Here, new energy can be developed more effectively: fluctuating solar energy can generate stable electricity, and green hydrogen can be produced efficiently, conveniently and low-carbon.
Here, traditional fossil energy is used more cleanly: coal can be converted into clean and efficient grades, and carbon dioxide emitted from coal-fired power plants and coal chemical plants can also be efficiently "captured" and absorbed by microalgae or special chemicals.
Here, even domestic waste, sludge, straw, etc. can be transformed into clean energy sources, such as electricity and heat.
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Here is the State Key Laboratory of Clean Energy Utilization.
For several years, researchers have been striving to find an effective path to achieve clean, low-carbon, efficient, and intelligent development and utilization of energy.
The reporter will take you into the State Key Laboratory of Clean Energy Utilization at Zhejiang University, and explore how scientific researchers turn "waste" into treasure through technological innovation and realize the energy and resource utilization of solid waste.
Watermelon peels, vegetable leaves, paper, plastics, etc. in the garbage are all "treasures", which are processed into electricity and enter thousands of households.
Hangzhou Xiaoshan Jinjiang Green Energy Co., Ltd. is surrounded by water on three sides and lined with green trees... If it weren't for the carousel information on the display screen at the entrance of the factory, it would be difficult for people to associate it with the waste incineration power plant.
Here, the traditional concept of garbage is subverted, and watermelon peel, vegetable leaves, paper, plastic, etc. are all "treasures".
After storage and degradation, incineration, energy conversion and many other complex links, they become electric energy and enter thousands of households.
It is understood that this waste incineration power plant can "swallow" 1,700 tons of waste daily and "spit" 150 million kilowatt-hours of electricity annually.
Nowadays, such waste-cleaning incineration power plants are not uncommon in our country.
Clean incineration and disposal of waste has also become an important link in promoting the construction of "waste-free cities" in many places.
"Incineration power generation is currently regarded as an important means to realize the harmless, reduction and resource disposal of waste." Member of the Standing Committee of the Party Committee of Zhejiang University, Vice President, Director of the State Key Laboratory of Clean Energy Utilization, Solid Waste Energy and Clean Utilization Technology and Yan Jianhua, director of the National Engineering Research Center for Equipment, told reporters.
As we all know, human beings will inevitably produce garbage in the process of production and life.
The "garbage" is a broad concept, mainly refers to solid waste, such as domestic waste, construction waste, industrial waste, hazardous waste, sludge, and so on.
It can be said that each of us is a garbage maker.
If these wastes are not disposed of properly, they will cause serious pollution to the atmosphere, water and soil.
One end is connected to pollution reduction, and the other end is connected to carbon reduction.
How to dispose of these solid wastes in a harmless, quantitative and resourceful manner is an important part of the construction of ecological civilization and one of the important research directions of the State Key Laboratory of Clean Energy Utilization.
"Trash is a misplaced resource." This is what Yan Jianhua, who has been working on this field for more than 30 years, often says.
According to reports, for garbage that cannot be recycled, there are two main methods of disposal: landfill and incineration.
The disadvantages of landfill are obvious: with the continuous development of urbanization, the amount of landfill is increasing, and the "garbage siege" is inevitable, and improper landfill is likely to cause pollution and safety hazards.
Incineration has become an important waste disposal method.
According to Huang Qunxing, a member of the State Key Laboratory of Clean Energy Utilization and deputy dean of the School of Energy Engineering of Zhejiang University, after 2012, my country's domestic waste incineration has entered a period of rapid growth.
The "2020 Urban and Rural Construction Statistical Yearbook" shows that in 2020, there will be 463 municipal solid waste incineration plants in the country, with an incineration processing capacity of over 560,000 tons per day.
In that year, the waste incineration treatment rate in my country increased from 14% in 2006 to about 60%, becoming the mainstream waste treatment method.
