Online computer control of pH in an industrial process

The paper reports on a collaborative, university/industry project to investigate the contribution which modern control technology can make to a difficult industrial problem: pH control. A digital computer was interfaced for online neutralisation of effluent from a full-scale production process. The investigation consisted of trials, some of them extended, using the computer to control neutralisation according to various algorithms and to monitor performance, and of simulation studies. Algorithms investigated include p.i.d., self-tuning control, and optimal-k-step-ahead (o.k.) adaptive control. The paper summarises work to date which leads to the conclusion that an online digital computer can contribute substantially to pH control and that o.k. control is a promising candidate for general-purpose feedback within a configuration of combined feedbadk, feeciforwardancilineansation