چكيده به لاتين
Today, paying attention to environmental issues has turned to one of the top concerns of the countries. In this respect, collecting recyclable waste has improved the conditions of environment around the globe and, at the same time, has reduced the consumption of raw materials. Consequently, the costs of production in factories and firms have been also decreased. Nevertheless, with ever-increasing population, finding suitable sites to dispose urban waste has itself became a challenge. Therefore, it seems that recycling urban waste, instead of waste disposal, can remove the need to landfills. In addition, the recycled materials can be reused in the chain of industrial production leading to decreasing consumption of raw materials, saving energy, costs and conserving national capital. So far, numerous studies have been conducted in the area of closed loop supply chain some of which addressed a give industry. However, the issue of recycling in the industry of aluminum has been only scantly examined. Accordingly, the present research aimed to propose an innovative model in this field. In fact, the object was to design a network of a closed loop supply chain to recycle aluminum products. Among a wide variety of aluminum objects, the used aluminum beverage cans were selected. Finally, a one-objective mathematical model was proposed the goal of which was maximizing profit considering the uncertainty of several parameters including demand, the amount of returns, the buy price of aluminum waste, the sell price of pure aluminum ingot, the minimum disposal fraction, minimum cost of sending to the secondary markets as well as the saved cost in the form of two-stage stochastic programming. The network designed in this project is multi-echelon, multi-product. In order to conduct the proposed model, a case-study in Tehran was done through collecting actual data in recycling industry. The proposed model was solved using GAMS software which was a function of the profitable target. In addition to economic advantages, this network improves the conditions of environment and saves energy consumption.
Keywords: Closed loop supply chain, Recycling, Used beverage cans, Two-stage stochastic programming