According to the "14th Five-Year Plan for the Development of Urban Domestic Waste Classification and Treatment Facilities" issued by the National Development and Reform Commission and the Ministry of Housing and Urban-Rural Development, by the end of 2025, the national urban domestic waste incineration capacity will reach about 800,000 tons per day. , the municipal solid waste incineration capacity accounts for about 65%.
At present, some cities in my country have achieved "zero landfill" of domestic waste, and garbage disposal has entered the "incineration era".
For example, in Zhejiang, starting from 2021, in addition to emergency disposal, 49 landfills in the province will be fully terminated, becoming the first province in my country to achieve "zero growth" in the total amount of domestic waste and "zero landfill" disposal.
"The current waste incineration power plant is no longer the smelly appearance that people have in the traditional impression. Thanks to modern technological innovation, some are like a modern smart factory, and some have become an environmental protection park where the masses are competing to check in. "Professor Chi Yong of the State Key Laboratory of Clean Energy Utilization said that after waste incineration, not only the waste reduction has been achieved, but the incineration products can also be used for harmless energy and resource utilization.
It has made breakthroughs in key technologies such as circulating fluidized bed incineration of domestic waste, whole-process control and detection of dioxin, and detoxification of heavy metals in fly ash.
To the north of the library of Zhejiang University Yuquan Campus is the State Key Laboratory of Clean Energy Utilization.
In the middle of the ring-shaped office building, there are many "big guys" with different shapes - large-scale experimental benches.
From a distance, it looks like a big workshop.
Some are used to burn pulverized coal, some are used for desulfurization and decontamination, and some are specially used to incinerate garbage... It is with the help of these "big guys" that the laboratory research team has carried out various researches on the clean utilization of energy. , to explore an environmentally friendly way to use energy efficiently and cleanly.
"In this laboratory, we can realize the whole process test of incineration and power generation of different solid wastes such as domestic waste, hazardous waste, sludge, etc." Huang Qunxing told reporters that the energy research at Qingshan Lake, more than 30 kilometers northwest of Zhejiang University's Yuquan Campus There are also many large-scale experimental benches and advanced analysis and testing instruments at the base. "The domestic waste incineration power generation test platform there is larger, covering an area about the size of a basketball court, and can achieve clean incineration of 12 tons of domestic waste per day."
So, since it is clean incineration, where do the waste gas, waste water and waste residue from incineration go, will it cause secondary pollution?
The smelly combustion products - what to do with dioxins?
"This is the key and difficult point that our research team has overcome." Facing the reporter's question, Yan Jianhua explained that waste incineration is not difficult, but the difficulty is to achieve environmental protection standards and improve the efficiency of incineration and power generation.
In this regard, the laboratory research team has carried out technical, technological and equipment research on advanced and efficient thermal disposal of solid waste, efficient utilization of thermal energy, efficient purification of flue gas, dioxin detoxification and heavy metal stabilization, and safe disposal of fly ash and slag. The research and development and engineering application have made breakthroughs in key technologies such as circulating fluidized bed incineration of domestic waste, sludge dewatering and drying incineration, rotary multi-stage pyrolysis incineration of hazardous waste, whole-process control and detection of dioxin, and detoxification of heavy metals in fly ash.
Among them, domestic waste, sludge and hazardous waste incineration technology has successively won awards such as the National Science and Technology Progress Award.
The reporter learned that the components of garbage are complex, and the thermochemical properties and moisture content of different components are very different, which poses a huge challenge to efficient, clean and stable incineration.
Therefore, the clean incineration of garbage is not simply burning it, but a set of strict and meticulous technological processes.
Take the clean incineration of domestic waste as an example.
Before incineration, the domestic garbage needs to be stacked to reduce the moisture content, or be crushed, and then be grabbed and transported to the incinerator for incineration. , high pressure steam, drive steam turbine to generate electricity.
