An internal combustion engine system is described herein. The system uses reactor to create pilot fuel from the primary fuel to assist in the ignition of the primary fuel. A controller is used to maintain an operational range of a level of the pilot fuel in an accumulator. The accumulator acts as a buffer to allow the engine to continue to receive the pilot fuel during dynamic and changing conditions of the engine. The controller increases or decreases the rate of production of the pilot fuel by a pilot fuel system to maintain the operational range of the level of the pilot fuel in the accumulator. The controller can receive inputs such as pilot fuel level or power signals from the engine to adjust the rate of production of the pilot fuel to meet engine demand.

A hyperbaric fuel system (10a, 10b) produces hydrogenated liquid fuel (30) for combustion reactions of compression or spark ignition engines and improves fossil fuel efficiency without requiring major changes to existing fuel systems. The hydrogenated liquid fuel (30) decreases the NOx, CO and unburned hydrocarbon particulate matter, and reduces the consumption of liquid fuel (26). The systems produces hydrogen gas (18) and dissolves the hydrogen gas (18) in the liquid fuel (26) using several chambers, including a hyperbaric mixing chamber (58), between the liquid fuel supply and a fuel pump (28) supplying the hydrogenated liquid fuel (30) to fuel injectors (40). Unused hydrogen gas (18) and hydrogenated liquid fuel (30) is recirculated to minimize loss of efficiency. The system preferably includes a water reservoir and electrolysis device to generate the hydrogen gas.

A multi-fuel rail apparatus for an internal combustion engine communicates fuel from 10 a first fuel source and a second fuel source to a plurality of fuel injectors. Each fuel injector receives fuel from the multi-fuel rail apparatus through a branch connection for each fuel. The multi fuel rail apparatus has a first elongate member including a first longitudinal bore spaced apart from a second longitudinal bore and first and second fuel inlets for fluidly communicating first and second fuels into the first and 15 second longitudinal bores respectively. There is a branch connecting structure for each fuel injector along the first elongate member for fluidly connecting the first and second longitudinal bores with respective branch connections from respective fuel injectors.

Techniques for separating a fuel on-board a vehicle include mixing an input fuel stream and a fluid solvent; separating the mixture into a first liquid fuel stream and a second liquid fuel stream, the first liquid fuel stream including a first portion of the input fuel stream defined by a first auto-ignition characteristic value and the fluid solvent, the second liquid fuel stream including a second portion of the input fuel stream defined by a second auto-ignition characteristic value that is different than the first auto-ignition characteristic value; separating the first liquid fuel stream into the fluid solvent and the first portion of the input fuel stream; directing the first portion of the input fuel stream to a first fuel tank on the vehicle; and directing the second portion of the input fuel stream to a second fuel tank on the vehicle.

Techniques for separating a fuel on-board a vehicle include mixing an input fuel stream and a fluid solvent; separating the mixture into a first liquid fuel stream and a second liquid fuel stream, the first liquid fuel stream including a first portion of the input fuel stream defined by a first auto-ignition characteristic value and the fluid solvent, the second liquid fuel stream including a second portion of the input fuel stream defined by a second auto-ignition characteristic value that is different than the first auto-ignition characteristic value; separating the first liquid fuel stream into the fluid solvent and the first portion of the input fuel stream; directing the first portion of the input fuel stream to a first fuel tank on the vehicle; and directing the second portion of the input fuel stream to a second fuel tank on the vehicle.