Road Transport Vehicles

Coatings on road transport vehicles are expected to have a minimum service life of ten years. Paint systems must therefore be of high quality. 

Trucks. Drivers cabins are coated in the same way as cars (see Section 11.2.1). Truck chassis are especially prone to corrosion caused by stone impact and road salts. Chassis parts are supplied by special manufacturers who normally provide an anticorrosive prime coating. 

Side and cross members are pretreated by blasting and phosphating. An electrode-posited primer coating follows and is sometimes immediately overcoated with a topcoat based on an air-drying alkyd or epoxy ester, or on an oven-drying alkyd-melamine resin combination. After assembly of the truck, a third layer (i.e., a second topcoat) is applied that serves as a supply finish. These finishes are mostly two-pack acrylic aliphatic isocyanate topcoats. Water-based two-pack systems and powder coatings are the most recent developments. 

Trailers. Trailer chassis are generally coated in the same way as truck chassis but with a two-coat system. The primer is either a one-pack alkyd paint or a two-pack epoxy paint that are cured at ambient temperature with amine adducts or isocyanates. 

Truck bodies are often constructed of steel frames with aluminum side walls. The aluminum alloys are pretreated by application of 5-8 pm of a chromate-containing wash primer. The topcoat is a two-pack acrylic resin bearing hydroxyl groups and is cross-linked with aliphatic isocyanates. 

---

Attention must be called to the fact that in practically all work concerning the use of fuel cells for road transport vehicles, only fuel cells using hydrogen as a fuel were considered. There can be no doubt that hydrogen-oxygen fuel cells (and in particular those of the PEMFC type) at present have been developed to such a degree that in all their technical parameters, they are fit for power plants of electric cars. Tests of different types of electric cars with such power plants, which have already been performed for almost 10 years, will undoubtedly be... 

Figure 16.1 shows part of a steel tank which came from a road tank vehicle. The tank consisted of a cylindrical shell about 6 m long. A hemispherical cap was welded to each end of the shell with a circumferential weld. The tank was used to transport liquid ammonia. In order to contain the liquid ammonia the pressure had to be equal to the saturation pressure (the pressure at which a mixture of liquid and vapour is in equilibrium). The saturation pressure increases rapidly with temperature at 20°C the absolute pressure is 8.57 bar at 50°C it is 20.33 bar. The gauge pressure at 50°C is 19.33 bar, or 1.9MN m . Because of this the tank had to function as a pressure vessel. The maximum operating pressure was 2.07 MN m" gauge. This allowed the tank to be used safely to 50°C, above the maximum temperature expected in even a hot climate. 

This is added to the price of fuel used in transporting vehicles over public roads. Its original purpose was to provide funds for the construction and maintenance of highways. 

The large scale adoption of PHEVs (or BEVs) in Europe might create a regulatory issue as electric vehicles will shift C02 emissions from the transport sector to the electric power sector, which - unlike road transport - is covered by the European Emissions Trading Scheme (ETS), a compensatory mechanism or the inclusion of road transportation within the scheme would be required. 

Today ethanol and biodiesel (FAME) are the most common biofuels. Alternative fuels from fossil energy sources are mainly LPG and CNG. Synthetic gasoline and diesel from coal (CTL) and natural gas (GTL) are produced mainly in South Africa. Electricity used in battery-electric vehicles plays a minor role today. The fuel consumption for road transport in the world today amounts to about 65 700 PJ per year (IEA, 2006a) in total, the share of alternative fuels for transport at the time of writing was about 2.7% (Table 7.24). 

Worldwide, there are more than 10 million LPG vehicles, with the majority in Italy, Poland, the Netherlands and France. Of around seven million CNG vehicles, about two-thirds are found in Argentina, Pakistan and Brazil, while in Bangladesh, Armenia, Pakistan, Iran and Argentina, CNG vehicles account for more than 20% of the total vehicle fleet in Europe, Italy has most CNG vehicles (I ANGV, 2008 NGV, 2008). The South African company Sasol produces about 7.5 million t ( 320 PJ) CTL and GTL (Sasol, 2007), which is about 0.5% of today s consumption of transportation fuel in the world. Sasol produces the major fraction of CTL and GTL worldwide. Adding up, the contribution of all alternative fuels today means that about 97% of the fuel demand for road transport is met by crude-oil-based gasoline and diesel. 

The European Commission set up a stakeholder Contact Croup in 2002 to advice technical and economic developments and to promote the use of alternative fuels for road transport, including natural gas and hydrogen. The Contact Croup conducted an in-depth study of options for motor fuels for achieving a 20% substitution of diesel and gasoline by these alternative fuels. They provided their views on the potential market penetration of 5% hydrogen vehicles... 

California Air Resources Board (CARB), Methodology for Estimating Emissions from On-Road Motor Vehicles, Vol. I Introduction and Overview, L. Hrynchuk and B. Effa, Planning and Technical Support Division Mobile Source Emission Inventory Branch, 1996. (For information about documents or MVEI7G Model, contact Public Information Office or Transportation Activity Section, California Air Resources Board. We thank Mr. E. E. Yotter and Dr. John Holmes, Chief, Research Division, for providing this information (1999).)... 

There are several transportation applications where natural gas storage as CNG provides inadequate range because of limited space and allowable weight for a CNG fuel system. The railroad industry and heavy-duty over-the-road trucks are the two current primary examples of transportation vehicles that as a practical matter must use LNG instead of CNG in order to use natural gas as a fuel. 

---