Bi-fuel vehicle

Diesel engines converted to use gaseous fuels fall into this class due to the different ignition system.

The most common technology and alternate fuel available in the market for bi-fuel gasoline cars is Autogas (LPG), followed by natural gas (CNG),[6] and it is used mainly in Europe.

Normally, standard gasoline vehicles are retrofitted in specialized shops, which install the gas cylinder in the trunk and the LPG or CNG injection system and electronics.

This system interrupts the gas supply to the cylinder during the long overlap of the intake and exhaust valves (just typical for slow-speed and medium-speed engines – within the valve overlap cylinder scavenging is performed).

Other benefits also include emissions reduction (due to different C/H atom ratio) and fuel flexibility.

The preferred method for diesel generators to be converted to dual fuel would be to use piped natural gas due to the volume of gas required based on the operating cycle of the engine.

[11] It is less common to use CNG (Compressed Natural Gas) or LNG (Liquid Natural Gas) for bi-fuel operations, due to logistics of fuel delivery frequency and amount of fuel required to maintain operations.

Natural Gas is preferred for generator sets conversions, because the engine does not lose the output power.

Additionally, the composition of the biogas has to lean towards ignitable gases and be filtered as much as possible of non-combustible compounds such as carbon dioxide.