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The South African Department of Science and Technology (DST) has established a biorefinery research consortium (BRC) to create new value chains from waste biomass.

The consortium is a partnership between the Council for Scientific and Industrial Research (CSIR), the Tshwane University of Technology, the University of the Witwatersrand, and Sekolong Sa Dimelana, a rural-based bioenterprise.

The objective is to identify opportunities for the beneficiation of waste by-products from forestry, timber, pulp and paper industries, such as sawdust, finding alternative and innovative uses for the waste and diverting it from landfills, the DST explained in a statement.

The BRC will use the recently launched R37.5 million Biorefinery Industry Development Facility (BIDF) at the CSIR's Durban campus.  Read more: 23 global regions make bold commitment towards zero waste

According to the DST, in its initial phase (2018 to 2021), the consortium will focus on the revitalisation of the forestry, timber, pulp and paper industries. The BIDF supports innovation in a range of industries, including forestry, agro-processing and other biomass-based industries.

Currently, biorefinery technology in South Africa's pulp and paper industry is practised on a very limited scale.  Most wood, pulp and paper waste ends up in landfill sites or is burnt, stockpiled or even pumped out to sea, the DST explained in a statement.

The Chief Director: Bioinnovation at the DST, Ben Durham, says the consortium was conceptualised with a strong emphasis on the full value chain approach, coordination and technology transfer, by providing broad access to technical expertise and the biorefinery demonstration infrastructure that the BIDF provides.

Cellulose nanocrystals

The BIDF has developed a novel process to produce cellulose nanocrystals (CNCs) directly from wood sawdust, without the need for the conventional pulping and bleaching processes that are currently used to isolate CNC from wood.

Cellulose nanocrystals are nanoparticles that have impressive optical, rheological and mechanical properties comparable with stainless steel, and have widespread applications in the automotive, construction, paper, medical, food, environmental and industrial sectors, among others.

According to the CSIR chief scientist at the BRC, Prof. Bruce Sithole, CNCs are high-value materials that currently sell for approximately US$1 000 per kilogram.  They are typically produced from high-purity wood-derived cellulose products such as microcrystalline cellulose, so producing CNC from wood sawdust is an achievement.

The CNCs produced at the BIDF will be used by other consortium members for downstream development of various CNC-based products, such as high-performance composites for packaging and construction applications, biopolymers for water filtration and biomedical applications, as well as biobinders produced from sawdust and castor oil.