Page 166 - Advances in bioenergy (2016)

Concept of Decentral Biomass Upgrading by Pyrolysis to Increase
the Energy Density for Transport and Central Gasification in

Extremely Large Scale (Bioliq Process)

29
The Karlsruhe BtL concept combines decentralized production of energy-rich bioSynCrude ®
by means of rapid pyrolysis of biomass (straw, wood) and central processing with final
industrial-scale refinement.

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Since the volumetric energy density of bioSynCrude is by more than one order of magnitude
higher relative to straw, it is clear that the method's efficiency is enhanced by decentralized
energy densification and conversion in a central large-scale unit. The process technology can

be seen in Figure 7.3.

The dry, comminuted biomass is mixed with hot sand at ambient pressure in the absence of air
in a twin-screw mixing reactor. Pyrolytic conversion of the biomass particles at approximately
500°C, and condensation of the pyrolysis vapors take a few seconds only. Depending on the
operating conditions and on the biomass selected, one obtains 40–70% of liquid pyrolysis oil
and 15–40% of pyrolysis char as well as a fraction of noncondensable pyrolysis gas whose
combustion heat can be used for heating or drying. In the pilot plant, 500 kg/h (2 MW) of
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biomass are converted by rapid pyrolysis into bioSynCrude .

Figure 7.3 Bioliq process. (Reprinted with permission from Ref 29. Copyright 2012 Karlsruhe
Institute of Technology)