BIGCLC Phase III

Goal of the Project:
Bring Chemical Looping Combustion (CLC) closer to commercialization. This will be achieved by developing new and optimized oxygen carriers and production methods, validate performance and operability of the 150 kW CLC rig by 600 hours of operation, and by educating 1 PhD and 1 post-doc researcher.

Technical content:
Chemical Looping Combustion (CLC) is a novel and promising CO₂ capture technology that has a large potential with respect to efficiency and CO₂ capture cost. It belongs to the oxy-combustion capture route and the oxygen needed is produced by oxidizing small particles of a metal oxide in an air reactor. The particles (the "oxygen carriers") are transported to a fuel reactor where the oxygen is used to combust the fuel. The particles are then transported back for a new cycle ("loop").
New oxygen carriers of perovskite type have been developed in Phase I and II. Phase III aim at producing the oxygen carriers directly from blending primary components using different precursors. If successful, this would reduce the number of process steps and costs of producing the oxygen carrier particles. The different types of the oxygen carriers will first be tested at small scale using a 3 kW fluidized bed reactor. The most promising materials will further be operated in the 150 kW CLC reactor system that has been developed and built during Phase I and II. It is now being installed in Trondheim. This size of operation will provide more realistic testing of both the oxygen carriers and the process operability. The test rig is based on two interconnected circulating fluidized beds aiming at high fuel conversion rate and with an industrial-like process control approach with the possibility to achieve long-term automated operation.

Technical advantages:
CLC technology produces an exhaust gas that consists mainly of CO₂ and water vapour, which makes CO₂ separation easy by just condensing out the water vapour. The oxygen needed is extracted from the air by rapid oxidation of metal particles, avoiding costly cryogenic air separation. Production of particles is costly and if the project can show that suitable materials can be produced using fewer production steps it will be an important benefit for the technology.

R&D challenges:
The drawbacks of the CLC process are that the process complexity increases compared to a standard combustion process, and the process performance becomes very dependent on the circulating particles and their chemical and mechanical stability in a very though and alternating environment. The main challenges are therefore to develop reactor and control systems which ensures stable and reliable operation, and to produce oxygen carriers with high enough attrition strength, oxygen capacity and reaction kinetics.

Results to date:
Full CLC operation of the 150 kW CLC rig performed with high fuel conversion and without need for external heating.
The PhD candidate has developed the first version of a numerical simulation tool for the fluid and particle flows in the 150 kW CLC reactor
Continuous operation of the 3 kW CLC test rig in Oslo for more than 100 hours in total has been achieved.
Four batches of oxygen carriers for CLC has been produced and tested in the 3kW CLC test rig.