On the rise

While Pinedale, Wyoming-based Raven SR is a relatively new company—formed in 2018—the roots of its technology date to the 1980s and early 1990s.

The process it uses to transform waste into renewable fuels, called Steam/CO2 (carbon dioxide) Reforming, was first developed and later patented by Terry Galloway in 1995 under the California company Intellergy.

Galloway, who died in 2019, was an environmental scientist who had worked at Lawrence Livermore National Laboratory and the University of California at Berkeley and was trying to find a cleaner alternative to waste incineration, says Matt Murdock, founder of Raven SR and Galloway’s second cousin.

“He developed Steam/CO2 Reforming and had several smaller commercial working units back in the ’80s and ’90s.”

Early on, Murdock says incineration was inexpensive and “no one really cared about greenhouse gases and CO2” emitted in the process, but Galloway developed and commercialized several projects, ranging from the decommissioning of nuclear power reactors that processed radioactive waste to the production of electricity from syngas.

Murdock told Galloway he was interested in the technology in 2015. Under Pinedale-based Sublette GTL, Murdock licensed Intellergy’s technology for use in Wyoming gas fields and landfills to make synthetic fuels via the Fischer-Tropsch (FT) process.

Murdock’s company eventually purchased Intellergy in 2017, leading to the creation of Raven SR a year later.

“In 2018, Raven SR was formed, and that’s kind of when we began moving in the commercial direction of converting all types of waste into fuels,” Murdock says. “While [Galloway] had been doing it for quite some time and was focused on the waste side, I came at it from the fuels perspective. … The marriage of the two created Raven, and here we are today.”

Creating clean fuels

At its core, Raven SR’s Steam/CO2 Reforming process is thermal decomposition with a chemical reaction, Murdock says. Operating in an oxygen-free environment free of combustion, the process uses heat, steam and CO2 to transform various waste feedstocks, including biomass, municipal solid waste, biosolids, industrial waste, sewer and medical waste and methane, into clean hydrogen and FT fuels.

“Our first-stage reformer converts the waste into a raw syngas, and then a second-stage reformer polishes the syngas into hydrogen-rich syngas perfect for the third-stage conversion into clean fuels,” Murdock says. “The two reformers together actually have a cold gas efficiency of about 95 percent as compared to [roughly] 65 percent for most gasifiers.”

Regardless of the feedstock, Murdock says the process can create stable, consistent hydrogen-rich syngas. This syngas, consisting of hydrogen and carbon monoxide, then enters a third-stage FT reactor to be transformed into various fuels, including sustainable aviation fuel (SAF), methanol, renewable diesel and jet fuel.

On average, Murdock says 60 to 70 tons of green waste can produce roughly 5 tons of hydrogen.

“If our feedstock is more [fossil fuel]-based, we can produce more syngas, but if it’s a low-grade woody biomass, we will produce less than that amount,” he explains.

For its first project, Raven SR is working with Phoenix-based Republic Services to convert green waste into hydrogen at a closed landfill site in Richmond, California. The company is expected to process up to 99.9 tons of organic waste per day at Republic’s West Contra Costa Sanitary Landfill, which will produce up to 2,000 metric tons of renewable hydrogen per year.

“We want to produce [fuels] kind of at the source,” Murdock says. “So, rather than producing a gigafactory of energy, where we bring in thousands of tons of waste or something like that, we’d like to focus on smaller, distributed hubs.”

Designated as a diversion technology, Murdock adds that a landfill could increase tonnage over time and will receive diversion credit for the project, which has sparked interest from other waste management firms, as well.

The sky is the limit

In addition to hydrogen production, Raven SR signed memorandums of understanding (MOUs) in January to supply SAF to Japan-based All Nippon Airways and Japan Airlines. The SAF will be used for the airlines’ global routes starting in 2025.

These MOUs will provide for an initial 50,000 tons of SAF to be supplied in the first year of the agreement, according to a news release, with annual incremental increases to 200,000 tons by 10 years into the partnership. The fuel will be produced at various Raven SR facilities using local waste.

“We can take that waste and, instead of [producing] hydrogen, add a Fisher-Tropsch reactor and produce sustainable aviation fuels right on location. It can be a drop-in fuel, ready to go into the aircraft just like that, or as a blended fuel, which is typical.”

According to Raven SR, its technology creates a synthetic SAF that is lighter by weight and has more power by volume than typical petrochemical fuels do.

“Currently, most aviation fuel is made from a process called HEFA [hydroprocessed esters and fatty acids], where they take used cooking oils or soybean oils and they refine them into fuel,” Murdock says. “This is being pushed back on, especially in Europe, because it’s not truly green because, essentially, you’re now competing with food crops and animal feed to produce fuel.”

Emissions are a major concern surrounding the aviation industry. This, combined with growing demand for soybeans, has pushed governments toward other sustainable fuels, Murdock says.

The Japanese airline industry is required by the country’s General Assembly of the International Civil Aviation Organization to reach net-zero CO2 emissions from aircraft by 2050. Beginning in 2024, Japanese airlines must reduce or offset 15 percent of their emissions using 2019 as a baseline.

Just the beginning

While Raven SR has achieved success in its early years, Murdock says the company also has experienced challenges. A lingering preference exists among consumers for electrolysis, a process that entails using electricity to split water into hydrogen and oxygen, he says.

“Electrolysis has the advantage that there’s a lot of renewable energy in the grid that they can use,” Murdock says. “Electrolysis uses about 50 to 60 kilowatts of electricity per kilo of hydrogen, plus 9 liters of water, whereas Raven only uses about 25 kilowatts of electricity [and] no fresh water.”

He adds that the other challenge is how SAF is defined.

“SAF is defined as fuel from a green source of waste. So, we have to take compost material or other green waste to produce it,” Murdock says. “I would love it if we could use any waste that has been put into a landfill to create sustainable fuel. That would open up a lot more opportunities.”

Raven SR has roughly 75 employees, most of whom work at its fabrication facility, Benicia Fabrication and Machine, which the company purchased in Northern California. An additional 10 people work in Raven SR’s corporate operations.

The company also has garnered interest from investors, such as Chevron, Hyzon Motors, Ascent Hydrogen Fund, Stellar J and Samsung Venture Investment Corp., which announced a strategic investment in Raven SR in March 2021.

According to a news release about the Samsung investment, it is expected to expand Raven SR’s reach to South Korea, which is currently a driving force in the hydrogen economy.

The author is the associate editor of Waste Today and can be reached at hrischar@gie.net.