- Cane Storage
- Transfer to Factory
- Power Production
- Loading and Dispatch
The sugarcane is harvested by Case 8800 H8 chopper-harvesters, and is delivered by trucks to the factory in billeted form (i.e. pre cut).
The large number of trucks allow for storage of cane on the trucks, which avoids double handling of the cane.
The trucks are self-tipping and discharge a maximum load of 20 MT to the mill per trip.
The four 54” Dedini mills can crush 4 500 MT sugarcane per day. The juice (sugars and moisture) is extracted by crushing the crystallised sugars by dissolution in hot imbibition water.
The juice (now called mixed juice) is screened prior to it going to the distillery.
The dry fibre, known as bagasse, is sent to the boiler and burnt as boiler fuel.
The Caldema steam generator burns sugarcane bagasse to generate superheated steam at 45 bar and 450°C. This drives the turbine alternator which, in turn, produces electricity to drive the mill turbines. Any excess power is then exported into the national grid.
The steam produced by the boiler is used in the distillation process and excess steam produced drives the Turbine and the Generator (TGM 22.5MVA), which has the capacity to generate 18.5MW at full capacity. The electricity is utilised in the factory and around the estate and excess is exported to the Nation Grid via a 32KVA 50 km power line constructed in 2014.
Mixed juice from the mill is delivered to the evaporator section. The primary function of the evaporator is to increase the concentration of the mixed juice from approximately 13°brix to 20-22°brix by boiling off excess water. The concentrated and sterilized syrup is called mash.
The mash is fed to the fermenters along with a dose of yeast. The yeast ferments the sugars in the mash, which then produces ethanol and carbon dioxide, along with small amounts of other intermediary products. This alcohol rich solution is referred to as beer. The fermentation cycle takes 48 hours to complete yielding beer with approximately 10 % alc.
The beer is fed into the hydrous section of the distillery producing ethanol with approximately 4 % water and 96 % ethanol, i.e. hydrous ethanol. The ethanol is pumped to the anhydrous section where cyclohexane is added to the alcohol to separate water from ethanol creating anhydrous ethanol, 99.6% alcohol with maximum of 0.4% water Vinasse is generated as a by-product, which can be used as a fertilizer.
The anhydrous ethanol is pumped from the day-receiver tanks to the loading bay where it is denatured with petrol (0.05%), to prevent consumption, and loaded into tankers. The quality of the ethanol is checked, the volumes and quality are recorded and the tanker is dispatched.