Reducing Rubbish: Incinerators in China

waste to energy plant in Shenzhen China built by Keppel Seghers.  Image from http://www.keppelseghers.com/

As China urbanises, its cities are producing a lot more rubbish. They are running out of good places for landfills and are turning instead to burning rubbish, generating electricity at “waste-to-energy” plants.. About 70 such incinerators are now being built, in addition to more than 180 in operation. Cities increased their capacity to incinerate waste tenfold in the decade to 2013, allowing the country to burn more than a quarter of its formally collected urban rubbish. Techsci Research, a consultancy, expects the market for incinerators in China roughly to double in size by 2018, much faster than the pace worldwide.

Cities in Japan and several European countries burn a higher proportion of their rubbish and recycle a lot of the rest (although only Japan ranks ahead of China in tonnes burned per day). Most rubbish in China ends up either in landfills or in unregulated heaps outside cities, where it gives off methane as it decomposes. There is a lot of informal recycling: people pick through rubbish at dumps looking for items such as plastic bottles that can be sold to recycling factories. But the heaps contaminate the soil and groundwater. Plastics flow down rivers into the sea, harming ocean life. A recent study concluded that China was by far the biggest source of plastics in the oceans… Building [incinerators] will require the government to do more to earn the trust of a public that is rightly suspicious of official pledges to protect the environment. Some older incinerators have not burned as cleanly as promised, belching foul-smelling smoke from their furnaces.

The latest generation of incinerators in China may help to overcome public scepticism. Shanghai is the city producing the most household rubbish in the country: 22,000 tonnes a day. Space for new landfills is becoming scarce as existing ones reach capacity, including China’s largest, Laogang, on the coast near the city. Each day about a seventh of the city’s rubbish glides past that landfill by barge to be dumped into two large pits at an incinerator next door. In odourless rooms overlooking each pit, workers use joysticks to manipulate gigantic German-made steel claws a bit like the ones in fairground games used to retrieve sweets and toys. The claws descend and close their jaws, grabbing seven or eight tonnes at each go. The workers then move them up towards the pit’s high ceiling and drop the waste into furnaces built with technology from Germany, Japan and elsewhere.

The waste burns at temperatures of 850°C or higher, hot enough to eliminate toxic dioxin pollutants. The gases heat water to produce steam, in turn driving turbines that generate electricity. On a recent visit to the site, there was no detectable odour outside. Digital displays monitored emission levels of sulphur dioxide, carbon monoxide and other pollutants. Zhang Yi, a senior manager at SMI Environment, a local state-owned enterprise that runs the Laogang furnaces, says its facilities were built to “the strictest standard” in the world. A high proportion of imported technology and a need for careful operation make SMI’s incinerators expensive to build and operate, Mr Zhang says. State-owned companies, he insists, have a special responsibility to the public.

Normally this sort of claim makes Chinese citizens scoff. Many of the factories and mills that have polluted rivers or made skies smoggy are state-owned…Environmental-impact assessments must be done, but these are paid for by the people who are building and approving the projects. Favourable assessments lead to more work and unfavourable ones to less. Neighbours of a planned project are often consulted in a desultory way, despite legal requirements for notices and hearings. The more controversial a project is, the less likely that rules about public consultation will be obeyed, and the more likely that nastier tactics, including hired thugs, will be relied upon to silence critics.

The Laogang incinerator is one of several that burn 3,000 tonnes of rubbish a day, including one in Beijing; the one in Hangzhou will be another. A planned new burner, to be completed in 2017, would make the Laogang facility the largest in the world, burning 9,000 tonnes a day. The goal by then is to increase the share of Shanghai’s household waste that is incinerated from about a third to three-quarters.

Nationally, China’s planners had wanted 35% of urban household waste to be incinerated by the end of 2015…[But]Incinerators are insatiable beasts and must keep being fed rubbish for decades to be economical. The more of them there are, the less incentive there is to recycle, and to produce less rubbish in the first place. But at present, as China’s waste problem keeps growing, the country most certainly needs to keep on burning.

Waste disposal: Keep the fires burning, Economist, Apr. 25, 2015, at 42

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