A novel technology for the operation and control of absorption towers in treating chlorinated compounds in the pulp paper bleaching process

摘要

This paper deals with the process control of absorption towers applied to the control of chlorinated compound emissions. The scrubbing liquid is normally an aqueous solution cintaining NaOH or sulfide which reacts with the contaminants contanined in the effluent gas. For economical reasons, the use of chemical reagents should be minimized. Due to fluctuation in the concentration of pollutants, it is difficult to maintain high removal efficiency without an excess of reagents. A dynamic process control approach is therefore a solution to optimize the use of chemical reagents while mainatining high removal efficiency. The dynamic process control uses a dual loops control which gives a fast response in time as compared to the simple loop feedback control system.