Thermodynamic assessment of CO2 to carbon nanofiber transformation for carbon sequestration in a combined cycle gas or a coal power plant

Our environment is now largely threatened by the climate change caused by emission of greenhouse gases especially carbon dioxide (CO₂). The amount of CO₂ in atmosphere continues to increase. Fossil fuel combustion which is used for electricity generation in power plants act as the main source for the emission of CO₂. Hence there arises a need of CO₂ transformation technology to reduce the amount of CO₂ in the atmosphere.

Researchers led by Professor Stuart Licht from George Washington University studied the thermodynamic feasibility of transforming the exhaust CO₂ from a combined-cycle natural gas power plant into a stable, valuable carbon nanofiber product using a lithiated carbonate high temperature electrolysis system.

This auspicious technology for CO₂ transformation includes electrolytic synthesis of carbon and carbon nanofibers (CNF). Here CO₂ is captured in molten lithium carbonate. To split the CO₂, voltage is supplied in the electrolyte chamber on a nickel anode and a galvanized steel cathode into pure oxygen gas and a solid carbon product. The CO₂ in the molten lithium carbonate split into carbon and oxygen. So these CO₂ either in atmosphere or natural gas power plants are electrolyzed with addition of some nickel into different forms of carbon like hollow carbon nanofibers, carbon nanotubes which are good in strength, conductivity, flexibility, and durability.

To evaluate the thermodynamic feasibility of transforming the exhaust CO₂ from a combined-cycle  natural gas power plant into a stable, valuable carbon nanofiber product using a litigated carbonate high temperature electrolysis system, two heat engines are utilized by the combined cycle gas turbine power plant to convert heat energy into mechanical energy, which is then transformed into electrical energy. These present power plants used for treating fossil fuels emitting CO2 in large amount.

In the carbon sequestration technology the electricity and carbon nanotubes can be cogenerated and that the CO₂ emission eliminated. And also it does not require a CO₂ pre-concentration step to eliminate the CO₂ emission.

The CC CNF appends a high-temperature molten Lithium carbonate electrolyze to a CC power plant design to remove exhaust CO₂ and convert it into a valuable carbon nanotube product. The CNF transformation is readily available CNF will be useful mostly in the industries of automobile, airline, trucking, shipping, etc.

As estimated in thermodynamic assessment, the energy saved from preventing CO₂ emission and the energy gained from only hot CO₂ instead of cold CO₂ adds to cost effective process of electrolysis. Through the secondary product of electrolysis, the energy output is increased substantially and enriched oxy fuel mixture can also be taken out efficiently. This study demonstrated that CC CNF carbon sequestration technology can reduce of CO₂ emission effectively.