Session: 12-02: Hydrogen Energy, Alternative Fuels, Bioenergy, and Biofuels

Paper Number: 121756

121756 - Network Optimization for Sustainable Integration of Decentralized Biogas Production 

Abstract: 

Facing the urgent need to mitigate anthropogenic climate change, reducing emissions from the combustion of fossil natural gas has become imperative. This is particularly challenging in industries like steel or cement, where high-temperature heat is essential. A promising solution is the substitution of fossil gas with biogenous gas. This allows investment-intensive plants to continue to be used until the end of their service life while avoiding uncertainties associated with new facilities. However, the highly decentralized biogas production presents a transportation challenge due to the high costs of gas transportation infrastructure.

This paper addresses this challenge by proposing an innovative approach to find a cost-efficient distribution network to connect biogas plants to the existing gas transportation network. The mathematical representation of the multiple tree-structured distribution networks is modeled utilizing highly efficient methods from graph theory. We fundamentally enhanced those graph-based approaches to use Mixed-Integer Linear Programming (MILP). Our objective is to minimize the specific transportation costs, including the costs of units for gas processing, injection, compression and distribution pipes. We depict the units’ economies of scale using nonlinear cost functions and transferring them piecewise linearly to MILP. Developing the novel MILP formulation of the optimization problem enables us to keep the problem tractable and guarantees optimal results within a defined solver gap. A comprehensive analysis of the results enables us to rank biogas plants according to their specific transportation costs. As a result, building the transportation network can be efficiently tailored to available investment capital.

We demonstrate the potential of our method on the Austrian gas network by developing a cost-efficient concept to connect 115 biogas plants to the existing gas transmission network. The results show that the average specific transportation costs are 1.87 ct/kWh. In addition, the breakdown of the biogas plant-specific transportation costs shows that some plants can already be connected for 1.18 ct/kWh. In contrast, connecting the most expensive plants would cost 4.17 ct/kWh. Through the comprehensive evaluation, we assign and rank the specific transport costs for each plant, facilitating an economically feasible network expansion.

This research is a pivotal step in strategically expanding the biogas distribution network. Through the seamless blending or substitution of fossil natural gas within the transport network, our approach ensures the continued cost-effective utilization of existing infrastructure with minimal emissions. By adopting these innovative strategies, we pave the way for a sustainable future, where the integration of biogas into the energy landscape becomes a cornerstone for reducing environmental impact while maintaining economic efficiency.

Presenting Author: David Huber TU Wien - Institute of Energy Systems and Thermodynamics

Presenting Author Biography: David Huber was born in 1994 in Schladming and grew up in rural Salzburg. He moved to Vienna to study mechanical engineering at the TU Wien. He graduated with distinction in 2020. Since 2018, he worked on research projects at the Institute for Energy Systems and Thermodynamics at TU Wien. His interest in energy engineering, thermodynamics and optimization finally led him to start a PhD at the same institute. In 2020, he started as a research associate (Univ.Ass.) and conducted research in the field of mathematical programming. The focus of his research is on innovative concepts for the optimization and decarbonization of industrial energy systems. He applies methods of linear and multi-objective optimization as well as heat exchanger network synthesis and graph-theoretical approaches.

Current information about his publications can be found at https://orcid.org/0000-0001-7164-8275. Additionally, there is the possibility to follow his professional career, as well as to contact him via his LinkedIn profile at https://www.linkedin.com/in/david-huber-068aa9203/.

Authors:

David Huber TU Wien - Institute of Energy Systems and Thermodynamics
Felix Birkelbach TU Wien - Institute of Energy Systems and Thermodynamics
René Hofmann TU Wien - Institute of Energy Systems and Thermodynamics