Biomass processing and pretreatment

Overview

Cost-effective biomass processing technologies are fundamental to the production of low cost fermentable sugars and other bio-intermediates. Research at QUT has focussed on lower cost and integrated technologies for feedstocks of particular relevance to Australian and other tropical region crops.

Low temperature, green solvent-based biomass pretreatment technologies

Professor William Doherty with team members Dr Lalehvash Moghaddam and Mr Adrian Baker

The majority of biomass pretreatment processes currently in commercial use or being developed suffer from major limitations including low sugar yields, produce carbohydrate degradationproducts and require high capital cost pressurised reactors. QUT has been developing lower temperature biomass pretreatment processes based on the use of green solvents such as glycerol, ethylene glycol and alkylene carbonates. These processes result in significantly enhanced sugar yields with much lower amounts of degradation products and lower enzyme rates. The use of non-toxic high boiling point solvents also enables the processes to operate at atmospheric pressure and hence significantly reduce the cost of fermentable sugars production. QUT has developed significant intellectual property around these novel processes.

In addition, QUT has significant experience with the use of other pretreatment processes including a range of acidic, alkaline and ionic liquid based pretreatments.

Enzymatic production of fermentable sugars

QUT has extensive experience in the application of enzymes for the production of fermentable sugars from biomass. Work at QUT has assessed commercial and developmental enzyme products to assess efficacy across a wide range of pretreatment technologies and feedstocks. In particular, QUT has developed techniques to screen and characterise cell wall modifying enzymes produced in planta. Screening protocols have been developed utilising (i) soluble, small molecule substrate analogs (both fluorogenic and chromogenic), (ii) insoluble, purified substrates, and (iii) insoluble, lignocellulosic substrates (both native and pretreated). Considerable work has been undertaken on the cost of production of fermentable sugars coupling simple enzyme mixtures with highly effective pretreatment processes.

Hydrothermal liquefaction of biomass

Hydrothermal liquefaction converts biomass to biocrude oil in moderate temperature environments. The primary advantage of this over other thermal conversion processes is its suitability for processing a wide range including low quality (high moisture and ash) feedstocks. QUT is establishing a significant track record in the development of proprietary process conditions and catalysts to optimise hydrocarbon and high value resin yields from biomass. QUT has extensive analytical capabilities in and bench scale facilities dedicated to hydrothermal upgrading of biomass. QUT is currently constructing a pilot scale continuous hydrothermal liquefaction reactor.

Banyo Pilot Plant