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The diesel engine represents the best alternative to meet the needs of the American motorist in terms of reducing both energy costs and greenhouse gas emissions

By 2010, annual sales of diesel vehicles are projected to be in excess of 15 million, with over 10 million of these sales being achieved in Europe. With a market share exceeding 50%, Europe has already made diesel the fuel of choice.
This success is explained by the great progress in diesel technology over recent years leading to diesel enjoying many advantages over gasoline. The situation in the US is somewhat different – whereas all trucks are powered by diesel engines, only a very small number of passenger cars use diesel motorization: because of its checkered past, diesel is haunted by its reputation for being slow and dirty. However, in the present context of economic and environmental concerns, the diesel engine represents the best alternative to meet the needs of the American motorist in terms of reducing both energy costs and greenhouse gas emissions.
A key supplier to the automotive industry, Rhodia continues to find innovative solutions to reduce vehicle weight, improve aerodynamics, lower rolling resistance and control exhaust emissions. For diesel vehicles, Rhodia proposes a wide range of materials for oxidation and De-NOx catalysts.
Durability, performance, drivability: diesel a clear winner
The durability of the diesel engine is universally recognized: its service life stretches to 250 000 – 300 000 km, some 60% longer than a gasoline engine. Technical progress has also meant that the performance and drivability of diesel vehicles are comparable to those of the corresponding gasoline vehicles: outstanding torque even at low engine speeds makes them flexible and powerful. Noise and vibration have now been largely eliminated. As a result of these advances, over the course of the past 15 years the diesel engine has reduced its noise levels by 60%, its emissions by 90%, and its fuel consumption by 30%. All this whilst increasing torque output by 100%. This progress means that the diesel engine is now a serious contender in automotive competition. In 2006, Audi’s diesel R10 beat gasoline-powered competition at the Le Mans 24-hour endurance race. This year, the French carmaker Peugeot will compete with its 908 prototype, powered by an HDi diesel engine equipped with a diesel particulate filter system (DPFS).
CO2 emissions reduced by 20%
Diesel vehicle fuel consumption is on average 30% less than the corresponding gasoline-powered vehicle. Recent trials performed by Autoweek magazine using an Ann Arbor–Lake Michigan drive cycle show that diesel even compares very favorably to electric/gasoline hybrid technology. An example of the latter achieved 42 miles per gallon, whereas a comparable diesel vehicle achieved 49 miles per gallon.
This energy saving enables a reduction of 20% in emissions of CO2 – a major contributor to global warming. Moreover, biodiesel (produced from vegetable oils) can be used in diesel vehicles without engine modification. This is an alternative offering the potential for further reduction in greenhouse gas emissions.
Pollutant emissions from diesel vehicles (in particular NOx and particulates) are strictly regulated (Euro V emissions limits in Europe and Tier 2 Bin 5 standard in the US). Proven emissions-control technologies enable these standards to be met and make new diesel vehicles cleaner in terms of CO2 emissions, and far more energy-efficient than gasoline-powered vehicles.
Nearly three times more affordable than hybrid technology
A diesel vehicle costs only slightly more than a comparable gasoline-powered vehicle (+ 7 to 10%), which compares very favorably to the additional cost of a hybrid vehicle (+17 to 25% for an electric/gasoline vehicle). As shown in a study by CNW Marketing Research, the total environmental cost of a hybrid car is very high if overall energy consumption is considered from vehicle design to end-of-life.
Performance, drivability, environmental impact, cost – for all these reasons, diesel motorization should soon see an increase in market penetration in North America in the segments of pick-up trucks, SUVs and light-duty vehicles.
