Life cycle analysis (cost and environmental) of different renewable natural gas from waste procedures based on a multivariate decision-making approach: a comprehensive comparative analysis

This article presents a framework that focuses on structural considerations within gas networks to evaluate and rank various feasibility options for renewable natural gas (RNG) cases. Specifically, the analysis examines and compares a range of methods for producing RNG using natural gas from waste (NGFW), considering different types of waste as feedstock. To analyze and evaluate the different methodologies, the article uses a decision architecture based on life cycle analysis (cost and environmental). These tools are used to determine the most favorable path for the NGFW process. The preferred pathway is identified by considering a range of decision scenarios that take into account variables such as geographical conditions, the availability of various feedstocks and the different stakeholders’ priorities. The results show that according to the economically neutral scenarios and those that favor economic considerations, the pathway involving RNG generation from landfill gas coupled with a pressure swing adsorption (PSA) upgrading technology emerges as the optimum choice. Conversely, in a scenario where environmental sustainability is a priority, the process that emerges as most advantageous is the use of animal manure with the addition of a PSA upgrading unit. The designed structure can be adapted to different regions, each with its own unique geographical features and feedstock resources, and can be customized to meet the varying interests of stakeholders. Based on both parametric assessments and analytical interpretations, this article not only identifies optimal pathways but also provides a set of recommendations and strategies aimed at improving economic behavior.