Stochastic optimization of sustainable industrial symbiosis based hybrid generation bioethanol supply chains

• This paper studies new industrial symbiosis based hybrid generation bioethanol supply chain (ISHGBSC).
• A mathematical model is developed to design the ISHGBSC that is both robust and sustainable.
• The impact of various sustainability regulations on the design of ISHGBSC is examined.
• Results provide guidelines for policy makers to select appropriate sustainability regulations.
• Results provide guidelines for investors to develop sustainable strategies.

Bioethanol has been considered as an important type of renewable energy that can help reduce energy crisis and environmental degradation. Under economic, technology, and sustainability consideration, food based 1st generation bioethanol and lignocellulosic-based 2nd generation bioethanol have to exist simultaneously. Therefore, it is necessary to design a hybrid generation bioethanol supply chain (HGBSC) to sustainably meet the ever-increasing energy demand and different government-mandated sustainability standards related to green sustainability such as greenhouse gas (GHG) emissions, irrigation land and water usage, and energy efficiency. This paper is the first to examine different type of bioethanol plant configurations including industrial symbiosis strategy in order to meet high sustainability standards and design robust and sustainable industrial symbiosis based hybrid generation bioethanol supply chains (ISHGBSC). A novel stochastic mixed integer linear programming (SMILP) model is proposed to design the optimal ISHGBSC under different sustainability standards. A case study of North Dakota (ND) in USA has been studied as an application of the proposed model. The results show that some sustainability standards are stronger than others in terms of the number of green sustainability requirements met. When stronger sustainability standards are applied, the economic performance of the ISHGBSC is sacrificed. The results provide a guideline for policymakers to determine the appropriate standard to use under different sustainable concerns, and for policymakers and investors the best ISHGSBC structure under each standard. In addition, the results provide investors a guideline to invest in different technologies under different sustainability standards. Sensitivity analyses is also conducted to provide deep understanding of the proposed ISHGBSC and to identify the factors that might impact the stability of the ISHGBSC under different standards.