An overview of biofuel as a renewable energy source: development and challenges

Depletion of petroleum derived fuel and environmental concern has promoted to look over the biofuel as an alternative fuel sources. But a complete substitution of petroleum derived fuels by biofuel is impossible from the production capacity and engine compatibility point of view. Yet, marginal replacement of diesel by biofuel can prolong the depletion of petroleum resources and abate the radical climate change caused by automotive pollutants. Energy security and climate change are the two major driving forces for worldwide biofuel development which also have the potential to stimulate the agro-industry. Nonetheless, there are other problems associated with biofuel usage such as automotive engine compatibility in long term operation and also food security issues that stem from biofuel production from food-grade oil-seeds. Moreover, severe corrosion, carbon deposition and wearing of engine parts of the fuel supply system components are also caused by biodiesel. Discussing all this advantages and disadvantages of biodiesel, it is comprehended that, a dedicated biodiesel engine is the ultimate solution for commercializing biodiesel. Brazil successfully boosted their bioethanol marketing by introducing flexible-fuel vehicles (FFV), which have a dedicated engine for both ethanol and gasoline. A similar approach can bring a breakthrough in biofuel commercialization and production. So dedicated biofuel engine is a challenge for mass commercialization and utilization of biofuel. In this lecture worldwide biofuel scenario is assessed by biofuel policies and standards. Different biofuel processing techniques are also summarized. Some guidelines on dedicated biofuel engine are prescribed. Minor modifications on the engine may not cost much; but continuous research and development is still needed. © 2012 The authors, Published by Elsevier Ltd. Selection and/or peer-review under responsibility of the Bangladesh Society of Mechanical Engineers