Preliminary status note: Thermal biomass conversion technologies ...

2.4. Fast Pyrolysis Technology
2.4.1 Short description of technology
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By pyrolysis of biomass in the absence of oxygen a large fraction of the biomass can be converted to bio-­‐
oil, and smaller amounts of char and gas. Biomass such as wood, agricultural residues and waste products
can be used as feedstock for fast pyrolysis processes. A maximum oil yield is in most cases obtained at
reactor temperatures between 450 and 600°C with a high feedstock heating rate and a short gas residence
time. The bio-­‐oil mass yield obtained from various biomass sources are in the range of 30 – 75 %wt. Wood
having a low ash content and a high cellulose content is often found to provide a high bio-­‐oil yield of 70 –
75 %wt. The generated bio-­‐oil has high oxygen content, cannot be distillated and may in some cases have a
limited storage stability. The oil can be utilized as a heavy fuel oil in boilers, while it in most cases needs
some upgrading by hydrogenation if the oil shall be used in diesel engines or gas turbines. Two classes of
reactor types that can obtain high biomass feedstock heating rates have mainly been developed for flash
pyrolysis plants, ablative reactors and fluid bed reactors. In an ablative reactor high heating rates is
obtained by pressing the fuel particles towards a hot metal surface, while the high heating rate in a fluid
bed reactor is obtained by a fast mixing of hot inert bed material and the fuel. Recently it has been
proposed, that the char from the pyrolysis process can be used as bio-­‐char that is distributed on
agricultural fields, and thereby act as a method to sequestrate carbon (Bruun et al. 2011).
2.4.2 Global status of technology development
The most active research community regarding fast biomass pyrolysis is at Aston University in the UK, and
the research group is headed by A. V. Bridgwater (Bridgwater 2012).
The construction of commercial and pilot pyrolysis plants has gradually increased the last 10 years and
initially most plants were constructed in Canada. Today both pilot and commercial plants are constructed in
several countries as seen in Table 1. The largest planed pyrolysis plant is the construction of a 400 tpd plant
that has been announced by Alberta placed Tolko industries LTD using the Ensyn developed CFB
technology.
Table 1: Global survey of major technology developments of fast pyrolysis. Tpd = Tons produced daily.
(Butler et al. 2011).
Company Technol Developments
Dynamotive BFB Several plants, largest is 200tpd at west Lorne (CAN)
Ensyn CFB Several plants, largest is 100tpd plant in Renfrew (CAN); construction of 400 tpd plant in
High Level, Albarta (CAN) with Tolko Industries LTD. Announced; Construction of 9
plants in Malaysia by 2015 announced
BTG RCR 120 tpd plant in Hengolo (NL) announced production of bio-oil, electricity, organic acids
B-O H N.V. RCR Largest plant is 12 tpd. Construction of two 5 tpd plants underway in NL and BEL
Biomass Eng. BFB 4.8 tpd facility (UK)
KIT/Lurgi Auger 12 tpd pilot plant in Karlsruhe (GER)
Pytec Abliative 6 tpd plant (GER)
Anhui Yineng M.FB Three 14 tpd units constructed (CHI)
Metso Consort CFB 7.2 tpd pilot plant at tampere (FIN)