Experimental Investigations on a Novel Chemical Looping Combustion Configuration
Résumé
Chemical Looping Combustion (CLC) is a promising novel combustion technology involving
inherent separation of carbon dioxide with minimum energy penalty. An oxygen carrier is
employed to continuously transfer oxygen from the air reactor to the fuel reactor where
the oxygen is delivered to the fuel. Consequently, direct contact between the air and fuel
is prevented. The resulting flue gas is CO2-rich, without N2
dilution. The reduced oxygen carrier is then transported back to the air reactor for
re-oxidation purposes, hence forming a chemical loop.Various CLC configurations have already been developed and tested on laboratory scales.
However, more investigations are required to achieve feasible CLC processes. Among the
different points to address, control of the solid circulation rate between the two
reactors is of the highest importance regarding its effect on achievement of an
appropriate oxygen transfer rate and solid oxidation degrees. Moreover, minimization of
gas leakage between the fuel and air reactors is another important issue to be considered.
A novel CLC configuration is proposed where reactions are carried out in two
interconnected bubbling fluidized beds. Solid circulation rate control is achieved
independently of gas flow rate in the reactors through use of pneumatic non-mechanical
valves (L-valves). Moreover, loopseals are employed to minimize gas leakage while
transferring solids.Experimental results from operation of a 10 kWth equivalent cold prototype are
presented in this paper. The effect of operating variables on the solid circulation rate,
gas leakage between the two beds and the pressure balance on all of the process elements
is studied. The results demonstrate stable solid circulation with efficient control of the
solid flow rate and effective gas tightness of the system.
Domaines
Physique [physics]
Origine : Publication financée par une institution
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