Coal Substitutes Touted as Way to Keep Coal-Fired Power Plants Open

The move away from coal-fired power generation has supported the growth of other technologies to produce electricity. Discussions often revolve around renewable resources such as solar and wind, or the increased use of natural gas. Another technology also is looking for a growth curve. The use of coal substitutes, fuels specifically designed to mimic coal but with lesser environmental impact, is being studied as a way to keep coal-fired power plants operating even as the use of coal is phased out.

A UK-based company, Active Energy Group (AEG), has planned a demonstration project at a Utah power plant to study the feasibility of its CoalSwitch product. AEG’s technology converts waste biomass into CoalSwitch, pellets that the company said perform the same as coal, but with a lower level of emissions, particulate matter, and fly ash. The drop-in pellets can be used to blend or replace coal, and can be “co-fired at high percentages with coal” in power plants, or used to “replace white pellet and biomass in biomass-fired power plants, without requiring any furnace logistics, handling or storage modifications,” according to AEG.

1. Active Energy Group (AEG) plans to test its coal substitute product at PacifiCorp’s Hunter Power Plant in Castle Dale, Utah, a three-unit, 1,455-MW coal-fired facility. Courtesy: Creative Commons / Tricia Simpson

AEG this June is planning to deliver a test quantity of 900 tons of its product to PacifiCorp’s Hunter Power Plant in Castle Dale, Utah (Figure 1), where it has burn dates set for later in the month. The company said that at the scale it envisions, the technology could be used to reduce the emissions of existing coal plants as the transition to cleaner energy sources continues—and it also could minimize the economic impact of plant retirements.

“The fact of the matter is, we crossed the watershed with PacifiCorp,” said Michael Rowan, CEO of AEG, in an interview with POWER. Rowan’s group is a London-based international biomass and forestry management business. Its key focus is the commercialization of CoalSwitch, which it calls “a unique, highly disruptive renewable biomass technology with proven scalability and high margins that can provide a solution to resolve real commercial and environmental issues.”

AEG is supporting CoalSwitch and securing feedstock through its own forestry management business, with agreements to harvest what it called “significant areas of mature forestry.” Rowan said the goal is to “take advantage of the robust market dynamics to become a leading renewable international energy business.” He said the planned demonstration in Utah already “has triggered additional interest from other coal-fired power plants,” adding that, “along the East Coast, there’s the opportunity for a co-firing mix, with 10% to 15% burn with CoalSwitch, and that other 85% to 90% with coal.”

Other companies also have been working on coal substitutes, which they say have different properties than biomass. Another London-based company, Helvellyn Group, manufactures SERF, what it calls a low environmental impact, direct coal replacement fuel for industrial and power generation applications. Helvellyn’s fuel is specifically designed to mimic the characteristics of coal, allowing for use of the same fuel delivery, preparation and combustion infrastructure, without modification and resulting in the same combustion characteristics, but with a substantial carbon dioxide (CO2) emissions reduction, according to the company. Frank Harris, Helvellyn’s CEO, recently told POWER his company is working to complete financial due diligence, and technical design works, to allow for the rapid rollout of significant production capacity across the UK.

Rowan said the Utah test provides AEG an opportunity to show the worth of CoalSwitch, particularly when compared to pellet alternatives. “I think it will be very attractive to power utilities,” he said. Rowan said his group has “had no pushback to date” from the coal industry. “We’ve just reached the milestone, the milestone of actually being able to produce the fuel,” he said. “The lumber industry is unquestionably very excited about it… it’s all about collaboration, [and] acknowledging the industry dynamics that are there now.”

2. AEG’s production plant for its CoalSwitch coal substitute is shown here under construction in Lumberton, North Carolina. Courtesy: AEG

Rowan said that when he founded AEG in 2015, “the business was somewhat different… I liked the opportunity to get into the lumber and forest industry, learned there was this industry with incredible amounts of waste. That’s what attracted me to look for ways to help. We looked at many things that came about through original connections.” He said that while his company’s forestry and production unit is based in Lumberton, North Carolina (Figure 2), work in Utah led to the PacifiCorp plant. “We did a test run of the plant in the spring of 2018, and there were members of Berkshire Hathaway [PacifiCorp’s parent] and PacifiCorp there, and we’re now ready to deliver the fuel in the quantities they need.”

