High-grade heat-of-compression storage system, and methods of use

The cryogenic energy storage system of claim1 , wherein the heat transfer fluid is a first heat transfer fluid, and wherein the cryogenic energy storage system further comprises:

• a power recovery sub-system comprising:
• a pump;
• an evaporator;
• at least one heater;
• an expansion stage corresponding to each of the at least one heater;
• a fourth arrangement of conduits, having an upstream end and a downstream end, and configured to pass a working fluid from the pump through the evaporator and each of the at least one heater and corresponding expansion stage, wherein each heater is positioned upstream of its corresponding expansion stage;
• and
• a fifth arrangement of conduits forming a closed circuit and configured to pass a second heat transfer fluid between the thermal energy storage device and each heater of the at least one heater;
• wherein each heater is configured to transfer at least a portion of high-grade heat of compression from the thermal energy storage device, via the second heat transfer fluid, to the working fluid;
• and
• wherein each expansion stage is configured to expand the working fluid and to extract work therefrom.

A method for heat-of-compression storage in a cryogenic energy storage system, comprising:

• providing a liquefaction sub-system comprising a first compressor and a second compressor;
• providing a thermal energy storage device configured to store high-grade heat;
• compressing a process stream in the first compressor;
• capturing at least a portion of high-grade heat of compression of the process stream from the first compressor and storing it, via a heat transfer fluid, in the thermal energy storage device;
• compressing the process stream in the second compressor;
• capturing at least a portion of high-grade heat of compression of the process stream from the second compressor and storing it, via the heat transfer fluid, in the thermal energy storage device;
• and
• capturing at least a portion of low-grade heat of compression of the process stream from the second compressor and transferring it back into the second compressor.