AP8 - Diesel engine for biogas

Today, gas engines typically are Otto-engines with a slightly modified fuel injection system adapted for either monovalent or bivalent gas-powered operation and a modified motor management. In many cases an additional market demand for (bio-)gas-powered Diesel-engines arises due to the fact, that the specific vehicle is manufactured exclusively with a Diesel-engine.

Especially in the sectors of freight vehicles, light duty vehicles and work machines as well as vehicles for communal, building industry, forestry and agrarian purposes one can find a high demand for monovalent (bio-)gas propulsion. Today’s market for these vehicles is strongly affected by the high number of manufacturers. The integrated engines, in most cases Diesel-engines, show very differing power concepts.

The focus within this work package therefore is the development of a refitting concept for these Diesel-engines. Only the crankcase and the essential accessories like generator, pumps and starter will be taken from the original construction by the project consortium. All other parts relevant for power, torque and exhaust emission standards will be substituted by own parts.

Main target is an advancement of the bivalent FLEX-POWER-System presented by the company LuPower exemplified at a Diesel-engine of a passenger car propelled by biogas using a combustion process according to Otto and complying to the following conditions:

  • all regulations concerning respirable dust have to be fulfilled
  • exhaust emission standard EURO 5 and EEV have to be fulfilled
  • noise emissions have to be reduced by 10dbA
  • a high stage of development has to be reached

Additionally, the efficiency of the CNG/biogas-operation shall exceed modern Diesel-engines.

Fundamental technical specifications of the elaborated concept comprise the following:

  • a special piston with a developed geometry for the gas operation
  • the power will at least be kept constant
  • the torque will at least be kept constant
  • the Diesel-engine will have its own ignition and CNG-control-device

CNG/biogas is less harmful to the environment compared to diesel or gasoline because of the lower content of potential pollutants. Additionally, the gas shows better anti-knock properties. This is why this fuel is clear of toxic additives like aromatic hydrocarbons usually used to improve the octane number of gasoline. As a result, a vehicle converted from Diesel or gasoline to CNG/biogas will always be more eco-friendly.

Vehicles equipped with Diesel-engine are widely spread (commercial vehicles, agrarian and forestry vehicles, building industry vehicles and work machines). Making this sector accessible for biogas would enlarge the market for this new fuel significantly. For the application of (bio-)gas in the automotive Diesel-engine no provider is available throughout Europe and these systems are like virgin soil to a large extent.