8 Ways People Are Turning Waste into Energy

Mounting waste in landfills is a significant environmental problem threatening human health through air, soil and water pollution. Thus, sustainability experts are continually developing strategies to turn waste into energy. While the widely used waste-to-energy solutions are great, they only partially solve the problem.

More advanced methods are required to provide a reliable solution. Find out the different approaches people employ to extract energy from waste, and which have the most potential for sustainable success.

Traditional Waste Management Methods

Technology has advanced at a surprising rate across all industries. However, its influence on sustainability lags, which is evident in how people still implement older remedies of turning waste into energy.

1. Incineration

Incineration is burning non-recyclable waste at temperatures high enough to destroy harmful gases. The heat from this process converts water into steam, which moves to a turbine generator that converts this into electricity.

While incineration is the easiest method to reduce waste, the disadvantages far outweigh the benefits. Processing the trash sent to plants increases the carbon impacts of incineration and harms local air quality.

One study found incinerators release more greenhouse gas emissions per unit of electricity than any power source. If people continue using them for the next 20 years, excess emissions could reach 637.7 million tons, worsening current environmental problems. Plus, the process leaves behind ash that needs proper disposal.

2. Anaerobic Digestion

Anaerobic digestion is a waste-to-energy solution for manure, food, wastewater biosolids and other organic trash. This process uses a digester — a massive vessel that houses different groups of bacteria — where waste decomposes without oxygen. Organic waste is fed to the tank for digestion to generate biogas and digestate. The biogas consisting of 50%–80% methane and 20%–50% carbon dioxide is captured as a green energy source, while the digestate is turned into a fertilizer.

Anaerobic digestion may be a better waste management alternative than incineration, but it has downsides. Typically, the digestion process lasts 20–30 days — a drawback limiting its efficiency. Additionally, environmental factors affect the process. The microorganisms require a pH near 7 for optimal activity and work best if the temperature is around 95° Fahrenheit. Otherwise, it will be less effective.

3. Gasification

In gasification, municipal solid wastes such as kitchen waste, light bulbs, used tires and plastic are fed into a high-temperature pressure vessel known as a gasifier. Incineration uses substantial oxygen, but this process heats them in an oxygen-starved environment to break apart the trash and generate syngas and ash. Syngas is processed into fertilizers, natural gas, and transportation fuels, whereas the ash in a molten form converts into a non-leachable slag for making roofing shingles, cement and asphalt filler.

The technology for gasification is more complex than incineration, so the equipment consequently costs more, capping the application on a small scale. Additionally, the equipment requires an external energy source to begin processing, relying on a nonrenewable fossil fuel. This generates emissions that pollute the air.

4. Pyrolysis

Pyrolysis is also based on a thermochemical process to decompose organic material using a reactor at or above 500° Celsius to extract energy from waste. It’s similar to gasification, but it’s a zero-oxygen heating process.

The three byproducts of this process are bio-oil, biochar and syngas. Bio-oil can be a boiler fuel source, while biochar is a soil amender in agriculture. Like gasification, pyrolysis requires tremendous energy input to operate, so it’s an expensive investment.

Advanced Waste-to-Energy Technologies

Waste management technologies advance with sustainability at the forefront. These new methods give new life to waste and provide a green solution to environmental problems.

5. Circular Economy Business Models

American households waste 108 billion pounds of food every year. When these break down, they release methane and carbon dioxide that harm the environment, but technology can convert food scraps into energy homes or facilities can use.

Compost pits produce heat as a by-product when organic compounds like banana peels and kitchen waste break down. A well-constructed system will generate 20–80° C heat, depending on the system’s chemical composition, size and shape. People can coil hoses or run water lines through their backyard compost pile and use this heat energy to warm the wash water at home.

Alternatively, they can capture it by installing a geothermal system and distributing it to various applications, like heating a room during winter through plumbing. This loop of processes helps promote a circular economy where waste transforms into useful energy.

6. Enhanced Anaerobic Digestion

As a modified version, this method improves the restrictions of conventional anaerobic digestion. The process uses advanced technologies to boost the environment within the digester — like a feature to adjust pH and temperature — and add co-substrates and specialized microorganisms to break down the compounds more efficiently, producing more biogas.

It also applies pretreatment techniques to enhance the uniformity and characteristics of waste. For instance, workers remove the chemical and physical contaminants from raw water before treating it, optimizing, and expediting the operation.

7. Hydrothermal Liquefaction

Hydrothermal liquefaction — also referred to as hydrous pyrolysis — is a process that converts a wide range of organic waste or biomass into bio-crude oil for transportation fuel. Wastes with high moisture content like sewage sludge and food scraps are often tricky to handle. Putting these feedstocks into a special reactor produces a crude-like oil that can be a sustainable energy source.

8. Advanced Recycling Technologies

Prevalently, only selected plastic materials are compatible for recycling, so a tremendous amount remains in the ocean and on land. Sustainability experts use advanced recycling technologies to keep all types of plastic out of the environment. These include conventional recycling methods like pyrolysis and gasification, which are boosted by improving the flaws to make them more efficient and environmentally sustainable. Some examples are vacuum pyrolysis, microwave pyrolysis and flash pyrolysis.

Vacuum pyrolysis makes the expensive investment worth it, as it can handle large biomass particles the older technology can’t. It also has more bio-oil yield and very little or no char formation.

Meanwhile, biomass flash pyrolysis technology is simple, versatile, and inexpensive. The pyrolysis or heating reaction takes only a few seconds, with an impressive liquid bio-oil yield of about 60% to seventy-five percent. Traditional plastic recycling methods have several limitations, but these advanced technologies make upgrading solutions to garbage problems possible.

Technology Can Develop Efficient Ways to Turn Waste Into Energy

By harnessing the power of technology to develop efficient waste-to-energy systems with little to no adverse environmental impact, people can slowly address pressing waste concerns. Modern methods like enhanced anaerobic digestion and chemical recycling can turn things around if they become available to small-scale applications, enabling people to work collectively in solving environmental troubles.

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