Waste-to-energy supply chain management with energy feasibility condition

Waste-to-energy (WTE) is the focus of academia and industry triggered by the over-increasing amount of waste and rapidly depleting energy resources. Designing a waste-to-energy supply chain, focusing on its supply chain aspects, this study aims at converting the waste into profit, reducing the environmental pollution, and generating the energy from bio-waste. The proposed model considers a two-echelon supply chain consisting of a waste collection center and a biogas production plant. The rate of return at collection center is improved by employing effective return policy, which is modeled by using the sigmoid function. The collected bio-waste is converted into biogas and fertilizer at a biogas production plant. An energy feasibility condition is developed to decide the supply of required energy for operating the production plant from its own output. Besides fulfilling the plant's energy requirements, excess amount of the biogas and all the amount of fertilizer is sold in market for earning profit. The study objective is defined as total profit of the supply chain in form of a mathematical model, which is maximized by searching the optimal solution for cycle time and acquisition/incentive cost. The results of the study exhibit almost complete (97%) removal of the organic waste, production of a substantial amount of energy (14.8 MW), and creation of a significant amount of profit ($23908/month) for the considered setup. Based on the proposed feasibility condition, the environmental, economic and energy feasibilities of the WTE system are calculated in three different scenarios. The proposed model is applicable to the domestic as well as commercial setup of biogas production plants for optimizing the supply chain system and obtaining the aforementioned benefits.