Original | Jaime RamosEdited | M. Martínez Euklidiadas

Waste management in China currently involves waste incinerators ‘recovering’ its energy, a model formally called “energy recovery by incineration” or ERI. According to latest figures, China incinerates 102 million tons per year, an almost exponential growth since figures began in 2002 and which by 2021 will convert incineration into the default choice of waste management leaving behind recycling.

A few years back, the standard procedure was to throw waste into a landfill where it would lie for decades, an unsustainable practice that threatens local biodiversity. Although incineration emits greenhouse gases, in return it provides the growing Chinese economy with electricity. As the population concentrates in cities, China hopes to solve part of the problem with state-of-the-art mega incineration plants such as the one in Shenzhen

Waste to energy conversion: new generation of incineration plants in Shenzhen

Although the impact per capita is extremely low, the total volume of waste produced by Chinese cities such as Beijing, Shanghai or Shenzhen is hard to manage. SHL, the firm behind the new incineration plant in Shenzhen designed to eliminate waste and obtain electricity, suggest around 15,000 tons of urban waste per day.

The increased population of Shenzhen —from 300,000 inhabitants in 1980 to 13 million in 2018 and with an expected annual growth of 7%— make waste management quite complicated. Furthermore, the city’s total energy demand, despite being dense and having a low impact per capita, is colossal.

The new plant, covering an area of 112,642 m2, will be capable of ‘managing’, through incineration, a third of the current waste of the city of Shenzhen, generating 550 GWh of electricity each year, although part of that energy will be from renewable sources thanks to a solar roof covering an area of 44,000 m2.

The idea behind the new complex is to change the image of China’s existing waste incineration plants. To do so, they will install more advanced technological systems with a lower impact and, at the same time, they will use these facilities as an information point for the citizens of Shenzhen.

Chinese waste incineration management model: advantages and disadvantages

Given what we know today about global warming and greenhouse gas emissions like those that will be emitted by the Shenzhen plant, the waste incineration model is classified as highly contaminating although the names given to it are euphemisms like “waste recovery”, which is true and it is not reversed by emissions.

However, the accelerated growth of the population in some regions renders unfeasible the creation of waste treatment and recycling plants, which will soon be obsolete. In this regard, the Chinese model tries to minimize the emission of nitrogen oxides, sulfur dioxide, carbon monoxide, particulate matter and heavy metals, among other fuel contaminants.

Pros and cons of waste incineration

Many forms of waste, given their hazardous nature, do not have any management alternatives, as is the case with some sanitary waste that is incinerated to prevent any contact. Another aspect in favor of the use of this technology is obtaining power from the combustion, particularly in countries in which the mix is particularly contaminating like China.

The clear disadvantage of the model is the emission of toxic, dangerous and polluting gases (they are not synonyms) which has received harsh criticism both inside and outside of the country by the actual inhabitants of the city of Shenzhen. These criticisms have not stopped another 300 state-of-the-art incinerators being planned.

The incineration of municipal waste entails various indirect problems, the first of these by associating the energy dependency of the waste generated and its subsequent combustion. The second problem is the large quantity of ‘contaminants’ burned. Although the energy ‘recovery’ focuses on organic matter, paper and polymers, the truth is that all sorts of elements are burned including batteries. A particularly concerning event.

Which countries incinerate their waste?

China is not the only country to incinerate a large part of its waste. Although Sweden has closed its coal plants, the reality is that it still has 32 WtE plants, in which up to 1% of its waste can be burned, around two million tons of waste each year, and which also incinerates 800,000 tons of waste imported from the United Kingdom, Italy, Norway and Ireland. So these countries also incinerate part of their waste.

To the detriment of air composition, experts confirm that “the competent authorities in the EU are legally required to consider waste to energy recovery”. On the continent, __Switzerland is one of the countries that incinerates the most waste__ with the aim of generating energy and not having to treat the waste in an expensive recycling process. They call it “tackling waste“, and it involves burning 17% of PET bottles and 30% of batteries.

On the other side of the Atlantic, in central America there are very few of these recovery plants, therefore, waste tends to pile up in landfill sites as it used to in Europe. To the north, the United States incinerates 12.5% of its waste (although it will burn more because China has stopped importing waste). In the south, the figures are not very reliable, except perhaps in Argentina, which burns a great deal of waste.

The problem is even more serious in a large part of Africa, partly because waste incineration does not take place in controlled plants, instead the phenomenon takes place next to the landfill sites and includes burning electronic waste from Europe, North America, South America and Australia.

Is there an alternative to waste incineration?

Criticism of the waste management model has gained momentum in recent years, particularly after the figures from the IPCC special report on climate change or the health and air quality figures. This had led to increased pressure to find a consumption model that prioritizes reduction, reuse and recycling, that opts for the recirculation of materials or makes use of artificial intelligence and data management techniques.

China’s growth is making it rapidly acquire habits, which previously developed countries may soon abandon and which could serve as a transition between coal-oriented energy generation and a renewable energy revolution which is already generating benefits. At the moment, practically every country is still burning part of their waste.

Images | iStock/Denise Hasse, iStock/TomasSereda, iStock/c1a1p1c1o1m1