US Patent 12129849 Pump system

One embodiment of a method for operating an internal combustion engine under a pressure less than atmospheric pressure includes the steps of positioning a vacuum pump such that said vacuum pump is in fluid communication with a crankcase of said internal combustion engine, connecting a discharge of said vacuum pump to a separator, wherein a portion of said discharge of said vacuum pump condenses in said separator, connecting a vapor discharge of said separator to a filter, wherein said filter removes a portion of volatile organic compounds from said vapor discharge, and venting said filter to an ambient atmosphere.