Liquid fuel synthesis system

A liquid fuel synthesis system comprising:

• a liquid fuel synthesis portion having a separation membrane permeable to a liquid fuel which is a product of a conversion reaction of a raw material gas containing hydrogen and carbon oxide to the liquid fuel, and water vapor which is a by-product of the conversion reaction, the liquid fuel synthesis portion being partitioned into a non-permeation side space and a permeation side space by the separation membrane;
• and
• a sweep gas supply unit configured to supply the permeation side space with a sweep gas for sweeping the liquid fuel permeating through the separation membrane;
• wherein
• a temperature of the sweep gas flowing into the permeation side space is higher than at least one of a temperature of the raw material gas flowing into the non-permeation side space and a temperature of a first outflow gas flowing out of the non-permeation side space, and
• a temperature of a second outflow gas flowing out of the permeation side space is higher than at least one of the temperature of the raw material gas flowing into the non-permeation side space and the temperature of the first outflow gas flowing out of the non-permeation side space.