Man's reliance on fossil fuel is slowly but surely beginning to see winds of change. One reason is the forever upward spiraling costs of crude oil, and the other reason is the damage it could cause to the environment in terms of unwanted emissions. Biofuel is the new mantra that can supposedly solve these problems.
Biofuels have lesser greenhouse gas emissions when compared to conventional fuels and they also benefit farmers in the sense that, the feedstock for making biofuels are mostly crop based.
Let's examine how biotechnology can help create biofuels.
This brings us to the point, what is a biofuel? One definition is "fuel made from organic material such as food wastes, and microorganisms," and another broader definition is "any solid, liquid, or gas fuel that can be derived from biomass". By that reckoning, even fossil fuels are also of biological origin as they are the result of biological activity over a million years or more, and so, there has to be a more apt definition for biofuels. For example, a car that runs on diesel made from oil, and another car that runs on biodiesel will both emit carbon dioxide. So where is the difference as regards causing pollution? The car that runs on diesel made from oil will release fresh quantities of carbon dioxide into the atmosphere which was originally entrapped in the oil and remained underground for millions of years. On the contrary, using biodiesel made from jatropa plant for instance, merely involves the recycling of the carbon dioxide, since the jatropa plants would have removed carbon dioxide from the atmosphere when the plant was growing up in the immediate past.
Therefore, biofuels are fuels that do not add to the cumulative carbon dioxide content of the atmosphere, or in other words, biofuels are carbon dioxide neutral. They do not add to the carbon dioxide levels in the atmosphere at all, and this probably is an accurate definition of a biofuel.
Types of biofuels
Biofuels could be biodiesel, biogas, and ethanol (derived from sugar, starch, lignin, cellulose, vegetative and animal waste), and butanol (made from organic matter in renewable biomass) or electricity generated from biomass. However, ethanol made from corn starch has lifecycle greenhouse gas emissions that are not substantially below baseline lifecycle greenhouse gas emissions, and cannot be called biofuels.
Biotechnological processes in making biofuels
In plants and trees, sugars and alcohol get configured to complex molecules to form cellulose, pectin etc and together with lignin results in complex matrixes that happens due to natural selection process occurring in the evolution of the plant. Significantly, it is these sugars that can produce biofuels. But the problem is to utilize these sugars from these matrixes to make biofuel (something which even the most efficient bacteria and fungus finds difficult)
The first step is to use specific engineered enzymes (or other less energy intensive methods) and release the cellulose, hemicellulose and pectin and eliminate the lignin. The idea is to get fermentable sugars for making the biofuel. For example, if it was a beet sugar plant that was being treated, the pulp residue can be fermented into biofuels like ethanol. Another method is to use the ammonia fiber expansion process which is to heat the plant cellulosic material with ammonia under pressure, and then use enzymes to convert the biomass to sugars suitable for making biofuels. Gasification and pyrolysis are other methods to break the matrix into sugars suitable for making biodiesel.
The final step is to convert the sugars into biofuels and this can be done mostly by fermentation or other technologies such as mixed alcohol synthesis, packed bed catalytic reactors, and acqueous phase reforming.
Examples of Biofuel Manufacturing Facilities
There has been a surge worldwide in setting up biofuel plants. Consider UK for instance. A biogas plant is being built by a UK energy company in Norwich County that intends to generate electricity based on anaerobic digestion technology utilizing maize grown on 1000 acres of land. Another biomass plant in Kent is planning to utilize 1, 60,000 tonnes of waste wood to generate 25 mega watt power. Using biodegradable household wastes, yet another UK company plans to make bioethanol (carbon neutral road transport fuel) and substantial electricity as well.
In Germany a pilot plant is being built to make 1 mega watt biogas electric power plant using Giant King Grass that has three times mass yields than corn. There are several thousand biodigesters in Germany, and if this pilot plant turns out to be successful it could probably provide non- food feedstock to those bio digesters giving higher yields as well.
A new biomass facility in New Hampshire intends using the wood waste from the local forest wood industry to make a whopping 70 mega watt of power. In Idaho, US, three anaerobic digestions plants intend to provide fuel to a power station on a 15-year contract.
In India, 4.6 million tones of ethanol blended petrol are produced each year. Sugarcane is used as the raw material for making ethanol and this benefit the cane farmer in addition to providing environmental benefits. The 2007 Energy Bill enacted in the United States mandates the manufacture of at least 21 billion gallons of Advanced Bio-fuels by the year 2022, which means new manufacturing processes for biofuels, especially advanced biofuels, will have to be found out, other than technologies already in place.
That apart, with the oil spill off the Gulf coast and the temporary ban on offshore drilling, the versatility of biofuels may gain more prominence. Surely biofuels are looking increasingly green at the moment. However there is a long way to go, in that, the technology to make biofuels is only in its nascent stage, and therefore very far from reaching a stage that it could possibly substitute fossil fuels.
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