Advances in Organic Liquid‐Gas Chemical Heat Pumps

Abstract

Compared with inorganic chemical heat pumps (CHPs), organic liquid-gas CHPs are more amenable to be run as a continuous process because the reactants and products can be fed or removed continuously. Therefore, increasing attention has been paid to investigations of CHPs using the organic liquid-gas reaction system. Relevant research topics involved reaction catalyst, chemical reaction kinetics, reactive distillation, energy efficiency evaluation, economic analysis, etc. Nevertheless, the research on an organic liquid-gas CHP system is still in the elementary stage. A detailed review on the current research status of catalyst-assisted CHPs employing an organic liquid-gas reaction system has been performed. Existing problems are identified and future research directions are proposed.

Excess‐Heat Recovery and Promotion through Organic Chemical Heat Pumps

“…The heat exchanger (HX) present in the system is responsible for preheating the exothermic reactor's feed stream. The excess heat utilized in these systems serves two purposes, driving the endothermic reaction and the separation process, the latter being the driving-force for the continuously operating system [3,21,22].…”

“…There are several metrics available to gauge a CHP's performance [21,23,25], however, this work will only make use of two of these, the effectiveness, which translates the system's enthalpy efficiency and the entransy efficiency, which translates its entropy efficiency.…”

“…( 1)) consists of the dehydrogenation of isopropanol into acetone and hydrogen, which occurs catalytically in the liquidphase at temperatures up to around 355 K. The exothermic reaction (Eq. ( 2)) consists of the reverse and typically occurs between 453 K and 493 K [20,21].…”

“…These can upgrade heat from various sources (industrial, solar, geothermal, etc.) to higher temperatures by taking advantage of catalytically reversible coupled endo-exothermic chemical reaction cycles [1,3,20,21]. In addition to requiring almost no mechanical work, these systems can operate in much higher and broader temperature ranges, allowing for higher flexibility and adaptability of the operating conditions to a situation's particular requirements [1,3,19,22].…”

Multiple Regression Analysis of Catalytic Dehydrogenation of Isopropanol in a Chemical Heat Pump System

“…Yurtsever et al investigated the functioning of a CHP 12. Cai et al reviewed the current research status of catalyst‐assisted CHPs employing an organic liquid‐gas reaction system and pointed out further future research directions 13. Fadhel et al analyzed a solar‐assisted solid‐gas CHP dryer system 6.…”