The EPA’s most recent report on waste found that the U.S. generation of municipal solid waste was 267.8 million tons in 2017. Based on the figure, the agency calculated that Americans generate an average of four and a half pounds of trash per day. Solid waste is a broad term encompassing food, packaging, household, and medical waste, to name a few.
Finding ways to convert municipal waste into energy for cooling and heating our homes, powering our vehicles, and generating electricity in a meaningful, large-scale way can keep a sizeable amount of our trash from landfills, but at what cost? Explore some of the current ways governments and private companies are addressing the issue.
Agricultural Waste Becomes Fuel
Microbiologist Gemma Reguera has developed a system that uses bacteria to breakdown farm waste through fermentation to convert it to ethanol. Fermentation affects the quality of the fuel. Reguera adds an extra bacterium that removes the waste’s byproducts caused by fermentation. This is revolutionary because Reguera has developed a completely organic process to clean and refine the fuel, removing byproducts that could end up becoming waste themselves.
There’s an added bonus — the process of removing the byproducts by using the second bacteria generates electricity, producing 20 times more energy than any comparable methods. The electricity isn’t currently harvested but is redirected to increase the efficiency of breaking down the agricultural waste.
Medical Waste Becomes Green Energy
Medical waste needs special handling for sanitary reasons. A California firm is taking organic medical waste and transforming it into clean, renewable energy by carbonising it using high heat and no oxygen. The high heat sterilises the waste, and according to the firm, “diverts 95 percent of treated medical waste away from landfills.”
Running a Country Using Trash
Sweden has 34 “waste-to-energy” power plants that burn trash to power the country. The efficiency of the country’s power plants means that less than one percent of trash ends up in a Swedish landfill. The Scandinavian’s trash is well managed — almost half of municipal waste is recycled, and the other half is sent to the waste-to-energy power plants. Amy Yee reports that “four tons of garbage contains energy equivalent to one ton of oil, 1.6 tons of coal, or five tons of wood waste.”
Burning trash has its drawbacks — Sweden recognises waste to energy power plants is a temporary solution. It’s the lesser of the current evils when compared to landfills and coal-burning plants. Until society as a whole minimises the amount of trash it creates, waste-to-energy plants may be here to stay.
From Trash to Gas to Renewable Energy
Several companies, including Aries Clean Energy, JBI, and Red Rock Biofuels, are using gasification to convert plastic and other forms of waste into energy. Red Rock Biofuels synthesises garbage into a gas that can be captured and converted into renewable ethanol, jet fuel, and diesel.
According to JBI, the company converts “plastics into oil.” The company shreds and granulates plastics to heat them. A catalyser converts the plastic into gases so they can be separated and individually stored. Some of the gases captured in the process include hydrocarbons, butane, methane, and propane, used for biofuels.
Aries Clean Energy’s gasification project is different. The company converts agricultural waste and the sludge left from water treatment plants to turn it into a Biochar, a soil amendment, and electricity.
A Large Scale Composting Project Converts Food Waste Into Electricity
The United Nations reports that it’s taking steps to reduce food waste. The Organisation revealed that one-third of the food produced worldwide every year is lost or wasted. The U.N.’s 2030 Agenda for Sustainable Development has set targets to reduce the amount of food waste by half.
Scientists and companies are looking for ways to work with high food waste. Harvest Power has developed an energy plant structure named Energy Gardens, producing biogas through a similar process to composting. The plants are located throughout the United and States and Canada, although the most famous of the company’s plants is located at Disney World!
The process starts by mixing organic waste from lawn trimmings and food waste, with oils, fat, and other forms of bio sludge. The mixture is introduced into massive tanks, so anaerobic microorganisms break down the biomass into clean-burning fuel in roughly one month. Harvest Power’s Energy Gardens facility at Disney processes 130,000 tons of food waste and turns it into 5.4 MW (megawatts) of combined heat and electricity. One megawatt can power an average of 200 homes, meaning Disney’s program with Harvest Power can generate enough electricity for over 1,000 houses.
The Evolution of the Waste to Energy Industry
As governments look to solve the waste problem, they look to encourage innovation in converting waste into another valuable resource — energy. Government grants, subsidies, and tax credits are available for improving green energy initiatives for businesses and homes. As companies look to lessen their carbon footprint, their innovations could benefit the world.