A doctorate study undertaken by Yuda Benjamin, a student at Stellenbosch University’s Department of Process Engineering, has found that the fibres of some sugarcane cultivars could potentially boost ethanol production at a lower cost.
“The South African Biofuels Strategy has identified sugarcane as having the biggest potential for ethanol
production, owing to its high productivity for each unit area of land compared to other crops.”
In the study Characterisation of bagasse from sugarcane cultivars for bio-ethanol production, Benjamin states that bio-ethanol – which is traditionally produced from high-cost sugars – is one of the most attractive alternative fuel sources. “Sugarcane crops represent a preferred crop for bio-ethanol production due to high biomass yields, high water utilisation efficiency and high fermentable sugar content,” he notes in his study.
“However, sugarcane cultivars currently used for sucrose extraction do not utilise the full potential of this crop for bio-ethanol production,” he points out. Benjamin adds that reducing costs is one of the biggest challenges that the sector faces with regard to processing sugarcane fibre for ethanol.
New research Currently, new research initiatives are being developed to find a way of reducing the production cost, especially reducing the pre-treatment costs and amount of enzymes required. Benjamin notes: “One of these initiatives is to use classical and precision breeding of feedstock for preferred characteristics, including higher biomass yields per hectare and chemical-physical composition that is amenable to pre-treatment hydrolysis.”
He adds that any attempt to change the structure matrix of the lignocelluloses biomass to make it easier for enzyme attack and reduce the pre-treatment cost will be a step forward for the development of large-scale crops, especially if this can be combined with higher biomass yields per hectare to maximise energy production per land used.
Methodology and findings In this context, the bagasse from 115 modified sugarcane cultivars was evaluated for bio-ethanol production. Benjamin set off by determining the composition of the bagasse from different sugarcane cultivars to evaluate differences in carbohydrates and lignin content. Hereafter he compared the varieties in terms of their response to pre-treatment and enzymatic hydrolysis. In his research, Benjamin concludes: “The genetically modified cultivars performed better than the cultivars from classical breeding.”
Full acknowledgement and thanks are given to “Characterisation of bagasse from sugarcane cultivars for bio-ethanol production” by Y Benjamin, JF Gorgens, and H Cheng from the Department of Process Engineering at Stellenbosch University for providing the information to write this article.