Abstract :
Since early human history and existence energy rich plants, wood and forest cellulosic material have been used for fire, light, heating, cooking and other daily activities. Fossil energy was the foundation of our modern society and industrialization since last two centuries, while exploration and exploitation of oil reserves and petrochemistry have largely shaped 20th century. Increasing concerns on environmental pollution, accelerated global warming, and global climate changes, continuing world's crude oil (fossil fuels) consumption and depletion, as well as energy security and energy crisis caused by daily burning large amounts of fossil fuels, led to the attraction, search and development of renewable, carbon-neutral, economically viable alternative energy sources, such as biofuels, slowly displacing petroleum fuels. In continuously growing human population reaching about 10 billion in 2050, various renewable energy sources are promoted and developed, to ensure rising energy demands in a world running out of fossil energy sources. Biofuels are produced from any kind of available biomass and categorized based on utilized carbon resources into first-, second- and third-generation. Nevertheless, biofuels’ future outlook is though beset by uncertainty. Hereby, various issues and concerns related to fossils and renewable biofuels are described and analyzed in present review article.
Keyword :
Carbon sources, biomass, bioenergy, fossil fuels, biofuels, bioethanol, biodiesel, atmospheric carbon dioxide, potential future scenarios of biofuels, fermentation, biotechnology, industrial microbiology