
Zeolites are used in the field of toluene nitrification reactions, but their intrinsic mechanism is not well explained. In this work, three typical zeolites including HZSM-5, HY, and Hβ are selected as catalysts and used for the nitration of toluene and typical monosubstituted benzenes with NO2, and it explores the intrinsic influences on the nitrification of toluene on various zeolites through experimental and theoretical methods. The acidic properties and pore structures of three different zeolites were investigated through appropriate characterization techniques. Hβ zeolite exhibited the highest catalytic performance among the three zeolites, attributable to its unique pore structure and acidic properties. The theoretical analysis of various zeolites indicates that the Hβ zeolite can effectively reduce the activation energy barrier, thereby significantly enhancing the transfer nitration performance. The theoretical calculations also suggest that the para-nitration product is more readily formed within the pores of Hβ zeolite, resulting in high para-selectivity. This study provides a theoretical basis for the selective catalysis of aromatics on zeolites.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ORGANIC PROCESS RESEARCH & DEVELOPMENT
·
2023
·
IF 3.4
Feng Xu,Zhiquan Chen,Lei Ni,Gang Fu,Jian Liu,Juncheng Jiang
In this work, the continuous flow nitration of naphthalene to 1-nitronaphthalene was systematically studied from the microreactor to mesoscale flow reactor and the safety issues during the reaction process were investigated. The effect of the molar ratio of nitric acid to naphthalene, residence time, reaction temperature, and sulfuric acid strength on the reaction process was comprehensively investigated in the microreactor. Under optimal conditions, the reaction yield could reach 94.96%. Due to the rapid exothermic characteristics of nitration, a quick heat transfer assessment was proposed to obtain the temperature profile during optimal conditions. It was found that the maximum overtemperature during the reaction was only 3.78 °C, which was consistent with the high yield under the optimal conditions. Then a scale-up of the microreactor to production was realized by a dimension-enlarging strategy. In the mesoscale flow reactor, the influence of volumetric flow rates was investigated. The annual output of the flow reactor could reach 2643 kg·a–1 while the highest overtemperature inside the reactor channel well exceeded 17.1 °C. In addition, a conventional semibatch experiment was carried out in the batch calorimeter RC1e to explore the reaction’s exothermic characteristics. Finally, the performances of the two reactors were compared, showing that the continuous flow reactor had more advantages than the batch reactor in economic benefit and inherent safety.
研究领域:
化学工程
·
安全科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2017
·
IF 0
Shenghui Zhou,Kuiyi You,Hongxu Gao,Renjie Deng,Fangfang Zhao,Pingle Liu,Qiuhong Ai,He’an Luo
Mesoporous silica-immobilized FeCl 3 (FeCl 3 -SiO 2 ) as a highly efficient and reusable catalyst for the nitration of benzene with NO 2 has been successfully prepared in this work. The physical-chemical properties of samples were characterized by BET, XRD, TG-DTG, NH 3 -TPD, FT-IR, UV–vis DRS, Raman spectra and SEM. The characterization results indicated that FeCl 3 could be immobilized on the silica surface by bonding of FeCl 3 and silicon hydroxyl groups (Si OH) in forming the new Lewis acid sites of Si O Fe Cl 2 . The results showed the immobilized 15%FeCl 3 -SiO 2 catalyst exhibited excellent catalytic performance (99% of benzene conversion with 99% of selectivity to nitrobenzene) under the optimized reaction conditions. Furthermore, the durability of catalyst was remarkably improved by immobilizing. The present immobilized FeCl 3 -SiO 2 catalyst as a solid heterogeneous and stable catalyst could be conveniently recycled from the reaction media by filtering and remained highly catalytic performance even after five runs of recycling. The possible reaction pathway for the nitration of benzene with NO 2 over FeCl 3 -SiO 2 catalyst was suggested. This method provides a promising strategy for highly efficient preparation of nitro aromatic compounds by using NO 2 as nitration reagent, with the potential industrial applications.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
ENZYME AND MICROBIAL TECHNOLOGY
·
2015
·
IF 2.322
Mingming Kong,Kun Wang,Runan Dong,Haijun Gao
Nitroaromatic compounds are important intermediates in organic synthesis. The classic method used to synthesize them is chemical nitration, which involves the use of nitric acid diluted in water or acetic acid, both harmful to the environment. With the development of green chemistry, environmental friendly enzyme catalysis is increasingly employed in chemical processes. In this work, we adopted a non-aqueous horseradish peroxidase (HRP)/NaNO 2 /H 2 O 2 reaction system to study the structural characteristics of aromatic compounds potentially nitrated by enzyme catalysis, as well as the relationship between the charges on carbon atoms in benzene ring and the nitro product distribution. Investigation of various reaction parameters showed that mild reaction conditions (ambient temperature and neutral pH), plus appropriate use of H 2 O 2 and NaNO 2 could prevent inactivation of HRP and polymerization of the substrates. Compared to aqueous–organic co-solvent reaction media, the aqueous–organic two-liquid phase system had great advantages in increasing the dissolved concentration of substrate and alleviating substrate inhibition. Analysis of the aromatic compounds’ structural characteristics indicated that substrates containing substituents of NH 2 or OH were readily catalyzed. Furthermore, analysis of the relationship between natural bond orbital (NBO) charges on carbon atoms in benzene ring, as calculated by the density functional method, and the nitro product distribution characteristics, demonstrated that the favored nitration sites were the ortho and para positions of substituents in benzene ring, similar to the selectivity of chemical nitration.
