Ammonia-Cyanuric Acid Co-Production in Boiler Denitrification System

Area of Science:

• Chemical Engineering
• Environmental Science
• Industrial Chemistry

Background:

• Existing urea-to-ammonia processes in thermal power plants suffer from poor economic efficiency and high CO2 emissions.
• Waste heat from thermal power plant boilers presents an underutilized resource for chemical synthesis.

Purpose of the Study:

• To propose and analyze an innovative ammonia production process for thermal power plants utilizing waste heat and urea pyrolysis.
• To optimize the process for ammonia and cyanuric acid production and evaluate its economic and environmental benefits.

Main Methods:

• Urea pyrolysis experiments were conducted using orthogonal experimental design to determine optimal process parameters.
• Aspen Plus software was employed for whole-process modeling and simulation of the urea pyrolysis.
• Key parameters investigated included melting temperature, melting time, reaction temperature, and reaction time.

Main Results:

• The optimal conditions identified were 160°C melting temperature, 45 min melting time, 240°C reaction temperature, and 20 min reaction time.
• Under optimal conditions, the process achieved 18.45% ammonia and 52.35% cyanuric acid yield.
• Controlled ranges for optimal performance were determined: 160-167°C melting temperature, 40-45 min melting time, 240-245°C reaction temperature, and 15-20 min reaction time.

Conclusions:

• The proposed two-stage urea pyrolysis process effectively utilizes waste heat for ammonia and cyanuric acid production.
• This innovative method offers significant advantages over existing processes, including nearly zero emissions and enhanced economic benefits.
• The findings provide crucial data for the potential industrialization of this sustainable ammonia production technology.