Abstract: A system for reducing dioxygen (O2) present in vapors from oil storage tanks. The system may include an inlet that receives vapors from the tanks; a heating device coupled with the inlet that heats vapors to a first temperature to form heated vapor; and a vessel coupled receiving heated vapor and containing at least one catalyst to reduce dioxygen from the heated vapor. The catalyst may include palladium, and the vessel may include zinc oxide to remove sulfur from the heated vapor. A compressor may be used to compress the vapors. A controller may be provided to monitor O2 concentration in heated vapor, and the controller directs flow of heated vapor to a gas pipeline if the O2 concentration is below a predetermined level; or if the O2 concentration is unacceptably high, the controller directs flow of vapor to be re-circulated within the system to further reduce O2 concentration therein.

Abstract: System and methods for recovering flash gas from at least one flash gas source. A system may include a controllable inlet valve having an input in fluid communications with the flash gas source to receive flash gas; a compressor having an input in fluid communications with an output of the inlet valve to receive the flash gas when the inlet valve is open, the compressor compressing the flash gas to form compressed gas; a controllable recirculation valve in fluid communications with an output of the compressor and the output of the inlet valve; and a controller coupled with and selectively controlling the inlet valve and the recirculation valve between i) a pass-through mode wherein the inlet valve is open and the recirculation valve is closed, and ii) a recirculation mode wherein the inlet valve is closed and the recirculation valve is opened. Various embodiments are disclosed.