Process for recovery and purification of nitrous oxide

A system for of recovering and purifying N2O, the system comprising:

• a gas stream comprising N2O and impurities comprising light and heavy impurities, water, and organic compounds, the gas stream first entering a wet scrubbing absorption unit that is selected from the group consisting of:
• a caustic scrubbing unit, an acid scrubbing unit, water scrubbing unit, and combinations thereof;
• a compressor having at least one stage of compression that compresses the gas stream from the wet scrubber to a preset pressure greater than 1.0 MPa;
• a cooling and drying unit that cools the gas stream from the compressor to less than 10.0° C. and removes condensed water;
• an adsorption unit comprising at least two parallel adsorption beds, each bed having at least one adsorbent layer adapted to remove heavy impurities, water and organic compounds from the gas stream from the cooling and drying unit;
• a buffer tank that stores the gas stream from the adsorption unit;
• a liquefaction unit that partially liquefies the gas stream from the buffer tank to create:
• (1) a first recycle gas mixture containing N2O and at least one non-condensation gas, and (2) a liquid mixture containing N2O;
• a releaser in fluid communication with the buffer tank and a distillation unit, wherein the releaser transmits the first recycle gas mixture from the liquefaction unit back to the adsorption unit and passes the liquid mixture from the liquefaction unit to the distillation unit, wherein the buffer tank is adapted to permit the gas to flow back to the adsorption unit via the releaser to repressurize the adsorption unit to the preset pressure, wherein
• the distillation unit is selected from a group consisting of a flash drum, a distillation column with reflux, and combinations thereof, wherein the distillation unit removes light impurities and organic compounds from the liquid mixture, and directs:
• (1) a second recycle gas mixture containing N2O and at least one non-condensation gas directly back to the compressor, and (2) purified liquid mixture to a holding tank;
• wherein,
• the gas stream exiting the wet scrubber has less than 500.0 ppm of NO2 and CO2,
• the gas stream exiting the adsorption unit has less than 0.5 ppm of NO2 and less than 1.0 ppm of CO2, and
• the purified liquid mixture has a N2O concentration of greater than 99.9% by volume.