Stationary Engine Emission Catalyst

Prototech Company manufactures catalyst parts that are sometimes referred to as "Catalyst Inserts." These inserts typically need to be canned in a stainless steel type can, equipped with the proper insulation and vibration control means. The finished can is referred to as a "Catalytic Converter." The converter is installed, together with other control devices on the exhaust port of small and medium size stationary engines. These engines are used mostly as onsite power generators.

The key to simultaneous destruction of NOx, CO and HC (Hydrocarbon) emissions coming out of Rich Burn engines is the inclusion of a means to control the Air/Fuel ratio in the combustion chamber. The optimal Air/Fuel ratio range is between 15.95:1 to 16.05: 1. Under these conditions the oxygen (O₂) content of the exhaust stream is about .5 percent or less, the CO level is in the few thousands of ppm (parts per million) and the NOx level is about 1000 to 3000 ppm. There are also small amounts of unburned HC. By maintaining the Air/Fuel ratio constant within the above range, the CO component is used to reduce the NOx component with a high 90% plus efficiency. The O₂ is used to destroy the remaining amounts of CO and HC with about 90% and 70% destruction levels respectively. The destruction products are: Nitrogen (N₂) water (H₂O), and carbon dioxide (CO₂).

These destruction levels will meet most States and EPA emission control requirements.

If, however, stricter controls of CO and HC are required, then the emission control system should include an additional catalyst element: PRO*VOC1a, CO and HC destruction catalyst. This catalyst should be installed downstream of the PRO*VOC 7 element with air injection installed between the two catalysts to increase the O₂, concentration in the PRO*VOC1a oxidation catalyst zone. The optimal catalyst inlet temperature range is 750ºF to 1000ºF and the optimal space velocity range is: 50,000 to 100,000 SCFH/CF.

Prototech Company has developed catalyst coating formulations, "Washcoat" formulations and precious metals application technologies. This has resulted in a very small, stable and uniform catalyst particle size, supported on the washcoat carrier. Thus, we are able to provide to the Engine Emission Control industry a state of the art product in terms of activity and durability. The table to the right summarizes some of Prototech's current NSCR and OXIDATION products available as catalytic elements for the stationary engine emission control industry.

Sud-Chemie Prototech Inc., a subsidiary of Sud-Chemie Inc., A Sud Chemie Group Company, 32 Fremont Street, Needham, MA 02494. Tel: 781-444-5188; Fax: 781-444-0130.