An onboard fuel separation apparatus separates a material fuel (gasoline) into a high-octane fuel having a higher octane value than the material fuel and a low-octane fuel having a lower octane value than the material fuel using a separation membrane which selectively allows high-octane value components (such as aromatic components) permeate through the membrane. The apparatus increases the ratio of the amount of the high-octane value components permeating through the membrane to the amount of the high-octane value components contained in the material fuel by, (A) Controlling the temperature of the material fuel supplied to the membrane (B) Increasing partial pressure of the low-octane value components on the high-octane fuel side of the membrane and removing volatiles from the permeate, and (C) Bypassing volatiles in the material feed around the membrane.

An onboard fuel separation apparatus for an automobile

A gasoline in a material fuel tank (3) is separated into a high-RON fuel having a higher octane value than the material fuel and a low-RON fuel having a lower octane value than the material fuel, by a separator device (10) equipped with a separation membrane (101). Using a fuel switching mechanism (21), one or both of the high-RON fuel and the low-RON fuel are supplied to the engine in accordance with the state of operation of the engine. As the octane value of a fuel can be changed in accordance with the engine operation state, the state of combustion in the engine improves, so that both an increase in engine output and an improvement in an exhaust property can be achieved.

Masahiro C

Papers

Fuel supply apparatus for an internal combustion engine having a membrane for separating gasoline into a high and a low octane number fuel