Aug 9, 2023
A pioneering BFB concept for 100 percent agrofuel and catalytic pyrolysis are examples of how Valmet is driving energy technology development forward. Key to these and other developments are our continuous innovation work and unique pre-industrial scale test facility for energy technologies.
The target of converting renewable resources into sustainable results keeps people at Valmet innovating. One of the facilities where this innovation takes place is Valmet’s Energy R&D Center in Tampere, Finland. Since 1990, this has carried out more than 11,000 hours of pilot operations. It offers complete fluidized bed combustion and pyrolysis pilots on a megawatt scale for customer pilot trials, including comprehensive analysis services and access to Valmet’s network of deeply knowledgeable and experienced experts.
In addition to serving customers from around the world, the facility plays a key role in Valmet’s own R&D work.
“This unique pre-industrial scale test facility has enabled us to develop our fluidized bed combustion and pyrolysis technologies. In combustion, fuel trends over the decades have changed from fossil fuels to more sustainable but at the same time more challenging biomasses and waste fractions. The driving force for development of pyrolysis technology has been to maximize the value of resources,” points out Katriina Jalkanen, R&D Project Manager, R&D.
One of Valmet’s long-term development projects is the Valmet BFB Boiler for agrofuels. This can run on high-alkaline fuels like wheat straw, sunflower husks, empty fruit bunches and rice straw – fuels that typically are agro-residues and previously were unsuitable for BFB combustion. The concept has been piloted on 30 kW and 2 MW scales at Valmet’s Energy R&D Center.
This unique R&D test facility enables Valmet to develop fluidized bed combustion and pyrolysis technologies.
“The main issue in fluidized bed technology that use high-alkaline fuels is bed agglomeration. This can now be prevented with Valmet’s advanced combustion principles,” says Jukka Leppälä, Project Manager. “Another risk for bed sintering with agrofuels is heavy furnace fouling. We have a patented solution for a furnace arrangement using two-zone combustion to keep the bed fluid without disruption.”
Compared to grate combustion, BFB combustion is significantly more efficient and features better emission control.
“After years of development work, the concept is now ready, and we’re looking for a customer to build a 30–80 MW demo plant. This could be a new BFB boiler or a boiler rebuild. The latter option is possible, as we can use a lot of an existing plant’s technology and just change the furnace structure,” Leppälä continues.
In accordance with its vision, Valmet is looking for ways to maximize the value of resources. For example, good-quality biomass should be used to produce more valuable products than heat and electricity, such as chemicals or transportation fuels.
Pyrolysis is the thermal decomposition of feedstock without air. In an ongoing R&D project, Valmet is further developing its fast pyrolysis technology with catalytic treatment. With catalytic pyrolysis, the target is to produce renewable feedstock – biocrude – for refineries and the petrochemical industry for the production of transportation fuel from sustainable biomass sources.
“Right now, we use wood biomass and forest residues as fuels, and later, we’ll also use agrofuels,” says Joakim Autio, Solution Development Manager, Valmet. “In the spring of 2023, our project entered the test phase in a 400 kg/h pilot plant at Valmet’s Energy R&D Center. We’ll follow successful piloting with demo-scale development.”
Text Marjaana Lehtinen
PHOTOS Markku Rintala and Hannes Frigård, Kuvabitti Oy