Keywords: process integration, mass integration, kraft pulping, water management, pollution prevention, environmental pollution, pulp and paper plants, water usage, water reduction, discharge
An integrated approach to the optimisation of water usage and discharge in pulp and paper plants
This paper is aimed at developing a systematic methodology for the cost-effective reduction of water usage and discharge in pulp and paper plants. As the industry moves towards increased system closure, the build-up of Non-Process Elements (NPEs) leads to serious consequences on the process equipment. In response, this paper achieves the following: a mathematical model to track water and primary NPEs throughout the pulping process; rigorous targeting for water usage and discharge; a systematic framework for water reduction using mass integration strategies including no/low cost techniques as well as capital-based techniques; an optimisation model for the optimisation of allocation, recycle and separation of aqueous streams. A case study for water management in a kraft pulping process has been solved to highlight the usefulness of the devised approach.