Coal Combustion in China
China is a country with coal as its main energy source. The raw coal still accounts for 75 percent of the total energy consumption, although various kinds of energy such as oil, natural gas, hydropower and nuclear power have been developed in recent decades. In the structure of coal consumption, the civil use of coal in China occupies a higher proportion than otherwise common in developed countries, amounting to about 30 or 40 times of those in Japan and US. Moreover, coal contains a high rate of sulphur and ashes.
Atmospheric pollution results mainly from coal-burning. Soot and sulphur dioxide were the major pollutants. In 1997, the total amount of sulphur dioxide emissions was 23.46 million tons, to which, industrial polluters contributed 18.52 million tons, accounting for 78.9% of the total SO2 emissions and domestic polluters contributed 4.94 million tons. With regard to the industrial emission of SO2 industrial enterprises at the county level and above contributed 13.63 million tons, accounting for 73.6% of total industrial emissions; the amount of SO2 emission by TVIE's was 4.89 million tons. The total amount of soot emission was 18.73 million tons, accounting for 83.6%; while domestic emission was 3.08 million tons. With regard to industrial soot emission, enterprises at and above county level were responsible for 6.85 million tons, accounting for 43.8% of the total; while TVIEs were responsible for 8.88 million tons. The total emission of industrial particles was 15.05 million tons, including 5.48 million tons of emission by enterprises at the county level and above (account for 36.4% of the total emission of fine industrial dust), and Township and Villages Industrial Enterprises (TVIE)'s emitted 9.57 million tons.
Acid rain was very serious in central and southwestern China, with notable increases in the southwest. Some areas in the north such as Tumen and Qingdao regions also suffered serious acid rain problems.
State of Acid Rain
Acid rain has mainly been distributed in the areas to the south of Yangtze River and to the east of the Qinghai-Tibet Plateau and in Sichuan Basin. In Mid-China, Southwest-China, East-China and South-China acid rain has reached or passed the critical load.
In 1996, the air pollution caused by acid rain was universally serious and the affected areas were expanded, covering 30 percent of the total territory. According to the monitoring data for 84 cities within the State-controlled-Network, the number of cities with annual average pH value of acid rain lower than 5.6 was 43.The acid rain frequency was higher than 60% in 24 cities.
In 1997, the annual average pH value of precipitation varied from 3.74 to 7.79.
There were 44 cities with annual average precipitation pH values lower than 5.6, accounting for 47.6% of the total number of the cities that were monitored. Of the southern cities (those south of the Yangtze River), 75% had average pH values lower than 5.6. Changsha, Zunyi, Hangzhou, and Yibin had the pH value lower than 4.5. Among the cities under monitoring, 71.7% of southern cities saw the occurrence of acid rain. Moreover, in 3 of the cities that were monitored, Changsha, Jingdezhen and Zunyi, the acid rain frequency was higher than 90%. Among the northern cities, Tumen, Qingdao and Taiyuan have seen precipitation with average pH values lower than 5.6.
Central China was the area that suffered most from acid rain, with the average pH value of precipitation lower than 5.0, and the acid rain frequency higher than 70%.
The acid rain pollution in the southwestern areas was also very serious. With the exception of Chongqing, the average pH value of the central districts was lower than 5.0 and the acid rain frequency was 70%
The acid rain in southern China was mainly distributed in the Pearl River delta and central and eastern areas of Guangxi. In 1997, the average pH value of precipitation was higher than that of the precious year, but the acid rain frequency had increased.
In the north, rain in Qingdao and Tumen was of a low pH value and the frequency of acid rain was relatively high. These two areas were the ones in the north to suffer most frequently from acid rain.
Use of lime to reduce acidification damages
The Chinese government has made great efforts and made significant progress in energy saving and consumption reduction. The energy consumption amount for every ten thousand RMB(Chinese Currency) worth of GNP has gone down year by year over the past two decades. The rate of smoke and dust removal from industrial waste gas has been reduced. In industry, the government has taken technical measures like the introduction of levying charges for pollution emissions and issuing license for discharging air pollutants.
In 1997, the rate of smoke prevention and particulate and dust control reached 88.4%, and the rate of gas emissions. The rates were 90.4% and 79.4% respectively for industries at and above the county-level, which increased by 0.4 and 4.4 percentage respectively. During the implementation of "China's Trans-century Green Project Plan", air pollution treatment and investment was increased. In 1997, 42 projects on air pollution control and prevention were completed, and there were 112 projects under construction.
In order to mitigate the acid rain, the government adopted a series of measures to help with the prevention of acid rain, such as the adoption of clean coal, energy conservation and desulphurization technologies. Some economic policies were carried out, such as levying on sulphur dioxide emission, implementing total amount control and promoting energy conservation. In past 20 years, there have been annual decreases in the amount of energy consumed per 10,000 Yuan (RMB) GNP (1 USD = 8.23 RMB).
Political goals in China
• To establish two Control Regions
For key regions that were affected by acid rain or SO2, China government plan for SO2 Controled Regions and Acid Rain Controled regions.
• To proceed to total amount control
In 2010 year , the total amount of discharged pollutants in industrial wastewater and the total amount of industrial waste discharged shall be lower than 1995 .Industrial emissions of dust, and discharges of COD and oil in wastewater shall be maintained at the same levels as in 1995.The capacity of treating SO2 emissions should be increased significantly.