Dynamic Operator Training Simulators for Sulphuric Acid, Phosphoric Acid, and DAP Production Units

Dynamic process simulators are widely used in the chemical and petrochemical industries for operator training, plant design, and optimization; but there is a lack of rigorous simulators in the phosphate fertilizer industry. Some of the many difficulties encountered in phosphate fertilizer simulation include: lack of knowledge of thermodynamic properties, presence of many phases (gas, liquid, and solids), high levels and variation of impurities in phosphate rock producing unknown effects, complexity in modeling particle size distribution, etc. Dynamic training simulators were successfully developed for sulphuric acid, phosphoric acid, and DAP production units of OCP Group's Jorf Lasfar complex using a commercial simulation platform. A new thermodynamic property package was developed for sulphuric acid and oleum to correctly predict vapor pressure, density, enthalpy, and SO2 solubility. Also, a rotary drum granulator was developed to consider the reaction chemistry of DAP production and the stochastic nature of solids created. The granulator can accurately predict particle size distribution, moisture content, ammonia and dust losses, and gas/solid temperatures. It was shown that the simulators could precisely reproduce control room and field operations to model plant start-ups, emergency or normal shutdowns, process upsets, and normal operations.