Analysis Supports Coal-Like Fuel for Power Plants [torrefaction]

A British company that manufactures a fuel that it says mimics coal said it “has received a significant endorsement” for the use of its product in the power generation sector. An analysis by Uniper Technologies said Helvellyn Group’s alternative fuel, known as SERF, “is technically suitable for use in large scale thermal power plants in a blend, and potentially up to full substitution, with little or no capital outlay and delivering a net reduction in operating costs.”

Research has been done for years on finding substitutes with similar characteristics for coal, specifically metallurgical or coking coal, which is used in steelmaking. Research and development also has focused on woody biomass, with projects aimed at transforming the product into dense, compact forms that have low ash content to minimize the risk of fire, and that can be easily transported, are water-repellent, and can be stored outdoors for long periods. That process, known as torrefaction, produces briquettes that can be burned like coal in existing coal-fired plants. Biomass plants, such as the Boardman plant in Oregon, have shown promise but also have been challenged by the same market forces that have disadvantaged coal-fired units in recent years, particularly low prices for natural gas and now renewable energy.

Helvellyn has said SERF is “specifically engineered to mimic the physical properties of coal,” with an ability to burn more efficiently and with fewer greenhouse gas emissions. The Uniper analysis, detailed in a report not yet publicly released but with some information provided to POWER, said individual power plant characteristics would need to be taken into account, but in most cases SERF will be usable “within existing ship/rail/road delivery and handling infrastructure.” The fuel is water-resistant, which means it can be handled and stored in open-air stockpiles. “Our process is able to take a wide range of carbonaceous feedstocks [including low grade coal, sludges, wastes, and/or biomass] and produce fuels to a precise specification consistently,” Frank Harris, Helvellyn’s CEO, told POWER on June 18. “We knew that the fuel would work in large-scale powergen, [and] now we have independent analysis, from one of the most experienced companies in the sector, to back that up, emphatically.”

‘Lifeline’ for Coal Plant Operators
The Uniper analysis looked at blends of SERF at 20% increments, up to 100% substitution, based on a 500-MW boiler that would traditionally burn a range of bituminous coal. Harris told POWER that the endorsement from Uniper “is a significant moment for EU [European Union] power plants that are facing early closure due to legislation against coal.” The group has said the coal substitute “could be a lifeline to operators of assets with a life expectancy that is longer than current or future legislation allows them to exploit.”
Helvellyn has said its product “allows operators to maintain their existing alternative fuel mix while, in most instances, adding Helvellyn fuel as a direct drop-in replacement for coal from the point of delivery through pre-combustion processing and in combustion.” The group has produced a document that details the company’s process and provides information about the fuel and its ash specifications.

“Our notional plan is to build out 1.2 mtpa [millon tons per annum, or year] of production in the UK, but we are not constrained in ambition and see a strategic partnership with someone in the power sector might provide the synergies to roll out plants across Europe, to support a phased fuel switch and allow the continued operation of thermal power plants that will otherwise be legislated out of business way before their natural end of lifecycle,” said Harris.
Helvellyn in February launched a direct coal replacement product for the cement industry. The group’s solid fuels “are designed to meet the needs of hard to adapt large industrial plants that are seeking to reduce, or even eliminate, their reliance on coal,” the company said. Harris told POWER: “We launched the product to the EU cement vertical in February and have some negotiations ongoing for supply to three European kilns.”

Product Valuation
Helvellyn commissioned the Uniper report as part of its ongoing assessment and refining of the coal substitute product for the European market. The Uniper analysis looked at several things, including delivery, storage, and handling; milling and delivery to boiler; combustion and boiler efficiency; and boiler slagging, fowling, erosion, and corrosion.