43 research outputs found

    A concise review on microwave-assisted polycondensation reactions and curing of polycondensation polymers with focus on the effect of process conditions

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    During the past 15 years, increasing application of microwave heating to polycondensation reactions has been witnessed. Experiments have been carried out at laboratory scale using widely different experimental procedures. The use of microwaves has often led to significant benefits compared to conventional heating experiments in terms of multi-fold decrease in reaction times and energy consumption and production of polymers with increased molecular weight and improved mechanical properties. In other cases, microwaves do not appear to produce any significant benefits compared to conventional heating. At present, guidelines to experimentalist as to the process conditions and experimental design that should be applied are missing and experimentation seems to be based on an empirical trial-and-error approach. In view of the very different experimental protocols that have been applied and the contradictory trends that are frequently reported, we aim in this review to shed light on the role of important process parameters, such as the presence and type of solvent, the dielectric properties of the mixture and the individual phases, the use of heterogeneous catalysts, pressure, stirring, reflux conditions, temperature measurement method and microwave absorbing fillers, which all seem to determine the occurrence and magnitude of the benefits enabled by microwaves during polycondensation reactions

    Process intensification education contributes to sustainable development goals: Part 2

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    Achieving the United Nations sustainable development goals requires industry and society to develop tools and processes that work at all scales, enabling goods delivery, services, and technology to large conglomerates and remote regions. Process Intensification (PI) is a technological advance that promises to deliver means to reach these goals, but higher education has yet to totally embrace the program. Here, we present practical examples on how to better teach the principles of PI in the context of the Bloom's taxonomy and summarise the current industrial use and the future demands for PI, as a continuation of the topics discussed in Part 1. In the appendices, we provide details on the existing PI courses around the world, as well as teaching activities that are showcased during these courses to aid students’ lifelong learning. The increasing number of successful commercial cases of PI highlight the importance of PI education for both students in academia and industrial staff.We acknowledge the sponsors of the Lorentz’ workshop on“Educating in PI”: The MESA+Institute of the University of Twente,Sonics and Materials (USA) and the PIN-NL Dutch Process Intensi-fication Network. DFR acknowledges support by The Netherlands Centre for Mul-tiscale Catalytic Energy Conversion (MCEC), an NWO Gravitationprogramme funded by the Ministry of Education, Culture and Sci-ence of the government of The Netherlands. NA acknowledges the Deutsche Forschungsgemeinschaft (DFG)- TRR 63¨Integrierte Chemische Prozesse in flüssigen Mehrphasen-systemen¨(Teilprojekt A10) - 56091768. The participation by Robert Weber in the workshop and thisreport was supported by Laboratory Directed Research and Devel-opment funding at Pacific Northwest National Laboratory (PNNL).PNNL is a multiprogram national laboratory operated for theUS Department of Energy by Battelle under contract DE-AC05-76RL0183

    Penrose triangles of fossil-to-bio-based transition

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    Transition within the chemical industry from fossil to green feedstocks is a complex process characterized by the generation of commercially viable feedstock–process–product triangles. The research in this area encompasses a great diversity of relevant topics. A number of those topics have been addressed within this volume of Faraday Discussions and are summarized in this paper. They are categorized and discussed along with seven general questions arising from the feedstock–process–product triangles. Opportunities are identified that should make more of these triangles technically and economically feasible. The future role of renewable electricity as the primary energy source for the bio-based industry is emphasized.Intensified Reaction and Separation System

    Industrial Applications in Europe

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    110th Anniversary: The Missing Link Unearthed: Materials and Process Intensification

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    For many years, process intensification has been seen and considered through the prism of equipment and methods. The current review paper adds a new perspective to it and examines the role of (advanced) materials in process intensification. The discussion is illustrated with numerous examples of various types of materials that have been shown to intensify chemical and catalytic reactions, mass transfer, heat transfer, and momentum transfer processes, respectively. The role of process intensification in manufacturing of new, advanced materials is also discussed. In view of the importance of materials for process intensification, an update of the classical approach to the field of PI is postulated.Intensified Reaction and Separation System

    Editorial for the Andrzej GĂłrak Festschrift

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    Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Complex Fluid Processin

    Beyond Electrolysis: Old Challenges and New Concepts of Electricity-Driven Chemical Reactors

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    With renewable electricity becoming the most widespread, flexible, and accessible form of energy on Earth, electrification of chemical processes presents one of the most promising transition paths to low-carbon-footprint, environmentally-neutral manufacturing of fuels and chemicals. The current paper provides a critical perspective on the entire spectrum of chemical and catalytic reactors, in which electricity plays different roles targeting either the reaction mechanism or the thermal energy supply. Related challenges and necessary developments to address those challenges are discussed.Intensified Reaction and Separation SystemsComplex Fluid Processin

    Catalyst Heating Characteristics in the Traveling-Wave Microwave Reactor

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    Traveling-Wave Microwave Reactor (TMR) presents a novel heterogeneous catalytic reactor concept based on a coaxial waveguide structure. In the current paper, both modeling and experimental studies of catalyst heating in the TMR are presented. The developed 3D multiphysics model was validated from the electromagnetic and heat transfer points of view. Extrudes of silicon carbide (SiC) were selected as catalyst supports and microwave absorbing media in a packed-bed configuration. The packed-bed temperature evolution was in good agreement with experimental data, with an average deviation of less than 10%. Both experimental and simulation results show that the homogeneous temperature distribution is possible in the TMR system. It is envisioned that the TMR concept may facilitate process scale-up while providing temperature homogeneity beyond the intrinsic restrictions of microwave cavity systems
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