This proved to be a blessing in disguise and with a Johannesburg Metro bus
testing his biofuel, Derek’s business’ future looks promising. Peter Mashala reports.

Derek Matthews was devastated when he heard about government’s refusal to register food crops as feedstock for biofuel plants.
A fourth-generation maize farmer on the farm Silverton outside Lichtenburg in the North West, Derek had already invested in an on-farm ethanol production plant. His whole operation was geared towards using maize as a feedstock, but now he needed to find an alternative if he wanted to sell his biofuel.
Derek and his brother Anthony produce sunflower, groundnuts and beans and run a cattle operation on the 700ha farm. But maize is the mainstay of the operation. When maize prices plummeted in 2005, they looked into the viability of producing ethanol from it.
Although there was talk of farmers starting an ethanol company, Derek couldn’t see the benefit in it. Instead, he established his own on-farm ethanol plant with Anthony, their cousin John, and business partner Jerry Basson.

“This was after I researched the industry and attended an ethanol conference in the US,” Derek remembers. “There I learned two things – that the ethanol industry was in its infancy, but had a promising future and that the only way to make an ethanol plant work was to add value to it.”
To add value, the partners established a feedlot, using distiller’s grain, a byproduct of ethanol production, to feed the cattle.
Derek started building the plant in June 2005 and it was operational by November, producing 1 500ℓ/day. With the plant in full production, Derek hoped to sell 30% as ethanol gel and the rest as regular ethanol fuel.

Changing tack
But things didn’t go according to plan. “I had no market because the South African ethanol industry was lagging behind,” Derek says. “I couldn’t export either because countries with established ethanol industries were already producing massive volumes.”
This forced Derek to produce more gel than pure ethanol.
When government took a stand against using food crops in biofuel production, Derek changed from using first-grade maize to using third-grade, non-food maize as a feedstock.
“But although non-food grade maize is cheaper, it isn’t as readily available,” Derek explains. He was forced to look for alternatives, and his search led him to sugar beet, which isn’t used for food in South Africa.

More fuel from sugar beet
Derek took the leap and became the first farmer in South Africa to plant sugar beet on a commercial scale.
“Although sugarcane is a good feedstock for ethanol production, I can’t grow it on my farm,” he explains. “Sugar beet, on the other hand, can be produced in dry areas such as Lichtenburg.” Last year, Derek imported the sugar beet variety 508, which is suitable for South Africa. “I planted 5ha under irrigation, and it yielded 124t/ha,” he says.
Sugar beet yields more ethanol per hectare than either maize or sorghum. While maize yields just 1 200ℓ/ha, sugar beet on irrigated land yields 16 000ℓ/ha. This year, Derek planted 10ha of sugar beet under irrigation. However, as it’s a seasonal crop, he supplements it with sorghum.

Surprise help from Joburg Metro
With his feedstock successfully sorted out, Derek still had no market for his product. Government’s concern over food security seems to have put a brake on its plans to support and develop the local biofuel industry.
However, an opportunity materialised in the unlikely form of a Johannesburg Metro bus. Vehicle company Scania had been in discussions with the city council about the viability of ethanol-run buses. Intrigued, the council started making enquiries.
Their investigations brought them to Grain SA, which referred them to a rather surprised Derek. After some discussion, it was agreed to launch a viability study using a single Metro bus, which runs on a whopping 4 500ℓ of ethanol a month.
The study will eventually include 20 buses. “The Johannesburg council says that at least 10 buses are needed to do a good assessment of the benefits,”
Derek explains. “But one is a good start, and we hope it’ll be 20 buses by the end of the year.”
Although the plant can produce enough ethanol to meet the current demand, it will have to expand if the number of buses increases. The 20 buses will need 90 000ℓ/month.
Contact Derek Matthews on 082 878 0056 or e-mail Derek@silversandsethanol.co.za.     |fw

The ethanol production process

The ethanol plant has two 4 000ℓ cookers. Two-thirds water and one-third milled maize goes into each. Once the water is boiling, the mixture, called slurry meal, resembles porridge.
The first enzyme, alpha-amylase, is added to convert starch into dextrose. The slurry meal is allowed to cook at 95°C for 2,5 hours. It’s cooled down to 65°C and the second enzyme, glucoamylase, is added to convert dextrose into glucose.
The mixture is further cooled to 30°C before yeast is added. This mixture is pumped into fermentation tanks and left to ferment for three days. At this stage, it has the properties of sorghum beer with a 10% ethanol content. It ‘s then distilled in a column to produce a clear liquid condensate, ethanol. The byproduct formed during the distilling process, called distillers’ grain, is used as cattle feed.
The ethanol is pumped into the 30 000ℓ storage tank linked to the 1 000ℓ gel mixing unit, in which the gel is formed. This process takes up to 10 minutes and involves mixing cellulose into the ethanol and adding a dye to give the end product its distinctive blue colour.
When the maize is replaced with sugar beet, the cooking step is omitted. The beet is milled to pulp, water and yeast are added, and the slurry is fermented and distilled. This means a substantial production cost-saving. The fermentation takes about 56 hours and the distillation about 10 hours, producing 2 000ℓ.
The ethanol used in the Metro bus consists of 90% ethanol. The rest is made up of an additive, added by the bus manufacturer.