Research On Process Industry Water Minimisation

Due to the increasing scarcity of water source and the environment pollution caused by wastewater, how to reduce the fresh water consumption and waste water generation has drawn more attention from the public. Process industry has consumed a large amount of fresh water and discharged a lot of waste water. Using the process integration technique to minimize the fresh water consumption is now becoming a hot topic. Based on the characteristics of continuous and batch process in process industry, this paper has done some research work on their water using network respectively.In the research work of the continuous process, the water using operations were briefly described. The concept of pure water surplus/deficit was put forward first, whose significance is then analyzed. Introduced this concept to the water cascade analysis approach (WCA) , thereafter proposed the detailed water targeting steps through WCA. After targeting the fresh water demand and determining the water pinch, combined with the Purity level-flowrate diagram to determine the water allocation. Used the water source determining rules and water volume allocating formulae and principles to decide the water source and flowrate distribution for processes. Thus the optimal water using network was obtained. The single pinch problem, the multi-pinch problems and regeneration reuse problem involving mass-transfer-based and non-mass-transfer-based processes were investigated.In the research work of the batch process, the water using operations were briefly described. The concept of pure water surplus/deficit was still used. Based on the relationship of batch process with time, the mathematical expression of the concept was deduced. To achieve the optimal target of the whole process, the storage tank was introduced. Calculated the water sources and water demands in the whole period, and then used WCA to determine the water target and the global pinch. Through the...