- Email: [email protected]
Regenerating diesel engine filters at low temperatures
8
Technology news
Filtration+Separation November/December 2011
Regenerating diesel engine filters at low temperatures Researchers at the Fraunhofer Institute for Solar Energy Systems (ISE) in Freiburg, Germany, have come up with a method that reliably regenerates diesel engine filters even at exhaust temperatures as low as 140°C. Soot particle filters found on diesel vehicles are designed to ensure that no harmful particles make their way through the exhaust pipe. However, exhaust gases from more modern engines are not hot enough to free the filters from soot particles on a regular basis. The new method removes impurities even at low exhaust temperatures. Current diesel engine filters are in place to capture the largest soot particles. After time, if too much soot accumulates in the filter, the soot is burned off and the filter is regenerated. The problem is that soot particles only burn above temperatures of 500-600°C. However, the temperature of truck exhaust continues to drop as manufacturers try to minimise emissions of nitric oxides harmful to the environment. There are two approaches to removing soot from the filter. The first involves an oxidation catalytic converter that converts nitrogen monoxide in the exhaust into nitrogen dioxide. If nitrogen dioxide is passed through the filter, the soot burns at lower temperatures. In some engine operating states - such as when the engine is still cold - this regeneration method does not suffice. In these cases, liquid fuel is added that combusts with residual oxygen in the exhaust to heat the exhaust and filter. However, this cleansing method only works at exhaust temperatures in excess of 230°C. At lower temperatures, the fuel-exhaust mixture fails to ignite, damaging the catalytic converter. A further problem is that exhaust streams from more modern truck engines are only 160-180°C.
Researchers at the Fraunhofer Institute have developed a method of regenerating diesel engine filters at lower exhaust temperatures.
Researchers at the Fraunhofer Institute for Solar Energy Systems have found a solution for exhaust temperatures as low as 140°C. “We add a synthesis gas consisting of carbon monoxide and hydrogen to the exhaust,” explains Dr. Thomas Aicher, group manager at ISE. “We introduce this gas mixture at the oxidation catalytic converter – lowering the ignition temperature to 140°C and freeing the filter from soot even at these low exhaust temperatures.” “We have two ways to generate this synthesis gas,” explains Robert Szolak, a scientist at ISE. “One is to heat diesel fuel in the absence of air. This produces hydrogen and carbon. Then, the carbon is burned with the exhaust, creating carbon monoxide, which is known as pyrolysis. The other way is to oxidise diesel with a very small amount of air so that the diesel combusts only partially. This is known as partial oxidation.” Researchers have already built and successfully tested prototypes for both approaches. Fraunhofer is now working with an industrial partner to investigate partial oxidation in greater detail. www.fraunhofer.de
Russell Finex develops self-cleaning filter Russell Finex has developed the Russell Hygiene crevice-free, self-cleaning filter for food and pharmaceutical applications.
Russell Finex’s filter dismantles completely and requires no tools for cleaning or maintenance. The filter is also fully enclosed.
The company says that this filter has been designed in accordance with the hygienic machinery standard BS EN ISO 14159:2008 and food contact regulation EU1935/2004. Every component has been designed to eliminate all crevices and bug traps to allow for sanitary standard cleaning. In addition, all product contact parts are polished to less than 0.6Ra as standard (0.1Ra is available if required).
Like the Russell Eco Filter, the Russell Hygiene Filter is self-cleaning, enabling the continuous removal of oversize contamination as fine as 10 microns, achieved by continuously cleaning the apertures of the filter element. Unlike traditional bag or cartridge filters it uses a reusable, reduced crevice filter element. www.russellfinex.com
Rake bar screen captures wastewater debris JWC Environmental has introduced the new Bar Screen MonsterT, the first self-contained reciprocating rake bar screen designed to capture and transport large amounts of wastewater debris to the discharge point. Bar Screen Monster utilises industry exclusive features such as a fully submersible, explosion proof brake motor that drives the rake along the tracking system.
