Race to waste
Pyrolysis is a developing technology that converts waste to energy, but developers may be rushing the process
Just outside Leadville, The Lake County Landfill lies somewhat hidden along the Mineral Belt Trail by a border of Aspen trees. The dump showcases a growing problem in Colorado, and the world for that matter — our trash just isn’t going away.
With the costs and difficulties often associated with recycling, especially in Colorado’s rural communities, our state’s 72 solid waste landfills are filling up and expanding. A new process in development known as pyrolysis is being touted as a solution to this growning problem, but according to several reports, it may actually create more problems than it solves.
Pyrolysis, according to the Center for Public Environmental Oversight, chemically decomposes organic materials using an oxygen-free process. While there are numerous types of pyrolysis, waste is typically transformed into various gases, small quantities of liquid and a residue containing carbon and ash. What makes pyrolysis such an attractive alternative to typical landfill and stockpiling practices is that minimal fossil fuels are needed to jumpstart the process. After a quick kick from conventional fuels, the technology powers itself while creating additional energy or fuel.
With no direct flame, many of the issues associated with incineration technologies, such as harmful air emissions, are avoided.
After Gov. John Hickenlooper signed Colorado’s waste tire legislation in June 2014, requiring the shutdown of tire landfills by 2024, the state had a problem — what to do with 600,000 tons of tires. Similarly, landfills are housing tons of solid waste. With tire stockpile owners scrambling to meet the requirements of Colorado’s new law and plenty of municipal waste lying idle, pyrolysis could be the light at the end of the trash tunnel.
Colorado-based companies Creative Energy Systems (CES) and CH2E are both seeking to create pyrolysis markets in Colorado. Looking at sites in Morgan and Otero counties, CES is looking to potentially build two plants focused on turning solid waste from Colorado’s landfills into energy. CH2E signed a letter of intent with German company Pyrolyx AG to build a plant geared toward repurposing the 60 million tires housed in CH2E’s Hudson, Colo. facility. Despite the applicability of pyrolysis technologies in numerous industries, the energy produced through the treatment process may not be enough for commercial production facilities.
With larger plants like the three proposed in Colorado, the process may require more energy than it produces, creating problems for the communities that build them.
“Scaling up has been one of the downfalls for a lot of [pyrolysis] projects,” says John Persichetti, an associate professor researching bio-fuels and wasteto-energy (WTE) technologies at the Colorado School of Mines. “This is a relatively new problem, and we’re still learning how to scale up some of these reactors. [But] it’s not insurmountable.”
Other research supports Persichetti’s position.
“It is a research challenge to optimize the [pyrolysis] process by maximizing product quality and quantity while paying proper attention to minimizing costs and environmental concerns,” a Central Queensland University study of pyrolysis processes states. “Although a lot of studies have been conducted on pyrolysis economy, most of those were limited in small or pilot scale production. Detail[ed] economical assessment of industrial scale pyrolysis plant[s] may be required to establish this technology as a competitor with conventional energy and other alternative energy sources.”
Using information provided by CES, a Colorado Department of Public Health and Education report concludes that the two proposed operations in Otero and Morgan counties would be “the largest pyrolysisfor-energy production facilities in the world.” And with solid waste from landfills required to fuel the plants, a steady stream of waste will be required to keep the plants running — even after existing landfills have been depleted.
In the past, WTE companies have instituted “put-or-pay” contracts that “require municipalities to pay a predetermined monthly fee … regardless of whether it makes economic or ecological sense to do so in the future,” according to a report by the Global Alliance for Incinerator Alternatives. “As a result, these contracts destroy the financial incentives for a city to reduce and separate its waste at the source, and reuse, recycle and compost.”
Highlighting a common obstacle in the pyrolysis treatment process, Persichetti agreed with the GAIA report, saying that pyrolysis’ worth lies in its practicality, rather than its economic viability.
“The problem tends to be that if somebody tries to do it for economic purposes, and say, ‘Yeah, we’re not going to be spending money, we’re going to be able to actually make money from this,’ that doesn’t always tend to work out — because of the costs of drying it,” Persichetti says, referring to the drying process required before pyrolysis can occur. “So it’s not a good business venture. But if you’re trying to reduce landfill it’s a great idea.”
The Pyrolyx AG technology tackling CH2E’s 60 million scrap tires is faced with a similar problem — how to create a large-scale production facility that is sustainable without ignoring environmental concerns. The plant, geared toward making recovered carbon black, which is added to rubber as a filler and strengthening agent, would be the first closed-loop pyrolysis process. Carbon black would be captured and utilized to create new tires.
The Colorado Waste Tire Management Plan, prepared for the Waste Tire Advisory Committee and the CDPHE, says that in order for Colorado to meet its goal of consuming the state’s waste tires by 2024, enduse capacity would have to increase by an additional 6 million tires per year. But despite the good intentions behind House Bill 14-1352, which instituted Colorado’s waste tire legislation, Marjorie Griek, executive director of the Colorado Association for Recycling, says that the law may be forcing monofills to consider pyrolysis before the technology has been adequately tested.
“I think that further research is definitely needed to make determinations about what will give us the best outcome in the long term,” Griek says. “I know that the tire monofills are under pressure to close within a certain number of years and therefore would look at something like pyrolysis as a great way for dealing with those tires. But I don’t know that they’re looking at the big picture.”
Monofills are required to stop adding to their stockpiles in 2018 and focus on depleting their remaining supply. Brian Gaboriau, waste tires grant administrator at the CDPHE, says pyrolysis could be a powerful tool in creating a new market for existing waste tires, as well as repurpose Colorado’s tires in the future.
“With the changes last year with House Bill 14-1352, we’re trying to do some changes and we’re trying to make them positive,” Gaboriau says. “Because at the end of the day, we all know that 2018 will be here before we know it, so we want to make sure that we have a good program and that we have sustainable markets out there for the tires. … When those tires have value, then they have a place to go.”
Due to the difficulties behind characterizing more rubbery materials, Persichetti advises steering clear of tire pyrolysis. But he says he still sees the process as an extremely promising prospect.
“In general, [pyrolysis] is on a pretty good track,” Persichetti says. “But it, in some cases, could still be a decade away. In other cases, we’re at a point of demonstrating some better application of some newer technologies to improve the efficiency.”