Performance improvement of air liquefaction processes for liquid air energy storage (LAES) using magnetic refrigeration system

It is essential to shift towards renewable energy for environmental concerns. Liquid air energy storage is an attractive option to store this energy in terms of energy savings, grid balancing and large-scale energy system with no geographical constraints. However, it has a low round trip efficiency, to which the energy intensity of air liquefaction is a major contributor. This study proposes novel configurations employing magnetic refrigeration pre-cooling for air liquefaction cycles (Linde-Hampson, Claude and Kapitza). The conventional and new lique-faction schemes are modeled and simulated on Aspen Hysys. The proposed schemes for the liquefaction step of the LAES process are assessed thermodynamically and economically based on specific energy consumption (SEC), exergy efficiency and levelized cost of product (LCOP). The results show that SEC for Linde-Hampson, Claude and Kapitza with AMR pre-cooling reduces by 11.20 %, 10.96 % and 7.24 %, respectively, compared with conven-tional air liquefaction cycles without precooling. Also, exergy efficiency for cycles with AMR pre-cooling in-creases by 1.03 %, 3.13 % and 2.12 %, respectively. It is found that Kapitza-AMR process gives the lowest value for LCOP of 7.62 US$/kgLAir as compared to 8.61 US$/kgLAir for the LH-AMR and 8.03 US$/kgLAir for the Claude-AMR process. A sensitivity analysis is also performed to study the effect of varying process parameters on per-formance of the active magnetic regenerator (AMR) pre-cooling section.

Automated summary

Shifting towards renewable energy is important for the environment, and liquid air energy storage (LAES) is a promising option for energy storage. This study proposes novel configurations incorporating magnetic refrigeration pre-cooling for air liquefaction cycles in LAES. The proposed schemes significantly reduce specific energy consumption and increase exergy efficiency compared to conventional cycles without precooling.