Research on power plants that generate "carbon nanotubes" from CO2 to zero carbon dioxide emissions is ongoing
Efforts to reduce carbon dioxide (CO 2) emissions, one of the greenhouse gas emissions, are urgently required around the world, and researches on reduction measures are under way in various fields. Among them, a lot of CO 2 is emitted from power plants that produce electricity, but it is necessary to take out the carbon contained in the gas discharged during power generationcarbon nanotubeResearch is being carried out to make CO2 emissions zero, by creating more substances with higher added value by making more products.
Researchers assess power plants that convert all of their CO2 emissions into carbon nanotubes
Thermodynamic assessment of CO2 to carbon nanofiber transformation for carbon sequestration in a combined cycle gas or a coal power plant
CO2 is emitted in various fields, but the statistics that the emissions from the energy field are mostly occupied are announced. In the case of Japan,Direct emissionsData on the fact that CO2 emissions from the energy conversion sector occupy 40% of the total are also announced.
4-4 CO2 emissions by sector in Japan (FY 2014) - JCCCA National Center for Global Warming Prevention Promotion Center
Mr. Jason Lau of the University of Washington in the USA collects all of the CO2 contained in the exhaust gas from such a power station and further from there the device that can produce carbon nanotube which future development is strongly expected in the materials field I am doing research on. This device is the same as obtaining oxygen and hydrogenElectrolysis, It is possible to decompose carbon dioxide contained in exhaust gas into carbon and oxygen and recover it.
In principle, this device is effective for all types of generators that burn fuel (= carbon dioxide is emitted) and it is effective for all types of generators, but Lau et al., In particular, use this device for gas turbine power generation and steam turbine power generation CombinedCombined cycle power generation(CC power generation) in the system. In conventional CC power generation, as shown in the following figure, first, power is generated by the upper gas turbine, water vapor is generated by the heat generated at that time, and the steam turbine is turned to make the second power generation . In other words, it is an efficient power generation method in the sense that it performs power generation twice by one combustion, basically the exhaust gas containing CO2 is released to the atmosphere as it is.
Meanwhile, a device that Lau et al. Can proceed with injects exhaust gas from a gas turbine into an electrolytic cell filled with molten carbonate of lithium, applying oxygen from the electrode to generate oxygen from the anode (anode) and It is a mechanism to take out carbon from the cathode. However, carbon nanotubes are not produced as it is. Therefore, by adding a trace amount of nickelNucleationTo generate carbon nanotubes with a hollow structure is adopted.
The generated carbon nanotubes can be divided into net type and straight shape type by controlling the conditions inside the electrolytic cell. By extracting and crystallizing carbon which was conventionally discarded as part of the exhaust gas, it becomes possible to be born again as a high added value product that can be used as any industrial material.
According to Lau et al., In addition to CO2 reduction, this "high added value" is a major point. In conventional CC power generation, we generated 2.94 tons of CO2 while generating electricity equivalent to 909 dollars (about 96,000 yen) from 1 ton of methane fuel. On the other hand, the power generation system incorporating this device generates electricity equivalent to 835 dollars (about 88,000 yen) from the same methane fuel. Although the power generation efficiency itself drops by about 8%, in exchange, the amount of CO2 emissions is completely reduced to zero, and by generating 0.75 tons of carbon nanotubes, it is possible to reduce the amount of CO2 emissions by 225,000 dollars We estimate that you can expect a large income such as).
This technology is still in the stage before commercialization, but Lau et al. And others can respond to this scale according to scaleScalabilityIt is said that it is equipped. In other words, it is possible to correspond basically from a small power plant to a huge large-scale power station, and it is considered possible to respond to fuels such as gas, oil and coal, so there is a certain existence in the future CO2 policy It may be to say that it is a technique to show feeling.