Soot Filter, SCR System Latest Products From DCL

Diesel Progress North American Edition, Sept, 2001 by Mike Mercer

With ever-tightening exhaust emission regulations and workplace air quality standards from EPA, CARB, OSHA, MSHA and other agencies, the market for emissions control devices, including catalytic converters and particulate traps, has grown substantially over the last 10 years. One of the companies most active in that arena has been DCL International Inc., Concord, Ontario, Canada.

DCL has been in the emissions control business for roughly 15 years, starting out by producing oxidation catalysts (purifiers) for diesel engine-powered mining equipment. The company has since expanded its product line and now markets to all types of off-road equipment as well as stationary applications.

"DCL'S core strength is the ability to make small batches or one-off designs of products in order to meet the requirements of the wide variety of equipment applications in the off-road market," said Joseph Aleixo, technical support manager for DCL.

The company's primary markets include construction, material handling, mining, electrical power generation, gas compression and airport ground support equipment. DCL's products cover engines ranging from 5 to 10,000 hp, depending on fuel type. The product line includes:

* Oxidation catalysts for lean-burn gaseous-fueled engines.

* Diesel oxidation catalysts for diesel engines.

* Three-way catalysts.

* Particulate traps.

* SCR systems.

* Catalytic mufflers and standard mufflers.

One of DCL's latest products is the new Titan Sootfilter System. This is a particulate trap regeneration system designed to eliminate soot at efficiencies of 99 percent for diesel particulate numbers (PZAG) and 87.2 percent for diesel particulate mass (PMAG), according to the company.

The system is designed to provide eight hours of continuous operation on low temperature diesel exhaust applications. It includes a pressure gauge that monitors pressure drop over the filter during the vehicle's normal operating cycle. Indicator lights inform the operator if the limiting backpressure has been reached.

The system combines a silicon carbide (SiC) filter with a fully automated off-board regeneration station. The SiC filter is contained in a stainless steel housing for durability. The filter's modular design speeds removal and installation before and after regeneration, the company said. The SiC filter is available in a catalytically coated version offering the added benefit of carbon monoxide and hydrocarbon reduction.

The system uses a base regenerator that contains a heating element to raise the filter's internal temperature to 1200[degrees] burning the soot trapped inside the filter. Total regeneration time is less than two hours, according to the company.

The BlueSky Sootfilter System is a MSHA certified particulate trap regeneration system for use on mobile equipment with low temperature exhaust.

DCL has also developed a selective catalytic reduction (SCR) system for stationary applications such as electric power generation, cogeneration, pumping or compression operations. This system includes a compact catalyst reactor housing, containing SCR catalyst bricks and an optional catalyst layer for CO and hydrocarbon abatement. A urea or ammonia metering and injection system is designed to evenly distribute the reducing agent into the exhaust stream while minimizing ammonia slip.

With this system, a parameter related to [NO.sup.x] emissions, such as engine load, is measured and used to control the flow of the reducing agent. The control system ensures all regulatory requirements for [NO.sup.x] reduction and NH3-slip are met, DCL said. For large systems, a continuous emissions monitoring system (CEMS) is available for monitoring and reporting.

"This is an excellent time for the emission control industry" said Aleixo. "New regulations in the U.S. and throughout the world are placing stricter emission standards on equipment that run on all fuel types. Regulations, such as the EPA Retrofit Verification Program, will encourage the retrofit of existing diesel- powered equipment with emission control devices."