Supporting the environmentJohnson Matthey Catalysts GmbH, based in Redwitz, Germany, supplies catalysts for pollutant emission controls. Its catalysts help to reduce dangerous Nitrogen Oxide (NOx) emissions, one of the major pollutants emitted from industries such as power plants, incineration plants, stationary diesel engines and heavy-duty diesel vehicles.
Two different types of catalyst are mainly produced in Redwitz – an extruded honeycomb-shape catalyst and a plate catalyst. Both operate according to the same principle of the so-called Selective Catalytic Reduction (SCR). SCR-technology chemically reduces NOx to harmless nitrogen and water by incorporating a reduction agent, such as ammonia.
Reliable testing is crucialReliable catalyst testing is crucial to Johnson Matthey's technical research laboratory when analyzing the efficiency and residual activity of newly developed and used catalysts in order to  avoid high production failures and operating costs.
Firstly, the catalytic activity in percent turnover is determined by measuring the residual ammonia after catalytic reduction during a test run. The exhaust gas is collected and converted into a liquid. After distillation, the ammonia content is measured by a simple acid/base titration using a METTLER TOLEDO DP5 Phototrode to measure the color change of the indicator. Since the ratio between NOx and ammonia is 1:1, the activity of the catalyst is inversely proportional to the ammonia concentration.
A second test measures catalyst side reaction. The sulphur dioxide is collected from the exhaust gas through a condenser, oxidized and determined as sulphuric acid with a simple endpoint titration using sodium hydroxide. The result gives the oxidation percentage which indicates side reaction efficiency.
Simple operationIn May 2009, Johnson Matthey Catalysts beta-tested METTLER TOLEDO’s new G20 Compact Titrator, which was greatly appreciated by Mr. Achim Hösch, a lab technician in their research laboratory.
The operators were briefly trained on the new titrator and then used the instrument to perform extensive sample testing and titration methods. The G20 features an intuitive and simple to use user interface with easy storage of up to five user methods allowing the user to create dedicated methods for varying sample sizes. Mr. Hösch comments that, ‘The ‘Short Cuts’ and ‘One Click®’’ start are outstanding features and most beneficial for our daily routine.’ He also liked the connected compact USB printer's small footprint.
Immediately after the new G20 Compact Titrator's successful beta-test and official market launch, Johnson Matthey Catalysts purchased three instruments to update their technical research laboratory to today’s state of the art level. Since the company is accredited according to DIN EN ISO 9001 / 14001, they will also benefit from METTLER TOLEDO's comprehensive services, such as instrument qualification and preventive maintenance.