The flow technique, technical character and mass balance of 300kt/a urea installation were introduced in this article.

Successful application of my company's patent technique on modification of urea plant with aqueous solution total cycle process;

Technology Progress of revamping urea process of solution full recycle with pre-separation & pre-distillation in urea plant;

Modifying the bottle-neck equipment to increase the urea plant capacity;

Dynamic simulation of 130 kt/a urea unit;

Dynamic analysis and optimizing operation of urea unit under circulating evaporation

The Application of Poisonous Medium Leakage and Diffusion Model on Safety Evaluation of Urea Unit

This paper makes a brief summary of the measures for technical t ra nsformation and practicing situation of many small urea units and their supporti ng works such as the decarbonizing workshop section, CO2 compressing and purifyi ng workshop section, N- H- aerostatic press, and main urea workshop building, etc.

Through the introduction of capacity expansion & reformation project in which the production capacity was increased by 50% in the large granule urea plant of Ningxia Petro-chemical company,the mult-item of technical reformation measures of process scheme,plant layout,equipment selection and structure improvement etc.