Flexibility in ethanol-based lignocellulose biorefineries

About the project

This project has produced a knowledge synthesis addressing flexibility in ethanol-based biorefinery processes using lignocellulosic feedstocks from the Swedish forestry and agricultural sectors. The flexibility of biorefinery operations is important as it determines their capacity to respond to fluctuations in feedstock supply and market demands. Here, the flexibility of feedstocks, processes, volumes and products, referred to as manufacturing flexibility, is reviewed. Particular emphasis has been given feedstock and product flexibility.

Increasing the product flexibility of a biorefinery is one means of reducing the risks associated with uncertainties in the future biofuel demand. A number of non-fuel products can be generated in a flexible biorefinery and there is future market potential in e.g. polyhydroxyalkanoates, lactic acid and other organic acids. Further, single-cell proteins may be produced with a number of microorganisms, using lignocellulosic sugars, simple nutrients and equipment similar to that of second generation ethanol plants.

It is concluded that a vast number of options to increase manufacturing flexibility in biorefinery operations exist. Although the present report does not include assessments of these options from a techno-economical perspective, it is indispensable that such analyses are made in conjunction with a scrutiny of the effects on the production as a whole, and the interdependency of the different processing steps in relation to the prerequisites of each biorefinery facility.