Endpoint-oriented Life Cycle Optimization Models for Sustainable Design and Operations of Shale Gas Supply Chains with Modular Manufacturing

Abstract

Abstract Modular manufacturing is identified with great potential in the exploitation of shale gas resource. In this work, we propose a novel mixed-integer nonlinear fractional programming model, where design and operational decisions regarding both the conventional processing plants and modular manufacturing devices are considered. The allocation, capacity selection, installment, moving, and salvage decisions of modular manufacturing devices are modeled with corresponding integer variables and logic constraints. To systematically evaluate the full spectrum of environmental impacts, an endpoint-oriented life cycle optimization framework is applied that accounts for up to 18 midpoint impact categories and three endpoint impact categories. Total environmental impact scores are obtained to evaluate the comprehensive life cycle environmental impacts of shale gas supply chains. A tailored global optimization algorithm is also presented to efficiently solve the resulting computationally challenging problem. To illustrate the applicability of proposed modeling framework and tailored global optimization algorithm, a case study of a well-to-wire shale gas supply chain based on Marcellus Shale is considered. Based on the optimization results, the application of modular manufacturing helps achieve the lowest LCOE of $59.4/MWh and the smallest ReCiPe endpoint environmental impact score per MWh electricity generation as 64.5 points/MWh.