چكيده به لاتين
The vast volume of oil and gas production in the oil-rich countries, which are mostly dry countries, has led them to focus on finding effective and cost-effective ways to recycle water as a complement to freshwater resources. Pinch water analysis is used as a new way to reduce fresh water consumption. Performing a water-pinch analysis for a single contaminant is simple, when more contaminants involve the analysis, although the method will be more accurate, but it will be more complex, and in this case either mathematical programming or software applications should be used. In this research, Water Design software has been used, considering that two contaminants have been studied. Since Pinch Analysis is involved with the process of re-circulation or reuse of fresh water, there is a discussion of water regeneration or water purification. Membrane methods in wastewater treatment are among the most effective available methods.
A case study was conducted on the water network of Tehran oil refinery. The refinery's desalination process, cooling tower, and general consumption were analyzed because of their high water consumption (around 340 t/h). Two important contaminants consist of suspended solids (SS) and chemical oxygen demand (COD) were also investigated. In the first case, the implementation of Pinch Analysis on the three units studied in terms of suspended solids contaminant was about 55% decrease of fresh water consumption, in the second case, the application of pinch analysis in terms of COD decreased fresh water by 54%, in the third case, in terms of both contaminants the suspended solids and COD decreased fresh water about 37% and in the fourth case, which was first performed the membrane wastewater treatment (RO process), then the pinch analysis was carried out in terms of suspended solids and COD, about 44% of the freshwater consumption in the refinery's water network was decreased.
