Williams-Otto plant

VI.24 Figure PVI.3 shows the Williams-Otto plant, named after T. I. Williams and R. E. Otto, who originally described it in Trans. Am. Inst. Electr. Engr., 79, 458 (1960). Raw materials A and B are mixed in a CSTR and yield the following reactions ... 

In this work we applied the proposed approach to the simulated CSTR reactor from the Otto-Williams benchmark plant modified by Forbes and Marlin (1996) that may be described by elementary kinetics. The reaction sequences are ... 

The mathematical descriptions of each plant unit are summarized in Tables P8.38.2 and P8.38.3. The return function for this process as proposed by Williams and Otto (1960) and slightly modified by DiBella and Stevens (1965) to a variable reactor volume problem is... 

For process optimization with respect to several economic criteria such as net present worth, payback period and operating cost, the classical Williams and Otto (WO) process and an industrial low-density polyethylene (LDPE) plant are considered. Results show that either single optimal solution or Pareto-optimal solutions are possible for process design problems depending on the objectives and model equations. Subsequently, industrial ecosystems are studied for optimization with respect to both economic and environmental objectives. Economic objective is important as companies are inherently profit-driven, and there is often a tradeoff between profit and environmental impact. Pareto-optimal fronts were successfully obtained for the 6-plant industrial ecosystem optimized for multiple objectives by NSGA-ll-aJG. The study and results reported in this chapter show the need and potential for optimization of processes for multiple economic and environmental objectives. 

Keywords Economic criteria, Enviromnental criteria, MOO, Williams and Otto Process, Low-density polyethylene plant. Industrial ecosystems. 

The above background provides the motivation for the study and applications described in this chapter. Here, two types of process optimization problems are described. The first type has only economic objectives the two examples considered for this are the classical Williams and Otto (WO) process used recently by Pintaric and Kravanja (2006), and an industrial low-density polyethylene (LDPE) plant based on our recent studies (Agrawal et al., 2006 and 2007). The economic objectives tried are PBP, NPW, IRR, profit before taxes, and/or operating cost. The second type has both economic and environmental indices for this, the industrial ecosystem with four plants employed by Singh and Lou (2006) is expanded to an ecosystem with six plants and then optimized for multiple objectives. 

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