Technological watch

BTG Biomass Technology Group have successfully launched operation of a first of a kind thermo-chemical fractionation plant, an important step towards the commercialisation of a fast pyrolysis based biorefinery. The plant enables the transformation of lignocellulosic biomass such as sunflower seed husks into products including phenolic resins, furan-based resins, paints, engineered wood and natural fibre reinforced products.

“I’m very excited about this milestone. The start-up of the pilot plant is a major step forward in producing new bio-based products from all kinds of biomass. It enables product development at an industrially relevant scale and it can contribute to the realisation of a truly sustainable process industry,” said Bert van de Beld, Chief Technology Officer of BTG and coordinator of the Horizon 2020 project Bio4Products, within which the plant has been built.

Innovative two-step conversion processThermo-chemical fractionation is an innovative two-step conversion process to transform different bio-resources into raw-materials for renewable chemicals and products.

In this approach, a short thermal treatment at elevated temperature (fast pyrolysis) is followed by a low temperature fractionation of the mineral free, liquid product (fast pyrolysis bio-oil) that keeps the key chemical functionalities intact in separate, depolymerised fractions.

The main products obtained are:

• Pyrolytic lignin: A raw material suitable for the production of renewable bitumen or various resins, as a replacement for fossil phenol. Although the pyrolytic lignin is not as reactive as the fossil phenol, it is shown to be much more reactive compared to other types of lignin such as natural or Kraft lignin.
• Pyrolytic sugars: A raw material suitable for the production of furan-based resins. The pyrolytic sugars can be obtained with various water contents depending on the exact process configuration.
• Extractives: A raw material for specialty chemicals (it is analogous to “pine chemicals”). The extractives stream is also quite similar in nature to tall-oil liquids, and could likely be used as co-feed to produce diesel like products by HDO.

Three tonnes per day plantFollowing extensive testing at bench scale, this year BTG have designed, constructed and commissioned a pilot fractionation unit with a throughput capacity of 3 tonnes per day of fast pyrolysis bio-oil – roughly a ten-fold scale-up of the bench-scale unit.

The properties of the fractions – in particular the lignin and sugar fractions – obtained with the pilot plant are very similar to those produced in the bench-scale unit.

Downstream partners already on boardWithin the Bio4Products project, BTG has launched partnerships with downstream partners interested in using the fractions to develop bio-based products.

The development of new products using pyrolytic lignin is led by Hexion GmbH from Germany.

Hexion is using the lignin stream to partially replace fossil phenol in a variety of its existing resin formulations, with possible applications in the automotive industry, insulation, steel industry/metal casting, household products and abrasives.

The pyrolytic sugars are being exploited by TransFurans Chemicals (Belgium).

As well as investigating their application in sand moulding resins, TransFurans are developing modified wood products in partnership with Foreco (Netherlands). The main application would be for fencing, as a replacement for creosote treated wood. Based on the promising results demonstration field tests are planned within the next year.

Source: Bio4Products, press release, 2019-06-19.