How to transform garbage into greener fuels

Photo; Reuters
Photo; Reuters

Summary

A handful of companies are working to turn household trash into low-emissions fuels for planes, trains and trucks

For centuries, people have burned waste to create energy, sending carbon billowing into the atmosphere. Transforming garbage into clean fuel, however, was an alchemy confined to fiction, like the movie “Back to the Future." Now, a handful of companies want to turn household trash into low-emissions fuels for planes, trains and trucks.

The newer, cleaner process, known as waste gasification or pyrolysis, involves cutting and drying non-recyclable trash from homes and offices, such as packaging and bottles, before blasting it with 4,000-degree-Fahrenheit steam and oxygen to break it down into hydrogen and carbon monoxide. The solids left behind are sold as road materials, and the gases produced can then be synthesized—using processes developed a hundred years ago—and refined into greener fuels, including biofuels and emissions-free hydrogen.

Sierra Energy, originally set up to provide low-carbon locomotive fuel for its parent company, Sierra Railroad Corp., has a prototype of a trash refinery in Monterey County, Calif. Canada’s Omni Conversion Technologies says it is on the verge of commercializing its waste gasifiers. In the U.K., the sustainable-fuel startup Velocys and aviation giant International Airlines Group SA aim to create Europe’s first garbage-to-jet-fuel plant and have received funding from Royal Dutch Shell PLC, while the European oil giant Repsol SA is also investing in the technology in the Spanish city of Bilbao.

“When you throw garbage into a hole in the ground, what happens is you get an enormous amount of methane coming out," says Mike Hart, chief executive of Sierra Energy. Methane comprises 20% of global greenhouse-gas emissions and is 25 times more potent than carbon dioxide in trapping the earth’s heat, the Environmental Protection Agency says.

“You’re preventing that if you can take that waste, and turn it into something valuable," Mr. Hart says.

Efforts to transform household waste, along with waste cooking oils and animal fats, come as the transportation sector fights an uphill battle to slash emissions. While the electricity industry is well on its way to decarbonizing, transportation accounted for almost a quarter of global carbon dioxide emissions in 2019, according to the International Energy Agency.

The European Union last year bailed out the continent’s airline sector after the coronavirus pandemic hit, tying some of that money to airlines increasing their use of biofuels, which includes fuels made from household waste, as well as cooking oil and agricultural crops. Airlines and shipping firms have signed up to emissions reductions pledges that are tied to the Kyoto Protocol and the Paris climate agreement.

Replacing the cheap and dirty fuels like kerosene and diesel that power the world’s largest vehicles has proven difficult.

It costs $0.45 to produce a liter of kerosene, less than half what it costs to produce commercial biofuel and a quarter of the cost of advanced biofuels, according to the IEA.

Transportation companies hope that one day emissions-free hydrogen fuel cells will power the sector, but they are currently heavy and too low in energy density for long-haul aviation or shipping journeys that don’t regularly pass refueling hubs.

Biofuels, including those produced from waste or other materials, produce emissions, but they release less carbon than conventional fossil fuels. Starting with trash avoids one of the longstanding criticisms of biofuels: that the land needed for the organic material from which they are made can lead to deforestation or higher food prices.

Waste gasification companies are aiming to make their fuel production economic. In doing so, they hope to recoup their considerable research and development costs, although when that will be possible remains uncertain. Many of the companies in the sector are still building prototypes or just taking their first commercial orders.

Some environmental groups, however, argue pyrolysis amounts to a “greenwashing" loophole for waste producers if they can simply gasify it. Gasifying plastic waste could allow oil companies a “perfunctory offset" to continue producing plastics, says nonprofit Greenpeace, which argues that the time and money spent on pyrolysis could be better spent elsewhere, including on battery storage research and phasing out internal combustion engines altogether.

Even so, companies have plowed money into pyrolysis, with demonstration models running over budgets and deadlines. Clean-energy technology typically requires long research and development periods, and investing in the sector has historically proven risky. “A lot of people had been burned the first time around" investing in clean-tech, says Eric Toone, co-chairman of the investment committee at Breakthrough Energy Ventures, the clean-tech venture capital fund led by Bill Gates.

Sierra Energy was set up in 2004 and its railway-operating parent company has poured more than $50 million from investors like the U.S. military, the California Energy Commission and Breakthrough Energy Ventures into research and development.

At U.S. Army base Fort Hunter Liggett, the company last year began operating its demonstration model, which can process 10 tons of garbage and produce a ton of hydrogen a day, enough to power six cars for a year, according to the IEA. The model is meant to power the base and create low-sulphur diesel for the California Energy Commission. Future units will be 10 times the size, the company says. Sierra Energy says it will turn a profit when it can produce its fuel on a mass scale.

In Ottawa, Omni has spent a similar amount of time and more than $400 million developing its own system. Initially conceived to produce synthetic natural gas for the power sector before fuel standards were improved, the company pivoted in 2015 to building a $30 million machine to allow its customers to produce fuels from trash.

Omni has been taking orders for around a year. Its system shreds feedstock to 4-inch blocks. Its customers will convert the synthetic gas that comes out of the other end into biodiesel, biogasoline and hydrogen. The system can take 200 tons of trash a day, but it can also take wood chips and other waste materials. The company says it has received interest from various cities considering fueling city buses with trash. Omni says it can use its gasification machines to produce emissions-free hydrogen at $2.40 a kilogram. Such fuel currently costs between $9 and $19 a kilogram to produce, according to the International Council on Clean Transportation.

With common biofuel feedstocks like used cooking oils limited in supply, “the ability to take unsorted urban waste and make that into a quality syngas that can be used to make biofuels…is a very substantial advantage," says Omni CEO Rod Bryden.

Meanwhile, in the U.K., Velocys has joined with British Airways in its quest to create Europe’s first waste-to-sustainable-jet-fuel plant near the U.K. port of Hull. Velocys says the emissions of its renewable jet fuel are 70% lower than regular jet fuel and by installing carbon-capture technology at its plant, it can make the production of the fuel carbon neutral.

The company aims to produce 60 million liters of sustainable jet and road fuel each year when it begins commercial operation, slated for late 2025.

The plant also received funding from the U.K. government and Shell—initially a partner before recently pulling out of the project. Shell’s head of new fuels, Matthew Tipper, says the company was pursuing its own emissions reducing technologies.

Repsol is investing $24 million into building a pyrolysis demonstration plant in Bilbao. The company says it will initially reduce the emissions of the adjoining refinery, before eventually producing hydrogen and biomethane for the aviation, marine and heavy duty transport industries.

Neste Oyj, the refiner and world leader in sustainable fuels, is also exploring making fuel from trash. That could make the Finnish company a market player in five to seven years, according to CEO Peter Vanacker.

“Pilot plants will have to be built up," he says, “then later scaled up so that the economics make it feasible."

This story has been published from a wire agency feed without modifications to the text.

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