Close-coupled emissions technology responds …...all times. Therefore, the emission control system should always be positioned close to the engine. Depending on the type of vehicle

Press Release 65th IAA Cars September 2013 _____________________________________________________________________________________________________________________

Press enquiries: Emitec Gesellschaft für Emissionstechnologie mbH Hauptstraße 128 53797 Lohmar www.emitec.com

Email: [email protected] Tel.: 0049 (0)2246 109-311 Fax: 0049 (0)2246 109-109

Close-Coupled Emission Control for Diesel Engines Close-coupled emissions technology responds faster and more effectively Diesel engines present a particular challenge in terms of emission control. Compared to petrol

engines they operate at relatively low temperatures yet still have to make sure that the exhaust

gas temperature is kept above the minimum light-off point of the exhaust system components at

all times. Therefore, the emission control system should always be positioned close to the

engine.

Depending on the type of vehicle and country-specific emission limits, diesel engines have to be

fitted with oxidation catalytic converters, diesel particulate filters, NOx storage catalytic

converters and/or selective catalytic reduction systems (SCR). EMITEC Gesellschaft für

Emissionstechnologie mbH from Lohmar near Cologne already has the right solutions or will

work together with its customer to develop new solutions for all these applications. The

company’s great systems expertise has turned Emitec’s engineers into sought-after

development partners for the automotive industry.

Diesel oxidation catalytic converters (DOC) consists of METALIT® metal substrates with effective

cell densities up to 1,200 cpsi (cells per square inch) and turbulence-generating profiles. Special

structures, such as LS (longitudinal structure), PE (perforated structure) or TS (transversal

structure), break up the laminar flow of the exhaust gas and create turbulence inside the

catalytic converter. This turbulence improves mass transfer between the harmful exhaust gas

molecules and the precious metal coating, during which the molecules are converted to

harmless substances. In addition to turbulent flow conditions, the PE structure also allows for the

first time gas and mass transfer between adjacent channels. In practice, this makes it possible to

build smaller and more efficient catalytic converters with less pressure loss (= better engine

performance) and lower CO2 emissions.

The DOC dramatically reduces harmful hydrocarbon (HC) and carbon monoxide (CO) emissions

and also generates sufficient exothermic heat to assist the downstream particulate filter in

burning off any soot deposits (during regular regeneration intervals). An extremely close-coupled




position and integrated heat insulation ensure that the DOC always lights off very quickly. There

is no risk of temperatures dropping below the light-off point at any time or under any engine

operating conditions.

Complex, electronically controlled exhaust gas recirculation (EGR) is a key component that

reduces raw emissions by around 50%. In order to ensure that the system functions properly at

all times, Emitec can supply a purifying catalytic converter for installation in the EGR system.

The METALIT® catalytic converter for high-pressure exhaust gas recirculation prevents deposits

from forming in the cooler and in the remaining EGR system. Hydrocarbons (HC) in the exhaust

gas are oxidised to stop them from condensing on the walls and add to the formation of more

particulate deposits. For low-pressure EGR systems Emitec’s engineers have developed an

EGR filter, which separates particles over 200 µm to protect the turbocharger and the entire

engine. The filter is very small and produces little gas back pressure.

Nitrogen oxides are temporarily stored on the catalytic coating of a metal substrate NOx

adsorber before they are reduced to nitrogen with the aid of additional fuel during a short

regeneration phase. This process occurs unnoticed and ensures that the storage catalytic

converter removes over 70% of the NOx from the exhaust gas under normal driving conditions.

Metal substrate NOx adsorbers can also be installed close to the engine.

Electrically heated catalytic converters (EHC) solve a number of emission control problems,

including those associated with SCR systems. The Emicat® raises the exhaust gas temperatures

of modern low-temperature diesel cars by up to 100° C (or by a critical 20 to 30° C in commercial

vehicles). The Emicat® can also prevent the catalytic converter from cooling during intermittent

diesel engine operation in hybrid vehicles or cars with a range extender, or ensure maximum

conversions rates immediately after the engine restarts. The injection of AdBlue urea solution

onto a hot EHC further improves the evaporation of the urea-water solution.

All of the above-mentioned components and systems can be positioned close to the engine for

maximum effect. A large number of car manufacturers have already made the most of this

advantage and more are likely to follow. Emitec’s representatives will be pleased to list specific

applications at stand B32 in hall 5.1 at the IAA 2013 in Frankfurt.




Close-coupled SCR catalytic converter system

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Close-coupled emissions technology responds …...all times. Therefore, the emission control system should always be positioned close to the engine. Depending on the type of vehicle