Coal-fired power plants chase "carbon", how to "capture carbon" for commercial use?丨"Carbon" Lushan City(2)
How do coal-fired power plants capture carbon and how do they use carbon?"We capture carbon dioxide in the flue gas in the plant, and cooperate with a company to establish a comprehensive test base for coal-fired flue gas purification, and carry out existing technology improvement and new technology research and development in many fields such as carbon dioxide capture, desulfurization, and denitrification in flue gas. Chen Jianhong, deputy director of the low-carbon research institute of Yuanda Environmental Protection Technology Company (hereinafter referred to as "Yuanda Environmental Protection"), told a reporter from China Environment News.
As we all know, thermal power plants are the "big contributors" of carbon dioxide emissions. So how do coal-fired power plants chase "carbon" and how can the "captured" carbon dioxide be reused by the downstream industrial chain? This reporter recently came to the Shuanghuai Power Plant in Hechuan District, Chongqing Municipality to find out.
How is carbon captured?
——Technology upgrading, the capture device has the characteristics of coal + gas
Walking into the test base, Chen Jianhong pointed to a large silver jar and said: "What is stored here is liquid carbon dioxide that has been captured and stored in an environment of minus 19 °C." ”
Chen Jianhong introduced that this device is mainly composed of flue gas pretreatment system, absorption system, regeneration system, compression drying system, refrigeration liquefaction system, etc. The flue gas of the coal-fired power plant after wet desulfurization treatment is introduced, and after the scrubber desulfurization, dust removal and cooling, the carbon dioxide in the flue gas is captured through the self-developed proprietary absorbent, the regeneration heat consumption is reduced by more than 40% compared with the traditional technology, the carbon dioxide capture efficiency is higher than 90%, and the carbon dioxide with a purity of greater than 99.5% can be obtained.
"It's like putting a big mask on a coal-fired power plant, filtering out clean gases that don't have any impact on the environment, and leaving carbon dioxide for centralized treatment. Chen Jianhong said figuratively.
The reporter learned that when it was initially completed and put into operation in 2010, this device was the first 10,000-ton carbon dioxide capture equipment for coal-fired power plants in China. After years of experimental research and process optimization, the chemical absorption carbon capture technology upgrade has been completed, and the newly transformed device has the characteristics of "coal + gas flue gas", realizing the double improvement of "absorbent + process flow", providing more possibilities for further expanding the use scenarios and scope, and the team also has a full range of capabilities from carbon capture technology development to engineering design, commissioning, operation and maintenance. In the next step, Yuanda Environmental Protection will continue to carry out the research and development of new phase change absorbers and processes on this device, and continue to improve the technical indicators.
How is carbon used?
——Connect with downstream users to give full play to the commercial value of captured carbon dioxide
What is the commercial use of high-purity carbon dioxide after it is captured? The reporter also found the answer here.
"You can make carbonated drinks directly, such as soda drinks such as Coke, which everyone usually drinks, or you can inject them into the oil field and store them in the oil field, and at the same time increase oil production. Chen Jianhong introduced that carbon dioxide has a wide range of industrial uses: in the machine casting industry, carbon dioxide is an additive, in the ceramic industry, carbon dioxide is a fixative, in the field of fire protection, carbon dioxide is a fire extinguishing agent, and in the agricultural field, carbon dioxide can be gas fertilizer......
"We have joined forces with Tsinghua University, Sichuan University and other universities and institutes to promote industrialization, and have achieved commercial operation, and are also actively promoting the establishment of cooperative relations with downstream enterprises, striving to develop the carbon emission reduction industry into a characteristic industry in Chongqing. Chen Jianhong told a reporter from China Environment News.
In 2022, Yuanda Environmental Protection and Shanghai Electric Power Co., Ltd. jointly built the first 100,000-ton full-process carbon capture project for welding shielding gas in China at Shanghai Changxingdao Thermal Power Plant - a full-cycle carbon dioxide capture and utilization innovation demonstration project for 100,000-ton coal-fired gas turbines.
The Changxing Island Thermal Power Plant in Shanghai is a major emitter of carbon dioxide, while several shipbuilders on the island are major consumers of carbon dioxide, using nearly 200 tons of carbon dioxide gas per day for welding protection. In the past, carbon dioxide could only be transported by water from outside the island, and gas-using companies had to invest in special CO2 storage and vaporization facilities, which was costly.
Changxing Island Thermal Power Plant has decided to launch the CCUS project, on the one hand, to help the power plant reduce carbon dioxide emissions, and on the other hand, to solve the problem of high-cost gas consumption of enterprises on the island, so as to achieve a win-win situation.
After the project is put into operation, carbon dioxide gas, which was originally regarded as a "burden", will be compressed, separated and purified to produce industrial-grade gaseous and liquid carbon dioxide, which can be transported to enterprises on the island for production and application through pipelines. As of the end of December 2023, it has accumulated more than 6,000 hours of continuous and stable operation, providing more than 50,000 tons of CO for surrounding enterprises2Products.
"This is the first commercial full-process CCUS demonstration project in China with the function of 'coal-fired + gas' flue gas carbon capture, which has a significant demonstration effect. It will diversify the innovation of carbon capture technology and carbon utilization scenarios, and will also promote the healthy development of industry industrialization. Chen Jianhong said.
