Catalytic Gauzes and Systems
For almost 100 years Heraeus has been manufacturing gauzes made from platinum group metal alloys. The main use of these gauzes has been to oxidise ammonia in the nitric acid process. The gauzes are made up of fine wires which are woven or knitted together to form a metal fabric. For oxidation of ammonia, alloys containing large proportions of platinum have proven to be most useful to withstand the conditions and high temperatures (830°C +) found in nitric acid plants.
Heraeus developed catalytic systems based on varying the physical parameters and metal alloys in the various gauze layers to achieve higher performance and economy. These solutions are referred to as catalytic systems.
FTC, Functional Total Control, is a concept for the catalytic oxidation of ammonia. Using computer models, a fully integrated catalytic package is designed to reduce total production costs: The cost savings are primarily achieved by reducing precious metal losses and reducing the precious metal weight of installed catalysts. FTC does away with the requirement of catchment systems to be installed in the reactor.
To accomplish this, FTC systems utilise specially developed, complex alloys which enable the total weight of precious metals required to be substantially reduced. When compared to conventional catalyst systems, cost reductions of up to 35 %per tonne of nitric acid have been achieved in numerous industrial applications. This result has been achieved without sacrificing ammonia conversion efficiency or campaign length. On the contrary, ammonia conversion efficiencies are bench marked over even extended campaigns.
The catalyst system, FTCplus, reduces the nitrous oxide emissions at source. After installation of the system, the emissions of nitrous oxide have been reduced by more than 30 % over extended campaign lengths in many industrial applications.
FTC and FTCplus consist of a number of metallic gauze layers and can be installed in virtually any reactor. No changes to the reactor itself and no additional catalyst is required in order to operate FTCplus.