CASE STUDIES

DCL metallic catalyst elements for greenhouses: more efficiency, less energy, higher quality

In the cold season cogeneration systems provide Dutch greenhouses with consistently warm temperatures and enrich the greenhouse atmosphere with carbon dioxide to stimulate plant growth. AG Smit Services, a company who specializes in the maintenance of engines, relies on DCL’s metal catalyst elements to ensure the required emission targets are maintained for cogeneration systems.

The energy obtained from combined heat and power systems is used in greenhouses in many ways: power generated in the system can be used for artificial lighting; heat generated by the engine exhaust is used to keep the temperatures consistently warm; and carbon dioxide from the exhaust gas acts as fertilizer for the plants. Dutch service company AG Smit Service specializes in the maintenance of gas and diesel engines used in cogeneration systems. Founded in 1988, the AG Smit team, from Uithoorn, is particularly proficient with Jenbacher and Rolls Royce gas engines.

There are approximately 1,600 cogeneration greenhouses systems in the Netherlands. AG Smit Services maintains engines equipped with DCL catalysts with metal elements, most of which have a capacity over 3 MW. "The engines in the greenhouses are operated predominantly during the cold season," says Dennis Van Leeuwen, who is responsible for maintenance, customer service, catalyst service and sales at AG Smit Services. The oxidation catalyst filters out toxins, such as ethylene "…the resulting carbon dioxide fosters the growth of plants and can be adjusted to suit the growth cycle of the plant," says D. Van Leeuwen. The increased level of carbon dioxide significantly increases the crop yield.

Metal catalyst elements are more stable

"Ceramic type elements are typically used for greenhouse systems, as they are cheaper," D. Van Leeuwen points out. "However, metal elements are much more stable and efficient." Ceramic elements can break as a result of engine related problems, but DCL’s metal elements resist these events without problems." DCL International Inc. is a global and market leading developer and manufacturer of emission control systems for industrial engines with headquarters in Canada, and offices in the US and Europe. The innovative technology and customized products - approved by leading environmental agencies and certification bodies - help to meet local and global air pollution standards and to reduce environmental pollution.

"We have known DCL for a long time and appreciate the high quality of their products" D. Van Leeuwen comments. "It is a long-standing and successful partnership, which extends back more than four years." DCL’s Metalcor® catalysts are specifically designed for stationary engines in greenhouse applications. They efficiently reduce carbon monoxide, ethylene and formaldehyde, while producing carbon dioxide for plant growth.

DCL’s thin-walled metal catalyst substrates are extremely compact with a depth that is almost 40% less than ceramic elements. Metalcor® elements also have a larger surface area and an advanced catalyst coating which provides lower back pressure and higher efficiency. "The reliability of DCL products is very high," D. Van Leeuwen knows. "The life cycle of ceramic elements reaches up to 20,000 hours, but DCL Metalcor® elements last up to 35,000 hours."

High reduction efficiency of pollutants

According to the AG Smit, customers are "…very satisfied with the DCL products because the targeted emission levels are lower with DCL’s catalysts" said D. Van Leeuwen. "Very good results are obtained, for example, for Rolls-Royce gas engines in greenhouses for growing roses. Our measurements have shown that the results are entirely satisfactory" said D. Van Leeuwen.

DCL catalysts also save energy because the elements used in gas engines of Jenbacher and Rolls-Royce function effectively with lower backpressure and exhaust temperatures of only 320° C to 340° C. "Other systems are not effective even at 350° C or need a long time to heat up with loss of CO2 dosing time" he adds. The high quality of DCL products can even impact insurance costs: "Today, insurance companies are dictating the maximum levels before shutdown and know exactly how the technology works" says the engine specialist. "Things like preventing damages is high on their agenda and because of the DCL Metalcor® don’t require sealant between the elements you reduce the chance of by-pass because of back-fire from engine in the reactor. This can lead to insurance savings."

According to D. Van Leeuwen, the main advantages of DCL products are the strong efficiency in the conversion of pollutants, the longer durability, high reliability, lower backpressure and exceptional temperature stability. The ease of element replacement is also a major advantage. "Ceramic elements must be fitted with expensive sealants," he explains. "The insulation material is supposed to make the fit air tight." DCL elements use practical mounting rails. "With these rails, the elements can be replaced as easily as Lego blocks. Thus, the time for replacing the element is shortened to a third.” Metalcor® catalyst elements are a perfect fit for both DCL housings and competitor's housings. The elements are available in hundreds of shapes and sizes and have been proven for many years in gas engines for greenhouses. "We really appreciate the quality and efficiency of the catalysts. The market position of DCL is unique, "concludes D. Van Leeuwen. "The price to quality ratio is very, very good."