Development of a MINLP model for the optimization of a large industrial water system

This paper presents the design of a large water system within the production and packaging areas of a brewery. In order to accomplish the task, mathematical models were developed based on a Mixed Integer Nonlinear Programming (MINLP) formulation from the open literature. These models enable the investigation of several integration options: a) direct water re‐use between batch and semi‐continuous consumers operating within the same time interval and b) regeneration re‐use options, by designing and scheduling an on‐site wastewater treatment system. A multilevel strategy was applied for this large‐scale industrial problem, which firstly decomposes design problem into several smaller integration problems concerning water consumers within each section of the brewery. At the following level, water re‐use and regeneration re‐use opportunities between the brewhouse and the packaging areas were explored for each working day. Finally, the design of an integrated water system was performed over the entire working week by fixing identified intra‐daily matches between sections. An optimum water integration scheme is proposed based on the results obtained.