Catalysts & Modules
This page features descriptions and literature for:
• Three-Way NSCR Catalysts
• SCR (SINox®) Catalysts
• VOC Oxidation Catalysts
• Engine Oxidation Catalysts
• Gas Turbine CO Oxidation Catalysts
• Ammonia Slip Catalysts
Three-Way NSCR Catalysts
Johnson Matthey's NSCR or three-way catalyst is used in rich-burn or stoichiometric engines for simultaneous conversion of NOX CO, HC, formaldehyde and HAPs. NSCR catalysts are effective in a wide variety of engine applications and fuels, including natural gas, propane and gasoline. A closed loop air-fuel ratio controller is required for the three-way catalyst to work effectively.
Three-way catalysts are designed to simultaneously convert three pollutants to harmless emissions:
Carbon Monoxide (CO) → Carbon Dioxide (CO2)
Hydrocarbons (HC) → Water (H20)
Oxides of Nitrogen (NOX) → Nitrogen (N2)
Concentrations of pollutants in the exhaust gas depend on the fuel mixture composition. At lean fuel mixtures the exhaust gases contain little CO or HC, but high concentrations of NOX. Rich mixtures produce high concentrations of CO and HC with little NOX.
In practice, three-way catalysts are used with air to fuel ratio controllers that maintain the mixture composition at stoichiometric. These controllers use a feedback signal from the oxygen sensor positioned in front of the catalyst in the exhaust system. The range of A/F ratio required for satisfactory catalyst operation is known as the "catalyst window". Precise A/F ratio control is especially important for efficient NOX control, as the NOX conversion drops dramatically at lean fuel mixtures.
There are many reaction pathways in a three-way catalyst system, including those shown for the oxidation catalyst. The most important reactions for removing NOX can be summarized as:
2CO + 2NO → 2CO2 + N2
[HC] + NO → N2 + CO2 + H2O
Johnson Matthey's three-way catalysts offer the ultimate in flexibility. Whether new, retrofit or replacement of any existing type or size element, we have a catalyst to meet your needs. With a wide range of sizes and shapes in stock, you always get the best possible catalytic solution for your application.
Download information below for the NSCR Three-Way Catalyst in PDF format:
SINox® SCR Catalysts
SINOx® is Johnson Matthey's SCR catalyst product. The SINOx SCR Catalyst System is based on the process of Selective Catalyst Reduction(SCR), the most effective and proven process for NOX reduction. In the SCR process, nitrogen oxides are transformed into harmless nitrogen and water by reaction with a reducing agent such as ammonia (NH3) or urea (CO(NH2)2) in the presence of the SCR catalyst.
Since 1987, Johnson Matthey has manufactured SCR catalysts for NOX abatement in a variety of industries worldwide. SINOx SCR catalysts are designed for specific operational requirements such as reduced back pressure and high dust conditions. As a result, SINOx SCR catalysts are available in a wide range of pitches and formats, including:
• Extruded ceramic honeycomb
• Coated ceramic honeycomb
• Coated metallic monolith
• Plate type
Our homogeneous extruded honeycomb catalysts consist entirely of catalytically active materials like titanium dioxide, vanadium oxides and tungsten oxides. Plate catalysts consist of catalytically active material composed of titanium dioxide, vanadium oxides and tungsten oxides or molybdenum oxides rolled onto stainless steel mesh. The catalyst plates are integrated into element frames that are installed in a steel module.
SINOx SCR catalysts have been successfully applied to reduce NOX from coal/oil/gas fired boilers, incinerators, stationary diesel engines, marine diesel engines, biomass/waste boilers and stationary natural gas engines. This wealth of experience makes Johnson Matthey uniquely qualified to assist customers in solving their NOX emission problems and to managing their fleet of installed SCR systems.
Utilizing our core competence in catalysis, Johnson Matthey continues to improve SINOx SCR catalysts and to develop new products to meet the needs of our customers now and in the future. A current R&D focus is an SCR catalyst or SCR companion catalyst to achieve very high mercury oxidation in coal-fired power plants. Flue gas desulphurization processes can then remove the oxidized mercury.
Johnson Matthey has an abundance of literature available for SINOx SCR catalyst products, categorized below by application:
VOC Oxidation Catalysts
Johnson Matthey has provided catalysts to reduce VOC emissions from industrial manufacturing processes since the 1960's.
VOCs, NVOCs, halogenated VOCs, as well as CO, NOX and other malodorous substances can be vented or discharged from a wide range of processes and the type and concentration can vary significantly depending on the process conditions and application. Most VOCs are emitted from solvent-based processes, but also can come from unreacted feedstock or decomposition products. Many process streams also contain inorganic material such as dust and carbonaceous PM that can influence the applicability of abatement technology.
