Toward sustainable refrigeration systems: Life cycle assessment of a bench-scale solar-thermal adsorption refrigerator

Abstract

Abstract Adsorptive refrigerators are an unconventional alternative to modern refrigerators employing the vapor compression cycle. Adsorptive refrigerators do not require electricity and can be constructed from widely available and environmentally benign materials, making them a particularly appealing approach to creating refrigeration in remote, impoverished areas where electricity is unavailable or unreliable. This paper describes a prototype that uses ethanol and activated carbon, two widely available and environmentally friendly materials, as the key components of a solar-powered adsorptive refrigerator. The Solar Thermal Adsorption Refrigerator (STAR) prototype obtained temperatures between 2⁰C and 8⁰C on the external wall of the vacuum tube. Results showed that a significant amount of life cycle environmental benefits can be achieved from STAR compared to a conventional refrigerator. Successfully replacing a conventional refrigerator with STAR can annually reduce: 292 ~ 1170 kg CO2-eq of global warming potential (GWP); 104 ~ 418 H+ moles-eq. of acidification; 1.15 ~ 4.61 kg benzene- eq. of carcinogenic; 6850 ~ 27,400 kg toluene-eq. of non-carcinogenic; 1.2 ~ 4.78 kg N-eq. of eutrophication; 0.556 ~ 2.22 kg PM2.5-eq. of respiratory effects; 0.0078 ~ 0.031 g of CFC-11 eq. of ozone depletion; 0.564~2.26 g NOx-eq. of smog. Considering the typical lifetime of a conventional fridge of 13~19 years, the reduction of the aforementioned environmental impacts of the STAR can be scaled significantly.