Clean-Burning Fuels: Materials For A Pollution-Free Future

Burning plastics is a highly polluting activity, as many plastics contain additives that generate toxic emissions when burned. However, scientists and researchers are working on ways to burn plastics in a more environmentally friendly way. One such method is pyrolytic gasification, which involves heating plastic to 800 °C in an oxygen-free environment, turning it into a gas which can then be burned as a clean fuel.

Plastics like PE, PP, PET, polyesters, and polyamides are safe to burn

However, plastics that contain elements like chlorine (PVC), fluorine (PTFE, PFA) or sulfur (rubber) can produce toxic gases when burned. These plastics are much more challenging to burn without causing pollution.

In addition, many plastics contain plasticisers, flame retardants and other additives that will generate much more toxic emissions when burned.

Scientists and researchers are figuring out ways to burn plastics in a more environmentally friendly way. One process, called pyrolytic gasification, involves heating the plastic to 800 °C in an oxygen-free environment. This causes the plastic to become a gas, which is then mixed with air before it is burned as a clean fuel free of oxygen-free organics like dioxins and furan.

Plastics with chlorine, fluorine, or sulfur produce toxic gases when burned

Burning plastics with chlorine, fluorine, or sulfur can produce toxic gases. Plastics like PE, PP, PET, polyesters, and polyamides are not something to worry about as long as they do not contain any elements besides carbon, hydrogen, oxygen, and nitrogen. However, plastics that contain elements like chlorine (PVC), fluorine (PTFE, PFA), or sulfur (rubber) can release harmful fumes when burned. These plastics require special care during incineration to prevent the release of toxic gases into the atmosphere.

Some plastics are more challenging to burn without generating toxic emissions due to the presence of plasticisers, flame retardants, and other additives. For example, even simple plastics containing C, H, and O (PET, PP, PE, PS) are not easy to burn because of the other additives in the actual plastic. Burning polyamides is also a terrible idea unless you have an industrial-grade furnace.

Scientists and researchers are working on ways to burn plastics in a more environmentally friendly manner. One such method is pyrolytic gasification, where plastic is heated to 800 °C in an oxygen-free environment, turning it into a gas. This gas is then mixed with air and burned as a clean fuel free of oxygen-free organics like dioxins and furan.

Burning plastics in an oxygen-free environment can reduce pollution

Some plastics, such as PE, PP, PET, polyesters, and polyamides, are not something to worry about when burned. However, plastics that contain elements like chlorine (PVC), fluorine (PTFE, PFA), or sulfur (rubber) can produce toxic gases when burned. Burning polyamides, for example, is a terrible idea unless you have an industrial-grade furnace.

Scientists and researchers are working on ways to burn plastics in a more environmentally friendly manner. One process, called pyrolytic gasification, heats the plastic to 800 °C in an oxygen-free environment, turning it into a gas. This gas is then mixed with air and burned as a clean fuel free of oxygen-free organics like dioxins and furan. This process also has the advantage of creating uniform carbon nanotubes when a bit of stainless steel is introduced into the reactor.

Additives in plastics can increase toxic emissions

Plastics can be burned with almost no pollution if they do not contain any elements besides carbon, hydrogen, oxygen and nitrogen, and if they are provided with enough oxygen during the combustion process. The only combustion products will be water, carbon dioxide and nitrogen. However, plastics that contain elements like chlorine (PVC), fluorine (PTFE, PFA) or sulfur (rubber) can produce toxic gases when burned.

Technologies such as pyrolysis or combustion of fluorinated polymers or fluoropolymer dispersion can result in the unintentional formation and release of toxic substances. For example, pyrolysis of plastics can result in the formation and release of highly toxic dioxins.

To address the problem of toxic emissions from plastic additives, efforts must focus on finding alternatives to such additives. This includes targeting chemicals exhibiting specific physicochemical properties (molecular weight, solubility, boiling point) to minimise their leaching and migration from plastics during their whole life cycle. For example, using additives with higher water solubilities increases their toxic potential to organisms in the water column, while less soluble additives are likely to leach out of plastic in reduced quantities but have an increased potential for bioavailability and bioaccumulation.

Burning polyamides requires an industrial-grade furnace

Burning plastics is generally not recommended as it can emit harmful fumes such as carbon monoxide, nitrogen oxides, carbon dioxide, heavy metals like lead, mercury, arsenic and carcinogens like dioxins, furans, polychlorinated biphenyls (PCBs) and brominated polyaromatic hydrocarbons (PAHS). However, some plastics like PE, PP, PET, polyesters and polyamides are considered less harmful to burn as long as they do not contain any elements besides carbon, hydrogen, oxygen and nitrogen.

Burning polyamides, in particular, requires an industrial-grade furnace. This is because polyamides are a type of plastic that can release harmful fumes if not burned properly. Industrial furnaces are designed to burn hazardous waste and are regulated by the EPA under the Resource Conservation and Recovery Act (RCRA). These furnaces are typically used for large-scale industrial heating applications and include kilns for the cement industry, blast furnaces for the metal industry, and electric arc furnaces for steelmaking.

To burn polyamides safely, it is essential to ensure complete combustion by providing enough oxygen during the process. This helps to prevent the formation of toxic gases. Additionally, the combustion of polyamides should occur in a controlled environment with proper ventilation and exhaust systems to capture and treat any harmful emissions.

It is worth noting that scientists are actively working on developing greener ways to burn plastics. One such method is pyrolytic gasification, where plastic is heated to 800 °C in an oxygen-free environment, turning it into a gas. This gas is then mixed with air and burned as a clean fuel, free of harmful organics.

Frequently asked questions