The fertiliser hotspot in the biorefinery value chain

Animals fed on green protein could help farmers lower the environmental footprint of feedstock crops for the BIO4Africa refinery in Uganda. Manure and intercropping reduce the need for chemical fertilisers.


Fertiliser use has emerged as a hotspot in the initial life cycle assessment (LCA) of the BIO4Africa green biorefinery in Uganda. The preliminary report suggests that changes in crop farming practices could have the biggest impact on the technology’s environmental footprint.

DRAXIS has compared fertiliser strategies to assess the potential for improvement in relation to eight indicators of environmental impact. According to circular economy project manager Georgios Lanaras-Mamounis, the findings highlight the benefits of using livestock manure and intercropping in the fertiliser mix for feedstock crops.

“Manure recycling reduces the need for nitrogen or phosphorus from chemical fertilisers. From research by GRASSA, we also know that chemical addition can be reduced even further if the manure comes from livestock fed on green biorefinery products and when farmers make use of intercropping with nitrogen-binding legumes.”

Essential insights
LCAs are essential to achieving a core BIO4Africa objective: to valorise farm waste and contribute to a circular bioeconomy in African rural communities.

DRAXIS has defined 20 LCA scenarios that describe the environmental, social and economic aspects of the project’s pilot biobased technologies. Fertilisation of feedstock crops for the Ugandan biorefinery is one of the first scenarios to be assessed in close collaboration with GRASSA.

“Using the data collected so far, we’ve been able to calculate the environmental impact of producing one tonne of protein in the biorefinery. This calculation is likely to change as more data becomes available. However, we expect the overall picture will still show that fertilisation has most impact on the protein life cycle,” Georgios says.

People, planet, profit
Work on the social LCA and life cycle costing of the biorefinery is now underway. Relatively new in the LCA toolbox, social LCAs assess the performance of the system in terms of a variety of social impacts, such as human rights, working conditions, and health and safety. As Giorgos explains, it’s about modelling the same system in a different way.

“The findings of the social or costing evaluation may not necessarily correlate with the assessment of environmental performance. This is why it is important to take all three dimensions into account to get a full picture of the triple bottom line for a sustainable value chain – in other words, the estimated impact on people, planet and profit.”

The green biorefinery in Uganda: the environmental LCA explained


LCAs are a critical and complicated task in the BIO4Africa project. 

This paper provides an explanatory overview of the initial environmental LCA (E-LCA) to evaluate potential positive and negative aspects of the green biorefinery in Uganda.

DRAXIS has conducted the E-LCA using data and knowledge provided by GRASSA. 

Click on the image to open the pdf.