ABSTRACT
This chapter presents a case study about a fertiliser plant. The case involves the successful introduction of a new system for feedback control of accidental emissions from the plant to the environment. It illustrates many principles of accident prevention through feedback control that are the same for all areas of health, safety, and environment (HSE). An integrated process control system was introduced at fertiliser plant. The system provided the control room operators with timely information on process deviations that had the potential to cause environmental pollution. Before the integrated process control system was introduced, emissions were registered continuously by measuring the nitrogen content in the exhaust pipe's air. Plant management analysed the causes of typical emissions and used timely information on process deviations as input for the new design. The new process control system provided management at different levels with filtered and summarised information according to their needs.
