|
:Bangkok Post (Eng)
|
| ѹ : 13/6/2551 |
| |
|
Brazil has made biofuel from sugar cane since 1975. Can it survive today's 'food or fuel' debate?
The bio-ethanol producers of Brazil are lieking their wounds following the "fuel versus food" debate.
Unica, the Brazilian sugar cane industry association, is trying ot convince the world that its biofuel is not a threat to food supplies, is entirely sustainable and is cheaper and cleaner than oil.
Its evidence is strong but applies only to certain parts of Brazil. The growers are aggrieved by accusations that they are clearing Amazonian rainforests for sugar cane; it needs drier conditions that occur near the Amazon and most cane is grown in south-central Brazil, some 2,000 kilometres from the Amazon.
There is also an argument that suggests that by growing cane in one place, it displaces agricultural activity to somewhere else-potentially, rainforest. But currently just 2.3% of Brazil's arable land is used to grow sugar cane.
Half is sold as sugar and the other half makes enough ethanol to power 50% of the cars on Brazil's roads.
The world's largest sugar cane facility is at Sao Marinho, north of Sao Paulo. Its processing plant is at the centre of 111,000 hectares of fields. In all directions, there is sugar cane as far as the eye can see, which isn't actually very far because it grows to over three metres high.
Brazil embarked on its ethanol fuel programme in 1975 to reduce its bill for imported oil. At that time, it had no oil of its own but subsequently big discoveries have been made off hte coast. That, combined with home-grown fuel, are reasons for the country's current prosperity.
Flex-fuel -cars that can run on petrol or ethanol, and pioneered in Brazil by Fiat-made the difference.
Today, 88% of cars sold in Brazil are flex-fuel and last month sales of ethanol exceeded petrol for the first time, Brazilian petrol contains 25% ethanol, while pure ethanol (E100) is 94% alcohol (the rest is water)
Ethanol's energy value is les than petrol (the fuel consumption is 30% worse), so ethanol needs to be at least 30% cheaper than petrol. The price varies with the time of the year and location.
With oil at around $ 120 a barrel, the Brazilian ethanol equivalent is $45. It is much more effcient than producing ethanol from corn, as done in the United Stats, or from the sugar beet and rapeseed used in Europe.
For one unit of fossil fuel energy spent in the process, sugar cane ethanol delivers 8.9 units of renewable energy; the energy balance for most other ethanol feedstocks rarely exceeds two units.
The Brazilianx calculated that in the complete lifecycle, ethanol use means a 90% net reduction in Co2, compared with petrol.
Key to this claim is the use of the bagasse (the plant materials left after crushing) and straw (the leaves) as fuel to generate electricity for the plant and the notional grid. The next step is to convert this biomass into more ethanol.
"It's the next big frontier," says Marcos Jank, presiednt of Unica, who claims that Brazil's sugar cane industry has leadership in hydrolysis, the process it favours to make this second-generation biofuel.
General Motors is pinning its hopes on ethanol production from this waste plant material: the car msker has in vested in teh processes developed by Coskarta and Maxcoma in teh US, and start-up businesses in Europe; where groeing food crops for fuel is increasingly unacceptable as well as uneconomic. AOTO CAR/BANGKOK POST SERVICE
|
| |
|
