Household waste can be burnt at ‘waste-to-energy’ power stations in order to generate energy for electricity or heating . How does this work?
Waste in many forms (paper, food, plastic, metal etc. ) is burnt at a power station . The heat created is used to evaporate water, producing steam which is then heated to about 380°C . The hot steam causes a turbine to turn, which runs a machine that generates electricity [4,5].
One benefit of burning waste is that less needs to go to landfill – the burning process still produces some waste that needs to be disposed of, but the volume (amount) is reduced by about 87% . It can also mean that less fossil fuel is used globally for generating energy . Although it would be better not to produce the waste to start with and generate energy from low-emission sources like wind, solar and nuclear [6,7].
However, there are major disadvantages to burning as a method of waste-disposal. Firstly, when waste burns it releases carbon dioxide into the atmosphere, contributing to climate change . In the future, this may be avoided by using chemical engineering to capture the CO2 released before it enters the air, but this technology is currently too expensive to be competitive [8,9].
Furthermore, burning waste releases toxic air pollutants such as sulphur dioxide [10,11] which makes rain acidic, killing trees , and is bad for human health, exacerbating breathing problems . One study found that women exposed to more pollution from waste burning stations in Italy had a higher chance of miscarriage during childbirth .
Many argue that we should not be burning materials, but instead be reusing and recycling them [15,16,17]. The idea is to have a ‘circular economy’ – materials that are no longer useful can be used to make new products . To achieve this, we would need a complete overhaul in how objects are manufactured and what happens to them when they are at the end of their (current) life .
 https://www.researchgate.net/figure/Schematic-of-the-waste-to-energy-WtE-plant-and-main-components-Red-dash-Grid_fig1_319994353 Download paper, and see materials and methods
 https://www.epa.gov/smm/energy-recovery-combustion-municipal-solid-waste-msw#HowWorks See: Energy recovery from combustion; The mass burn process
 https://www.bbc.co.uk/bitesize/guides/zbsdmp3/revision/1 See flow diagram – the water, turbine, generator stage of the process also applies to waste-to-energy plants
 https://www.ipcc-nggip.iges.or.jp/public/gp/bgp/5_3_Waste_Incineration.pdf See: Estimation of the specific emissions of a power plant mix per kWh Net, 690g CO2/kWh
 https://www.parliament.uk/documents/post/postpn_383-carbon-footprint-electricity-generation.pdf See: Fig 2, even the highest range bar (solar PV) emits fewer grams of CO2-equivalent (CO2 and other greenhouse gases combined) than waste-to-energy does for just CO2 (see reference [M)
 https://www.globalccsinstitute.com/wp-content/uploads/2019/10/Waste-to-Energy-Perspective_October-2019-5.pdf See: Waste-to-Energy + CCS
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