Green biorefinery optimisation – a work in progress

Ongoing adjustments to the BIO4Africa biorefinery in Uganda aim to secure the best output under local conditions

 

A continuous fine-tuning process is adapting the BIO4Africa biorefinery in Uganda to locally available feedstock and the regional climate. Since the pilot facility went into operation at Kabarole Research & Resource Centre in late 2022, a series of adjustments have improved processing efficiency and the yield and quality of the final feed products.

The test feedstock is elephant grass – also called napier grass – grown and harvested by local farmers. At the biorefinery, the grass is squeezed to extract the protein-rich juice, which is then dried into protein concentrate.

 

 

Maximising protein yield
Juice optimisation is a primary focus. As technology supplier, Grassa introduced a sieve bend early on to remove fibres from the juice and ensure the quality of the protein concentrate. An issue with foam formation has also been solved, ensuring all the protein stays in the juice.

The introduction of an alternative coagulation vessel with a longer sedimentation time has increased the amount of protein concentrate obtained at the end of the process.

 

Faster, safer drying
An efficient drying process is essential to secure the quality of the protein concentrate during transport and storage. To this end, the passive solar drying house that was initially used has been replaced by an electric drying unit, which runs on Uganda’s 100% renewable power supply. This safer, more stable drying process means the protein concentrate can be dried in a matter of hours instead of days, eliminating the risk of mould growth.

Progress in Ghana
Work on the second green biorefinery in Ghana continues in collaboration with SavaNet. After the robust platform was constructed and basic power supply and water supply put in place, initial operations started up in November, before the start of the dry season.

A full power supply is expected to be available this spring so, when the new growing season arrives, the biorefinery can be completed and pilot production begin.

 

Read more about the BIO4Africa green biorefinery in Fort Portal, Uganda – the first in Africa and only the third of its kind in the world.