Gilles Richner - Nonisothermal Calorimetry for Fast Thermokinetic Reaction Analysis: Solvent-Free Esterification of n-Butanol by Acetic Anhydride

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      Publication Details (including relevant citation   information):

      Organic Process Research & Development,   2010, 14, 524-536


      An enhanced small-scale reaction calorimeter has been built for   nonisothermal applications. Its unique design, combining   compensation heater and heat flow sensors together with a solid   intermediate thermostat is particularly suited for data oriented   process development (determination of chemical reaction   parameters, i.e. rate constants, reaction enthalpies, and   reaction monitoring with optional in situ devices) in a wide   range of applications in chemical and life-science oriented   industries. The performance of the calorimeter is successfully   demonstrated for kinetic investigation under nonisothermal   conditions. Three different methods for determining the   time-resolved reaction heat have been tested. The first is based   on the traditional heat balance, the second on the twin   principle, while the third is a novel method based on a rigourous   heat flow modelling using mathematical finite methods. As a case   study, we investigated the esterification of n-butanol with   acetic anhydride catalysed by tetramethylguanidine using a   temperature ramp from 30 to 80 degrees C. Each method accounts   differently for the dynamics and the heat accumulation in the   system. However, all three methods show minor differences in the   resulting kinetic parameters and reaction enthalpies. In this   temperature range, kinetic and mechanistic analysis resolved two   competitive parallel catalytic and noncatalytic steps.

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