Retrofit of absorption heat pumps into manufacturing processes: Implementation guidelines

Abstract

Integration of absorption heat pumps (AHP) in industrial processeshas not yet been fully exploited due to the lack of clear implementation guidelines for this technology. In this work, a systematic methodology for the integration of AHPs in a process has been developed and is presented. Guidelines are formulated for the proper selection of heat sources and sinks that will maximise the benefit derived from heat pumping while respecting process constraints and operating requirements of the AHP. The principles of AHP operation and its efficient process integration are thus described. The methodology relies on data extracted from a Pinch Analysis of the plant. The advantages and outputs of the methodology are illustrated using an AHP implementation in a Kraft pulping process. Two realistic implementation options are presented along with their detailed design and preliminary economic evaluation. L'intégration de pompesà chaleurà absorption (PCA) dans les procédés industriels n'a pas encoreété exploitée pleinement en raison du manque de lignes directrices de mise en oeuvre claires pour cette technologie. Dans ce travail, une méthodologie systématique pour l'intégration de PCA dans un procédé aété créée et est présentée. Des lignes directrices sont formulées pour choisir adéquatement les sources de chaleur et puits qui maximiseront l'avantage dérivé des pompesà chaleur tout en respectant les contraintes des procédés et les exigences relatives au fonctionnement des PCA. Les principes du fonctionnement des PCA et leur intégration efficace dans les procédés sont par conséquent décrits. La méthodologie repose sur les données extraites d'une analyse Pinch de l'usine. Les avantages et résultats de la méthodologie sont illustrésà l'aide d'une mise en oeuvre des PCA dans un procédé kraft. Deux options de mise en oeuvre réalistes sont présentées avec leur conception détaillée etévaluatioń economique préliminaire.Keywords: absorption heat pump, process integration, energy upgrading, pulp and paper INTRODUCTIONH eat pumps (HP) are thermal machines used to increase the temperature at which a certain amount of heat is available. Absorption heat pumps (AHP) are emerging as a potential alternative to the more common vapour recompression heat pumps (VRHP). AHPs use the effect of pressure on the absorption-desorption cycle of a solution to create a temperature increase of the available heat, that is, the temperature lift. They are thermally driven and, when judiciously positioned into an industrial process, they can be operated in such a way that heat is pumped and energy is recovered at the same time.Early methods to identify and evaluate heat pumping opportunities generally used a unit operation-oriented approach. Large utility consumers, such as evaporators and distillation columns, were easily identified and a HP could be integrated within the chosen unit (Flores et al., 1984;Ferre et al., 1985;Supranto et al., 1986;Eisa et al., 1987). More recent work introduced a complete process approach for HP integration and showed the importan...

Process Design, Integration and Optimisation: Advantages, Challenges and Drivers

“…From then, other papers have been published in this respect, worth being mentioned. Bakhtiari et al (2010) developed a systematic methodology for the integration of absorption heat pumps (AHP) in industrial processes; guidelines are formulated for the proper selection of heat sources and sinks that will maximise the benefi t derived from heat pumping while respecting process constraints and operating requirements of the AHP. The principles of AHP operation and its effi cient Process Integration are thus described.…”

Enhanced CO2 separation performance by PVA/PEG/silica mixed matrix membrane

“…[11][12][13][14][15][16][17][18][19][20][21][22][23] Common organic and inorganic fillers incorporated include zeolite, fumed silica, activated carbon, carbon molecular sieve, silica nanoparticle, carbon nanotube, metal organic frameworks, graphene oxide, polymeric submicrosphere silica, and nano-sized particle with considerable separation results. 24 However, the major constraint involved in this technology is the improved affinity between the polymer-filler interface which may otherwise lead to the creation of nonselective interface voids and less resistance paths against gas molecule diffusion. [25][26][27] Also the homogeneous dispersion of the filler within the polymer matrix and good compatibility between the two phases is a major contributor to ensure good separation performance.…”