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Conrado Borraz Sánchez
Ph. D., stipendiat, optimering

PhD Thesis


"Optimization methods for pipeline transportation of natural gas"

Download: [ My PhD thesis ] and [ my presentation ]


Nowadays, the world is facing several major challenges that include the air and water pollution, global warming and the rising market prices of the primary energy resources, among others.

Natural gas, as an energy source, offers several advantages in comparison with other non-renewable energy sources to overcome these problems. For example, natural gas is a cleaner fossil fuel than oil and coal, i.e., it emits a lower percentage of carbon dioxide than gasoline, diesel and coal. Natural gas is also more economically attractive than gasoline despite that its listing on the financial sector has been increasing in recent years (which represents better profits for the industrial sector).

As a consequence, the natural gas industry has had to quickly expand its transmission networks in order to satisfy the increasing demand of the gas consumption. This motivates the research work conducted in this thesis, which focuses on optimizing the transport of natural gas via pipeline network systems.

Three research projects constitute the PhD thesis. The first project deals with minimization of compressor fuel cost on large pipeline transportation networks for natural gas. The contributions from the project are three solution methods fo the fuel cost minimization problem. The second project is on mathematical modeling of network flow problems under gas volumetric properties variation. We develop a mathematical model that estimates accurately maximum flows in transmission network systems, and a fast heuristic algorithm based on an approximate model to solve the original problem. Finally, in the third project, we study how gas pipelines can be exploited as a combination of transportation units and storage units of compressed gas. The output of the project is a strategy to alleviate the consequences caused by scheduled events that occur in a day-to-day planning in transmission pipeline systems.

Time and date of the trial lecture: 30.11.2010, at 14:15 hrs.
Given topic: "Models and solution methods for the fixed-charge network flow problem".
Place: Room 2143 at 2nd floor in the High Technology Center, Thormøhlensgate 55, N-5008 Bergen.

The PhD studies were accomplished under the supervision of Associate Professor Dag Haugland in the Department of Informatics at the Faculty of Mathematics and Natural Sciences, University of Bergen, Norway.

Time and place for the defence: 16.12.2010, at 10:15 hrs, Auditorium VilVite, Thormøhlensgate 51, N-5006 Bergen, Norway.

Contact information:
tlf: + 47 55 58 4150
email: Conrado.Borraz-Sanchez@ii.uib.no