A fuel separation system includes a fuel separator configured to receive a fuel stream and separate the fuel stream, based on a volatility of the fuel stream, into a vapor stream defined by a first auto-ignition characteristic value and a first liquid stream defined by a second auto-ignition characteristic value, the second auto-ignition characteristic value greater than the first auto-ignition characteristic value; and a control system communicably coupled to the fuel separator and operable to receive an input from an engine, the input including an engine operating condition, the control system configured to adjust an operating parameter of the fuel separator, based at least in part on the engine operating condition, to vary at least one of the first or second auto-ignition characteristic values.

Fuel vapor emissions from a fuel tank directed to a canister containing adsorbent are minimized by an intermediate condenser and conduit configuration. Condensing and cooling fuel vapor emissions allows a reduction in canister capacity, where the canister can still meet and accommodate refueling and/or diurnal emissions control requirements. Pressurized and unpressurized fuel tanks for various vehicles, including vehicles with an internal combustion engine and hybrid electric vehicles, can be configured with the present fuel vapor recovery systems.

Fuel vapor emissions from a fuel tank directed to a canister containing adsorbent are minimized by an intermediate condenser and conduit configuration. Condensing and cooling fuel vapor emissions allows a reduction in canister capacity, where the canister can still meet and accommodate refueling and/or diurnal emissions control requirements. Pressurized and unpressurized fuel tanks for various vehicles, including vehicles with an internal combustion engine and hybrid electric vehicles, can be configured with the present fuel vapor recovery systems.

An onboard, in-line fuel cooling system for a motor vehicle includes a chiller adapted to be powered by an onboard direct-current electric power source such as, for example, a motor vehicle power system or an auxiliary battery, and a fuel conduit adapted to form at least a portion of a fuel supply line between an onboard fuel tank and an onboard engine of the motor vehicle. The fuel conduit is in thermal communication with the chiller to cool fuel passing through the fuel conduit from the onboard fuel tank to the onboard engine. Thus, the engine is provided with fuel at a temperature lower than the temperature of the fuel in the fuel tank. The chiller can be a vapor-compression refrieration system, a thermo-electric cooler, or any other suitable type of chiller powered by the onboard direct-current electric power source.

A fuel separation system includes a fuel separator configured to receive a fuel stream and separate the fuel stream, based on a volatility of the fuel stream, into a vapor stream defined by a first auto-ignition characteristic value and a first liquid stream defined by a second auto-ignition characteristic value, the second auto-ignition characteristic value greater than the first auto-ignition characteristic value; and a heat exchanger fluidly coupled between a fuel input of the fuel stream and the fuel separator, the heat exchanger configured to transfer heat from the vapor stream to the fuel stream, and output a heated fuel stream to the fuel separator and a second liquid stream defined by the first auto-ignition characteristic value.

A fuel separation system includes a fuel separator configured to receive a fuel stream and separate the fuel stream, based on a volatility of the fuel stream, into a vapor stream defined by a first auto-ignition characteristic value and a first liquid stream defined by a second auto-ignition characteristic value, the second auto-ignition characteristic value greater than the first auto-ignition characteristic value; and a heat exchanger fluidly coupled between a fuel input of the fuel stream and the fuel separator, the heat exchanger configured to transfer heat from the vapor stream to the fuel stream, and output a heated fuel stream to the fuel separator and a second liquid stream defined by the first auto-ignition characteristic value.

A fuel separation system includes a fuel separator configured to receive a fuel stream and separate the fuel stream, based on a volatility of the fuel stream, into a vapor stream defined by a first auto-ignition characteristic value and a first liquid stream defined by a second auto-ignition characteristic value, the second auto-ignition characteristic value greater than the first auto-ignition characteristic value; and a heat exchanger fluidly coupled between a fuel input of the fuel stream and the fuel separator, the heat exchanger configured to transfer heat from the vapor stream to the fuel stream, and output a heated fuel stream to the fuel separator and a second liquid stream defined by the first auto-ignition characteristic value.

A fuel separation system includes a fuel separator configured to receive a fuel stream and separate the fuel stream, based on a volatility of the fuel stream, into a vapor stream defined by a first auto-ignition characteristic value and a first liquid stream defined by a second auto-ignition characteristic value, the second auto-ignition characteristic value greater than the first auto-ignition characteristic value; and a heat exchanger fluidly coupled between a fuel input of the fuel stream and the fuel separator, the heat exchanger configured to transfer heat from the vapor stream to the fuel stream, and output a heated fuel stream to the fuel separator and a second liquid stream defined by the first auto-ignition characteristic value.

A fuel system in particular of a motor vehicle, includes a fuel tank and a ventilation device for ventilating the fuel tank. The ventilation device has at least one separation device which has a temporary accumulator for liquid fuel. The separation device is made at least in part of a porous material and/or is filled with the porous material.

A fuel system in particular of a motor vehicle, includes a fuel tank and a ventilation device for ventilating the fuel tank. The ventilation device has at least one separation device which has a temporary accumulator for liquid fuel. The separation device is made at least in part of a porous material and/or is filled with the porous material.