Hands-on dual fuel engines workshop

If you've been waiting for a forum to identify and explore the most important technology, marketing and regulatory issues related to gaseous fuelled (natural gas and liquefied petroleum gas – LPG) ‘dual fuel’ diesel engines, register to Clean Fuels Consulting's next 'critical issues workshop'.

Engine experts, fleet operators and government regulatory specialists will meet in Brussels on 30th-31st March 2010 to discuss the range of different dual fuel technologies, operating experiences and regulatory issues that must be addressed in order to overcome the market entry challenges faced by these economic and low polluting engine technologies.

Jeffrey Seisler of Clean Fuels Consulting: "There is a strong strategic element in this since we are trying to create a framework for new regulations to allow these vehicles to be certified. At this moment there are no certification regulations (at the United Nations) and this means that the use of these interesting natural gas or LPG truck engines has to be certified on a country-by-country basis. Not an optimal situation.”

Not unambitious
The goal is for speakers and the audience to participate in an open dialogue and together create a strategy to encourage the development of a new regulatory framework that results in increased worldwide market penetration of dual fuel gaseous/diesel engines and vehicles. Not unambitious for a two-day workshop, but Jeffrey stresses that the workshop is not intended only for informational exchanges and network opportunities. A strategy paper will be produced after the workshop that summarizes the issues and the recommended actions that need to be taken to move fully certified dual fuel engines into the market.

Nonetheless, the workshop also "provides an excellent opportunity to network and engage with NGV and LPG industry experts, equipment suppliers, customers, public sector policy-makers and others. A small table top exhibit adjacent to the workshop room provides an opportunity for companies to display information and materials about their equipment and services," Clean Fuels Consulting point out on their website.

Background

Dual fuel gas engines are designed to operate on natural gas or LPG, blended with varying amounts of diesel for ignition. Natural gas variants replace up to 85-95% diesel; dual fuel LPG engines replace about 35-40% diesel. These so-called ‘giesel engines’ approach diesel efficiency, only cleaner and cheaper. This makes them especially valuable in circumstances where the use of natural gas or LPG is desired for environmental or economic reasons but where the gaseous fuel supply is not available in all locations.

Many of today’s sophisticated, computer controlled dual fuel retrofit systems are being developed as ‘bolt on’ technologies that can be removed if necessary, for instance to resell the vehicle as a normal diesel engine truck. (One company produces a high pressure direct injection system that is purpose-built to run on compressed or liquefied natural gas but cannot be returned to original diesel operation.) This flexibility makes these engines very useful for heavy duty applications, affording a good business case in many global markets.

Dual fuel systems, provided by a small number of technology companies, are becoming more widespread for on-road and off-road applications, notably in North America, Europe, Australia and China. Most of these are retro-fit systems, however, original equipment manufacturers (OEMs) are showing more interest in the technologies:

• Volvo is working with dual fuel system suppliers to offer OEM-quality dual fuel trucks.
• Bosch has been developing a natural gas dual fuel injector that, if brought to market, could make a major contribution to the growth of OEM dual fuel technology.
• Some OEMs, such as Wärtsilä, supply dual fuel gas engines for large ocean-going ships and smaller internal waterway vessels.

Impediments
There is a variety of regulatory and technical challenges that impede rapid market penetration of dual fuel engines and vehicles. It would help if regulations to enable certification of dual fuel engines would be created at the international, United Nations level. As it is, in the absence of clear regulatory guidelines, some countries allow dual fuel vehicles, some provide ‘exemptions’ on a case-by-case basis, and other countries prohibit the systems altogether.

Questions remain about which emissions test cycles should be used, or whether these engines should be tested only as a diesel or as a gas engine, or both. Because dual fuel systems continue to use diesel fuel, complicated emissions after-treatment systems also may be necessary, which increases the cost and complexity of the vehicle system.