The state of minimum entropy production of membrane processses for enhanced oil/gas recovery

CO2 in natural gas has to be removed for several reasons. For instance, it lowers the heat of combustion, and it might freeze in the LNG pipelines. Nowadays several technologies are available for CO2 removal, but the membrane technology has some interesting advantages over its competitors, especially when combined with Enhanced Oil/Gas Recovery.

Several physical phenomena may affect the performance of a membrane module. To capture these effects and to provide a realistic description of the membrane module, a proper model has to be prepared.  

With realistic models for the process units, the next step is to incorporate these in the overall process design in the combination with EOR. Once a reliable reference has been established, we propose to use optimal control theory to find the most energy efficient state. The conservation equations of the membrane module are used as constraints and the total entropy production is the objective function. It is possible then to characterize the state corresponding to the most energy efficient operation and design. The methodology has never been applied to membrane processes, and a large potential for improvement is expected.

Picture: Visit to the Department of Arctic and Marine Biology at UiT.

We are also working on a side project in collaboration with UiT The Arctic University of Norway, on the study of heat and mass exchange inside of a reindeer nose. Reindeer are known to be able to survive under very harsh climatic condition, and the efficiency of their breathing system plays a fundamental role in the energy balance of the animal. Further knowledge on these systems might guide the development of new and more efficient Nature-inspired process

The reindeer nose project has received considerable news coverage. Read more about the project in Teknisk ukeblad, Forskning.no, and Science dayly.

Publications:

-      Magnanelli, Elisa; Wilhelmsen, Øivind; Johannessen, Eivind; Kjelstrup, Signe. "Enhancing the understanding of heat and mass transport through a cellulose acetate membrane for CO2 separation." Journal of Membrane Science 513 (2016): 129-139.

-      Magnanelli, Elisa; Wilhelmsen, Øivind; Acquarone, Mario; Folkow, Lars P.; Kjelstrup, Signe. ''The Nasal Geometry of the Reindeer Gives Energy-Efficient Respiration''. Journal of Non-Equilibrium Thermodynamics. July 2016