How Does Waste-To-Energy Work?

Across the world, countries are beginning to see an explosion of food waste as the coronavirus outbreak stresses the global food supply chain. Items meant for restaurants and pubs have nowhere to go following government-ordered closures of public spaces, and are likely to end up in landfills.

These items, however, don’t necessarily have to go to waste. It may be possible to recoup on these losses and help manage this waste with waste-to-energy (or WTE) programs that recapture the energy stored in waste products, like unused food items.

Here is everything you need to know about WTE right now — what it is, how it works and why it’s being turned to right now.

What is Waste-to-Energy? / How Does Waste-to-Energy Work?

Waste-to-energy is a broad term that encompasses all types of energy recovery that convert waste directly into energy.

At their simplest, waste-to-energy processes generate power via the incineration of safely combustible waste — like food scraps, cardboard, cloth and paper. However, it’s also possible to harness the gases — called landfill gases — that are naturally generated by decomposing waste. These gases are made up of nearly 50 percent methane. As methane is a greenhouse gas, if these gases escape, they’ll contribute significantly to the greenhouse effect. If captured, however they can also be used as a component of natural gas.

Other waste-to-energy methods convert biomass — the biological material in municipal waste — into solid fuel. Torrefaction and pyrolysis use elevated temperatures to chemically alter the structure of biomass, producing solid fuel that’s sometimes called bio-coal.

Waste-to-energy processes can also create liquid biofuel — sometimes called agrofuel — from biomass. This fuel can then be used likely any other liquid fuel, although it may require specialized equipment — as in the case of biodiesel, which can only power diesel engines that have been retooled to work with the fuel.

Why is Waste-to-Energy Being Used Now?

Developed economies tend to waste both energy and physical resources like foodstuffs. In a typical year, for example, around 9.5 million tonnes of food is wasted in the UK.

Now, food waste has noticeably increased as a result of the current coronavirus outbreak. Supermarket sales in the UK jumped by a fifth in mid-March. Around the same time, restaurants were ordered to close by the government, leaving large amounts of food with no buyers.

When demand becomes so volatile so quickly, the supply chain can’t respond and often becomes highly inefficient. Food that was destined for restaurants and restaurant suppliers has nowhere to go — and, rather than be redirected to consumers that need it, tends to be wasted.

Waste-to-energy programs provides an alternative to the landfill for these food items. Instead of being completely wasted, the energy in the food can be recaptured, either by incineration or other WTE methods.

WTE has also been used experimentally to recapture energy from healthcare waste. If waste generation trends follow those seen in Wuhan, the Chinese city most impacted by the coronavirus outbreak, the UK will soon face expecting a surge of healthcare waste in in the form of used gloves, gowns and masks generated by doctors and nurses treating COVID-19 patients. WTE may be effective at managing this waste in the most efficient way possible.

Managing Food and Healthcare Waste With WTE Programs

Countries across the globe may soon see a major increase in production of waste as a result of the coronavirus outbreak. This waste, made up of medical equipment and unused food items, may be destined for the landfill. It could also be used a fuel source by WTE programs that recover some of the energy trapped in waste items.

The increase in food and healthcare waste is likely to continue into the near future as restaurants remain closed and hospital staff work overtime to treat COVID-19 patients. While WTE programs likely won’t be able to handle all of the new waste that will be generated, they can provide a valuable alternative to landfills and help recover a bit of energy that would have otherwise gone to waste.