Chapter 4: Modern Urea Synthesis

Urea is an important chemical compound used predominantly in the agricultural industry as a nitrogen-based fertilizer, while having many other applications in various industries. The main impediment to producing urea in a sustainable manner is fossil fuels being the main feedstock for its production and its energy intensive process. Therefore, sustainable design principles need to be adopted for green urea synthesis. For this to occur, based on the theory of change, sustainability in the production of the hydrogen (H₂) required for ammonia (NH₃) and the NH₃ needed for urea synthesis must take place. Unsustainability throughout each stage of the integrated H₂-NH₃-urea production process is the main problem associated with current urea production methods. In this study, a review of various sustainable H₂ and NH₃ production technologies required for sustainable urea production has been carried out. The reviewed technologies are in the early stages of development and are yet to be adopted into industrial level production.