As the carriage moves up, the rake removes debris from the bar rack. The unit consists of a fully replaceable, non-lube pin rack and tracking system for easy maintenance without removing the screen from the channel. The pin rack and tracking system can be removed in sections removing the carriage from the screen is not necessary. www.jwce.com
Merck Millipore develops singleuse stirred tank bioreactor Merck Millipore, the life science division of Merck KGaA, has added a 200 litre single-use stirred tank bioreactor to its Mobius CellReady Bioreactor range. The single-use bioreactor is designed for pilot and clinicalscale mammalian cell culture and helps implement complete singleuse bioprocess templates. The Mobius CellReady 200 L bioreactor features Mobius® SensorReady technology which can configure process monitoring at the point of use, reducing the need to customise bioreactor process containers and enabling easy integration of new sensor technologies. It has a rigid base and top panel design, improving
installation. The system is available as a complete, turnkey system or as a modular system to integrate with different platforms. “The biopharmaceutical industry is increasingly incorporating single-use technologies to address cost pressures and accelerate the biomanufacturing process,” said Paul Chapman, vice-president of Biopharm Process Solutions. “Through incorporation of a full-train modular system that includes upstream technologies, such as the Mobius CellReady bioreactor, maximum benefit can be realised as times are reduced, risk is minimised, and market agility increases.” www.millipore.com/mobius
Technology news
Filtration+Separation November/December 2011
Regenerating diesel engine filters at low temperatures Researchers at the Fraunhofer Institute for Solar Energy Systems (ISE) in Freiburg, Germany, have come up with a method that reliably regenerates diesel engine filters even at exhaust temperatures as low as 140°C. Soot particle filters found on diesel vehicles are designed to ensure that no harmful particles make their way through the exhaust pipe. However, exhaust gases from more modern engines are not hot enough to free the filters from soot particles on a regular basis. The new method removes impurities even at low exhaust temperatures. Current diesel engine filters are in place to capture the largest soot particles. After time, if too much soot accumulates in the filter, the soot is burned off and the filter is regenerated. The problem is that soot particles only burn above temperatures of 500-600°C. However, the temperature of truck exhaust continues to drop as manufacturers try to minimise emissions of nitric oxides harmful to the environment. There are two approaches to removing soot from the filter. The first involves an oxidation catalytic converter that converts nitrogen monoxide in the exhaust into nitrogen dioxide. If nitrogen dioxide is passed through the filter, the soot burns at lower temperatures. In some engine operating states - such as when the engine is still cold - this regeneration method does not suffice. In these cases, liquid fuel is added that combusts with residual oxygen in the exhaust to heat the exhaust and filter. However, this cleansing method only works at exhaust temperatures in excess of 230°C. At lower temperatures, the fuel-exhaust mixture fails to ignite, damaging the catalytic converter. A further problem is that exhaust streams from more modern truck engines are only 160-180°C.
Researchers at the Fraunhofer Institute have developed a method of regenerating diesel engine filters at lower exhaust temperatures.
Researchers at the Fraunhofer Institute for Solar Energy Systems have found a solution for exhaust temperatures as low as 140°C. “We add a synthesis gas consisting of carbon monoxide and hydrogen to the exhaust,” explains Dr. Thomas Aicher, group manager at ISE. “We introduce this gas mixture at the oxidation catalytic converter – lowering the ignition temperature to 140°C and freeing the filter from soot even at these low exhaust temperatures.” “We have two ways to generate this synthesis gas,” explains Robert Szolak, a scientist at ISE. “One is to heat diesel fuel in the absence of air. This produces hydrogen and carbon. Then, the carbon is burned with the exhaust, creating carbon monoxide, which is known as pyrolysis. The other way is to oxidise diesel with a very small amount of air so that the diesel combusts only partially. This is known as partial oxidation.” Researchers have already built and successfully tested prototypes for both approaches. Fraunhofer is now working with an industrial partner to investigate partial oxidation in greater detail. www.fraunhofer.de
Russell Finex develops self-cleaning filter Russell Finex has developed the Russell Hygiene crevice-free, self-cleaning filter for food and pharmaceutical applications.
Russell Finex’s filter dismantles completely and requires no tools for cleaning or maintenance. The filter is also fully enclosed.
The company says that this filter has been designed in accordance with the hygienic machinery standard BS EN ISO 14159:2008 and food contact regulation EU1935/2004. Every component has been designed to eliminate all crevices and bug traps to allow for sanitary standard cleaning. In addition, all product contact parts are polished to less than 0.6Ra as standard (0.1Ra is available if required).
Like the Russell Eco Filter, the Russell Hygiene Filter is self-cleaning, enabling the continuous removal of oversize contamination as fine as 10 microns, achieved by continuously cleaning the apertures of the filter element. Unlike traditional bag or cartridge filters it uses a reusable, reduced crevice filter element. www.russellfinex.com
Rake bar screen captures wastewater debris JWC Environmental has introduced the new Bar Screen MonsterT, the first self-contained reciprocating rake bar screen designed to capture and transport large amounts of wastewater debris to the discharge point. Bar Screen Monster utilises industry exclusive features such as a fully submersible, explosion proof brake motor that drives the rake along the tracking system.
As the carriage moves up, the rake removes debris from the bar rack. The unit consists of a fully replaceable, non-lube pin rack and tracking system for easy maintenance without removing the screen from the channel. The pin rack and tracking system can be removed in sections removing the carriage from the screen is not necessary. www.jwce.com
Merck Millipore develops singleuse stirred tank bioreactor Merck Millipore, the life science division of Merck KGaA, has added a 200 litre single-use stirred tank bioreactor to its Mobius CellReady Bioreactor range. The single-use bioreactor is designed for pilot and clinicalscale mammalian cell culture and helps implement complete singleuse bioprocess templates. The Mobius CellReady 200 L bioreactor features Mobius® SensorReady technology which can configure process monitoring at the point of use, reducing the need to customise bioreactor process containers and enabling easy integration of new sensor technologies. It has a rigid base and top panel design, improving
installation. The system is available as a complete, turnkey system or as a modular system to integrate with different platforms. “The biopharmaceutical industry is increasingly incorporating single-use technologies to address cost pressures and accelerate the biomanufacturing process,” said Paul Chapman, vice-president of Biopharm Process Solutions. “Through incorporation of a full-train modular system that includes upstream technologies, such as the Mobius CellReady bioreactor, maximum benefit can be realised as times are reduced, risk is minimised, and market agility increases.” www.millipore.com/mobius