We cannot imagine transportation without petrol and diesel which are both made of oil. The demand for crude oil is zooming up day by day urging developed countries to seek for domestic, and what is even more important, renewable alternative to fossil fuels such as crude oil. Biofuels made from by-products and agricultural products are considered more eco-friendly and beneficial in terms of national security sources of energy. But are they able to compete with conventional oil in price and quality when it comes to high-performance engine oil and car fuel?
Ethanol, biogas, and biodiesel: what comes after oil?
There are 3 major types of cellulosic biofuel derived from organic matter such as plants, domestic/agricultural/industrial wastes, and non-food feedstock. They are biogas, biodiesel, and ethanol.
Biogas (or methane) is a material produced by bacteria acting on the organic waste matter (such as wastewater treatment plants, sanitary landfills, and so on) which can be compressed and purified for us e as car fuel. Methane sources could be a great cost efficient fuel alternative, but, unfortunately, it is found in very insufficient quantities and can contribute to air pollution with Nitrogen Oxides if used in inappropriate engines.
Biodiesel, which is made out of plant seed oil, waste oil and other carbon-rich waste products, has a low air pollution risk and a highly competitive cost if made out of waste oils. But like biogas, it can only be produced in small quantities.
Ethanol derived from starch, sugars or cellulose is commonly added to petrol to achieve cleaner burning. Fuel blends containing more than 40% ethanol pollute air much less than petrol. This biofuel isn’t, however, price competitive.
Are biofuels ready to replace traditional petrol?
Taking into account high food prices and doubtful climate benefits, biofuels raise questions concerning their sustainability. A viable substitution for petroleum must not only give a net energy gain and be beneficial for the environment but also be cost efficient (also in terms of not increasing the cost of food or causing its shortage). So far, none of the biofuels is able to meet these requirements. Therefore, they stay a niche product unavailable for ubiquitous public use.
Biodiesel derived from soybeans has an EROI of 5.5 which is almost one-third as much as petroleum has (16). EROI (energy return on investment) means the amount of net energy gain the finished product saves in comparison to the total energy put into its production. Heat produced by biofuels is more expensive due to the high price of raw feedstock and low energy density.
Corrosion and cracks in steel
If petroleum contains 20% and more ethanol, the latter causes corrosion of steel with developing further cracking. It is a very important concern for the biofuel researchers because transportation of ethanol by pipelines would be more efficient than getting it transported via trains, trucks or barges as the demand grows.