A method for processing a gaseous fluid, said method comprising: - providing an incoming gaseous fluid comprising at least 50% by volume methane; - increasing a pressure of said incoming gaseous fluid; - liquefying a stream derived from the pressurized gaseous fluid, said liquefying comprising cryogenic cooling said stream to liquefied fluid having a temperature between -100°C and -140°C, a pressure of between 10 and 50 bar, and a methane content of at least 85% by volume; - flashing said liquefied fluid into a container, retrieving from said container: • a processed liquid fluid at a first container level at a pressure of between 1 and 10 bar, a temperature of between -120°C and -160°C and a methane concentration of at least 85% by volume, • a slurry flow comprising solid CO 2 and water ice at a second container level below said first container level, and • a flash gas stream at a level above said first container level; characterized in - increasing said pressure of said incoming gaseous fluid to between 10 and 50 bar; - before liquefying said stream derived from the pressurized gaseous fluid, pre-treating said gaseous fluid with increased pressure, said pre-treatment comprising filtering said gaseous fluid using membrane filtering to a retentate with a pressure of between 10 and 50 bar, a temperature of between 0°C and 50°C, a carbon dioxide content of between 0.1 - 2 % by volume, a water content below 10 ppm by volume and a methane content of at least 85% by volume, said retentate being the stream derived from the pressurized gaseous fluid that is liquefied; - providing said flash gas stream to said membrane filtering as a sweep gas at a permeate side in said membrane filtering; - the processed liquid is retrieved from the container into a storage device. - providing an incoming gaseous fluid comprising at least 50% by volume methane; - increasing a pressure of said incoming gaseous fluid; - liquefying a stream derived from the pressurized gaseous fluid, said liquefying comprising cryogenic cooling said stream to liquefied fluid having a temperature between -100°C and -140°C, a pressure of between 10 and 50 bar, and a methane content of at least 85% by volume; - flashing said liquefied fluid into a container, retrieving from said container: • a processed liquid fluid at a first container level at a pressure of between 1 and 10 bar, a temperature of between -120°C and -160°C and a methane concentration of at least 85% by volume, • a slurry flow comprising solid CO 2 and water ice at a second container level below said first container level, and • a flash gas stream at a level above said first container level; characterized in • a processed liquid fluid at a first container level at a pressure of between 1 and 10 bar, a temperature of between -120°C and -160°C and a methane concentration of at least 85% by volume, • a slurry flow comprising solid CO 2 and water ice at a second container level below said first container level, and • a flash gas stream at a level above said first container level; - increasing said pressure of said incoming gaseous fluid to between 10 and 50 bar; - before liquefying said stream derived from the pressurized gaseous fluid, pre-treating said gaseous fluid with increased pressure, said pre-treatment comprising filtering said gaseous fluid using membrane filtering to a retentate with a pressure of between 10 and 50 bar, a temperature of between 0°C and 50°C, a carbon dioxide content of between 0.1 - 2 % by volume, a water content below 10 ppm by volume and a methane content of at least 85% by volume, said retentate being the stream derived from the pressurized gaseous fluid that is liquefied; - providing said flash gas stream to said membrane filtering as a sweep gas at a permeate side in said membrane filtering; - the processed liquid is retrieved from the container into a storage device.