B4E-thermal-conversion AS211014The Bio4Energy Thermochemical, Environmental and Pretreatment and Fractionation Platforms work across the areas of biomass combustion, gasification and pyrolysis of woody feedstock, including wood, forestry residues and pulping by-products. Photo by Bio4Energy© 2014.

Late October, leading researchers on the quality of biomass-based fuels met as an Impacts of Fuel Quality on Power Production conference—given this year at Snowbird, Utah, U.S.A.—with one in five talks being delivered by a scientist from Bio4Energy.

While the conference is one of the most respected recurrent events on biomass combustion and gasification research, this year was special a special one for Bio4Energy—and indeed for its offshoot research and development programme Bio4Gasification.

"This is not just any conference but The Conference in fuel quality and with a large international following. This year we have 15 presentations related to Bio4Energy, mostly from the [Bio4Energy] Thermochemical Platform. This happens to be 20 percent of all presentations", Umeå University professor This email address is being protected from spambots. You need JavaScript enabled to view it. said just ahead of travelling to the conference from northern Sweden.

"What is so nice about this is the fact that all our presentations are based on scientific articles which will be published in well-respected journals next year", said Backman, who took over the leadership of the Bio4Energy Thermochemical Platform earlier this year.

So what puts Bio4Energy apart when it comes to having a handle on the quality of biomass-based fuels?

For starters, its researchers have long-standing expertise on wood as a raw material in biofuel production. A string of reports have shown that woody feedstock is among the most efficient in terms of energy use and environmental impact, if the conversion method used is entrained-flow gasification.

The high-heat entrained-flow gasification method is the Bio4Energy researchers’ technology of choice because it can be used to produce synthetic gas that has few impurities. In turn, this means that costly and time consuming process steps can be avoided when the so-called syngas is turned into biofuel.

However, the technology must be further developed and this is precisely what the researchers have set out to do. Their chief aim is to provide fundamental knowledge, including a set of experimentally-based models which can be used by all of the research community and which so far has been lacking so far.

"We have long-standing experience in forest-sourced biomass which gives us a head start", Bio4Energy PI This email address is being protected from spambots. You need JavaScript enabled to view it. said, adding: "We also have strength in that [we have expertise across the areas of] ash chemistry and how the technology performs at the production plants and of emissions", he added.

While professor Boström's research group at Umeå University currently studies the reactions of the mineral phosphorous as a biomass ash element in combustion and gasification processes, This email address is being protected from spambots. You need JavaScript enabled to view it. and his colleagues at the Luleå University of Technology take over where slag formation begins inside the biomass reactor. This means that they also look at the overall composition of ash which forms as a result of the conversion process. This may cause corrosion of the inside wall of the biomass reactor and bring about polluting emissions in the exhaust, notably of particulate matter. At worst, the slag clogs the reactor so badly that it breaks down.

"You have to be able to handle ash-related problems, of which slagging is one. Otherwise your efforts at making biofuels will not work. This is fundamentally important", professor Öhman said. He added that the composition of the feedstock and the way in which it would react when exposed to high temperatures inside a biomass combustion or gasification reactor had to be known in advance of any upscaling of the syngas production to industrial levels.

"[Before the end of] the next programme period of Bio4Energy [2015-2020] we hope to have constructed enough fundamental knowledge for these problems to be effectively handled", Öhman said, "at least when it comes to the ash chemistry".

Could Bio4Energy envisage hosting a future edition of the international Impact of Fuel Quality on Power Production conference?

"In a second round of Bio4Energy this could be envisaged", according to Öhman, who is Bio4Energy's vice programme manager.

"Then we could invite the ash kings and queens to Sweden", he joked, with reference to the international scientific elite in ash chemistry and the quality of biofuels.

Bio4Energy's research and development efforts from 2010 to mid 2014 are currently being evaluated. In the balance hangs a renewed mandate and funding from the Swedish government for 2015-2020. The Bio4Energy leadership has learned that final notice on whether the research environment will continue to receive funding may not come until late summer 2015.


Interventions by Bio4Energy scientists at the Impacts of Fuel Quality on Power Production conference, 26-31 October 2014

Fuel Preparation and Additives

  • Strandberg M, Kollberg K, Nordin A. Powder Characteristics of Torrefied and Pelletised Biomass

  • Piotrowska P, Rebbling A, Boström D, Näzelius IL, Grimm A, Öhman M. Waste Gypsum Board as a Fuel Additive in Combustion of Grass and Waste Derived Fuel—Bench and Full-scale Studies

  • Wagner DR, Holmgren P, Persson A, Boström D, Broström M, Molinder R, Wiinikka H. Fate of Inorganic Species during Biomass Devolatilisation in a Drop Tube Furnace

  • Wagner DR, Qu Z, Brostöm M, Schmidt FM. Validation of Reacting Flow Models via Tunable Diode Laser Absorption Spectroscopy


  • Skoglund N, Bäfver L, Renström C, Fahlström J, Holmén E. Full-scale Co-combustion of Municipal Sewage Sludge and Demolition Wood Chips in a Combined Heat and Power Plant - With the participation of industrial partners as co-authors

Deposition and Blending Issues—Full Scale

  • Skolund N, Bäfver L, Renström C, Fahlström J, Holmén E. Full-scale Co-combustion of Municipal Sewage Sludge and Demolition Wood Chips in a Combined Heat and Power Plant 


  • Qu Z, Fagerström J, Steinvall E, Broström M, Boman E, and Schmidt FM. Real-time In-situ Detection of Potassium Release during Combustion of Pelletised Biomass Using Tunable Diode Laser Absorption Spectroscopy

Deposition and Blending Issues—Pilot Scale

  • Fagerström J, Rebbling A, Steinvall E, Boström D, Boman C, Olwa J, Öhman M. Control Strategies for Reduction of Alkali Release during Grate Combustion of Biomass—Influence of Process Parameters and Fuel Additives in a 40 kW Reactor

  • Werner K, Piotrowska P, Boman C, Boström D, Gentili F, Holmlund M. Characterisation of Thermochemical Fuel Properties of Microalgae and Cyanobacteria

  • Sevonius C, Yrjas P, Hupa M, Piotrowska P, Boström D. Agglomeration Tendencies of Algae and Wood Mixtures in Fluidized Bed Incineration

Fundamental Studies

  • Holmgren P, Persson A, Wagner DR, Broström M, Umeki K, Molinder R, Wiinikka H. Size, Shape and Density Changes of Biomass Particles during Devolatilisation in a Drop Tube Furnace

  • Wagner DR, Broström M. Effect of Particle Size, Temperature and Residence Time on Biomass Devolatilisation Behavior in a Wire-mesh Reactor

  • Ma C, Öhman M, Carlborg M, Backman R. Slag Formation during Pressurised Entrained-flow Gasification of Woody Biomass: A Thermochemical Equilibrium Study

  • Carlborg M, Boström D, Backman R, Öhman M. Reactions Between Ash Forming Elements and Two Mullite-based Refractories in Entrained-flow Gasification of Wood

  • Strandberg A, Wagner DR, Holmgren P, Broström M, Molinder R, Wiinikka H, Umeki K. Influence of Biomass Particle Properties and Pyrolysis Conditions on Char Reactivity

In addition to the oral presentations listed above, Bio4Energy had two poster presentations

  • Nordwager M, Nordin A. Biomass Upgrading by Torrefaction—Resulting Powder Characteristics

  • Ma C, Weiland F, Öhman M, Wiinikka H, Backman R. Fractionation of Potassium during Pressurised Entrained‐flow Fasification of Woody Biomass and Peat


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