Environment and Control Issues in Design

Abstract: The basic principles guiding the operation of the processing units of a chemical process are based on the following objectives:- Safe operation of the processing units.- Specified production rates must be maintained.-Product quality specifications must be maintained.- Perform satisfactorily under conditions different from the nominal design conditions. While process design aids in performing the principal function of the industry, that is to convert raw materials into products, it is process control and operability that is responsible for satisfying the above objectives. Currently, the most striking flaw in any industrial operation is the lack of associative interaction between the design and control systems. An improper interaction between the two not only leads to a design which might be uncontrollable, and hence infeasible, but also incurs a lot of expenses while attempting to operate in the uncontrollable regions. This research mainly focuses on analyzing the importance of the interaction between design, controllability and operability issues. A qualitative and a quantitative analysis of the criterion for operability that could be used during the design phase of a process have also been performed. These criteria have then been tested on several test processes. Controllability has been assessed by the method of Singular Value Analysis (SVA), which helps in the design of different control strategies, and compare them with a controllability index called condition number. Operability is assessed by the economic feasibility, environmental impact, safety, resiliency (ability to tolerate an