Intensification of Chlorine Processing
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Intensification of chlorine processing Citation for published version (APA): Jovic, S. (2016). Intensification of chlorine processing. Technische Universiteit Eindhoven. Document status and date: Published: 15/12/2016 Document Version: Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication: • A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. 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If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license above, please follow below link for the End User Agreement: www.tue.nl/taverne Take down policy If you believe that this document breaches copyright please contact us at: [email protected] providing details and we will investigate your claim. Download date: 03. Oct. 2021 Intensification of chlorine processing PROEFSCHRIFT ter verkrijging van de graad van doctor aan de Technische Universiteit Eindhoven, op gezag van de rector magnificus prof.dr.ir. F.P.T. Baaijens, voor een commissie aangewezen door het College voor Promoties, in het openbaar te verdedigen op donderdag 15 december 2016 om 16:00 uur. door Slaviša Jović geboren te Belgrado, Servië Dit proefschrift is goedgekeurd door de promotoren en de samenstelling van de promotiecommissie is als volgt: voorzitter: prof.dr.ir. E.J.M. Hensen 1e promotor: prof.dr.ir. J.C. Schouten 2e promotor: prof.dr.ir. J.T.F. Keurentjes copromotor: dr.ir. J. van der Schaaf leden: prof.dr.ir. H.J. Heeres (RU Groningen) prof.dr.ir. T.J.H. Vlugt (TU Delft) prof.dr.ir. M. van Sint Annaland adviseur: dr.ir. M.T. de Groot (AkzoNobel Industrial Chemicals B.V.) Het onderzoek of ontwerp dat in dit proefschrift wordt beschreven is uitgevoerd in overeenstemming met de TU/e Gedragscode Wetenschapsbeoefening. Intensification of chlorine processing Slaviša Jović Eindhoven University of Technology, 2016 A catalogue record is available from the Eindhoven University of Technology Library ISBN: 978-90-386-4189-8 This project was funded by the Action Plan Process Intensification of the Dutch Ministry of Economic Affairs (project PI-00-04) Cover designed by Iliana Boshoven-Gkini (AgileColor) Printed by Gildeprint Contents Summary ix 1.Introduction 1 1.1 Development of chemical industry 1 1.2 Chlor-Alkali process 2 1.3 Material selection 7 1.4 Intensification of chlorine processing 10 1.5 The structure of the thesis 14 1.6 References 15 2.Thermodynamics of chlorine-water system and its application for 19 the chlorine liquefaction 2.1 Abstract 19 2.2 Introduction 20 2.3 Theory 21 2.4 Solubility of water in dichloromethane 22 2.5 Solubility of water in chlorine 26 2.6 Liquefaction efficiency 28 2.7 Conclusions 30 2.8 Nomenclature 30 2.9 References 31 3. Adsorptive water removal from dichloromethane and vapor phase 33 regeneration of a molecular sieve 3A packed bed 3.1 Abstract 33 3.2 Introduction 34 3.3 Model 35 - Mass and energy balances 35 v - Modeling of the vapor-liquid flow 39 - Estimation of model parameters 40 - Discretization scheme 41 - Fitting procedure 42 3.4 Experimental section 42 - Adsorption isotherm measurements 42 - Adsorption and desorption breakthrough curve measurements 43 3.5 Results and discussion 46 - Adsorption isotherm results 46 - Adsorption breakthrough curves 47 - Desorption breakthrough curves 51 - Desorption with external bed heating 56 - Cyclic steady state experiment (with external heating regeneration) 58 3.6 Conclusions 59 3.7 Nomenclature 60 3.8 References 63 4. A hydrate based process for drying liquids 67 4.1 Abstract 67 4.2 Introduction 68 4.3 Process description 70 4.4 Materials and methods 71 - Batch experiments 72 - Spinning disc crystallization 73 - Image analysis 74 4.5 Results and discussion 75 - Batch experiments 75 - RSSD crystallization 79 4.6 Conclusions 84 4.7 Nomenclature 85 4.8 References 86 5. Co-current drying of dichloromethane with concentrated sulfuric 89 acid using the multistage spinning disc contactor 5.1 Abstract 89 5.2 Introduction 90 5.3 Experimental section 91 vi 5.4 Results and discussion 94 - Holdup of concentrated sulfuric acid 94 - Mass transfer measurements 96 5.5 Conclusions 100 5.6 Nomenclature 100 5.7 References 101 6. The multistage spinning disc extractor for drying liquids with 103 concentrated sulfuric acid 6.1 Abstract 103 6.2 Introduction 104 6.3 Experimental section 105 6.4 Results and discussion 109 - Physical separation efficiency 109 - Mass transfer measurements 114 6.5 Conclusions 115 6.6 Nomenclature 116 6.7 References 117 7. Process design