Cane Preparation
The 100 cane delivery trucks that bring harvested sugarcane from the field direct to the factory ensure that cut to crush is achieved in under two hours, resulting in minimal post-harvest deterioration of the cane and the highest quality ethanol as the end product.
As the cane is billeted by our mechanical harvester, cane preparation is minimised and only shredder is needed. We aim for a preparation index of 87% before milling.
Front end shredding and milling
Shredded cane is transported to the mills, which are driven by the latest technology 72 inch planetary drive milling tandem with variable speed drive (VSD) which ensures maximum milling efficiency.
​
The crushed sugarcane goes through 6 milling tandems while Green Fuel’s specialist welders continuously arc the mills in order to extract the maximum amount of juice.
The Boiler
The bagasse, which is the dry residue left over after the extraction of juice from the sugarcane, is then transported to the boiler in order to produce green, renewable electricity.
Distillation
Producing anhydrous ethanol for vehicle fuel involves a multi-stage distillation process designed to overcome the ethanol-water azeotrope. After fermentation, which yields a "beer" typically containing 8-12% ethanol, the mixture undergoes initial distillation in a series of columns.
01
Beer Column (Stripping)
The fermented mash (beer) is fed into a "beer column" where it's heated. Ethanol, having a lower boiling point than water, vaporizes, separating it from the yeast solids and most of the water and other non-volatiles, which exit as "beer bottoms." The resulting ethanol-rich vapor is then sent to the next stage.
02
Rectification Column
The ethanol vapor from the beer column is further purified in a rectification column. This column works to increase the ethanol concentration by repeatedly vaporizing and condensing the mixture. However, ethanol and water form a minimum-boiling azeotrope at approximately 95-96% ethanol (by volume), meaning that conventional distillation cannot achieve higher purity than this. The product at this stage is called "hydrous ethanol".
The Final Step
The final anhydrous ethanol product is then ready for use as vehicle fuel or for blending with petrol.
Green Fuel’s distillation plant has recently been upgraded to a capacity of 700 kilo litres per day and produces ethanol with a purity level of 99.6%, suitable for blending with Petrol.