研究领域:
生物化学
·
有机化学
·
环境科学
✓ 已验证
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2015
·Vol. 41
·期 11
·8307-8315
·
IF 1.221
You Kuiyi,Zhou Zhongcang,Jian Jian,Deng Renjie,Liu Pingle,Ai Qiuhong,Luo He’an
A simple method for the preparation of dinitronaphthalene from the nitration reaction of 1-nitronaphthalene with NO 2 as nitration reagent under the mild conditions has been successfully developed in this work. The results indicated that Ni(CH 3 COO) 2 ·4H 2 O catalyst shows better catalytic performances, and the conversion of 1-nitronaphthalene is 33.10 % with 34.10, 23.56, 19.30, and 3.56 % of the selectivity to 1,5-DNN, 1,3-DNN, 1,4-DNN, and 1,8-DNN, respectively, under the optimal reaction conditions. This is a mild, environmentally benign, and economical method for the preparation of dinitronaphthalene.
研究领域:
化学
·
环境科学
✓ 已验证
DOI
高影响因子
LETTERS IN ORGANIC CHEMISTRY
·
2023
·Vol. 20
·期 11
·1089-1093
·
IF 0.8
Li Runlai,Zhang Zhenming,Ji Jiangyu,Li He,Liu Chi,Li Shu-an
The conventional mixed acid nitration of aromatic hydrocarbons has been extensively applied in the industry, but usually, it is not highly selective and may cause environmental concerns regarding the disposal of large volumes of mixed acids. This paper proposes a new method of orientational
para-nitration of easily hydrolyzable aromatic compounds. Under the optimized reaction conditions, the easily hydrolyzed aromatic compounds were nitrated in the H2SO4-HNO3-H3PO4 system to yield paste-like products. And the product could
be directly filtered out from the mixed acid, avoiding a large amount of waste liquid caused by pouring the reaction mixture into ice water by the traditional post-treatment method. The selectivity and yield of nitration by this method have been improved, and the mother liquor could be reused,
thereby reducing the cost and pollution.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
Reaction Chemistry & Engineering
·
2022
·Vol. 7
·期 11
·2322-2333
·
IF 5.2
Jing Song,Chencan Du,Junjie Wang,Yongjin Cui,Yujun Wang,Jian Deng,Guangsheng Luo
Microreaction technology provides a powerful tool for reactions under extreme conditions, but the micro-dispersion performance of those processes under real reaction conditions is hard to visualize. Therefore, we constructed a novel observation platform by placing the downstream observation window vertically. We successfully achieved the accurate measurement of droplets ranging in size from microns to millimeters for real reaction systems in a T-junction microdevice, and proved that the droplet coalescence can be avoided at the outlet of the microreactor. The actual micro-dispersion state of different types of systems can be exactly reflected in the observation window. We further investigated the effect of shearing routes on the droplet size in toluene nitration by using this platform and provided design guidance on the choice of shearing routes for nitration. The scaling laws under different shearing routes have been established based on the obtained micro-dispersion data in this work. This work has promoted the connection of fundamental research studies with real applications of microreaction technology, which is critical for the future development of microreaction technology.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2018
·
IF 3.649
Heng Yu,Chao Fan,Yu Cheng,Benhua Huang,Yu Li,Junjie Zhang,Aqun Zheng,Yang Sun
