Alternative fuels key to reducing operating costs

Natural gas (NG) is used in industry and households alike for heating, cooking,  drying and various manufacturing processes. For use in a mobile application like road transport we must first compress it to 240 bar (3500psi) or liquefy it by cooling it to  -160?C to create the necessary storage density. Compressing it requires less  infrastructure, but takes up more storage space on the vehicle and therefore it is more  suited to short operating trips. Liquefying it, by comparison, takes less vehicle space, allowing greater distances, but has very high infrastructure costs for manufacture and distribution.

William Adams has worked closely with Clean Air Power to market and support their dual-fuel product for Caterpillar C-12 and C-15 truck engines. The first demonstration project occurred back in 1999 when a Kenworth T401, fitted with a C-12, was converted to dual-fuel and used compressed natural gas (CNG) storage. At this time, only CNG was available and the practical operations were limited to short-haul and dedicated routes. Since 2004, LNG (liquefied natural gas) has become the storage method of choice and William Adams have progressed to having converted nearly 60 vehicles. These are  in operation across Victoria in a variety  of applications. All of these operate using LNG as storage, providing a range of 400km to 600km from a single fill.

Dual-fuel is the use of two fuels, in this case NG and diesel to produce the power. The technology divides the total fuel requirement between NG and diesel, with the substitution rate varying, dependent on numerous operating factors. NG is injected into the inlet manifold during the intake stroke, and mixes with the incoming air. Diesel is injected to provide the ?liquid spark? and ignite the gas air mixture. The power curves are similar to the equivalent diesel rating, but peak torque is produced at approximately 200 rpm higher than diesel. Overall, the substitution rates average between 60 per cent and 80 per cent.

William Adams offers conversions on most on-highway trucks which suit the C-12 and C-15 engines. The C-12 is rated at 410hp at 1800rpm and the C-15 at 500hp at 1800rpm. This covers most requirements from intrastate and regional deliveries through to interstate operations with both single- and multi-trailer combinations.

While dual-fuel technology is suited only to the on-highway market, biodiesel is an alternative fuel that can be used in  Caterpillar?s range of diesel-powered product. Biodiesel is the name given to fuel derived from animal- and plant-based product and is therefore a non-petroleum based product. The process used to convert these oils and fats into useable fuel is called trans-esterification. The end result is 100 per cent biodiesel or B100. This is then blended with mineral diesel to produce the end result, a blended fuel for use in diesel engines.

Caterpillar has released guidelines for the use of biodiesel, based on the product in use. These describe the accepted levels and use of biodiesel in Caterpillar product. The current publications are:
SEBU6250-15 Caterpillar machine fluids recommendations.
SEBU6251-10 Caterpillar commercial diesel engine fluids recommendations.
SEBU6385-07 Caterpillar on-highway diesel engine fluids recommendations.
SEBU7003-03 Caterpillar 3600 Series and C280 Series diesel engine fluids recommendations.

It is important to use these documents to assist in determining whether biodiesel is a viable alternative for your business. This is because the accepted levels of biodiesel vary according to the engine model. The levels vary between B5 and B30. More information can be obtained from William Adams at

This article was originally printed in the Winter issue of William Adams ?PLUS? magazine and is reproduced with the kind permission of William Adams.

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