Method for Liquid Air and Gas Energy Storage

A method for liquid air and gas energy storage (LAGES) comprising in combination:

• pumping the liquefied natural gas (LNG) from the tanks of LNG Storage and Regasification (LNGSR) terminal into a co-located Liquid Air Energy Storage (LAES) system for continuous regasifying the LNG in the said system and final injecting the regasified LNG into a transmission pipeline;
• interchanging a waste thermal energy between the LNG being regasified and the process air being continuously liquefied in the LAES system;
• consuming a required power from the grid and/or other energy source for production of the liquid air with its storing only in the periods of low demand for energy in the grid;
• on-demand discharging the said LAES system with generation of the on-peak power delivered into grid through consuming both a stored and directly produced liquid air at a rate exceeding a rate of its direct production;
• and
• wherein the improvement comprises in combination:
• pumping the whole amount of LNG destined for regasification and its delivering into LAES system at the first low pressure and first low temperature during the LAES system discharging;
• using a minor part of cold thermal energy of discharged liquid air for deep cooling the said delivered LNG down to the second low temperature, which is below the first one;
• controlled dividing the deeply cooled LNG stream into two parts, first of which is further pumped at the second high pressure and regasified in the LAES system during its discharging;
• storing the second part of deeply cooled LNG at a pressure not exceeding the first low one and at a temperature not exceeding the second low one;
• pumping the stored second part of deeply cooled LNG at the second high pressure and its regasifying in the LAES system during its charging only;
• using most of the cold thermal energy of discharged liquid air for reliquefying a part of highly pressurized NG extracting from the outlet of LAES system;
• and
• depressurizing and recycling a reliquefied NG into the tanks of LNGSR terminal, resulting in enhancement of LAES power output at the given LNGSR terminal send-out capacity.