to the thermo tank 12 to a point closer to the condensation temperature of the carbon dioxide at the 900 psi state of the thermo tank 12 as the vapor is re introduced into the thermo tank 12 removal of the latent heat in the vapor results in the elevation of the temperature of the liquid carbon dioxide in the thermo tank 12 from the reduced point which follows initial pressure equalization this latent heat transfer is accomplished by introducing the heated vapor into the bottom of the thermo tank 12 and preferably through a sparging tube 34 in the bottom of the thermo tank 12 the carbon dioxide bubbles thus formed are dispersed in the tank offering a large surface area for heat transfer to the liquid phase thus the need for a heat exchanger i e a chiller for the vapor recovery line is avoided it may still be necessary to provide a trim chiller 42 in the thermo tank to offset some of the heat resulting from vapor recovery such a chiller 42 can take the form of an r22 refrigerant coil a chilled water coil from an on board cooling system or simply and preferably a chilled water coil.