Abstract: Cryogenic fluid piston pump functions as stationary dispensing pump, mobile vehicle fuel pump etc., and can pump vapour and liquid efficiently even at negative feed pressures, thus permitting pump location outside a liquid container. Piston inducts fluid by removing vapour from liquid in an inlet conduit faster than the liquid therein can vaporize by absorbing heat, and moves at essentially constant velocity throughout an induction stroke to generate an essentially steady state induction flow with negligible restriction of flow through an inlet port. Stroke displacement volume is at least two orders of magnitude greater than residual or dead volume remaining in cylinder during stroke changeover, and is greater than volume of inlet conduit. Cryogenic tank has a liquid compartment, a vapour compartment, and inlet and overflow conduits. Inlet conduit receives liquid from dispensing pump and widely disperses liquid into liquid tank to contact and condense vapour.

Abstract: The process for the recovery of light hydrocarbon fractions from off-gases derived from the transfer of petroleum material, particularly from a marine loading operation. One process comprises introducing the off-gases containing a light hydrocarbon fraction to be recovered into a refrigerated absorbent column through a liquid ring compressor, employing as a motive fluid a heavy hydrocarbon fraction, recovering a bottom stream from the absorber column having the heavy oil and the light hydrocarbon fraction, then venting an overhead air stream with a low total hydrocarbon content. The process also includes an integrated process for the recovery of light hydrocarbon fractions from off-gases and includes, in addition to a refrigerated absorber column, a recovery stripper column for the removal of the light hydrocarbon fraction from the bottom liquid of the absorber column and the recovery and recycling of a heavy hydrocarbon fraction for use in the absorber column and with the liquid ring compressor.