EDITORIAL

Abstract

Fossil fuels are currently recognized as unsustainable because of depleting supplies and the contribution of these fuels to the accumulation of carbon dioxide in the environment. Therefore, renewable, carbon neutral, alternative fuels are necessary for environmental and economic sustainability. Several countries have been considering the use of alternative fuels derived from agriculture. In that context, ethanol derived from sugar-cane and/or corn crops, and biodiesel derived from oil crops are potential renewable and carbon neutral alternatives to fossil fuels. Unfortunately, fuel from crops, waste and animal fat cannot realistically satisfy even a small fraction of the existing global demand for fuels. In Brazil, the government has been subsiding ethanol from sugar-cane crops for more than 30 years, and together with research investment on oil off-shore exploration, the initiative made possible for the country, at least for the moment, to become energy self sufficient, but due to oil supplies depletion, that scenery will change in the near future. Another limiting factor is cost. For example, the economic aspect of biodiesel production limits its development and large-scale use. Biodiesel usually costs almost twice the price per liter of conventional diesel fuel, currently in the US.

Apart from economic aspects, it is clear that biofuel production technology needs to be improved to meet global fuel demand rate. One possible direction is the use of microalgae, that appear to be the only source of renewable biodiesel that is capable of meeting the diesel fuel global demand. Like plants, microalgae use sunlight to produce oils but they do so more efficiently than crop plants. Oil productivity of many microalgae greatly exceeds the oil productivity of the best producing oil crops.
Approaches for making microalgal biodiesel economically competitive therefore need to be developed.

The mission of Engenharia Térmica is to document the scientific progress in areas related to energy, particularly oil and renewables. We are confident we will continue to receive articles’ submissions that help enable sustainable energy solutions in the near future.