Process Systems Engineering (PSE) deals with decision-making, at all levels and scales, by understanding complex process systems using a holistic view. Computer Aided Process Engineering (CAPE) is a complementary field that focuses on developing methods and providing solution through systematic computer aided techniques for problems related to the design, control and operation of chemical systems. The ‘PSE’ term suffers from a branding issue to the point that PSE does not get the recognition it deserves. This work aims to provide an informative industrial and academic perspective on PSE, arguing that the ‘systems thinking’ and ‘systems problem solving’ have to be prioritized ahead of just applications of computational problem solving methods. A multi-level view of the PSE field is provided within the academic and industrial context, and enhancements for PSE are suggested at their industrial and academic interfaces.

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Compression-resorption heat pumps (CRHP) enhanced by wet compression are considered a very promising option to upgrade low grade waste heat from the industry. This is especially true for applications where the heat source and/or sink have a large temperature glide. But commercial solutions using wet compression are not yet available on the market. Compared to the classically used vapor compression heat pumps (VCHP), CRHP can provide much better performance but only if the efficiency of the compressor exceeds 0.7. In this respect, a twin screw compressor has been identified as a potential solution to reach this efficiency goal. This study makes use of the entropy production minimization to identify where the major irreversibilites are located in a CRHP system operated with an ammonia-water mixture. A detailed model of the wet compressor and the resorber are coupled with simplified models of other components of the HP cycle to analyze where potential improvements can be made. The results show that significant benefits can be obtained using CRHP.@en

Microwave plasma (MWP) technology is currently being used in application fields such as semiconductor and material processing, diamond film deposition and waste remediation. Specific advantages of the technology include the enablement of a high energy density source and a highly reactive medium, operational flexibility, fast response time to inlet variations and low maintenance costs. These aspects make MWP a promising alternative technology to conventional thermal chemical reactors provided that certain technical and operational challenges related to scalability are overcome. Herein, an overview of state-of-the-art applications of MWP in chemical processing is presented (e.g. stripping of photo resist, UV-disinfection, waste gas treatment, plasma reforming, methane coupling to olefins, coal/biomass/waste pyrolysis/gasification and CO₂ conversion). In addition, two potential approaches to tackle scalability limitations are described, namely the development of a single unit microwave generator with high output power (>100 kW), and the coupling of multiple microwave generators with a single reactor chamber. Finally, the fundamental and engineering challenges to enable profitable implementation of the MWP technology at large scale are discussed.

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Compression resorption heat pumps (CRHP) are a promising option to upgrade waste heat from industry. Alternative working fluids can further improve the efficiency of CRHP. The ternary mixture NH3-CO2-H2O has been identified as a promising working fluid for CRHP and has the potential to further enhance the coefficient of performance (COP) of the cycle compared to the traditionally used ammonia water mixture. So far the studies on the NH3-CO2-H2O mixture have focused mainly on carbon capture applications. But the desired operating conditions are different than for CRHP applications, e.g. the NH3 concentration. Additionally the absorption process with the mixture in tubular absorbers has not yet been reported. The focus of this study is therefore to investigate experimentally the absorption process of a CRHP with this ternary mixture. To reach this goal a model is developed for ammonia-water that takes into account the kinetics and mass transfer during the absorption process. To validate the model, experiments were performed for an absorption process in a mini channel heat exchanger with NH3 concentration of 35 wt%. The results show a good match between the model and the experiments. Additionally CO2 has been added to the solution and the experimental performance was compared with the experimental performance of the NH3-H2O mixture. A concentration of 2 wt% CO2 resulted in a performance increase of up to 5% however the working fluid flow became limited by pumping instabilities.@en