What's wrong with burning our waste?
Resource Conversation
Waste-to-energy technologies use discarded materials to create a limited amount of energy or fuel in a one-time process rather than returning them to the production cycle. This means we must continue to extract more resources from the Earth to make new materials and products. These technologies are capital intensive and typically designed for 20 to 30 year lifespans. They depend on a steady stream of waste material to burn, which makes the case for maintaining waste flows rather than reducing them. This has the effect of locking communities into the linear “take-make-waste” economy by extracting and processing virgin materials only to waste them at the end. For every item that is turned into enegy or fuel, a new one must be manufactured from raw or virgin resources.
Climate Impacts
Waste incineration is not a climate-friendly waste management option. When discarded materials like plastics, paper, textiles, food and wood are burned, their stored carbon is released into the air. Depending on the composition of the waste stream, each ton of solid waste incinerated typically generates between 0.7 and 1.8 tons of greenhouse gases.
Applying high temperatures in a pyrolysis or gasification system to break plastic waste down into burnable fuels and/or small amounts of chemicals has the same climate drawbacks as conventional waste incineration. Most plastics are manufactured from petrochemicals sourced from crude oil and fracked natural gas. This means plastic-derived fuel functions as another fossil fuel. Plastic-to-fuel systems generate synthetic gases and oils. The gases are burned on-site to power the facility, while the liquid products are converted into diesel or aviation fuel that is burned for energy offsite.
From a climate mitigation perspective, it is always preferable to reduce, recycle or compost discarded materials rather than burn them. Waste-to-energy produces only a fraction of the energy that can be saved through recycling. Using recycled materials to make new products reduces the need for virgin raw materials, which avoids greenhouse gas emissions that would result from resource extraction and processing. In addition, manufacturing products from recycled materials typically requires less energy than making products from virgin materials.
According to an EPA study, waste prevention is even more effective at reducing greenhouse gas emissions that result from product consumption. When we buy less or reuse products, less energy is needed to extract, transport and process materials to manufacture products.
Toxic fumes
Mass burn incineration and other high heat systems increase the risk of environmental and human health threats as compared to waste reduction, recycling and composting options. Burning anything, especially the mix as varied as what we toss in the trash, releases harmful chemicals and pollutants into the air, including:
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Criteria pollutants such as particulate matter, which cause lung and heart diseases;
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Heavy metals such as lead and mercury, which cause neurological diseases;
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Toxic chemicals, such as PFAS and dioxins, which cause cancer and other health problems.
Like conventional waste incineration, converting plastic waste into fuel or chemicals can also produce highly toxic emissions. Plastic contains thousands of chemical additives that are designed to enhance its material properties, including heavy metals, phthalates, flame retardants, bisphenol A and PFAS. Pyrolysis and gasification of plastic waste and the final combustion of produced fuel release a variety of toxic substances into the environment, including dioxins, benzene, toluene, polycyclic aromatic hydrocarbons, lead, and more.
While air filtering devices can reduce some of the toxic emissions from incinerator exhaust, the captured pollutants are transferred to other byproducts, such as fly ash and bottom ash. The fly ash is particularly dangerous because it contains a high concentration of toxic compounds, including heavy metals like lead, mercury, cadmium, and arsenic. Toxic ash poses a threat to our air and water resources, which is harder to contain and usually more toxic than waste in its original form.
Chemical additives in plastics can also go on to contaminate the fuel products of pyrolysis and gasification systems, in addition to becoming part of the solid waste output (ash, slag and char) from these processes.
