LINEAR IDENTIFICATION AND CONTROL OF REACTOR FOR PHTHALIC ANHYDRIDE PRODUCTION PROCESS - CASE STUDY

Phthalic anhydride is one of the most essential and rare chemicals used in manufacturing of paints, pigments, dyes and esters. Now a day, the demand for the purest form of Phthalic anhydride is increasing but the production is low to meet the demand. Phthalic anhydride is produced by maintaining the constant ratio of air and ortho xylene at 3: 1 at very high temperature in mixing column. The mixture is passed through the reactor for reaction with catalyst. Finally, it enters the switch condenser for product separation. The main problem is if the reactor is not maintained below its critical value , leads to explosion. As feed material is a petroleum product, the energy released is enormous, it can endanger the life of employees and to surroundings. For efficient control, linear and nonlinear model identification using AR, ARX and ARMAX is done and conventional controller is included to operate the plant in closed loop.