Environmental impact assessment of a rotary compressor in Thailand based on life cycle assessment methodology

Abstract

This paper aims to evaluate and identify the environmental performance of a fixed speed rotary compressor produced in Thailand throughout the whole compressor life cycle, in comparison with an inverter twin rotary compressor. This study covers all life cycle stages, including raw material production, manufacturing, compressor use, final disposal, and all related transport. This research is performed in accord with ISO 14040/14044 standards. Life cycle assessment methodology is employed in this research. The investigation results are showed in terms of ten impact categories using the ReCiPe midpoint (H) V1.13 method. The ten environmental impact categories are investigated: climate change (CC), ozone layer depletion (OD), terrestrial acidification, freshwater eutrophication, human toxicity, photochemical oxidant formation, particulate matter formation, water depletion, metal depletion (MD), and fossil depletion. The results show that the use stage of the compressor has the largest contribution to the environmental impact due to most energy being consumed in this stage. The raw materials production stage is important due to the contribution from copper and steel production. In the manufacturing stage, the electricity consumption in the machining process is the most contributing process. While the end-of-life stage, the R22 refrigerant emitted to the atmosphere is a significant effect on the CC and OD impacts, whereas metal recycling is an environmental benefit in terms of the MD category due to the reduction in virgin material requirements. The shifting from a fixed speed rotary compressor with R22 refrigerant to an inverter twin rotary compressor with alternative refrigerants, the results show that complete termination of ozone layer depletion affected by the R410A and R32 refrigerants are confirmed. Also, the inverter twin rotary compressor with R410A and R32 refrigerant can reduce impacts in all impact categories, in the range of 21.7–53.1% and 28.7–53.2%, respectively. Results demonstrated that the use stage should improve energy efficiency due to it resulting in the largest contribution to the environmental impact, which is induced by electricity consumption. To develop the new types of the compressor with high energy efficiency, such as a twin rotary compressor with the inverter system to control the operation, is the best option in order to reduce the environmental impact from the use stage of the compressor.