Experimental and Theoretical Investigation of a Novel Hydrate Cooling Technology Using Low Global Warming Potential Refrigerants

The Kingdom is legally bound according to the Kigali Amendment of the Montreal Protocol of 2016 to freeze and phase down its production and consumption of hydrofluorocarbons (HFCs) by 2032. HFCs are characterized by their high global warming potential (GWP) and they are used as the main working fluids in air-conditioning and refrigerator instalments. As a result, it is necessary to start developing new fourth generation refrigerants with low GWP as well as to investigate new cooling technologies that are more efficient than currently used vapor-compression cycles. This proposal aims to theoretically and experimentally examine the thermophysical properties of hydrofluoroolefins (HFOs) as future replacements to HFCs. Furthermore, the knowledge gained in studying the thermodynamics of these systems will be extended to study the application of HFOs in a novel hydrate-based cooling technology. In this case, a hydrate dissociation tank will replace the evaporator found in conventional technologies to cool the air feed. The resultant hydrate slurry will be pumped to higher pressures and fed into a hydrate formation tank that will replace the condenser found in conventional technologies. Conditions at which refrigerant hydrates are formed will be measured and a molecular model will be developed to predict the process. The effect of brine concentration on hydrate phase behaviour will also be covered within the scope of this project. The coefficient of cooling (COP) for the proposed technology will be computed and compared to that of conventional vapor-compression cycles. The proposed work is directly related to KFUPMs specific research areas namely: oil and gas, water and environment. We believe that the results and conclusions that will be drawn out of this project will contribute to the Kingdoms effort in establishing a national environmental policy and strategy that is in line with its international commitments and Vision 2030.