As a youngster when I travelled to the KZN coast I always arrived with an empty fuel tank. It was not because I was platsak, but because, besides fishing and seeing my parents, one of the best things a young man like me could do was to fill up my Mini Cooper S at the coast with the biofuel made there from sugarcane. Being able to make the best use of the high compression ratio of the Cooper engine, the 100-octane fuel made my car go like a missile, proving that biofuel is by no means a new idea. In fact it is an older concept than most people realise. It is as old as the motorcar itself. Not only did Henry Ford originally design the Model T in 1903 to run on ethanol, but so did the German Nikolaus Otto when he invented the internal combustion engine. Even Rudolf Diesel, the inventor of the engine that carries his name, conceived it to run on peanut oil.
Biofuel was once actually in widespread use, especially in Europe, but its production and use declined when cheap Arabian oil became available in the 1920s. Life cycle of energy All fuel from wood to coal and petroleum is stored solar energy, derived from plants that captured the sun’s power and absorbed carbon dioxide (CO2) from the atmosphere to grow. When burnt, this CO2 is released back into the atmosphere. A balance exists between the amount of CO2 absorbed by plants and that released by burning them, known as the carbon cycle. When we burn fossil fuels which were formed in ancient times we upset this balance, releasing more CO2 into the atmosphere than what can presently be reabsorbed by plants. This surplus CO2 is the major component of greenhouse gases resulting in global warming. It will not help to plant trees on a massive scale to remove this surplus, as some well-meaning people propose.
All the CO2 they absorb during their lifetime will again be released into the atmosphere when their wood goes up in smoke. he only solution is to not add any more fossil CO2 to this existing surplus by a worldwide switch-over to biofuel. To be sustainable it will have to be derived from current living organisms and manufactured within 10 years of being harvested. Whether biofuel will indeed be the blessing to the environment and humanity that it is deemed to be, depends on how it is produced. Basically there are two mainstreams of biofuel production – first to replace petrol with various plant-generated alcohols and second to produce biodiesel from plant oils. A variety of plants have been identified as possible sources to produce various forms of bioenergy, and a growing number of countries are already using biofuel. Of these, Brazil, which uses sugarcane to produce bioethanol, is at the forefront.
The US is becoming a major producer of ethanol from maize, while the Germans use potatoes. the 25 vegetable oils suitable for biodiesel, 17 are edible and the main candidates for large-scale production are seeds of soya beans, peanuts, sunflowers and oil palms. Pumping food into the petrol tank Almost all species that are currently used for this purpose or are seriously considered for the future have one thing in common – they are all human food sources which raises a serious moral question. With a considerable portion of the world’s human population suffering from malnutrition and starvation, how can anyone justify that food be grown on a massive scale but instead be used to make fuel for motorcars? Although one would like to believe that the move towards biofuel is for the sake of the environment and that it’s a step towards avoiding the catastrophic results of global warming, as well as to relieve struggling economies from the burden of the ever-increasing cost of fossil fuel, you start to wonder when you look a bit closer. Consider maize, which is increasingly being used in the US to produce bioethanol.
The fermentation process to turn maize seed into ethanol is far from straightforward and is energy-intensive. energy gain is also far from substantial – it requires one input unit of fossil energy to gain only 1,34 output units of bioenergy, provided you grow maize as efficiently as the Yanks. But to use bioenergy for your input – which is logical – you must realise that petroleum produces about 1,5 times more energy than ethanol, so ultimately you’ll probably work at a loss. Although ethanol will cost somewhat less than petrol, this gain is offset by the fact that the performance will be lower and fuel consumption about 50% higher with ethanol. Dedicated ethanol engines will perform equal to petrol engines but will have to be stronger to withstand a compression ratio of about 19:1, and like diesels will cost substantially more. Americans know all this, but it makes sense to them to rather turn their massive maize surplus into fuel, than to give it mahala to Africa. o plant the massive quantity of crops to replace fossil fuel worldwide, vast vacant areas will be required.
Although the highest energy consumption takes place in the northern hemisphere, most of these countries – especially in Europe – simply haven’t got significant vacant areas left. It’s therefore logical that they would see to it that huge areas of natural vegetation in the southern hemisphere – notably in Africa, South America and South East Asia – be cleared to satisfy their demands. The clearing of rainforests has already begun in the Brazilian Amazon, Argentina, Bolivia, Paraguay and the Philippines and this, together with applying huge quantities of pesticides and fertiliser, is bound to create more environmental damage than global warming can. It seems that the concept of biofuel is just another global scheme to make new fortunes.
The grass that is greener But fortunately all is not doom and gloom. There are better sources from which to make biofuel than mealie pap. There is the grass in the veld. No, I’m not joking. About 30 years ago I read an article by a scientist from the CSIR in the magazine Archimedes, which stated that if we use only a portion of the veld which goes up in smoke every year to make ethanol, we can be totally self-sufficient. In those days it was laughed off. Sasol was still regarded as a miracle, but not anymore – the Sasol process is obsolete. The time for “grassfuel” has arrived. The problem with turning grass into ethanol is that it contains too little sugar or starch. It consists mainly of cellulose and lignin, so fermentation wouldn’t work. But like the coal-to-oil breakthrough of the previous century, new technologies have recently been developed by at least two companies in Canada with the potential to establish biofuel as a truly viable alternative to fossil fuel.
The first is the Iogen Corporation which is able to produce cellulose ethanol from various waste products like saw dust and straw through a combination of thermo, chemical and biochemical techniques. Then there’s Dynamotive Energy Systems Corporation which uses a rapid, extremely hot pyrolysis process to convert agricultural, forestry and household waste in less than two seconds into bio-oil, char and non-condensable gas. This waste includes straw, sugarcane bagasse (leaves and hard fibre), sawdust and even waste paper. Bio-oil is the ideal clean fuel which does not produce the usual harmful emissions, and is greenhouse neutral. Two tall grass species have so far been evaluated. The one is Miscanthus sinensis which is widespread in Africa and southern Asia. The other is switchgrass (Panicum virgatum), a dominant species of the North American tall grass prairie. Grass can achieve ethanol yields far in excess of any agricultural crop, primarily because it grows very dense and almost the whole plant can be utilised.
According to research, maize yielded up to 3 461ℓ of ethanol per hectare (US conditions), sugarcane 6 192ℓ per hectare, while switchgrass yielded a surprising 10 757ℓ per hectare and Miscanthus topped the list of 11 source crops tested with 14 031ℓ of bioethanol per hectare. Maize was stone last! So why mess around with an ethanol source that is in short supply in Africa, while on this continent millions of tons of grass are burnt every year? We don’t have to plant, fertilise or irrigate it; we don’t need tons of pesticide or fertiliser either. All we have to do is harvest it and spread the ashes back into the veld to prevent mineral depletion. We’re sitting on a virtual grass-covered gold mine, but like our locusts and quelea we choose to destroy it. The Canadian companies are seeking expansion of their technology under license around the world in countries where they don’t have a presence.
The coal-to-oil process was after all borrowed from the Nazis and developed with the cooperation of Israel. Maybe Sasol can still change from blue to Canadian green and together with the gold of tamboekie fuel it will be a more worthy sponsor of the Springboks, and this time it will be good for the environment. – Abré J Steyn (083 235 4822, [email protected]). Or visit www.iogen.ca or www.dynamotive.com. |fw
