As of the end of 2010, China's large scale, high efficiency, energy-saving emission reduction effect of wet granulation carbon black production capacity has reached 5.3 million tons, ranking fifth in the world for the first time. Although the current production capacity of wet granulation carbon black accounts for 94% of the total capacity of the carbon black industry, and the lagging dry granulation carbon black has been eliminated, the carbon black industry has not slowed down the pace of technological innovation. On the eve of New Year's Day in 2011, information from the China Rubber Industry Association's carbon black section and related production companies showed that the carbon black industry is still planning and practicing to continuously improve the level of low-carbon development.
Tail gas power generation into efficiency highlights
In the past, during the production of dry granulated carbon black, a large amount of carbon black exhaust gas was directly discharged into the atmosphere, polluting the environment and wasting resources. After the wet granulation process is popularized and applied, carbon black tail gas becomes a prominent highlight of emission reduction and efficiency enhancement.
At present, there are three ways to increase the value of carbon black tail gas: first, use an exhaust gas boiler for power generation; second, set up a quench boiler and a waste heat boiler and sell the generated steam to the companies; third, sell the carbon black tail gas directly to supply local residents. City gas. The power generation capacity per 10,000 tons of carbon black exhaust gas can reach 1,400 kilowatts, and the production of one tonne of carbon black can generate approximately 1,120 kilowatt hours, which is equivalent to a reduction of 1.12 tons of CO2 emissions.
According to the statistics of the China Black Rubber Association of the China Rubber Industry Association, the carbon black power generation capacity that has been built and under construction in 2010 is 74,000 kilowatts. According to the calculation of full-load power generation, the amount of power generation in 2010 is as high as 2.8 billion kWh, which is equivalent to reducing CO2 emissions by 2.8 million tons. It can be seen that the most effective use of carbon black tail gas is tail gas power generation, which is also the most effective way to reduce carbon dioxide emissions.
It is worth noting that because some enterprises' carbon black emission exceeds their own power consumption, they need to be connected to the local power supply department for power transmission. Many companies have encountered difficulties in this process. In some localities, the power sector is not allowed to transmit power because of transmission instability. For example, a company's electricity tariff is 0.8 yuan/kWh, while carbon black companies send electricity to the grid at a price of only 0.1 yuan/kWh. Some places do not even pay a penny, allowing companies to send electricity. This phenomenon is relatively common, especially in recent years. The company called for: It is necessary to make such initiatives as networking and power transmission to promote the implementation of energy saving, emission reduction, environmental protection and low-carbon development.
Promote new filter bags to cure pollution
Carbon black dust is one of the major sources of environmental pollution. Wet granulation of carbon black reduces carbon black dust from the source of the process. However, to thoroughly eradicate dust pollution, carbon black filter bags and carbon black collection systems are particularly important.
Glass fiber filter is a new type of high temperature glass fiber needle felt filter material with excellent performance. In the 90s of last century, the Nanjing Glass and Fiber Research Institute has put into production glass fiber needle felt felt filter media and bulk yarn filter media. The felt fiber is a three-dimensional microporous structure of a single fiber, which has a high porosity and a low filtration resistance to gases. The filtration effect can reach 99.5% to 99.8%. Using this technology, the carbon black dust content can be controlled within 18mg/m3, and the Ringermann blackness (observing the blackness of the smoke from the chimney by naked eye) can be controlled below the first level, and can all meet the national environmental protection standards. At present, this technology has matured and has been applied in more than 90% of the domestic carbon black enterprises.
Full popularity of high-temperature air preheater
The main purpose of the air preheater is to recover the system's residual heat, enhance the reaction conditions, increase the heat value of the exhaust gas, reduce the bagging load, and increase the yield and yield of carbon black, thereby reducing the consumption of carbon black feedstock oil. Theoretically speaking, the higher the temperature of the air preheater, the better, but limited by the material of the air preheater, the high temperature will affect the service life of the equipment. In the 1980s, the temperature of the air preheater imported from abroad by the carbon black industry was 650°C. At that time, the average consumption of raw material oil was about 2.2 tons/ton. As energy becomes increasingly tense, the adoption of highly efficient energy-saving equipment has become an urgent need for the carbon black industry.
In 2004, Qingdao Deguite introduced the 950°C high-temperature air preheater for the first time and put it into operation. However, the current maximum temperature of foreign air preheaters abroad is only 900°C, indicating that the domestically produced high-temperature air preheater has already occupied the international level. Leading level. Over the past few years, the domestic newly-built carbon black production line has almost adopted the 950°C high-temperature air preheater. The original production line also eliminated the 650°C air preheater through technical transformation, and modified the 950°C high-temperature air preheater.
According to incomplete statistics from the China Black Rubber Branch of the China Rubber Industry Association, as of now, more than half of the carbon black production lines are equipped with high-temperature air preheaters. Enterprises in the production process, through the adjustment and testing of process parameters, generally control the temperature at 850 °C. The use of high-temperature air preheaters can not only improve the yield of carbon black, but also increase the heat value of carbon black exhaust gas at the same time. The production cost is greatly reduced, which brings huge economic benefits to the company.
Another energy-saving measure in the carbon black industry is the replacement of carbon black fuel oil with natural gas or coal gas. Generally, carbon black fuel oil consumption accounts for about 10% of the total raw material oil consumption.
After the above two major measures are implemented, the average raw material oil consumption in the carbon black industry will decrease year by year. During the “Twelfth Five-Year Plan” period, the target of the carbon black industry is that all the production lines are equipped with exhaust gas power generation devices and high-temperature air preheaters, to achieve zero discharge of sewage, and to use 5 to 7 world-renowned carbon black companies.
