Waste incineration, in the eyes of many people, seems to produce secondary pollution, and the dioxin produced in it alone makes people talk about it. However, for advanced waste disposal countries such as Germany and Japan, incineration is the highlight, even the key link, of waste disposal. In these countries, dense waste incineration plants have not been generally rejected by the people. Why is this?
Work hard on harmless treatment
The reporter recently visited the Taisho Waste Treatment Plant under the Environmental Bureau of Osaka City in Japan. Here not only greatly reduces the amount of Waste by incinerating combustibles, but also efficiently utilizes waste heat to generate electricity and provide heat energy, which can be said to serve multiple purposes.
The prerequisites for waste incineration to play multiple roles at one stroke must be safety and low pollution. The reporter saw in the factory area of the Dazheng Waste Treatment Plant that the huge Waste shaft is 40 meters deep and has a capacity of 8,000 cubic meters, which can hold about 2,400 tons of Waste. The staff remotely controls the crane behind the glass curtain wall at the top, and can grab 3 tons of wastes at a time and send it to the incinerator.
Although there is so much Waste, there is no disgusting smell in the factory area. This is because the odor generated by the Waste is extracted by the exhaust fan, heated to 150 to 200 degrees Celsius by the air preheater, and then sent to the incinerator. Due to the high temperature in the furnace, the odorous substances are all decomposed.
In order to avoid the production of carcinogen dioxins during incineration, the incinerator uses a high temperature of 850 to 950 degrees Celsius to completely burn the Waste. Through the monitoring screen, the staff can watch the situation inside the incinerator in real time.
The dust generated during the waste incineration process is absorbed by an electric dust collector, and the exhaust gas is also processed by washing devices, filter dust collection devices, etc., and is discharged from the chimney after meeting safety standards.
The final ashes formed after combustible waste incineration are only about one-twentieth of the original volume, and some harmful substances that cannot be completely avoided are harmlessly treated with drugs. The ashes were finally transported to Osaka Bay for landfill.
Of course, waste treatment plants that focus on incineration also have a value-added business, which is to extract useful resources for large non-combustible waste such as iron cabinets, mattresses, and bicycles. There are also various large-scale crushing equipment in the factory. After the above-mentioned substances are finely crushed, the metal part is selected by a magnetic separator and sold as a resource; while the paper and rags attached to the metal are removed by wind screening, and the Other combustible parts are sent to the incinerator together.
The heat generated by waste incineration is used to make steam, which is then piped to steam turbines for power generation. The heat can also provide hot water and heating for factories at the same time. In 2011, about 133,400 tons of Waste were incinerated here, the power generation reached 19.1 million kwh, the electricity sales were 2.86 million kwh, and the income reached 23.4 million yen.
According to reports, in Osaka alone, there are still 7 waste treatment plants like Taisho. Throughout Japan, the good operation of many municipal waste incineration plants is of great significance to avoid problems such as “Waste siege” and “landfill pollution of water sources”.
Post time: Mar-15-2023