Making the stuff of bio-based plastics, identifying new value chains in 'forest' biorefinery, finding the perfect method for quick drying sludge or pinning down the best kind of pine for making bio-based products. These are the topics of four research projects whose instigators, all Bio4Energy researchers based in northern Sweden, were awarded grants in the latest round of funding by the Swedish Research Council Formas.
'Swedish forestry industry needs to transition from traditional production of wood and pulp to a more varied and sustainable production of bio-based products', said Formas first secretary Gia Destouni in a press release announcing the grants, in lieu of justification for the need of the research projects thus enabled.
This is taken to mean that the industry could benefit from a move from pulp and paper making only, to full-scale biorefinery operations in which products as diverse as biofuels, 'green' chemicals and specialty acids or the like could be made in one production unit.
Each of the four Bio4Energy research proposals, applied projects expected to result in methods or processes for industry to incorporate in their production within a few years, aim to add one small piece of the puzzle of such a transition:
- Efficient conversion of forest biomass insoluble polyesters with potential use in lignocellulosic feedstock biorefineries;
- Rapid drying of sludge from forestry industrial operations using vacuum technology;
- Large-scale expansion of biorefinery: New value chains, products and the efficient use of woody biomass and;
- Selection of elite populations of pine for the sustainable production of new bioenergy and carbohydrate products.
Turning tree wax into monomers using enzymes
Take professor Paul Christakopoulos, and his Biochemical Process Engineering group at the Luleå University of Technology in northern Sweden. They intend to make use of a type of wax found in the outer bark of trees and which thus far has been regarded as a residual product of the pulping process or, as Christakopoulos said, as 'waste'. The wax is called suberin and is a by-product of Kraft pulping, of birch in this case. Just like lignin, suberin has traditionally been burnt in local biomass incinerators for the purpose of heating the production premises. However, in Sweden suberin is turned out in volumes that approach 200,000 tonnes per year, according to Christakopoulos, and could find use in value-added products from biorefinery production based on woody feedstock.
In a research project called 'Efficient bioconversion of forest biomass insoluble polyesters with a potential use in lignocellulosic feedstock biorefineries', Christakopoulos and colleagues want to use the latest kinds of industrial enzymes to turn suberin from the outer bark of trees into new monomers. A monomer is a molecule able to bond in long chains, which is a useful quality in building blocks of value-added products in the oleochemical industry. Such building blocks may be polymers or polyurethanes, both widely used in the production of frequent-use plastics and foams; only those derived from suberin will have the advantage of being bio-based instead of derived from petrochemicals.
Once supplied to manufacturers, the new monomers may be used by industry as a base material for making either bulk or high-value added products, said Christakopoulos, who is a senior PI on the Bio4Energy Biochemical Platform.
'The most [promising] applications for suberin components involve their use in synthesis of polymers, especially polyols through oxypropylation, polyurethanes from the mixture of aliphatic monomers and polyesters either from depolymerised suberin mixtures or from isolated monomers', a scientific summary of the project said.
Editor's note: Suberin has been defined as a wax like, fatty substance, occurring in cork cell walls and in or between other cells, that on alkaline hydrolysis yields chiefly suberic acid.
'Biosludge' from industrial forestry operations could yield new materials
Sludge from industrial forestry operations may be a source of new bio-based materials. However, economically and environmentally sustainable methods for drying such sludge need to be worked out, if cost-efficiency is to be achieved. Researchers on the Bio4Energy Pretreatment and Fractionation Platform and the Bio4Energy strategic partner SP Processum have been working to perfect and test a new method at the pilot scale for quick drying of 'biosludge' using excess heat from industrial operations.
'Thus far we have carried out pilot trials involving [drying the sludge in a] cyclone reactor, at high speed and low temperatures in a vacuum situation', said lead researcher Sylvia Larsson of the Swedish University of Agricultural Sciences (SLU) at Umeå, Sweden.
'We were surprised at how well it worked and saw a possibility to achieve a breakthrough that could mean that we have found a solution to the problem of industrial sludge', she added.
In fact, the forestry and pulp and paper industries had a long-standing issue of what to do with the wet and rather slimy bio-based sludge which is a residual product of their industrial processes, the assistant professor said. It followed that several commercial companies were interested and involved in trialling the quick-dry method.
'The grant from Formas means now we can start working for real' to perfect the method previously trialled on a pilot scale, according to Larsson: 'We have had great support from SCA Obbola, Husum, Metse Board and SP Processum... If we can dry the sludge then we can start looking at making new materials step by step'.
The project by Larsson and colleagues is called 'Rapid drying of sludge from forestry industrial operations using vacuum technology'.
Expansion of biorefinery and pines for products and energy
Two further projects were awarded grants. Researchers on the Bio4Energy Process Integration Platform will be looking at, 'Large-scale expansion of biorefineries: New value chains, products and the efficient use of woody biomass'. LTU professor Robert Lundmark is at the helm of this project which Bio4Energy expects to report on in more detail in connection with the project start, late this year or early next.
SLU professor Harry Wu will be leading Bio4Energy feedstock researchers in a project called 'Selection of elite populations of pine for the sustainable production of new bioenergy and carbohydrate products'.