Optimal Location of Biomethane Gas Manufacturing Plants and Allocation of Feedstock and Liquified Carbon Product

Biomethane gas (BMG), known for its sustainability, low environmental impact, and high profitability, has received wide attention in recent years. To facilitate the process of making strategic plans for building a BMG production system, this dissertation leverages the mathematical modeling and optimization techniques to minimize the supply chain cost for such a system. Typical elements in a BMG production system consist of the local farms that produce the feedstock, the hubs that collect and store the feedstock produced by farms, the reactors that generate BMG from the feedstock transported from the hubs, the condensers that liquefy the BMG from the reactors, and the delivery points that act as end distributors and accept the liquefied BMG from condensers. The logistics of a BMG production system can be divided into four stages: farm-to-hub (F2H) stage, hub-to-reactor (H2R) stage, reactor-to-condenser (R2C) stage, and condenser-to-delivery point (C2DP) stage. Depending on the variation on the elements and stages of a BMG production system, four supply chain configurations for BMG facility locations are proposed with increasing level of complexity: single-stage, single-reactor system (SS-SRS); single-stage, multi-reactor system (SS-MRS); three-stage, multi-facility system (TS-MFS); and four-stage, multi-facility system (FS-MFS). The objective for each configuration is to locate facilities optimally and to design the transportation/pipeline connecting network such that the supply chain cost, including the total of feedstock costs, labor costs, facilities building costs, and transportation/pipeline layout costs are minimized. A systematic approach, containing mathematical modeling and heuristic design, is proposed for each configuration. Numerical experiments are conducted for each designed heuristic to verify its performance