Electricity is traditionally generated at large-scale (500-1000 megawatt), combustion-based power plants and transported long distances along high-voltage power lines. Current strategies to reduce CO2 originating from these power plants include capturing the CO2 and storing it underground.
Distributed electricity generation (DG) systems employ small-scale technologies to produce electricity close to the end users of power with little reliance on the distribution and transmission grid. Solid oxide fuel cells, or SOFCs, are small units particularly suitable for a DG system to provide electricity up to one megawatt to single homes or larger buildings, from a carbon source such as natural gas or syngas. In these systems, a local solution for CO2 management is needed.
Abdelhamid Sayari of the University of Ottawa is leading a research team to develop an integrated system comprising: electricity generation using SOFC technology; selective capture of CO2 with proprietary nanoporous adsorbents; detection and treatment of contaminants such as SO2 through development of sensors and selective adsorbents; and a ground-breaking opportunity to demonstrate a truly zero-emission system by tailoring the SOFC to convert to a solid oxide electrolysis cell, or SOEC, which uses CO2, water and energy during off-peak periods of electricity demand to yield fuel in the form of syngas.
$635,000/3 years; Awarded in 2011
Affiliation with the NSERC Solid Oxide Fuel Cells Strategic Research Network fosters partnerships with academic, industrial, and governmental organizations. The success of CO2 and SO2 adsorbent development may broaden the range of adsorbent applications. CO2 adsorbents were patented prior to this project (US 7,767,004, 2010; Can PCA 2600751, 2011), and patent applications have been submitted for SO2 adsorbents.
DG is well-suited to Canada’s low population regions and offers much higher fuel-to-energy efficiency than fossil-fuel power stations (50-90% versus 25%), which directly translates into reduced greenhouse gases. A scaled-up zero emission system can benefit other industries in Canada which generate large amounts of CO2, such as bitumen extraction and upgrading processes in the oil sands and coal-fired power plants.
Advancements in SOFC-SOEC design can improve energy efficiency and environmental footprint across numerous industries. Highly selective sensors and adsorbents for CO2 and SO2 have extensive potential for technologies associated with treatment of industrial gases. Demonstration of a fully integrated system incorporating fuel cell, adsorption and advanced sensors provides valuable insight into engineering the scale-up of these and other new technologies.
The overall objective is to demonstrate the integration of SOFCs, nanoporous adsorbents, and sensors for efficient electricity generation with the production, use, and storage of pure CO2. Specifically, this project will identify operating conditions and component unit designs for the integrated system to work seamlessly.
If successful, this unprecedented development will have a major impact on greenhouse gas mitigation, through both high-efficiency heat and power generation and CO2 removal. It will uniquely address the problem of CO2 capture/storage from distributed electricity generation sources.
Prior to the outset of this project, little was known about SO2 adsorbents, particularly at the necessary level of selectivity, and no sensors were available that are selective to SO2 in the presence of CO2. Limited knowledge existed to combine SOFC and SOEC in a single unit.
The innovations required to fulfill the project goal are:
Significant progress has been made on each component of the proposed SOFC system. Adsorbent materials synthesized for the selective removal of SO2 show excellent performance and will be tested, along with optimized CO2 adsorbents, at actual operating conditions using gas mixtures representative of the SOFC exhaust stream. The SOEC function is currently being developed to take advantage of the potential for CO2 recycling. Sensors have been developed to detect SO2 and continue to be refined for expected gas mixture compositions and quick response time required.
Dr. Abdelhamid Sayari
Department of Chemistry
University of Ottawa
T: 613-562-5800 x 6480
E: Abdel.Sayari@uottawa.ca
