According to the UN, the eight billion earth population mark was cracked in mid-November 2022. For an ever-growing population, sufficient basic raw materials for food production must be produced. Urea plays a major role in this as a fertilizer. That is why the manufacturers of urea, now the most important nitrogen fertilizer in agriculture, particularly care about the efficient and safe use of existing and future plants.

What solutions has LESER developed for the urea industry?

Safety valves are needed to safeguard key sections in urea plants such as ammonia and CO2 supply, synthesis, recirculation, and for secondary steam and cooling water supply. In the high-pressure synthesis sections of urea, CO2 and NH3 react to form carbamate, an intermediate product produced during urea production. Carbamate is highly corrosive and can easily crystallize.

The LESER Urea Synthesis Safety Valve has been specifically designed to meet these technical requirements. The choice of materials is optimized for critical urea applications and ensures corrosion resistance.

The safety valve materials of construction are selected according to the medium properties:

• Special stainless-steel grades such as 316L Urea Grade or 1.4466 - UNS S31050 are used for the highly corrosive carbamate at pressures up to 200 bar / 2900 psig and temperatures up to 200°C / 392°F.
  

LESER is licensed by Stamicarbon, the leading international fertilizer plant licensor, and is thus authorized to use the specially developed Safurex material in Stamicarbon plants. Crystallization of the carbamate gas is prevented by a steam purge concept. The optimal flow of steam through the design of the safety valve also reduces the amount of steam required and thus operating costs.

Customer benefits

• Special stainless-steel grades, minimizing service and maintenance costs
• Minimized steam requirement promotes reduced operating costs
• Only one injection point requires less piping
• Permanent steam purging avoids crevice corrosion and crystallization
• LESER Supplementary Loading System allows increasing the operating pressure and improves the conversion efficiency in the synthesis reactor
  

Since 2008, LESER has supplied more than 1,500 safety valves in more than 50 urea plants worldwide.