Part of #Increasing the DAP Production Capacity of DAP2 Plant of Razi Petrochemical Complex by Controlling the Concentrations of Aluminum and Iron Oxides# :
Publishing year : 2008
Conference : Iran's first petrochemical conference
Number of pages : 11
Abstract: Di-ammonium phosphate (DAP) is one of the best chemical fertilizers used individually or in combination with other fertilizers or soil nutrients. It is usually produced by reacting wet phosphoric acid with ammonia in a pipe or tank reactor followed by granulation process. Produced slurry in the reactor is sprayed onto seed granules, and granulation growth occurs. The granules leaving the granulator are first dried and then screened to separate the product size. In this work, the effect of phosphoric acid impurities on the granulometry and production rate of the produced DAP in the Razi Petrochemical Complex is experimentally investigated. It has been found that generation of a large number of fine particles due to the deficiency of Al2O3 and Fe2O3 in the reactor can accelerate the adhesion and coalescence of DAP granules in the granulator, and thus large quantities of weak large pieces of the product are obtained. When these lumps pass through the crushers, there is produced a large amount of dust and fine particles in the recycle stream, which leads to serious operational problems and reduces the production rate. According to the experimental measurements in the DAP2 plant (based on a pipe reactor) of the Razi Petrochemical Complex, there is a correlation between the total concentrations of Al2O3 + Fe2O3 in the phosphoric acid entering the pipe reactor and DAP granulometry. In order to improve the granulation quality without operational difficulty, the total concentration of alumina and ferric oxides in the reactor entering the phosphoric acid should be controlled at 2.2 0.1 wt%. This is an interesting result that can be used to improve the operating conditions of DAP production plants. Applying this to the DAP2 plant of Razi Petrochemical Complex in Iran resulted in a 80% decrease in C.V. of the produced DAP granules and a 65% increase in production rate.