Carbon capture could prevent up to 90% of fossil power plants’ CO2 emissions, according to some estimates, but conventional CCS technology remains expensive and largely unproven, and where it has been successfully implemented it had fallen short of expectations.
It is also expensive, requiring massive amounts of energy to capture and store CO2, thus reducing the power plant’s output and making the electricity produced more expensive
ExxonMobil says that using fuel cells to capture CO2 from power plants reduces emissions and increases power generation.
The plan is to redirect the exhaust from the plants into a fuel cell, replacing air that is normally used in combination with natural gas during the fuel cell power generation process. As the fuel cell generates power, the CO2 becomes more concentrated, allowing it to be more easily and affordably captured from the cell’s exhaust and stored deep underground.
FuelCell, which develops carbonate fuel cells that convert waste gases into energy, says CCS with carbonate fuel cells “is a potential game-changer for affordably and efficiently concentrating carbon dioxide for large-scale gas and coal-fired power plants.”
While the staged pilot development is unlikely to be commercialised for at least five years, if it does work, FuelCell says it has already put two years into completing laboratory tests, and that it appears that integrating carbonate fuel cells and gas-fired power generation captures carbon dioxide more efficiently than existing scrubber conventional capture technology.
The potential breakthrough comes from an increase in electrical output using the fuel cells, which generate power, compared to a nearly equivalent decrease in electricity using conventional technology.
The resulting net benefit has the potential to reduce costs associated with CCS for natural gas-fired power generation, compared to the expected costs associated with conventional separation technology.
The technology also eliminates around 70 % of smog-producing nitrogen oxides from power plants.
So far the partners expect potential savings on conventional CCS of up to 30%, based on lab results, but that is yet to be proven at commercial scale.
The next phase will spend 1-2 years examining now to improve efficiency in separating and concentrating carbon dioxide from the exhaust of gas-fuelled power turbines.
The second phase will more comprehensively test the technology for another 1-2 years in a small-scale pilot project prior to integration at a larger-scale pilot facility.
The news comes as ExxonMobil and Chevron Corporation face votes at their annual general meetings this month aimed at forcing them to accept a 2C global warming limit, and more fully report their operations.
Shareholders are urging ExxonMobil and Chevron to stress test their business models against the 2C goal.
The same time last year, only 4% of Chevron investors supported a similar resolution, while Exxon blocked the vote entirely. Chevron’s board dismissed the analysis as “flawed, if not dangerous”
Since then, Financial Stability Board chair Mark Carney has spoken out about climate risk, pushing it up the mainstream agenda.
Norway’s $900 billion sovereign wealth fund, the seventh largest investor in both firms, added its weight to the campaign this week.
