News from Flagship Project “Negative CO2”
The ultimate goal of the Negative CO2 project is the development of new competitive technology that: enables CO2 capture and negative CO2 emissions with the lowest possible cost and energy…
The ultimate goal of the Negative CO2 project is the development of new competitive technology that:
- enables CO2 capture and negative CO2 emissions with the lowest possible cost and energy penalty
- is able to produce power and/or steam for industrial and other applications
- utilizes Nordic expertise and competence in fluidized bed technology
- eliminates thermal NOx emissions and has potential to achieve more efficient fuel utilization compared to ordinary biomass combustion.
The technology capable of achieving these goals is Chemical-Looping Combustion of biomass (Bio-CLC), a unique and innovative combustion technology that will be studied and developed in the project. Chemical-Looping Combustion (CLC) involves oxidation of fuels with oxygen provided with solid oxygen carrier particles rather than with air and both the high energy penalty and the high capital cost associated with gas separation can be avoided. Because of this CLC is expected to have at least 50% lower energy penalty and cost than any other CO2 capture technology.
Scientific and technical progress
In the project an experimental campaign in a semi-commercial facility (Chalmers Research Boiler) is scheduled for 2018. However, already in November 2015 an opportunity arose to make preliminary experiments in the said facility. During 3 days the gasification reactor of Chalmers Research Boiler was successfully operated as a CLC fuel reactor, although it should be noted that the gasifier is not designed for this purpose. Wood pellets corresponding to a thermal power of up to 2.4 MW was topfed to the gasification reactor. The oxygen carrier was a pre-calcined manganese ore. Fuel powers up to 2.4 MW were examined and the fuel conversion was in the order of 60-70% at 820°C. Much higher conversion is attained in CLC pilot reactors and is also expected in full-scale boilers. For the 2018 campaign, improvements with respect to fuel feeding and temperature of operation are planned. Nevertheless, these experiments constitute a considerable leap forward and have potential to contribute greatly on many issues that is to be examined in the project.
A number of key decisions have been taken with respect to planned experimental work. This includes selection of two reference fuels (Finnish White Wood Pellets and Norwegian steam treated Arbapellets) and a number of oxygen carrier materials for examination (three manganese ores and three ilmenite sands available via the project partner Sibelco, one sintered manganese product provided by advisory board member Alstom and rock ilmenite provided by advisory board member Titania).
Samples of fuels and oxygen carriers are currently being distributed among parties involved. Initial experiments are being planned and performed at SINTEF MC and Åbo Akademi. VTT’s 50 kWth scale bio-CLC test rig, located in new piloting center called Bioruukki in Espoo, Finland, has been very recently successfully commissioned by tests using ilmenite as oxygen carrier and wood pellets as fuel. During the test campaign on April, a special interest is to study the conditions, deposit formation and risk for high-temperature corrosion in the flue gas paths to evaluate the possibility for improving power generation efficiency by using enhanced steam values. Also at SINTEF experimental facilities are currently under commissioning and rock ilmenite will be used as oxygen carrier during the first campaigns.
For general questions about the project or subscription, please contact the coordinating party, which is Chalmers University of Technology:
Anders Lyngfelt, firstname.lastname@example.org, +46 (0) 31 772 1427
Magnus Rydén, email@example.com, +46 (0) 31 772 1457