Diesel Particulate Filter: elimination of 99.9% of particulate emissions
In 2000, the PSA Peugeot Citroën Group, a leader in the application of DPF technology, commercially launched diesel vehicles equipped with DPF technology using the Rhodia-developed Eolys™ additive. This technology is commonly referred to as either Additive-based Diesel Particulate Filter (A-DPF) or FBC-DPF for Fuel Borne Catalyst Diesel Particulate Filter. Eolys is added to the diesel fuel in very low concentration (only a few ppm). After passing through the combustion process, it is trapped in the particulate filter along with the soot particulates emitted by the engine. By catalyzing the combustion of these trapped particulates, Eolys solves a crucial problem, namely, how to regenerate the particulate filter at low temperature. In other words, how to clean the filter when it is completely filled with soot particulates and the temperature of the exhaust gas is too low to initiate combustion on its own. This technology has been developed to meet the requirements of vehicles used in urban and semi-urban cycles, currently the most widespread use for vehicles.
This technology eliminates more than 99.9% by number of the particulates in the exhaust gas. In emissions terms, this translates to approximately 1-3 mg/km particulates emitted over the standardized European MVEG cycle. This is about 25 times lower than the average emissions level of comparable diesel vehicles sold without filters in 2005, and more than 50 times lower than the average emissions level of comparable older vehicles. It is similar to the emissions levels of most gasoline vehicles and even lower than some.
Rhodia’s Eolys: nearly 2.5 million vehicles on the road
To date, over 4 million European vehicles are fitted with a particulate filter, of which about 60% use A-DPF technology and Rhodia’s Eolys.
After more than 6 years’ experience and with over 2.5 million vehicles on the road, the A-DPF + Eolys technology has demonstrated its efficiency, robustness and durability under all driving conditions. Furthermore, this experience has shown that under real life conditions this technology has virtually no fuel-penalty. Improvements made to the activity and thus the performance of the Eolys additive have enabled the onboard volume to be reduced. Whereas with the first generation of Eolys the additive tank required refilling every 80 000 km (50 000 miles), with the second generation (launched in 2002) the service interval was extended to 140 000 km (87 500 miles). The third Eolys generation, which is currently being launched, combined with advances made in ceramic filter technology, enables a maintenance-free system with a range exceeding 250 000 km (155 000 miles).
A key technology for retrofit applications
In parallel to the passenger and utility vehicle markets, A-DPF + Eolys technology is also used in truck and retrofit applications. These applications are particularly demanding in terms of cost, durability and performance under conditions that can be relatively difficult as regards thermal management. Eolys is currently used in retrofit applications for buses, and delivery and utility vehicles, but also in off-road applications such as construction machinery, forklift trucks, and generators.
Rhodia is actively involved in urban vehicle retrofit partnerships with numerous cities in Europe and Asia. It also develops Euro V application programs with truck manufacturers.
For these programs, a complete technology ‘package’ is offered which brings together several leading suppliers such as Inergy Automotive (INSAS system) for the additive dosing system (additive tank, pump and electronic control unit), filter suppliers, and whole-system suppliers such as Aaqius & Aaqius, who supply the Exoclean technology for the retrofit market.
Ongoing approval for the US market
In the US, registration by the EPA of fuel additives for on-road applications is subject to a specific regulatory procedure. Rhodia is currently following this procedure in order to register the third generation Eolys additive. Demonstration programs have been carried out with American partners that have confirmed the benefits of additive-based technology: performance, flexibility as regards fuel sulfur content, durability under difficult driving cycles, no impact on NO2 emissions, and cost benefits.
These benefits should also be seen in off-road applications in the US, given the specific difficulties met in applications in this area. The Eolys additive is to be included, through DPF systems such as the Exoclean technology, in the CARB Showcase program which will be launched in California in the first half of 2007.
Rhodia: chemistry at the service of sustainable mobility
As a global leader in materials for emissions control, Rhodia is a key supplier to the automotive industry and is committed to sustainable mobility. For diesel vehicles, in addition to an efficient and well-proven additive for DPF regeneration (Eolys), Rhodia also proposes a wide range of materials for oxidation and De-NOx catalysts. As regards gasoline emissions control, Rhodia’s materials are present in over a third of the vehicles worldwide equipped with a catalytic converter. No doubt the approval of Rhodia’s technology by the EPA will open up new prospects for the American market.

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