Regarding bioenergy alternatives, biomethane (BM) emerges as a highly competitive option with the potential to reduce the world's dependency on fossil fuels. Among the various forms of BM, liquefied biomethane (LBM) stands out as the most suitable for both storage and transportation to remote regions across the globe. However, it's worth noting that the process of liquefying BM is both costly and energy-intensive. This is mainly due to the significant electricity consumption associated with the compressors used in the BM liquefaction process, similar to those used in natural gas processing. Furthermore, unlike conventional natural gas, which is generated under high pressure, biomethane is produced at atmospheric pressure. Consequently, the liquefaction of BM demands more energy because the pressure at which BM is produced is substantially lower than its critical pressure counterpart. To address these challenges and create a cost-effective, energy-efficient system, we propose the integration of a biomethane liquefaction process with a liquid air energy storage (LAES) system discharge end. Notably, the thermal exergy of a compressed mixed refrigerant (MR) contributes to the expansion stage of liquid air, adding another layer of advantage to the system. In this research paper, we assess the impact of this innovative integration of LBM and LAES through both conventional and advanced exergy analyses.The outcomes of the conventional exergy analysis highlight that compressors and heat exchangers are the primary sources of irreversibility, accounting for 16.5% and 39.6% of the total, respectively. However, the integration of these two energy systems has yielded promising results. It has been observed that the exergy efficiency of the process has increased to 53%, in contrast to the conventional SMR LBM process, which maintains an exergy efficiency of 35.5%. Advanced exergy analysis showed that 50% of the overall destruction of exergy in the modified process could be avoided. Compressors and turbines had the most potential for improvement and could avoid 54% and 94% of exergy destruction, respectively. However, cryogenic heat exchangers and coolers had the highest percentage of unavoidable exergy destruction, 62% and 83%, respectively. A rigorous comparison was performed among multiple cases like conventional LBM process, LBM-LAES integrated process and optimized LBM-LAES process in terms of avoidable exergy destruction and maximum exergy saving potential was observed in the third case.