Dynamic Study of a New Small Scale Reaction Calorimeter and Its Application to Fast Online Heat Capacity Determination
Total Page：16
File Type：pdf, Size：1020Kb
Research Collection Doctoral Thesis Dynamic study of a new small scale reaction calorimeter and its application to fast online heat capacity determination Author(s): Richner, Gilles Claude-Alain Publication Date: 2008 Permanent Link: https://doi.org/10.3929/ethz-a-005686831 Rights / License: In Copyright - Non-Commercial Use Permitted This page was generated automatically upon download from the ETH Zurich Research Collection. For more information please consult the Terms of use. ETH Library DISS. ETH NO. 17972 Dynamic Study of a New Small Scale Reaction Calorimeter and its Application to Fast Online Heat Capacity Determination A dissertation submitted to ETH ZURICH for the degree of Doctor of Sciences presented by Gilles Claude-Alain Richner Ing. Chim. Dipl. EPF. Lausanne born March 11, 1980 citizen of Gr¨anichen - AG accepted on the recommendation of Prof. Dr. Konrad Hungerb¨uhler,examiner Prof. Dr. Philipp Rudolf von Rohr, co-examiner Dr. Yorck-Michael Neuhold, co-examiner Zurich 2008 \S'il n'y a pas de solution, c'est qu'il n'y a pas de probl`eme." Devise Shadok Acknowledgements First, I would like to thank Prof. K. Hungerb¨uhler. Thanks Konrad for offering me the possibility to accomplish my PhD thesis in the friendly working environment of the \Safety and Environmental Technology Group" in ETH, Z¨urich, and for supporting me and my ideas during the last four years... I would like to express my gratitude to Prof. von Rohr for being in the examination committee, and for his contribution to the final improvement of the manuscript. I know that summertime is often booked for other tasks than thesis reviewing! I am extremely grateful to Bobby Neuhold, that supervised my job during the last two years. Even if, with my engineering vocabulary and his chemistry background, the first discussions were somehow chaotic, we finally managed to do the job together! Thanks to the Calorimetry Team, Graeme, Julien, S´ebastien,Tamas, Stefano, and also Fabio, who gave me some precious time during the last steps of his thesis. I am indebted to Stavros for the input in Neural Network. The experimental parts of this work would have been simply impossible without the pre- cious contribution from Max Wohlwend for the electronics and from Hans-Peter Schl¨apfer for the mechanics. I thank Max Linder and his staff at Mettler Toledo, especially Benedikt Schenker, for providing technical instrumentation and their suggestions for the success of this project. I would also like to thank Urs, Gregor, Andrej, David, Matt, Matze, Hiro, Roland, Levi, G¨otz,Christine, Andrea, Harald, Laurent and all the members of the S&U Group for the great time in H¨onggerberg, and also for biking, skating, concert, BBQ, swimming, climb- ing, T¨oggele,hiking, skiing, and all other activities. Thanks also to the administrative support from Prisca and IT support from Erol. v Acknowledgments vi Life in Z¨urich has been a great time, especially due to the contribution of Matthias, Hermann, Nic, Sacha, Chrigi, Indy, JM, Sven, Tania, Jonas, and few others.... Finally, many thanks to Amanda for sharing my life and to my mother Catherine for supporting me for more than 28 years. Contents Acknowledgementsv Abstract xi Zusammenfassung xiii Version abr´eg´ee xv Symbols xvii Greek letters xxviii Acronyms xxix 1 Introduction1 1.1 General situation................................1 1.2 Process development..............................2 1.3 Motivation and aims..............................3 2 Theoretical Background5 2.1 Calorimetry...................................5 2.1.1 Reaction calorimetry..........................6 2.1.2 Overview of the different types of reaction calorimeters.......7 2.1.3 Determination of the heat transfer coefficient............. 13 2.2 ATR-IR Spectroscopy.............................. 17 2.3 Data treatment and kinetics analysis..................... 21 2.3.1 Calorimetry............................... 22 2.3.2 Spectroscopy.............................. 23 2.3.3 Combined calorimetry and spectroscopy............... 26 2.4 Assessment of thermal risk........................... 27 vii Contents viii 3 The New Reaction Calorimeter 31 3.1 History...................................... 31 3.2 Requirements.................................. 32 3.3 Design...................................... 33 3.3.1 Reactor vessel.............................. 33 3.3.2 Compensation heating......................... 34 3.3.3 Lid and connectors........................... 35 3.3.4 Solid state thermostat......................... 38 3.3.5 Cooling system............................. 39 3.3.6 Pressure equipment........................... 40 3.4 ATR-FTIR Measurement............................ 41 3.5 Measuring with the CRC.v5.......................... 