Biocoal

Biocoal, often referred as biochar, is as the name refers a product that is made from bio based material and resembles very much char coal. As it has been previously explained biochar is produced by torrefaction of biomass in a temperature 225-300ºC (Alén, R. 2011. p. 67). The torrefaction process results in the biomass changing into a coal-like product and the best quality torrefied pellets (TOP-pellets) are produced when chips are torrefied at 240-250ºC. When it is milled and pelletized its energy density is higher that the energy density of traditional wood pellets. TOP-pellets are good energy carriers in large volumes and endure long transportation distances a lot better than other similar products.

(Wilén, C. 2011. p. 41)

In large scale utility boilers TOP-pellets give high energy volumetric density and their properties are similar to char coal. The production units can operate in

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alone mode, like the torrefaction unit constructed in the BIOTULI-project, or they can be integrated to industrial CHP or forest industry bed boilers. TOP-pellets offer a tempting business opportunity to companies with existing raw material and forest residue logistics. (Wilén, C. 2011. p. 41) That is why biocoal and TOP-pellets have been chosen to be concentrated on in this report as a part of the forest biorefinery concept.

Coal has been created from biomass for centuries but traditionally it has been used to improve soil, or in backyard grilling or small scale heat production (Mitchell, D. & Elder, T. 2010. p. 1 and 6). When used for soil improvement biocoal is also an effective carbon sink as it captivates carbon to the soil. The increased pressure to find alternative energy sources for fossil based fuels has made the bio char a currently interesting topic in energy use as well and it has been developed in order to replace fossil coal.

There are countless coal fired condensing power plants in the world that would be operational for decades to come but are threatened by coal prices getting more expensive and a strong political desire to reduce the use of fossil coal. On the other hand the political atmosphere favours bio based energy production. The properties of bio char are similar to fossil coal and therefore it could be possibly used in existing power plants with minimum modifications. (Hämäläinen, E. &

Heinimö, J. 2006. p. 7)

The high temperature of torrefaction process decomposes the polymers of the bio mass giving it suitable characteristics for use in power plants (Bergman. P. C. A.

et al. 2005. p. 14). Untreated biomass is difficult to use as its grindability is poor and requires a lot more energy (Abdullah, H. & Wu, H. 2009. pp. 4177 - 4179).

There are a number of different processes to produce biocoal. The bases for suitable torrefaction reactors come mainly from three fields: drying, pyrolysis (carbonation), and gasification. These technologies can be divided to two categories: indirectly heated and directly heated. (Bergman, P. C. A. et al. 2005. p.

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27) In the BIOTULI-project biocoal is produced by a screw type reactor. Such demonstration plant was built already in the 1980s in France producing 12,000 ton/a biochar. The plant was shut down in the 1990s due to economic reasons. The screw reactor has low energy efficiency and its scalability is poor and therefore its production costs are not very competitive although the technology itself is feasible. The plant in France was shut down in 1990s. (Bergman, P. C. A. et al.

2005. p. 22) Also the dust formation in the torrefaction process is a common problem which can lead to dust explosions and spontaneous ignition (Wilén, C.

2011. p. 44).

There are commercialized TOP-pellets on the market and some power plants have used small amounts of TOP-pellets combined with fossil coal in order to test the suitability of the fuel. Probably also image purposes are behind these testings. The research of biocoal is widespread but the real breakthrough hasn’t happened yet and for now biocoal is just one option in a wide range of promising possible future biofuels.

For now the price of TOP-pellets is higher than the price of char coal. The total cost of torrefied pellets is somewhere around 6,5 € per GJ with a difference of one euro compared to coal. Almost half of the cost of TOP-pellets come from the cost of biomass. As the emission rights get more expensive the price of TOP-pellets becomes more competitive compared to coal. Already TOP-pellets are cheaper than wood pellets. The total cost of wood pellets is around 9 € per GJ. (Bergman, P. et al. 2011. p. 15)

7 ENERGY COMPANY EXAMPLES

The energy markets are changing and this offers opportunities for new companies.

Although, this report mostly concentrates on integrated production in the forest industry, two energy companies are introduced in this chapter to highlight how the current possibilities can be taken advantage of.

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The first company presented in this chapter is Topell Energy. This is because this report focuses on biocoal from all biofuels and Topell Energy is one of the leading companies in that field.

Chempolis is a Finnish company providing biorefining technologies and solutions for production of bioethanol, biochemicals and biocoal as well as co-production of non-wood pulp, biochemicals and biocoal. This company has been chosen to be presented here because it is innovative, Finnish and seems to have a promising future. Chempolis is also interesting in the sense that it is a biorefinery that concentrates in integrated processes and especially the production of transportation fuels.

Chemrec is a similar example and is thus covered more shortly. The purpose of these examples is to showcase that there already are companies providing solutions for turning traditional pulp mills into a biorefineries. The focus when looking into Chemrec is on the Chemrec process and the BioDME-project which is a great example of a successful research and development project profiting companies from different industries.

All of these companies are on markets with great growth potential. The competition is going to get more fierce in the future but for now all three companies seem to have good starting positions and if they keep open-mindedly developing and innovating the late starters may have a hard time catching up to these two.