Air purification units

A method of operating a liquid air energy storage system, comprising:

• liquefying a stream of input air by:
• receiving the stream of input air through an air input, compressing the input air and cooling the input air;
• purifying the stream of input air in an adsorption air purification unit to produce a stream of purified air;
• and
• liquefying the stream of purified air in a cold box;
• storing the liquefied air in a liquid air storage facility;
• and
• recovering power from the liquefied air by:
• pressurizing the liquefied air with a pump to produce a stream of high-pressure liquefied air;
• evaporating the stream of high-pressure liquefied air in an evaporator to produce a stream of high-pressure gaseous air;
• heating the stream of high-pressure gaseous air to produce a stream of heated high-pressure gaseous air;
• expanding the stream of heated high-pressure gaseous air in an expansion turbine;
• generating electricity in a generator coupled to the expansion turbine;
• and
• exhausting a stream of low-pressure gaseous air from the expansion turbine;
• and
• regenerating the adsorption air purification unit using at least a portion of the stream of low-pressure gaseous air exhausted from the expansion turbine,
• wherein the step of regenerating takes place in two periods such that during a first of the two periods, an arrangement of valves directs a portion of the low-pressure gaseous air exhausted from the expansion turbine through the adsorption air purification unit bypassing the heat exchanger for heating the adsorption air purification unit and during a second of the two periods, the arrangement of valves directs at least a portion of the low-pressure gaseous air exhausted from the expansion turbine through the heat exchanger and then through the adsorption air purification unit for cooling the adsorption air purification unit.

An adsorption air purification device for use in a liquid air energy storage system, the device comprising:

• first and second fluid openings;
• at least two adsorbent vessels connected between the first and second fluid openings;
• an arrangement of conduits and valves configured to direct a first stream of air to pass through a combination of one or more of the adsorbent vessels to remove contaminants from the first stream of air, and to direct a second stream of air to pass through the combination of one of more of the adsorbent vessels to regenerate the adsorbent vessels;
• and
• a controller configured to open and close said valves;
• wherein the arrangement of conduits and valves is such that the controller may open and close said valves so as to selectively direct:
• a) the first stream of air to pass between the first and second fluid openings through at least a first adsorbent vessel in series during a first phase of operation;
• and
• b) the second stream of air to pass between the first and second fluid openings through at least the first and a second adsorbent vessel in parallel during a separate second phase of operation.