Biofuel Pumping up SA’s

future

By Kerry Pritchard

What Is Biodiesel?

Biodiesel is a nontoxic, biodegradable replacement for petroleum diesel. Biodiesel is made from vegetable oil, recycled cooking oil and tallow. Chemically biodiesel is described as a mono alkyl ester. Through a process called esterification, oils and fats are reacted with methanol and a sodium hydroxide catalyst to produce fatty acids along with the co-products: glycerin, glycerin bottoms, soluble potash and soaps. Biodiesel belongs to a family of fatty acids called methyl esters which are defined by the medium length, C16-18 fatty acid linked chains. These linked chains help differentiate biodiesel from regular petroleum diesel.

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While scientists have long known how to produce ethanol from sugar and molasses , it was only during the South African fuel embargoes of the 1970’s and 1980’s that the govermennt invested in research to produce fuel from ethanol using bagasse , a by product of the sugar manufacturing process.

Biofuel Bagasse

Pronunciation: (bu-gas'), crushed sugar cane or beet refuse from sugar making

Significant progress was made in this line of reasearch and today scientists know how to produce ethonal from bagasse in two ways. `The first step is both ethanol fuel production processes originates in the sugar manufacturing process.Juice is extracted from sugarcane,with the squeezed cane stalks constituting the bagasse.The process where sugar juice is crystallised produces molasses as its by product,and the primary product of sugar from the processes is either used domestically or exported.

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ETHANOL

Ethanol (ethyl alcohol, grain alcohol) is a clear, colorless liquid with a characteristic, agreeable odor. In dilute aqueous solution, it has a somewhat sweet flavor, but in more concentrated solutions it has a burning taste. Ethanol, CH3CH2OH, is an alcohol, a group of chemical compounds whose molecules contain a hydroxyl group, –OH, bonded to a carbon atom. The word alcohol derives from Arabic al-kuhul, which denotes a fine powder of antimony used as an eye makeup. Alcohol originally referred to any fine powder, but medieval alchemists later applied the term to the refined products of distillation, and this led to the current usage.

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Ethanol melts at –114.1°C, boils at 78.5°C, and has a density of 0.789 g/mL at 20°C. Its low freezing point has made it useful as the fluid in thermometers for temperatures below –40°C, the freezing point of mercury, and for other low-temperature purposes, such as for antifreeze in automobile radiators.

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Molasses, sugar byproduct, the brownish liquid residue left after heat crystallization of sucrose (commercial sugar) in the process of refining. Molasses contains chiefly the uncrystallizable sugars as well as some remnant sucrose. Centrifuges are used to drain the molasses off from the sucrose crystals. Molasses is often reprocessed to retrieve more of this remnant sucrose.

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The first bagasse-to-ethanol process requires the cane husks to be exposed to an acid,hydrolysate,in which a third of it is dissolved.The dissolved bagasse is then fermented to produce ethanol.In the second process,the remaining two thirds of the undissolved bagasse is treated with an enzyme and then put through a mill to produce a slurry of lignin cellulose.From here,ethanol and lignin by-product are produced.

Lignin's are derived from an abundant and

renewable resource: trees, plants, and agricultural crops. Lignin's are nontoxic and extremely versatile in performance, qualities that have made them increasingly important in many industrial applications.

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Sugar cane has the potential to help ease the impending energy dilemma.Reasearchers aim to achieve conversion yields of 13 tons of sugar to 5,7 tons of ethanol and 15 tons of dry bagasse to 3,4 tons of ethonal . If ethanol was available locally,consumers would only pay about R3,25 for a litre at current price compared to about R6 for petrol .

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Although the 200 000 tons of surplus molasses available in South Africa per year is a relatively small quantity for the needs of ethanol production, if it was added to additional sources such as bagasse and surplus sugar stock. The local sugar industry could produce nearly 10% of the of the country’s annual fuel requirments.

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Reasearch and development and use,it appears as though South Africa is lagging behind a number of other countries .Since 2003,Brazil has moved between exporting its sugar or converting it to ethonal locally, while the USA has already legislated the blending of ethonal with fossil fuels.

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However the the downside of ethanol fuel is that it has a 30% lower energy value than petrol,so although it burns very efficiently vechicles would get fewer kilometers per litre.

It would still be more cost effective than fossil fuels with the added benefit of less polution.

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Trends in biodiesel production

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USING RAPESEED:EUROPE PRODUCED 2,5 BILLION LITRES OF BIODIESEL IN 2004, AND COULD BE PRODUCING 14 BILLION LITRES IN 10 YEARS TIME.

CHINA IS PLANNING ON ESTABLISHING A TWO MILLION HECTARE BIODIESEL IN SOUTH EAST ASIA.

USA CURRENTLY PRODUCES 0.16 MILLION LITRES OF BIODIESEL ANNUALLY FROM SOYA

INDIA IS INVESTING HEAVILY IN THE PRODUCTION OF BIODIESEL FROM JATROPHA AND HAS SET A TARGET OF 20% OF ITS DIESEL CONSUMTION BEING MADE UP OF BIODIESEL

• Source • Farmers weekly South Africa • South African Sugar cane Association

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• In formative sites • http://www.lignin.info/ • http://www.r-p-a.org.uk/home. • http://www.altenergy.org/ • http://www.energyinst.org.uk/ • http://www.fwi.co.uk/ • http://www.sasa.org.za/ • http://www.nbb.org/ • http://www.osti.gov

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