 |
Lawrence Berkeley National Laboratory recently released a news report saying that one of their research teams is expected to invent a new power generation technology that uses carbon dioxide to generate geothermal power. At the same time, this method can also permanently block a portion of carbon dioxide underground. Currently, the technology is still in the design and testing phase. If it goes well, a pilot test will be conducted next summer.
This is a world-first new power generation method. This summer, the research team has just received $5 million in funding from the U.S. Department of Energy. Barry Freifeld, project manager at the Berkeley Laboratory, said that this is the first research project in the world to convert geothermally-heated carbon dioxide into electricity. It is also the first to reduce greenhouse gas emissions while also being able to use it. Geothermal energy is a demonstration project for clean energy.
According to reports, the technology injects carbon dioxide into the sedimentary layers that are 3,000 meters deep and 125 degrees Celsius underground. Under this condition, carbon dioxide will enter a supercritical state - both liquid and gaseous. After that, high-temperature carbon dioxide will be pumped to the ground and pressed into the turbine to convert thermal energy into electricity. Then, the cooled carbon dioxide is sent back to the ground and begins to circulate. After a period of time, part of the carbon dioxide will be permanently deposited. The system will add more carbon dioxide to keep the turbine running.
Currently, carbon capture and storage (CCS) technology is considered to be one of the major technologies for reducing global carbon dioxide emissions. It can make greenhouse gases emitted from burning fossil fuels not enter the atmosphere and slow down global warming. However, this technology is faced with the problem of expensive construction. And this new technology just can offset the high cost of geological storage of carbon dioxide through power generation.
This technology also facilitates the development of geothermal energy in arid regions. As early as 20 years ago, scientists at the Berkeley Laboratory and other research institutes proposed theoretically that supercritical carbon dioxide could be used instead of water. Their research has demonstrated that supercritical carbon dioxide is more suitable for obtaining geothermal energy from the ground than water. However, no one has made such an attempt before this project.
According to Freyfield, in the first phase of the project, scientists at the Berkeley Lab will use digital models to predict how the underground gas storage caves will improve as more and more carbon dioxide passes. Due to the rise from the ground, carbon dioxide can mix many hydrocarbons and water, and ordinary turbines are difficult to use directly. Therefore, U.S. Echogen Energy Systems will design a turbine that can use this much more carbon dioxide. Combining these two models, scientists can estimate how much energy can ultimately be obtained from carbon dioxide. At the same time, scientists at the University of Texas at Austin will analyze the environmental impact of the entire life cycle.
In the second phase, the research team will build and test the turbine. If they are progressing smoothly, they will conduct a pilot test and be selected for a CO2 injection project funded by the US Department of Energy from 2009. In this project, a storage cave with a depth of 3,000 meters has been formed, and it has been proved that carbon dioxide sequestration works well. In addition, many other infrastructures required for this test, such as injections and gas wells and pipelines, have already been completed.
This technology also exploits one of the disadvantages of traditional geothermal energy development. In traditional geothermal energy development, thermal energy loses 5% to 10% of water when transported underground. "But we just need some CO2 to stay in the formation," said Freyfield. "Our method just uses this loss to store CO2."
At present, scientists cannot estimate how much electricity this technology can actually produce for the United States. They say it depends on the scale of the CCS project and the maturity of underground high-temperature gas storage caves.
Engineered Parquet Wood Floors
Engineered Parquet Wood Floors,European Oak Parquet,Engineered Wooden Floors
Shaoxing Haohua Timber Industry Co., Ltd. , https://www.woodtopiafloor.com