In a bid to make its air cleaner, Beijing has been eliminating coal-fired boilers and upgrading gas-fired boilers with low nitrogen combustion technology.
The city has eliminated 4,453 coal-fired boilers heating 13,259 tonnes of water per hour (T/h) this year, the local environmental protection bureau said. At the same time, improvement has been made to 7,000 gas boilers heating 23,000 T/h, so less nitrogen oxides will be produced.
As a result, the city has managed to cut over 10,000 tonnes of nitrogen oxide, 3 million tonnes of coal, 5,500 tonnes of smoke and 6,600 tonnes of sulfur dioxides this year.
The sulfur dioxide emitted by coal-fired boilers and the nitrogen oxide emitted by gas-fired boilers can both become sources of PM2.5 after chemical reactions.
Over the past five years, Beijing has eliminated coal-fired boilers heating 39,000 T/h, and about 99.8 percent of the city's coal-fired boilers have been removed, cutting the use of coal by nearly 9 million tonnes.
The density of sulfur dioxide has been reduced from 28 microgram per cubic meter in 2013 to 8 microgram per cubic meter as of the end of October.
Beijing has finished the work of replacing coal with clean energy -- electricity or gas -- in 700 villages so far this year, according to the municipal commission of rural affairs.
Since 2013, about 900,000 households in 2,036 villages have shifted from coal to clean energy, cutting the use of coal by 2.7 million tonnes per year.
