China’s capital has become notorious for its smog but the biggest contributors to local air pollution are industrial furnaces, district heating systems, residential fires and trucks rather than power plants.
Industrial firms, heating plants and residential fires in the capital and neighbouring provinces consume 240 million tonnes of coal per year compared with about 130 million tonnes burned in power plants.
There are many ways to assess pollution but one of the most common is to measure the amount of tiny particulates measuring 2.5 micrometres or less in diameter (PM2.5) suspended in every cubic metre of air.
These tiny particles, which can be inhaled deep into the lungs, have been blamed for a variety of cancers and other respiratory diseases by the World Health Organization.
In 2013, the air over Beijing contained an average of 88 micrograms of PM2.5 per cubic metre, compared with just 14-16 micrograms in the air over London or New York.
Pollution in the neighbouring megacity of Tianjin and the surrounding province of Hebei was even worse at 113 micrograms per cubic metre.
Pollution is responsible for more than half a million early deaths each year across China according to researchers at Tsinghua University (“The true cost of coal” 2014).
The problem is much worse in the north of the country, according to official data on air quality compiled by the National Bureau of Statistics (http://tmsnrt.rs/1TzIwXJ).
Life expectancy in China’s northern cities is 5.5 years lower than in cities in the south, where the air is cleaner (“Evidence on the impact of sustained exposure to air pollution on life expectancy,” Chen et al, 2013).
HEAVY INDUSTRIAL HUB
Coal-fired power plants are often blamed for the smog, but while they are major emitters of carbon dioxide and contribute to climate change, they are not the main cause of local air pollution.
The biggest contributors are industrial processes, including steel, cement and coke manufacturers, as well as residential fires, district heating systems and transport.
Bejiing, Tianjin and Hebei, collectively known as Jing-Jin-Ji, are home to a total population of 130 million and account for roughly 10 percent of China’s GDP (“Sustainable economic transition: how Jing-Jin-Ji can lead the way”, Paulson Institute, 2015).
The economies of Beijing and Tianjin are mostly based around services and government administration, but Hebei contains some of the largest concentrations of energy-intensive heavy industry in the country.
Hebei produced 5 percent of all the cement, 13 percent of all the coke, 15 percent of all the plate glass, and 25 percent of all the steel in China in 2013, according to the National Bureau of Statistics.
Hebei on its own produces more steel every year than the next largest steel-producing country, Japan.
Many factories in the region have inefficient boilers and furnaces, outdated equipment and few if any pollution controls.
DISTRICT HEATING SYSTEMS
Pollution from industry is compounded by emissions from thousands of district heating systems.
Most of the heating for homes and offices in Beijing, Tianjin and the larger cities in Hebei is supplied by district heating systems, nearly all of which are fuelled by coal.
In a typical system, coal is burned in a central furnace to heat water which is sent at high temperature through a system of large diameter pipes before being piped at lower temperatures into individual homes and offices.
A few systems have been updated to use modern combined heat and power plants (CHPs) that produce electricity as well as hot water but most still rely on older less-efficient heat-only boilers (HOBs).
The sector remains fragmented and has been slow to modernise. In 2012, there were more than 2,700 district heating providers in Beijing alone (“Enhancing the Institutional Model for District Heating Regulation”, World Bank, 2012).
Most of them employ old and inefficient equipment fitted with inadequate pollution controls so fly ash, particulates and oxides of sulphur and nitrogen go straight up the chimney.
“District heating systems were built step by step following heat demand growth, driven by China’s rapid urbanization,” according to the World Bank.
“As cities grew, heating plants became surrounded by higher population densities, increasing population exposures to related air, noise and other pollution.” “As urban areas continued to expand, coal-fired boilers surrounded the city, with some smokestacks barely clearing apartment building rooftops” (“Hebei clean heating project”, World Bank, 2015).
The problems are compounded because in most cases customer bills are based on the size of the building rather than the amount of heat actually used so customers have no incentive to use heating efficiently.
Heating consumption in China is three times higher than in developed countries with similar climates and indoor temperatures, according to the World Bank.
District heating systems consume prodigious amounts of coal and the environmental impact is concentrated because they operate for only about five months of the year.
If district heating contributes to pollution in urban areas, in rural areas most heating is still supplied by burning coal or crop stalks, with no pollution controls at all.
Despite its closeness to Beijing and concentration of industry, half of Hebei’s population is still classified as rural, and even in smaller townships many households and offices rely on small fires and furnaces for heating.
CLEANING UP THE AIR
In 2012, coal combustion across Jing-Jin-Ji by industrial plants (180 million tonnes), district heating systems (31 million tonnes) and residential users (18 million tonnes) outstripped coal use by power plants (130 million tonnes).
Spurred by growing concerns about the health impact of worsening smog, China’s central government and the provincial administrations in Beijing, Tianjin and Hebei have agreed a set of action plans to cut pollution.
The plans employ a mix of structural adjustments (designed to change the mix of industry in the area) and end-of-pipe controls (designed to cut emissions from processes that remain).
For example, Beijing has announced plans to shut down all coal-fired power plants within the city limits, reduce the number of cement kilns, and close a large number of coal-fired heating plants or convert them to gas.
Hebei has plans to shut 29 smaller thermal power plants, shut down 61 million bonnets of cement production capacity, and convert 140 million square metres of centralised heating systems from coal to gas.
Beijing, Tianjin and Hebei all have plans to require power plants, heating plants and industrial users to fit more pollution control equipment (“Can Beijing, Tianjin and Hebei achieve their PM2.5 Targets by 2017?” Clean Air Alliance of China, 2015).
The World Bank is supporting the efforts to cut pollution with loans designed to upgrade district heating systems.
The Bank has already lent $100 million to help modernize the district heating system in Urumqi, capital of Xinjiang Uighur Autonomous Region, and one of the most polluted cities in the country.
The Urumqi project is replacing hundreds of old small heat-only boilers with a small number of larger and more efficient combined heat and power plants (“Urumqi District Heating Project,” World Bank, 2011).
Part of the Urumqi project is the installation of improved metering and control systems across the network that could eventually be used to bill customers based on the amount of heat they use rather than their floor space.
Last month, the Bank approved a similar $100 million project to upgrade district heating systems in Hebei in the cities of Chengde, Xingtai and Zhangjiakou, as well as Pingshan county.
The project includes upgrading some boilers and converting others to gas, extensions to the pipeline network, and the installation of improved control systems and heat meters.
Upgrading district heating offers some of the most direct opportunities for improving environmental quality in China’s northern cities, according to the World Bank.
The idea is to create best practice and expertise that can be applied in other cities.
In the short term, replacing old coal-fired heat-only boilers with modern gas-fired boilers or CHP plants offers the biggest benefits.
In the longer term, the introduction of consumption based billing is probably the most important step, by creating incentives to use energy more efficiently.
