Anyone who has ever hesitated in front of a trash bin knows the problem: It’s hard to determine what can be recycled. Consider the average potato chip bag. It’s got film plastic, metal, dyes, and food residue; it’s complicated. Today’s recycling doesn’t handle complexity well, so the typical chip bag is destined for the landfill.
Landfills take up space, of course, but there is a much more serious problem associated with them — one that was underscored for Daniel R. Cohn, currently an MIT Energy Initiative (MITEI) research scientist, when he was the executive director of MITEI’s Future of Natural Gas study. That problem is greenhouse gas emissions.
“About 130 million tons of waste per year go into landfills in the U.S., and that produces at least 130 million tons of CO2-equivalent emissions,” Cohn says, noting that most of these emissions come in the form of methane, a naturally occurring gas that is much worse for the climate than carbon dioxide (CO2).
For Cohn, working on the MITEI study made it clear that the time was ripe for InEnTec — a company he co-founded — to expand its business. Spun out of MIT in 1995, InEnTec uses a process called plasma gasification to turn any kind of trash — even biological, radioactive, and other hazardous waste — into valuable chemical products and clean fuels. (The company’s name originally stood for Integrated Environmental Technologies.)
The process is more expensive than throwing trash in a landfill, however, and climate change considerations weren’t a major driver of investment 25 years ago. “Back in the early ’90s, global warming was more of an academic pursuit,” says InEnTec president, CEO, and co-founder Jeffrey E. Surma, adding that many people at the time didn’t even believe in the phenomenon.
As a result, for many years the company concentrated on providing niche services to heavy industries and governments with serious toxic waste problems. Now, however, Surma says the company is expanding with projects that include plastics recycling and low-cost distributed hydrogen fuel production — using advanced versions of their core technologies to keep waste out of landfills and greenhouse gases out of the air.
“People today understand that decarbonization of our energy and industrial system has to occur,” says Surma. Diverting one ton of municipal solid waste from landfills is equivalent — “at a minimum” — to preventing one ton of CO2 from reaching the atmosphere, he notes. “It’s very significant.”
Roots at MIT
The story of InEnTec begins at the MIT Plasma Science and Fusion Center (PSFC) in the early 1990s. Cohn, who was then head of the Plasma Technology Division at the PSFC, wanted to identify new ways to use technologies being developed for nuclear fusion. “Fusion is very long-term, so I wondered if we could find something that would be useful for societal benefit more near-term,” he says. “We decided to look into an environmental application.”
He teamed up with Surma, who was working on nuclear waste cleanup at the Pacific Northwest National Laboratory (PNNL), and they obtained U.S. Department of Energy funding to build and operate an experimental waste treatment furnace facility at MIT using plasma — a superheated, highly ionized gas. Plasma is at the core of fusion research, which aims to replicate the energy-producing powers of the sun, which is essentially a ball of plasma. MIT provided the critical large-scale space and facilities support for building the plasma furnace.
After the MIT project ended, Cohn and Surma teamed up with an engineer from General Electric, Charles H. Titus, to combine the plasma technology with a joule-heating melter, a device Surma had been developing to trap hazardous wastes in molten glass. They filed for patents, and with business help from a fourth co-founder, Larry Dinkin, InEnTec was born; a facility was established in Richland, Washington, near PNNL.
InEnTec’s technology, which the team developed and tested for years before opening the company’s first commercial-scale production facility in 2008, “allows waste to come into a chamber and be exposed to extreme temperatures — a controlled bolt of lightning of over 10,000 degrees Celsius,” Surma explains. “When waste material enters that zone, it breaks down into its elements.”
Depending on the size of the unit, InEnTec processors can handle from 25 to 150 tons of waste a day — waste that might otherwise be landfilled, or even incinerated, Cohn points out. For example, in a project now under way in California, the company will produce ethanol using agricultural biomass waste that would typically have been burned and thus would have both generated CO2 and contributed to air pollution in the Central Valley, he says.
Supporting the hydrogen economy
Unlike incineration, which releases contaminants into the air, InEnTec’s process traps hazardous elements in molten glass while producing a useful feedstock fuel called synthesis gas, or “syngas,” which can be transformed into such fuels as ethanol, methanol, and hydrogen. “It’s an extremely clean process,” Surma says.
Hydrogen is a key product focus for InEnTec, which hopes to produce inexpensive, fuel cell–grade hydrogen at sites across the country — work that could support the expanded use of electric vehicles powered by hydrogen fuel cells. “We see this as an enormous opportunity,” Surma says.
While 99 percent of hydrogen today is produced from fossil fuels, InEnTec can generate hydrogen from any waste product. And its plants have a small footprint — typically one-half to two acres — allowing hydrogen to be produced almost anywhere. “You’re reducing the distance waste has to travel and converting it into a virtually zero-carbon fuel,” Surma adds, explaining that the InEnTec process itself produces no direct emissions.
Already InEnTec has built a plant in Oregon that will make fuel cell-grade hydrogen for the Northwest market from waste material and biomass. The plant has the potential to make 1,500 kilograms of hydrogen a day, roughly enough to fuel 2,500 cars for the average daily commute.
“We can generate hydrogen at very low cost, which is what’s needed to compete with gasoline,” Surma says.
Recycling plastic
Another initiative at InEnTec zeroes in on plastics recycling, which faces the kind of complexity illustrated by the chip bag. Different grades of plastic have different chemical compositions and cannot simply be melted down together to make new plastic — which is why less than 10 percent of plastic waste in the United States today is recycled, Cohn says.
InEnTec solves this problem with what it calls “molecular recycling.” “We’ve partnered with chemical companies pursuing plastic circularity [making new plastics from old plastics], because our technology allows us to get back to molecules, the virgin form of plastics,” Surma explains.
Recently, InEnTec teamed up with a major car-shredding company to process its plastic waste. “We can recycle the materials back into molecules that can be feedstock for new dashboards, seats, et cetera,” Surma says, noting that 40-45 percent of the material in the waste generated from recycling vehicles today is plastic. “We think this will be a very significant part of our business going forward.”
InEnTec’s technology is also being used to recycle plastic for environmental cleanup. Notably, a small unit is being deployed on a boat to process ocean plastics. That project will likely require subsidies, Surma concedes, since InEnTec’s business model depends on waste disposal payments. However, it illustrates the range of projects InEnTec can address, and it shows that — in both large and small ways — InEnTec is keeping waste out of landfills.
“We initially put a lot of effort into medical and hazardous waste because we got more money for disposing of those,” says Cohn, but he emphasizes that the team has always had broader ambitions. “We’re just arriving now at the point of getting more customers who believe that an environmentally superior product has more value. It’s taken a long time to get to this point.”
This article appears in the Autumn 2020 issue of Energy Futures.
Source: Energy - news.mit.edu