A series of titanium-aluminum binary oxides are prepared through co-precipitation of metal salts with polyvinylpyrrolidone (PVP) in alkaline solution, along with dehydration. Most of synthetic oxides are composed of micro- or nano-sized blocks, while one of them shows an interesting two-dimensional morphology. Furthermore, loading of aluminum into co-precipitation would increase product porosity compared with the non-loaded case, while addition of PVP shows influences on building micropores of synthetic oxide. In catalysis, the synthetic oxides usually show high activities for nitration of various arenes. The key factors affecting catalytic outputs are carefully discussed, and the matching relation between shape of substrate and pore distribution of catalyst may affect catalytic efficiency too. Moreover, the binary oxide featuring PVP shows more durable recycling behavior than the non-doped one. On the other hand, nitration reactions of naphthalene and benzene halides show better stereoselectivities than those of alkylbenzenes. In general, this study may contribute to the catalytic progress of new oxide materials.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Zifei Yan,Grace Dai Zhen Lee,Jian Deng,Guangsheng Luo
Nitrosation of alcohols with nitrous acid is widely used to prepare alkyl nitrites, but the reaction mechanism and formation pathways of gaseous side products remain unclear. Here, we propose a nitrosation mechanism based on a highly reactive intermediate, dinitrogen trioxide (N 2 O 3 ). The N 2 O 3 -based mechanism shows a lower energy barrier than the previously reported acid-catalyzed and nitrosyl cation mechanism. Furthermore, a microfluidic platform was established to investigate the gas–liquid-liquid reaction system and characterize the gas holdup of the multiphase reaction system. The results suggest that the reaction rate and selectivity primarily depend on the interfacial mass transfer of N 2 O 3 between the aqueous-organic and gaseous-organic phases. A tubular microreactor was employed to intensify the nitrosation process of isopropanol. In contrast to the batch process operated by adding reactants dropwise in several hours, the product yield of 95 % can be achieved in a residence time of only 10 s in the microflow reactor.
研究领域:
化学工程
·
反应工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Flow Chemistry
·
2021
·Vol. 11
·期 2
·171-179
·
IF 2.786
Lan Zhou,Lu Yangcheng
The matching of the micro-dispersion method and the reaction kinetics is of the utmost importance for the fast and strongly exothermic nitration reaction. Taken as an example to discuss this issue, a synthesis of 3,4-dichloronitrobenzene via the nitration of o -dichlorobenzene with mixed acid of nitric acid and sulfuric acid was conducted in continuous-flow reactors in this work. Through combining the adiabatic reaction environment, the use of a micropacked-bed reactor, and introducing partial product circulation, it successfully achieved the matching of the micro-dispersion state and the reaction kinetic characteristics. The good two-phase dispersion state can be maintained throughout the micropacked-bed reactor and the reaction can be completed within 5 s with above 89% selectivity under adiabatic condition. Furthermore, the reaction activation energy was conveniently obtained by processing the temperature distribution data, providing a fundamental to realize a reliable design of the nitration reaction process with high efficiency and inherent safety. Graphical abstract
研究领域:
化学工程
·
反应动力学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2018
·Vol. 125
·期 1
·199-211
·
IF 1.515
Hao Fang,Yang Yongzhe,Xiong Wei,Liu Pingle,You Kuiyi,Luo He’an
Mesoporous SiO 2 –Al 2 O 3 supported Cr 2 O 3 catalysts were prepared by the sol–gel and impregnation methods. These catalysts were characterized and applied in cyclohexane nitrosation reaction. The effects of the preparation conditions and the catalyst deactivation were studied. The results show that 20% Cr 2 O 3 /SiO 2 –Al 2 O 3 catalyst calcined at 400 °C exhibits not only the larger surface area, smaller particle size, but also the larger amount of Cr 2+ and Brønsted acid sites. These catalysts show good catalytic performances in the cyclohexane nitrosation to ε-caprolactam and could be recycled for several times in this reaction system for the first time. The catalyst of Cr 2 O 3 /SiO 2 –Al 2 O 3 calcined at 400 °C gives 10.8% conversion with 79.9% selectivity to ε-caprolactam.
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
危险品化学品经营许可证（带存储）