Natural gas-Diesel dual fuel for commercial vehicle engines

In commercial vehicle applications, particularly in the heavy-duty long-distance traffic use, the internal combustion engine is expected to remain a dominant engine type in the medium term. Beside high cruising range with moderate weight, the performance and torque characteristics are the decisive properties of today’s Diesel engines.With respect to global CO₂ targets, natural gas in commercial vehicle applications could play an increasing role. Compared with Diesel it provides a theoretical CO₂ advantage of 25% based on the C/H ratio of the fuel. Furthermore, improvements for regenerative production of natural gas are on the way that could further improve the CO₂ balance of natural gas combustion engines. However, due to the lower cycle efficiency, today’s state of the art natural gas engines based on a spark ignited Otto combustion principle, do only partially achieve the theoretical CO₂ benefit compared to Diesel engines. Furthermore, higher thermal load and disadvantages in the transient behavior have to be taken into account.