High-throughput in-silico screening of oxygen carrier candidates for chemical looping oxygen uncoupling -Thermodynamical and practical considerations of data mining from ab-initio databases — towards a cost-effective negative emission technology
Typ
Examensarbete för masterexamen
Program
Applied physics (MPAPP), MSc
Publicerad
2020
Författare
Rehnberg, Viktor
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
It is clear that different techniques of carbon capture and storage will prove to
be important in achieving the current global climate goals. One such technique is
combustion of biofuel with chemical looping combustion or chemical looping oxygen
uncoupling (CLOU). These are techniques where a metal oxide is used as an
intermediary to transport oxygen between a chamber with an air inlet to a chamber
with a fuel inlet. In CLOU the metal oxide is oxidised in the air chamber and
then transports the extra oxygen to the fuel chamber. Thanks to the low partial
pressure of oxygen in the fuel chamber the metal oxide is reduced and releases the
extra oxygen. This oxygen in gaseous state will then react with the fuel and thus
the partial oxygen pressure in the fuel chamber remain low. The metal oxide can
continue looping through the two chambers transporting oxygen. As only oxygen
and fuel are present in the combustion the only exhaust gases under full combustion
are carbon dioxide and water. No toxic oxides of nitrogen are produced and
expensive post-combustion gas separation of nitrogen and other flue gases can be
avoided. The water can easily be separated by condensation and the carbon dioxide
can then be captured cheaply and later stored in, for instance, geological formations
underground.
This report proposes a new method based on using the bountiful data from abinitio
databases, for instance available in the Open Quantum Materials Database, to
propose possible candidates for oxygen carriers in chemical looping oxygen uncoupling
(CLOU). The data, in this case formation energy at 0K and 0Pa, is extrapolated
based on thermodynamic considerations to find the stable phases of oxygen
carriers under realistic conditions used for CLOU. Further considered criteria include
mainly cost, toxicity and oxygen transfer capacity. A quantitative summary
of all the considered criteria is proposed and also used to list potential metal oxide
oxygen carriers in the order of how promising they seem for CLOU. The list can
be used to guide what experimental investigations should prioritise, thus, it has the
potential to significantly speed up the search for better oxygen carriers.
Beskrivning
Ämne/nyckelord
chemical looping , material screening , data mining , Ellingham diagram , thermodynamics