Vapor recovery method and system

Claim 3

The method of claim 1, wherein the volatile liquid transferred is hydrocarbons and the saturated vapor mixture is compressed to the range of 25 to 85 psig in the order of 90*F and the dehydrated stream is refrigerated to the range of 5*F to 25*F.

Claim 4

The method of claim 2 wherein the liquids condensed by the cooling of the first compression of the vapor mixture are conducted to the step of saturation of the collected vapor mixture for recycle of any air mixed with the condensate.

Claim 5

Apparatus for liquefying vapors released when volatile liquid is transferred between containers, including, means for collecting a mixture of the released vapors and air from the receiving container, a vessel connected to the collecting means to receive the mixture and in which the mixture is saturated with the vapors from a collection of the volatile liquid, a first compressor connected to receive the saturated vapor mixture and elevate its pressure, a first heat exchanger connected to receive the compressed vapor mixture and reduce its temperature with volatile liquid from a stored quantity of the liquid, a scrubber vessel connected to receive the compressed and cooled vapor mixture and separate condensed liquids from the mixture, a second compressor connected to receive the saturated vapor mixture from the scrubber vessel and elevate its pressure, a second heat exchanger connected to receive the compressed vapor mixture and reduce its temperature with volatile liquid from the stored quantity of the liquid, a dehydrator connected to receive a stream of volatile liquid from the stored quantity of the liquid and reduce its water content, a refrigeration unit connected to receive the stream of dehydrated volatile liquid and reduce its temperature, an absorption tower connected to receive the compressed and cooled vapor mixture from the second heat exchanger in its lower end and to receive the refrigerated stream of dehydrated volatile liquid in its upper end, whereby the fluids are passed on countercurrent flow to absorb the vapors released by transfer into the dehydrated volaTile liquid, and a conduit connected from the lower portion of the tower to the vessel receiving the mixture from the collecting means for saturation of the collected vapors with the dehydrated volatile liquid which has absorbed the vapors released by transfer.

Claim 6

Apparatus for liquefying vapors released when volatile liquid is transferred between containers, including, means for collecting a mixture of the released vapors and air from the receiving container, a vessel connected to the collecting means to receive the mixture and in which the mixture is saturated with the vapors from a collection of the volatile liquid, a first compressor connected to receive the saturated vapor mixture and elevate its pressure, a first heat exchanger connected to receive the compressed vapor mixture and reduce its temperature with volatile liquid from a stored quantity of the liquid, a scrubber vessel connected to receive the compressed and cooled vapor mixture and separate condensed liquids from the mixture, a second compressor connected to receive the saturated vapor mixture from the scrubber vessel and elevate its pressure, a second heat exchanger connected to receive the compressed vapor mixture and reduce its temperature with volatile liquid from the stored quantity of the liquid, a dehydrator connected to receive a stream of volatile liquid from the stored quantity of the liquid and reduce its water content, a refrigeration unit connected to receive the stream of dehydrated volatile liquid and reduce its temperature, an absorption tower connected to receive the compressed and cooled vapor mixture from the second heat exchanger in its lower end and to receive the refrigerated stream of dehydrated volatile liquid in its upper end, whereby the fluids are passed on countercurrent flow to absorb the vapors released by transfer into the dehydrated volaTile liquid, and a conduit connected from the lower portion of the tower to the vessel receiving the mixture from the collecting means for saturation of the collected vapors with the dehydrated volatile liquid which has absorbed the vapors released by transfer.

Claim 7

The apparatus of claim 4 wherein the volatile liquid transferred is hydrocarbons and the second compressor elevates the pressure of the saturated hydrocarbons to the range of 25 to 85 psig and the second heat exchanger reduces the temperature of the compressed vapor mixture to the order of 90*F and the refrigeration unit reduces the temperature of the dehydrated liquid hydrocarbons to the range of 5*F to 25*F.

Claim 8

The apparatus of claim 5 wherein the liquids condensed in the scrubber vessel are conducted to the vessel in which the collected mixture is saturated for recycle of any air mixed with the condensate.

Claim 9

The apparatus of claim 5 wherein, a second conduit is provided between the scrubber vessel and the vessel receiving the mixture from the collecting means for saturation of the collected vapors with the condensed liquids from the mixture, a second conduit is provided from the liquid in the bottom of the receiving vessel to storage for the liquids, and a third conduit is provided from the second conduit to the first conduit to insure maintenance of the liquid level in the receiving vessel.

Claim 10

The apparatus of claim 7 wherein, a fourth conduit is provided from liquid used in the interstage cooling of the compressed vapor mixture to the third conduit, and a control system for the fourth conduit from the liquid level in the receiving vessel.

Claim 11

The apparatus of claim 5 wherein a control system is provided for the liquid used is temperature reduction in the heat exchangers to regulate the temperature of the vapor mixture compressed for reception by the absorption tower.