Value creation from the valorization of condensable volatile substances
A by-product of SHS torrefaction is a condensate made up of water and potentially valuable substances, such as organic acids, methanol or furfural. In the “VALORKON” project funded by the BMBF, Fraunhofer IGB worked to develop separation processes that could be used to recover such platform chemicals at high purity levels from the condensate produced by the torrefaction of beech wood chips.
Separation of condensate streams
Fraunhofer IGB set up a batch rectification unit to separate the condensate streams into individual fractions. In combination with other separation processes such as extraction and electrodialysis, the researchers were able to recover furfural from the condensate at a very high purity level (95 percent). The purification of other valuable substance fractions, for example organic acids, is part of the ongoing work.
Environmental and economic assessment
In parallel to the technical work carried out at Fraunhofer IGB, Reutlingen University conducted an environmental and economic assessment of the entire process – from drying and torrefaction through to resource recovery using the condensate. The result is encouraging so far: The current process has a positive CO2 balance and promising economic potential.
Outlook: Entire biorefinery process
The next steps towards pre-industrial development are the recovery of other products from the condensate, the transfer to a continuous, scalable complete process and its application using other biomass residues.
In addition, there are plans for a joint publication with Reutlingen University on the environmental and economic potential of the entire biorefinery concept.