Sorghum To Ethanol (Set of photos)

On our search for cotton farms we stumbled across a sorghum farm on the Western Darling Downs near Dalby in Queensland Australia. Did you know that E10 (ethanol) fuel is produced from sorghum? This once struggling industry is now in full swing with hopes of expanding because of this grains-to-ethanol plant.

United Petroleum is buying all locally grown sorghum and processing the grain's starch into ethanol with leftover grain turned into animal feed. The biorefinery processes up to 190,000 tonnes of grain a year. Fuel wise, 3000-3500 tonnes of sorghum is processed each week at the biorefinery producing 1.4 million litres of ethanol fuel. The local farmer here produces on average 7000 - 10,000 tonnes of sorghum a year, all of which goes to the biorefinery.

So how do you turn sorghum into ethanol? It starts with going through a hammer mill which pounds it into a fine powder starting the liquidification process. An alpha-amylase enzyme is then added breaking down the starch into complex sugars. These are broken down further with another enzyme, glucose amylase into single sugar molecules or glucose.

The glucose is then fed into the main fermentation stage with the addition of yeast that has been separately propagated from a dry yeast product. During fermentation, the yeast is able to break down the glucose directly to ethanol. The total fermentation process takes between 38 and 42 hours. The ethanol in the fermenter at this stage is at around 11-12% .

The fermented material is then added continuously to a distillation process to extract the ethanol. In the first of this stage around 50% ethanol vapour is created through a steam heated process. That 50% vapour then goes through the next stage of distilling where it is concentrated to 96 per cent. It is then fed through a molecular sieve dehydration process that produces a 99.6% ethanol. From here it is transferred into storage tanks where 1 - 1.5% unleaded petrol is added as a denaturant, this is now the final product we find at the pumps.

It is the leftover products from this process, minus the ethanol that are turned into animal feed leaving no waste of the product. It amazes me standing here that I'm looking at a possible 3 million litres of ethanol fuel!!