PacifiCorp’s Hunter Power Plant is a three-unit, 1,455-MW coal-fired plant. Units 1 and 2 each have 480 MW of generation capacity; Unit 3 can produce 495 MW. The start of this month’s test of CoalSwitch at the facility follows an earlier burn test conducted by Dr. Andrew Fry at the University of Utah’s Industrial Combustion and Gasification Research Facility. That burn test, according to AEG, confirmed that the fuel “burned at near-identical temperatures to coal, burned more efficiently than coal, and produced far less ash.” The test showed CoalSwitch “burned cleaner than coal, and when co-fired with coal generated less sulfur dioxide (SO 2) than coal alone.” The group also said that because the fuel is “essentially free of both potassium and sodium,” its combustion “will not cause fouling.”

Testing also showed the fuel, when blended with coal, “had a lower LOI [loss on ignition] than the pure coal, leaving far less unburned carbon in the ash.” AEG has said CoalSwitch “possesses comparable Btu levels to coal, almost identical bulk density and handling/storage characteristics, and has similar handling and friability characteristics, which combined with greatly reduced low and mid-volatiles post-production makes it safer to handle than traditional biomass pellets or other fuels.”

Rowan said for utilities, having a coal substitute available is about “extending the life of the asset, and meeting the demands of environmental regulations. Europe is definitely ahead of the U.S. on this… the biomass industry in the UK has been doing this for years.” Rowan pointed to the transition of the massive Drax Power Station in the UK from coal to biomass. “You need this substitute, period, with the politics around coal,” Rowan said. “It’s a big business and you can’t shut it down tomorrow. So, now we have utilities asking, ‘Can we just take a sample of your fuel and test it?’ ”

Helvellyn’s Harris told POWER his company—which received endorsement for its coal substitute fuel from Uniper in 2020—has noted bullish fundamental drivers in the European energy market, leading his company to make plans to produce more than 2 million tons of SERF annually. “Why would one decommission a perfectly good, modern power plant with a lifespan of several decades, when there is a zero-cost option to switch to an alternative low-emissions fuel?” Harris asked. He said that policies driving the electrification of transport, home heating, and an array of other sectors across European Union (EU) member states are on what he called “a crash course” with policies designed to phase out coal-fired generation, which he said could cause power supply issues.

Harris said his company’s product, like that of AEG’s, is a renewable fuel that can be used in modern coal-fired power plants without modification to the transport, storage, handling, milling, or combustion infrastructure. He said it can achieve government goals of phasing out coal, without the risk of power supply issues caused by a lack of reliable baseload electricity.

“Well-intentioned knee-jerk policies to shut down coal-fired generation plants when there is no plan to fill the capacity gap will result in the lowest-cost technology being deployed,” he told POWER. “In most of the EU this means increased combustion of Russian gas, and an increased output of GHG [greenhouse gases] compared to switching existing plants” to a product like SERF.

“We are not limiting our ambitions, based on the market drivers and our position to inject value into stranded coal-fired generation assets by virtue of our unique solid renewable fuel product,” Harris said. “COVID-19 has caused slight delays to our development timeline, but Helvellyn is working on a pipeline of 30-year assets, so a few months’ delay, while frustrating, is not significant. If anything, it has given us breathing space to look at the market and increase our ambition.”

Rowan said a coal substitute product should not be confused with biomass. “It’s a totally different process. A biomass process is different, we are feedstock agnostic, we use all parts of the tree. It’s a whole different ethos,” he said. He said in his company’s process, “the idea is that you’re not torrefying in any way, shape or form, but the product breaks down into its original carbon element, and you’re able to combine it with coal. It’s a process we’ve had verified by engineers in the U.S. We approached it with the mantra of, ‘How do you create a fuel that can be used in the existing infrastructure?’ ”

Rowan noted there is a “much greater responsiveness about the environmental agenda” surrounding power generation today, “and that’s what we can resonate with. If you really are on a pure ESG [environmental, social, governance] agenda, the idea is to say, ‘Listen guys, burners can’t be used unless you have an equivalent fuel.’ The infrastructure around the world has been built on fossil fuels. The idea is here, we’re able to take existing assets and extend the life of these assets, and they don’t feel under pressure to just say, ‘We’re going to close up shop.’ They can become more green, and check other boxes at the same time.”

Darrell Proctor is associate editor for POWER (@POWERmagazine).

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