Catalytic infrared can be used in processes to add value, improve quality and yield, and reduce operating costs in many segments of the agricultural/food processing industry.

This catalytic dryer is configured with 116 ft2, or 6,000 BTU/hr-ft2, of catalytic infrared heaters producing 90 percent of their wavelengths in the 3 to 7 micron range.

Catalytic infrared processing has proven to be compatible with a range of fruits, vegetables and herbs. Examples include the production of edible dried foods with excellent flavor, texture and color; the extraction of vitamins or minerals from herbs such as rosemary; and the production of botanicals for food, cosmetic or medicinal purposes.

Technology. Flameless catalytic infrared energy is generated by catalyzing natural gas or propane with a proprietary enhanced platinum catalyst. When combined with air across the platinum catalyst, natural gas or propane reacts by oxidation-reduction to yield a controlled bandwidth of infrared energy and small amounts of CO2 and water vapor.

Radiant Energy. With catalytic infrared, the bulk of the radiant energy bandwidth generated is in the far infrared range, with wavelengths ranging from approximately 3 to 7 micron. By directing this energy spectrum at water-containing products, evaporative energy is targeted to the water within the product. Far infrared does not heat the air; therefore, energy is transferred efficiently to the organic matter.

Safety. Flameless catalytic infrared energy is safe. Because it is flameless, catalytic systems are approved for use in environments where other systems are not, such as in dusty environments and environments where volatile compounds (alcohols, etc.) are present in the vapors generated by the heating or drying processes.

Energy Use. A typical convection conveyor dryer or column dryer requires as much as 50 hp just to move heated air. Catalytic infrared energy is transferred directly to the product without the requirement to heat large volumes of air. Therefore, horsepower requirements are reduced. In typical applications, a catalytic infrared system uses 12 to 25 hp to move the conveyor and operate small recirculation and ventilation fans.

Regarding fuel use, conventional convection dryers that use open-flame burners or heat exchangers are less efficient at utilizing all of the energy in the fuel when compared to the direct energy transferred using catalytic infrared energy systems.

Applications in Agricultural and Food Processing. Catalytic infrared processing has proven to be compatible with a range of fruits, vegetables and herbs. Some processes that can be accomplished with catalytic infrared include:

  • Preconditioning Rice and Other Grains Prior to Milling. By preheating brown rice and wheat, for example, prior to milling, significant increases in yield, throughput and quality are possible while reducing overall electrical energy usage.
  • Stabilizing Rice Bran. Preliminary testing has shown that by heating the surface of brown rice prior to milling, the resultant rice bran removed during the milling process is much less susceptible to rancidity for several weeks after milling.
  • Puffing Rice and Small Grains. Tasty rice and grain snacks can be made by the intense application of flameless catalytic infrared energy to rice and grain under appropriate conditions.
  • Dis-infesting Grains Prior to Packaging or Final Storage. Stored grain insects, larvae and eggs are rapidly killed by heat. Once insects are heated to 140oF (60oC), they quickly die. Insects contain more than 55 percent moisture, so the catalytic infrared targets this moisture to effectively heat the insects to lethal temperatures. Because the grains contain much lower moisture, rapid heating of the insects, larvae and eggs occurs without significantly drying the grains.
  • Dehydrating Small Fruits. Small fruits such as sliced apples and strawberries can be dehydrated with catalytic infrared, delivering high quality, shelf-stable, low water activity products.
  • Adding Value to Agricultural Byproducts. Byproducts such as grape pomace, cranberry skins, tomato skins and citrus peels can be quickly dried to stable moisture content without reducing the potency of valuable nutraceutical components such as polyphenols and vitamin E.
  • Dehydrating Delicate Vegetables. Catalytic infrared processes for dehydrating broccoli and cauliflower can cut process times by as much as half and deliver high color, high flavor and aroma while maintaining the integrity of the florets.

Product Testing. Some catalytic infrared suppliers offer pilot- and large-scale testing facilities for delivering flameless catalytic infrared energy in ways designed to answer your questions about quality, capacity, operating conditions and equipment specifications. PH