Project outcomes
- Fundamental grasp of the main process challenges of the fermentation processes of succinic and fumaric acids
- To enable the sugarcane processing industry to assess the opportunities for additional revenue generation by production of succinic and fumaric acids.
Focus areas
- Investigate the feasibility of unrefined sugar feedstocks for producing succinic and fumaric acid
- Examine the effect of CO 2 mass transfer on succinic acid productivity and byproduct formation
Succinic and fumaric acids have been identified as potentially important biochemicals that can be manufactured from sugar feed stocks by fermentation processes. However, the solid-state fermentation processes are not currently efficient, and this project has been investigating the processes and developing improved fermentation technologies to increase yields. Should suitable markets for these chemicals develop, such technologies based on sugar feed stocks would give the biorefinery a competitive advantage over other processes.
With regards to the succinic acid process, the research work contributed to improved start-up procedures to enable optimal biofilm formation.
With regards to the fumaric acid process, it can now be operated in homofumerate mode where only fumaric acid and CO₂ are produced. This is the first group to achieve fumerate production without any ethanol byproduct. The yield on glucose is in the order of 0.85 g/g but the group believes this can be further improved by reducing the fumerate export cost via pH manipulation.
The reactor is completely scalable with all biomass attached on a tube and problems with other reactors such as clogging with loose biomass is avoided with this design. Biomass-broth separation is automatically achieved, an advantage over existing designs. The group is currently developing a complete package for a pilot scale experiment and considers that the work has true commercial potential.
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Prof. Willie Nicol
Department of Chemical Engineering, University of Pretoria