Urea plant safety in relation to flammable gas mixtures has been an important issue for the entire history of the urea process industry. The risk of flammability of gas mixtures is a result of the necessity to introduce passivation air in the process to avoid excessive corrosion to plant equipment. Minimizing the amount of introduced passivation air reduces the (already small) chance that the gas composition in the urea plant comes within the flammability ranges of such gas mixtures, thus making the plant safer.
The traditional construction materials in urea plants however did not allow minimized passivation air. A new construction material, suitable to operate with far lower oxygen passivation requirements, had to be found.
Sandvik and Stamicarbon developed this material together. The so developed material has been given the name Safurex, which was registered. Safurex was extensively tested on laboratory scale and in plant experience on commercial scale has been obtained for several years already. Safurex does have far lower oxygen passivation requirements and is therefore the material of construction needed to improve plant safety. Moreover this material has other advantages in the field of investment, environment and maintenance as well.