01530nas a2200169   4500008004100000022001400041245005900055210005600114260007100170300001400241490000700255520093100262100002301193700002801216700002301244856009301267       2014                        eng d  a0888-588500a3D flow reactors: flow, hydrodynamics, and performance0 a3D flow reactors flow hydrodynamics and performance  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB  a1916-19230 v533 a<p>A device comprised of a sequence of converging or diverging units aligned either in an axisymmetric or nonaxisymmetric manner can be used as a continuous flow reactor. Here we report the analysis of flow and hydrodynamics (pressure drop, residence time distribution, and mass transfer) for an axisymmetric geometry of a 3D flow reactor for single phase and two-phase flows. CFD simulations of the single phase flow have been used for identification of the precise geometrical configuration. The sequence of converging units as a flow reactor has been found to always be better than the sequence of diverging units. The residence time distribution analysis also favored the choice of converging flow as a better option. The performance of the device was verified by successfully carrying out a highly exothermic two-phase aromatic nitration of benzaldehyde (Delta H-r approximate to -172 kg/mol) with fuming nitric acid.</p>1 aSharma, Mrityunjay1 aReddy, Venkateswara, S.1 aKulkarni, Amol, A.  uhttps://library.ncl.res.in/content/3d-flow-reactors-flow-hydrodynamics-and-performance-002617nas a2200133   4500008004100000245009500041210006900136260000800205520208600213100002302299700002802322700002202350856011102372       2019                        eng d00a Exploring the steady operation of a continuous pilot plant for the di-nitration reaction 0 aExploring the steady operation of a continuous pilot plant for t  cAUG3 a<p><span class="hitHilite">Continuous</span>-flow synthesis <span class="hitHilite">of</span> <span class="hitHilite">the</span> selective herbicide pendimethalin was demonstrated in both <span class="hitHilite">a</span> laboratory-scale and <span class="hitHilite">a</span> <span class="hitHilite">pilot</span>-scale reactor using only concentrated nitric acid as nitrating agent. <span class="hitHilite">The</span> <span class="hitHilite">di-nitration</span> <span class="hitHilite">reaction</span> follows second-order kinetics where <span class="hitHilite">the</span> <span class="hitHilite">reaction</span> is first order with respect to both reactant and nitric acid. <span class="hitHilite">The</span> pinched-tube reactor was chosen <span class="hitHilite">for</span> <span class="hitHilite">pilot</span>-scale reactor fabrication due to its excellent mixing and mass transfer characteristics compared to <span class="hitHilite">a</span> straight-tube reactor. <span class="hitHilite">The</span> estimated mass transfer coefficient showed similar nature in <span class="hitHilite">the</span> laboratory-scale and <span class="hitHilite">the</span> <span class="hitHilite">pilot</span>-scale pinched-tube reactor, ensuring similar performance at <span class="hitHilite">the</span> <span class="hitHilite">pilot</span> scale. <span class="hitHilite">Di-nitration</span> in <span class="hitHilite">continuous</span> flow, inline quenching, extraction, and phase separation are some <span class="hitHilite">of</span> <span class="hitHilite">the</span> salient features <span class="hitHilite">of</span> <span class="hitHilite">the</span> developed <span class="hitHilite">pilot</span> <span class="hitHilite">plant</span>. <span class="hitHilite">The</span> importance <span class="hitHilite">of</span> <span class="hitHilite">the</span> start-up time <span class="hitHilite">for</span> achieving <span class="hitHilite">steady</span> state in <span class="hitHilite">the</span> flow system at <span class="hitHilite">the</span> large scale is highlighted.<br />
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1 aSharma, Mrityunjay1 aAcharya, Roopashree, B.1 aKulkarni, Amol, A  uhttps://library.ncl.res.in/content/exploring-steady-operation-continuous-pilot-plant-di-nitration-reaction01728nas a2200277   4500008004100000022001400041245009200055210006900147260000800216300001200224490000700236520085900243653002001102653001401122653001701136653000801153653001301161100002001174700002301194700001801217700002801235700001701263700002601280700002301306856012101329       2021                        eng d  a2062-249X00aDesign and scale-up of continuous di-nitration reaction using pinched tube flow reactor0 aDesign and scaleup of continuous dinitration reaction using pinc  cSEP  a611-6240 v113 aScale-up of the di-nitration reaction for synthesis of selective herbicide pendimethalin using only nitric acid in continuous flow is presented in this work. This work showcases an approach for smooth scale-up for an herbicide for a production capacity of 50 kg/day using a pinched tube reactor. The approach begins with the batch experiments followed by flow synthesis using a 1/8-inchSS316 helical coil tube where kinetics of the di-nitration was determined, and process optimization was done. Systematic approach was followed for quantification of heat transfer, mass transfer and residence time distribution and scale-up. Detailed scale-up methodology is presented with effect of relevant parameters for successful scale-up. Modular pilot plant with inline quenching, extraction and separation are some of the salient features presented in this work.10acontinuous flow10anitration10aPinched tube10aRTD10ascale-up1 aHussain, Arshad1 aSharma, Mrityunjay1 aPatil, Suneha1 aAcharya, Roopashree, B.1 aKute, Mahesh1 aWaghchaure, Aishwarya1 aKulkarni, Amol, A.  uhttps://library.ncl.res.in/content/design-and-scale-continuous-di-nitration-reaction-using-pinched-tube-flow-reactor