Typical examples of VOC emissions include ethanol and acetaldehyde from bakeries, caffeine and other VOCs from coffee roasting from formaldehyde, phenols and phthalates from resin manufacturing. Petrochemical plants emit a variety of aromatic and aliphatic Chemical plants that make Purified Terephthalic Acid (PTA) resins emit methyl bromide and benzene. Printing plants emit alcohol and acetate-based compounds.
Other VOC sources include chlorinated HCs used in the manufacture of pharmaceuticals or as solvents in wooden furniture manufacture and ethylene oxide from hospital sterilization ovens.
PTA (Purified Terephthalic Acid)
Johnson Matthey is a world leading supplier of oxidation catalysts used to reduce VOC emissions from PTA (purified terephthalic acid) plants. PTA plants emit CO and a variety of VOCs - methyl bromide, methyl acetate, xylene, acetic acid and methanol. Together they cause smog; methyl bromide also is a stratospheric ozone depleter. Until recently, oxidation catalysts using precious metals were the only way to control these emissions.
Our R&D programs continue to reduce the cost of PTA catalyst giving our customers more favorable economics.–Our recent introduction of SC29 PTA catalyst, which contains no precious metals, but maintains the same performance has been a breakthrough for the industry.
One of the first applications for Johnson Matthey's SC29 PTA catalyst produced some incredible benefits:
• Reduced the operating temperature from 375° to 280°C, which cut operating costs.
• Replaced the existing precious metals catalyst, making the catalyst replacement cost very effective, especially since the price of precious metals has escalated.
• Lowered the cost of ownership since the original catalyst containing platinum and palladium was reclaimed for $322,000, and the same volume of SC29 PTA with its sale price plus site costs for removal of the old catalyst and installation cost only about $300,000.
Download information below for the VOC Oxidation Catalyst in PDF format:
Engine Oxidation Catalysts
Johnson Matthey's oxidation catalysts can be designed to reduce over 90% CO, 60% VOC and 25% PM from stationary engine exhaust.
Our core expertise in catalysis has allowed Johnson Matthey to stay at the cutting edge of new catalyst development meeting the challenges of ever increasing regulatory requirements.
Our oxidation catalysts are formulated with Platinum Group Metals (PGM's) to achieve maximum conversion of CO, HAPs, VOC and HC from stationary gas or diesel engines. Our high activity catalyst plus flow through metal monolith design delivers the smallest catalyst package and the lowest backpressure in the industry. They are available in a variety of shapes and sizes and can be washed a number of times.
Download information below for Diesel Oxidation Catalysts in PDF format:
Gas Turbine CO Oxidation Catalysts
Johnson Matthey pioneered Oxidation Catalyst for gas turbines in the 1970's.
Since then, Oxidation Catalysts have been installed in some of the most environmentally challenging applications, consistently providing greater than 90% destruction of CO, VOCs, formaldehyde and other toxic compounds. Our Oxidation Catalysts are formulated with Platinum Group Metals (PGM's) to achieve maximum conversion of pollutants at various gas turbine temperatures, whether it is a simple cycle or combined cycle gas turbine.
Our high activity catalyst plus flow through metal monolith design delivers the smallest catalyst package and the lowest back pressure in the industry. Side reactions such as NO to NO2 are minimized.
Johnson Matthey gas turbine Oxidation Catalysts have an established durability of 10 or more years of continuous operation. Catalytic performance can be easily maintained or restored through washing if necessary. And at the end of the effective life of the catalyst, Johnson Matthey closes the loop at its West Deptford, NJ facility where spent catalyst can be recycled and precious metal value is credited to you. Johnson Matthey also provides field support during catalyst inspections, bed rotations, and partial bed replacements.
Ammonia Slip Catalysts
Johnson Matthey's ammonia slip catalysts are designed to prevent ammonia breakthrough, while providing at the same time high NOx reduction efficiency in our urea-based SCR systems.
The ideal ratio of ammonia (NH3) to NOx is 1:1 based on having ammonia available for reaction of all of the exhaust NOx without ammonia slip. However, SCR efficiency can be less than ideal at low temperatures (potential low SCR activity), and at higher temperatures with high exhaust flow rates (high space velocities).
Optimizing the ammonia to NOx ratio is shown to lead to potential improvements in overall NOx conversion efficiency with little additional ammonia slip. Ammonia slip past an SCR catalyst can be oxidized to NOx or it can be selectively oxidized to nitrogen. Johnson Matthey's ammonia slip catalyst is highly selective to N2 and can convert the NH3 to >90% N2 depending on the operating conditions.
Johnson Matthey's ammonia slip catalysts have achieved < 5 ppm ammonia slip on diesel engines operating with very rapid changes in engine load.