Process integration design methods for water conservation and wastewater reduction in industry. Part 3: Experience of industrial application

This paper is Part 3 in a three-part series of papers addressing operational techniques for applying mass integration principles to design in industry with special focus on water conservation and wastewater reduction. The presented techniques derive from merging U.S. and Danish experience with industrial applications of process integration, as a result of a recently established co-operation between the U.S. companies Solutia Inc., Cleaner Process Technologies Inc. and McSwain Engineering Inc. and the Technical University of Denmark. Parts 1 and 2 covered design techniques for any number of wastewater streams containing single and multiple contaminants respectively. Part 3 in this series presents experience from applying methods in industry and also illustrates the work related to each of the steps of the methods and discusses the benefits from the insights provided by each step. The presented experience comprises application in small-scale batch productions in textile dyeing and laundering as well as large-scale continuous productions in chemical industry, and it is documented that the methods are robust and independent of the volume and continuity/discontinuity of the production. Industry's experience with defining the scope of the system and with identifying water flow constraints and water quality constraints is discussed. It is shown how physical constraints for the system design often set a limit for the sophistication of the water recycle network and thereby also a limit for how sophisticated the method for system design should be. Finally, pinch analysis and system designs for water recycling in a practical case study are shown, documenting large water saving potentials and achievements. Electronic Publication