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Catalytic Strippers & Filters

Catalytic Strippers & Filters

Catalytic strippers, catalytic vapor filters and related products from Catalytic Instruments can make a world of difference when trying to make accurate and repeatable particle measurements. Catalytic Instruments GmbH develops, manufactures and markets products to condition the exhaust and to allow accurate measurement of particle concentration. Their catalytic strippers and related technologies are designed to remove the volatile compounds and to avoid re-nucleation effects by means of an oxidizing catalyst.
The core technology was developed at the university of Minneapolis with a focus on environemental aerosols, today a growing interest is the investigation of combustion generated particles. The technology has a broad range of applications, which have only been investigated in a narrow research and application area. Customized OEM solutions, integrated into particle measurement equipment or as stand alone solutions, they provide tailored units to meet specific customer requirements and research needs.

Ambient Air Monitoring

Catalytic strippers can be used to determine the solid and semi-volatile particle concentrations in ambient air, in urban and rural environments. This can help in source apportionment – determining the source of emissions. Catalytic strippers can also be used at high altitude to determine the volatility characteristics of aircraft plumes. Measurement of solid and semi-volatile particle concentrations on-road and nearby roads can give an indication of particle aging due to growth by the uptake of semi-volatile material.

Engine Generated Solid Particle Measurement

Catalytic strippers can be used to determine the solid and semi-volatile particle concentrations in engine exhaust in the laboratory or during on-board vehicle measurements. Engines burning gasoline, diesel fuel, and natural gas all produce solid and semi-volatile particles. For oxygen rich combustion such as diesel, engine exhaust can be directly sampled by the catalytic stripper and measured by a suitable instrument.

However, for oxygen lean combustion such as gasoline, engine exhaust must be diluted prior to measurement so that the oxidation reaction can occur. The residence time in the catalytic stripper is low, so this device can be used in transient engine exhaust measurements. Another application is measuring emissions from gas turbines in laboratory and ambient environments.

Combustion Generated Solid Particle Measurements

Catalytic strippers can be used to determine the solid and semi-volatile particle concentrations in combustion aerosol sources. Some examples are biomass burning in the ambient environment or in laboratory evaluations of cooking stoves. Solid and semi-volatile particles are created by open flames such as candles. Most commercial soot generators do not produce completely “dry” soot so our catalytic strippers can be used to remove the majority of the organic carbon concentration.

Butanol Removal

Measurement of ultrafine particles with a condensation particle counters (CPC) or scanning mobility particle size analysers (SMPS) commonly requires the use of butanol as working liquid.  Butanol based CPC’s are widely used througout Australasia and the world as they are generally very reliable and are not as maintenance intensive as other types of CPC’s. Water also does not condensate on oil or other oleophilic materials, making it impossible to use certain types of CPC`s for many measurement applications.

Indoor Measurements

In laboratories and indoor environments butanol vapor from butanol based CPC’s and other equipment is generally released into the atmosphere as an environmental pollutant or it is released into the laboratory, where it is a potential health hazard. Some organizations do vent this exhaust outside however others dont or cant. Using a portable catalytic vapor filter in conjuction with a butanol based CPC, SMPS system or other equipment can remove 99.99% of the butanol vapor emitting clean CO2 and H20 gas only.

Having your own portable catalytic vapor filter in your laboratory provides tremendous flexibility. Our catalytic vapor filters can be used with any butanol based CPC, SMPS system and or related equipment on the market. You wont be locked in to using one piece of equipment from any manufacturer. These devices may be used indoors or outdoors allowing customers to utilize existing or new butanol based devices for quality particle measurements. Many of the world’s leading metrology institutes, universities and aerosol research groups already use these devices and Catalytic Instruments technology is used inside or alongside many particle instruments provided by global particle equipment manufacturers.

Outdoor Measurements

Environmental agencies measure ultrafine particles especially in areas with heavy traffic. Ethene is commonly used as tracer for traffic and is monitored by the ambient air stations. The instrument used to measure the concentration of Ethene in the range of ppm is highly cross-sensitive to butanol. Hence no butanol vapor can be present when measuring Ethane. In order to remove 99.99% of the butanol vapour emitted by CPCs, a catalytic vapor filter is the method of choice. The catalytic vapor filter oxidizes the butanol vapor to CO₂ and H₂O and effectively removes the butanol, making accurate measurements of Ethene possible.