and comparison of drying alternatives 119 7.1 Abstract 119 7.2 Introduction 120 7.3 Downscaled current process 120 7.4 Adsorption alternative 124 7.5 Crystallization 128 7.6 Sulfuric acid drying 130 7.7 Conclusions 132 7.8 References 135 8. Conclusions & Outlook 137 Publications 143 About the author 145 Acknowledgements 147 vii viii Summary The current chemical industry has been improved and optimized since the development of the first big complexes two centuries ago. However, the time of big centralized production may be behind us. Nowadays, chemical plants are re-invented using process intensification (PI) principles, since the market laws and other regulations are pushing towards an adaptable and versatile distributed production, close to consumers or to raw materials. One of the large industries going through the major overhaul is chlor-alkali production. The electrochemically produced chlorine and caustic soda are the raw materials of different essential commodity products. The chlorine processing consists of drying, compression and liquefaction before shipment and consumption. Phasing out the use of mercury together with the strict chlorine transport regulations provides an incentive for the development of an intensified distributed plug-and-produce chlorine unit. The research presented in this thesis aims to intensify the chlorine processing step of the chlor-alkali technology by developing new alternative processes. For the accurate design of separation processes (i.e. drying by adsorption, liquid-liquid extraction or crystallization), an accurate representation of the system thermodynamics is a prerequisite (Chapter 2). The NRTL model is used for the activity coefficient calculations, as suggested in literature for partially miscible liquid mixtures. The activity coefficient of chlorine in water is accurately predicted as a function of pressure and temperature, using a linear correlation for the energy parameters. The activity of water in chlorine is more difficult to model because of a lack of data. The chlorine-water interaction characterizes the chlorine liquefaction and liquid chlorine drying process. The activity coefficients are used to calculate the liquefaction efficiency of chlorine depending on the total operating pressure and content of incondensable gases. The approach is tested for the activity coefficient calculation of the dichloromethane (DCM) and water system due to the availability of ix Summary___________________________________________________________ the mutual solubility data. DCM is used in experiments as a paradigm for liquid chlorine due its similarity in size and properties. The adsorption drying of DCM in a packed bed (Chapter 3) is studied. The measured water adsorption equilibrium on molecular sieve 3 A matches the literature data and is accurately represented by the General Statistical Thermodynamic Approach (GSTA) model. The packed bed is adequately modeled as a plug flow reactor with axial dispersion. The molecular sieve particles in the bed are modeled by a pore diffusion and surface diffusion model. The water surface diffusion coefficient is used as a fitting parameter of the model to the experimental adsorption DCM drying breakthrough curves. This model demonstrates that intraparticle diffusion of water is the adsorption rate limiting step. The water saturated bed is regenerated by the superheated DCM vapor. The DCM and water vapor condensation on the particles is the main heat source for the bed heat up. The experiments with the additional external bed heating increases the process efficiency while decreasing the consumption of the DCM vapor and the regeneration time. The cyclic steady state experiments demonstrate the feasibility of this novel drying process. Water removal by hydrate formation is to be feasible in a rotor-stator spinning disc (RSSD) crystallizer in Chapter 4. The high shear force acting on the fluid prevents sticky hydrate adherence on the heat exchange surfaces of the RSSD crystallizer, compared to the conventional heat exchangers. Lower crystallization temperatures result in shorter induction times of the DCM hydrate formation and thus faster water removal rates. Higher mass transfer rates at higher rotation speeds have the same effect. Continuous drying of DCM by hydrate formation did not block the spinning disc contactor. The results show that the RSSD heat exchanger facilitates an elegant, energy-efficient water removal process that can be applied to the removal of trace amounts of water from hydrate forming liquids.