At the same time, waste incineration will also produce some pollutants, such as carbon monoxide, nitrogen oxides, sulfur dioxide and other conventional gas pollutants, heavy metals such as mercury, cadmium, lead, special organic pollutants such as polycyclic aromatic hydrocarbons and dioxins, and Slag, fly ash, etc. "Incinerators with different components generate different pollutants".
"Slag can be used to make bricks, but harmful flue gas, fly ash, etc. must be treated by the tail purification device and dust filter system before they can be discharged." According to Yan Jianhua, they proposed "source reduction, process block, removal and degradation. , monitoring and feedback" is a new concept of controlling the generation and emission of pollutants such as dioxins in the whole process.
Research has verified that dioxins will decompose after the flue gas after waste incineration stays in a high temperature environment above 850 ℃ for two seconds.
"In order to achieve this, it is necessary to design the furnace type according to the calorific value of the garbage to ensure stable working conditions, and the decomposition rate can exceed 99%. In addition, after the garbage is fully burned, some adsorption or catalytic degradation technologies will be used to remove the regeneration at low temperature. dioxins and other pollutants, so as to achieve harmless disposal." Professor Lu Shengyong of the State Key Laboratory of Clean Energy Utilization introduced that these technologies are relatively mature at present.
Artificial intelligence and big data make waste incineration power generation greener and more efficient
Although it was summer vacation, He Junjie, a doctoral student at the School of Energy Engineering of Zhejiang University, did not leave the school.
On the morning of July 28, he arrived at the laboratory (Yuquan Campus).
When the reporter contacted him, he was studying the formation mechanism of carbon black particles with the help of thermogravimetric analyzers, mass spectrometers and other equipment.
According to reports, with the continuous advancement of waste classification, more refined requirements have also been put forward for waste incineration equipment and technology, control conditions, and pollutant purification and disposal systems.
"We need to make corresponding adjustments and optimizations to equipment and technologies according to the characteristics of different solid wastes in order to reduce emissions and increase efficiency more effectively." He Junjie told reporters that with the help of artificial intelligence, big data and other means, the feeding system, furnace The intelligent diagnosis and control of the whole process of exhaust motion system, combustion system and flue gas purification system will greatly improve the stability of equipment operation and the ton of power generation of waste-to-energy, making waste incineration power generation more green and efficient.
Online real-time measurement of flame temperature field, waste composition and material layer thickness in the furnace, intelligent identification of the combustion state in the furnace, intelligent diagnosis and real-time optimization of the operation of the combustion system... A series of intelligent automatic control technologies have been developed and applied .
Kunming, Yunnan, produces about 8,000 tons of domestic waste every day.
More than 40% of the domestic waste will be sent to Zheneng Jinjiang Environment Kunming Xishan Waste-to-energy Power Plant and Wuhua Waste-to-energy Power Plant for disposal.
850℃ is a key indicator that domestic waste can achieve clean incineration.
In the past, to ensure stable combustion temperatures, waste incinerator monitors had to adjust parameters every 5 seconds.
Now, after the Kunming Xishan Domestic Waste Power Plant has installed a "brain" on the domestic waste incineration system, the hands of the incineration monitor are free.
If the equipment fails, the system will automatically alarm, and then manual intervention and adjustment can be done.
Not only that, the "method for online monitoring of dioxins by tunable laser spectroscopy combined with time-of-flight mass spectrometry" developed by the scientific research team of the State Key Laboratory of Clean Energy Utilization has obtained the 168-hour continuous detection map of dioxin emissions from waste incinerators for the first time in the world. , to solve the worldwide problem of real-time online rapid measurement of dioxins.
"The system can obtain real-time detection data of dioxin without gaps within a certain period. Through data accumulation and analysis, it can continuously feedback to optimize the incineration operation and clean production, and improve the operation level of the waste incineration power generation system." Yan Jianhua told reporters that the method has just been obtained. The 23rd China Patent Gold Award.
At present, the patented technology has been applied in many waste incineration projects in Zhejiang, Shandong, Chongqing and other places.
Our reporter Wang Zhen