Kinetic Study and Intensification of Acetyl Guaiacol Nitration with Nitric Acid-Acetic Acid System in a Microreactor

Zhang, Chaoyu; Zhang, Jisong; Luo, Guangsheng

doi:10.1556/1846.2016.00011

Cited by 31 publications

(8 citation statements)

References 20 publications

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“…This requires a trade-off between energy consumption and heat exchange capacity according to the actual industrial process. For the highly exothermic industrial process carried out in the microreactor, such as the synthesis of benzaldehyde 27 and the ortho-directed nitration of acetyl guaiacol, 28 since the pressure drop of the microreactor is much smaller than that of the traditional industrial reactor, the heat exchange capacity is often more important. In general, the MP structure is the optimal heat exchange channel structure of the three.…”

Section: Effects Of Configurations Of the Heat Exchangementioning

confidence: 99%

Development of a Mini-Channel Heat Exchanger Reactor with Arborescent Structures for Fast Exothermic Reactions

Jiang

Yang

Zhang

et al. 2022

Ind. Eng. Chem. Res.

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Uniform flow distribution, efficient mixing of reactants, and rapid removal of reaction heat are very crucial to ensure a safe operation and high product yield for fast and highly exothermic reactions. In this study, a plate-type mini-channel heat exchanger reactor with arborescent structures (AR reactor) was developed. A numerical simulation is first performed to investigate the effects of the arborescent structures and configurations of heat exchange channels on the fluid flow and heat transfer characteristics. The simulation results show that the arborescent structure with smoothed junctions presents better heat transfer performance with a lower pressure drop than the original one with a rectangular cross-section, and more uniform flow rates and temperature distributions can be achieved when the parallel flow channels of the heat exchange plates are arranged based on the uniform flow resistance by adding two micropillars. A better AR reactor based on the simulation results was then fabricated, and its overall heat transfer coefficient was measured experimentally, which is in good agreement with the simulation data. The AR reactor is further utilized to conduct the nitration of phenol, and it is demonstrated that this reactor endows more aim product in a very short time in comparison with the traditional reactor. The insights gained here could provide a new avenue for the design of microchannel heat exchange reactors suitable for fast exothermic reactions.

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Section: Effects Of Configurations Of the Heat Exchangementioning

confidence: 99%

Development of a Mini-Channel Heat Exchanger Reactor with Arborescent Structures for Fast Exothermic Reactions

Jiang

Yang

Zhang

et al. 2022

Ind. Eng. Chem. Res.

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“…Some reactants can be dissolved in the nitrating agent to form a homogeneous reaction system, which brings convenience for kinetic measurement. Zhang et al 17 carried out the nitration of acetyl guaiacol in a microreactor using nitric acid/acetic acid as the nitrating agent. The microreactor enabled the process to be conducted at high temperature, thus elevating the selectivity of target product, 5‐nitroacetylguaiacol, due to its higher value of E a .…”

Section: Introductionmentioning

confidence: 99%

Determination of the kinetics of chlorobenzene nitration using a homogeneously continuous microflow

Cui

Song

et al. 2022

AIChE Journal

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The nitration of chlorobenzene with concentrated mixed acids is a fast and highly exothermic process, which suffers from considerable mass transfer resistance and poor heat transfer rates. The reaction kinetics has not been thoroughly reported before. In this work, a continuous‐flow microreactor system and a homogeneous reaction condition were proposed to obtain accurate chlorobenzene nitration kinetics parameters at high mixed acid concentrations. A general model for predicting the observed reaction rate constants was established. With a new method for estimating the equilibria associated with HNO3 in aqueous sulfuric acid, the rate constants based on nitronium ion and activation energies were obtained. Compared with batch reactors, the continuous‐flow microreactor system allows for a sufficient heat transfer efficiency and accurate residence time control, making it possible to study the reaction performance more quickly and sensitively. This work may provide a reliable reference for the kinetic study of similar processes.

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“…In recent years, microreactors − had been applied for the ammoxidation reaction, , like from propane to acrylonitrile, and showed good performance by its high heat transfer coefficient. However, the reported MP ammoxidation mainly used Φ20–30 mm fixed-bed reactors (FBR), and the reaction temperature was limited within 450 °C because of possible hot spots at higher temperature.…”

Section: Introductionmentioning

confidence: 99%

Continuous-Flow Ammoxidation of 2-Methylpyrazine to 2-Cyanopyrazine with High Space-Time Yield in a Microreactor

Wei

et al. 2022

ACS Omega

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A microreactor (MR) with a vaporization microchamber and a sinusoidal wave microchannel was fabricated to synthesize 2-cyanopyrazine (CP) directly with an aqueous 2-methylpyrazine (MP) solution. A continuous-flow process with high space-time yield was achieved under the premise of strong exothermality of this ammoxidation reaction. The vanadium metal oxide catalysts with four different supports (α-Al2O3, γ-Al2O3, ZSM-5(50), ZSM-5(80)) were evaluated by simply stacking in the wave microchannel from 350 to 540 °C. The process parameters (temperature, reactant ratio, and size of catalysts) were optimized with the selected CrVPO/γ-Al2O3 catalyst, and an optimal ammoxidation process with MP conversion (X MP) of 71.5% and CP selectivity (S CP) of 93.7% was obtained by a volume space velocity (GHSV) of 13 081 h–1 at 480 °C. Correspondingly, the space-time yield of CP (STYCP) was 1724–77 082 gCPkgcat –1h–1, which was the highest value ever reported for this reaction. Meanwhile, the ammoxidation reaction showed a great continuous-synthesis stability of 50-h running in the microreactor with the CP yield (Y CP) remaining 56%–68%.

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Kinetic Study and Intensification of Acetyl Guaiacol Nitration with Nitric Acid-Acetic Acid System in a Microreactor

Cited by 31 publications

References 20 publications

Development of a Mini-Channel Heat Exchanger Reactor with Arborescent Structures for Fast Exothermic Reactions

Development of a Mini-Channel Heat Exchanger Reactor with Arborescent Structures for Fast Exothermic Reactions

Determination of the kinetics of chlorobenzene nitration using a homogeneously continuous microflow

Continuous-Flow Ammoxidation of 2-Methylpyrazine to 2-Cyanopyrazine with High Space-Time Yield in a Microreactor

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