Tribological Issues Related to the Use of Biofuels: A New Environmental Challenge.

Due to gradual depletion of world petroleum reserves and the impact of environmental pollution of increasing exhaust emissions, there is an urgent need for suitable alternative fuels for use in engines. The heightened awareness of green house gas emissions and global warming compels introduction of more stringent environmental regulations worldwide. Renewable biofuels are considered potential solution for these problems. But use of biofuel is creating tribology related new challenges world over. In this paper a critical analysis of tribology related issue of three main biofuels, namely Straight Vegetable Oil (SVO), biodiesel and alcohols are discussed. Many issues like lubricity of blends, carbon deposit, viscosity, corrosion of engine components, etc are discussed in detail. Quality control of biofuels, identified as a key factor for sustainable market growth of these fuels and can lead to many tribological issues. In this regard a dire need for global harmonized standards is also discussed. Different solutions for alcohol fuel related engine problems are discussed. Critical discussion in relation to the problems due to the use of SVO in engine, like engine performance decrease, injector choking, oil ring sticking, etc took place in this paper. Potential solutions to these problems found by academia as well as industry are discussed here.