42 3.5.1 Heat balance.............................. 42 3.5.2 Data acquisition and reactor control................. 45 3.5.3 Determination of the reaction heat.................. 46 3.6 Characterisation of the reactor......................... 49 3.6.1 Time constant.............................. 49 3.6.2 Heat loss and dynamics with the cover heater............ 50 3.6.3 Hydrolysis of acetic anhydride..................... 53 3.6.4 Overview of the results......................... 61 4 Heat Capacity Determination by Temperature Oscillation Calorimetry 63 4.1 Introduction................................... 63 4.2 Theory...................................... 66 4.2.1 Principle of temperature oscillation calorimetry (TOC)....... 66 4.2.2 Determination of heat capacity.................... 68 4.3 Experimental.................................. 69 4.3.1 Evaluation of calorimetric measurements............... 69 4.3.2 Experiments............................... 70 4.3.3 Calibration procedure......................... 71 4.3.3.1 Calibration with the global heat transfer coefficient.... 73 4.3.3.2 Multivariate calibration................... 73 4.3.4 Applications of the method...................... 74 4.4 Results and discussion............................. 75 4.4.1 TOC under different experimental conditions............. 76 4.4.1.1 Variation of the frequency.................. 76 4.4.1.2 Variation of the working conditions............. 77 4.4.2 Calibration procedure......................... 79 4.4.3 Applications of the method...................... 84 4.4.4 Critical assessment........................... 85 Contents ix 5 Reactor Heat Flow Modelling 89 5.1 Introduction................................... 89 5.2 Numerical techniques and mathematical model................ 92 5.2.1 Fundamental equations......................... 92 5.2.2 Finite Methods............................. 93 5.2.2.1 Model dimension....................... 95 5.2.2.2 Subdomains.......................... 97 5.2.2.3 Internal heat transfer coefficient............... 98 5.2.2.4 Meshing............................ 99 5.2.2.5 Boundary conditions..................... 100 5.2.2.6 Solving the model...................... 101 5.2.3 Model parameter optimisation..................... 102 5.2.3.1 Steady-state conditions................... 102 5.2.3.2 Dynamic conditions..................... 104 5.3 Overview of the model............................. 107 5.4 Experimental.................................. 109 5.4.1 Steady-state conditions......................... 109 5.4.2 Dynamic conditions........................... 110 5.5 Results and discussion............................. 111 5.5.1 Modelling under steady-state conditions............... 111 5.5.1.1 Characterisation of the heat loss.............. 111 5.5.1.2 Characterisation of the internal heat transfer coefficient.. 116 5.5.1.3 Convergence and uncertainty of the model......... 117 5.5.2 Modelling under dynamic conditions................. 119 5.5.2.1 Temperature step....................... 122 5.5.2.2 Temperature oscillations................... 124 5.5.3 Optimisation of the reactor design................... 128 5.6 Critical assessment............................... 131 6 Final Discussion and Conclusions 135 6.1 Development of the new reaction calorimeter................. 135 6.2 Determination of heat capacity by temperature oscillation calorimetry... 137 6.3 Modelling of the heat flow........................... 138 7 Outlook 141 7.1 Calorimeter................................... 141 7.2 Heat capacity determination.......................... 142 7.3 Simulation of the calorimeter......................... 143 Bibliography 144 Contents x Appendices A Construction of the New Reaction Calorimeter, CRC.v5 A-1 A.1 Jacket and thermocouples........................... A-1 A.2 Cooling system................................. A-2 A.3 ATR-FTIR system............................... A-4 A.4 Pressure system................................. A-4 A.5 Data acquisition and amplifications...................... A-6 A.6 Dimension of the reactor............................ A-8 B Calculation of the Heat Balance B-1 B.1 Calibration of the Peltier elements....................... B-1 B.2 Calibration of the heat flow sensors...................... B-4 B.3 Critical assessment on the heat of cooling................... B-6 C Experimental Details of the Hydrolysis of Acetic Anhydride C-1 D Temperature Oscillation Calorimetry D-1 D.1 Temperature Oscillation Reaction Calorimetry................ D-1 D.2 Temperature Oscillation Differential Scanning Calorimetry......... D-4 D.3 Additional experiments............................. D-6 D.3.1 Heat capacity determination: Effect of PID.............. D-6 D.3.2 Heat capacity determination of heterogeneous mixtures....... D-6 D.4 Heat capacity determination with temperature step modulations.....