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In order to avoid the food vs. fuel debate, other than food-based products, agricultural products are effective sources for fuel development. Various parts of plants and trees are used to produce sustainable, low-viscous biofuels, which are gaining much attraction due to their superior burning abilities. The turpentine biofuel produced from pine tree oil has been used for gasoline engines because of its better calorific value and other notable benefits. An attempt has been made to investigate the suitability of turpentine biofuel as a 50% replacement for gasoline in automotive applications to identify the optimum blend ratio. In this study, the experiments are conducted in the port-fuel-injected gasoline engine at different loading conditions of 0 kg to 15 kg at 1800 rpm. Using turpentine blends in a port-fuel-injected SI engine, performance characteristics have been observed with up to a 3–5% improvement in brake thermal efficiency and fuel economy for all concentrations of turpentine biofuel due to their higher calorific value. However, the implementation of turpentine biofuel has shown remarkable reductions in unburnt hydrocarbons by 50% and carbon monoxide emissions by 90% due to its superior burning ability. However, this reduction is not witnessed in oxides of nitrogen and carbon dioxide emissions due to the lower octane number and higher viscosity, which result in a 30% and 5% increase, respectively. Interestingly, the combustion characteristics are observed to be better at part load operations for lower concentrations (30%) of turpentine biofuel in the blends, and this trend has not been noticed at higher concentrations of turpentine biofuel. Finally, it has been concluded that turpentine biofuel would be a better option for the partial replacement of gasoline by up to 30%. However, for further investigation, the anti-knocking characteristics of the turpentine biofuel need to be improved, especially in 40% and 50% turpentine biofuel blends using suitable anti-knocking agents. [ABSTRACT FROM AUTHOR]

• Notable stages in the history of butanol production are outlined. • Efficacy biobutanol production methods are summarized with various biomass sources. • Upstream processes have been initialed for efficient production of butanol. • Suitability of butanol for SI and CI engine applications are presented. • Techno-economic analysis of butanol is emphasized to enhance large scale production. Biobutanol has been emerging as a sustainable biofuel due to its superior form of heat content, sustainable volatility, better anti corrosive nature and more importantly low moisture content. The waste resources utilization for biobutanol production has sustainability and economic feasibility due to their easier availability and landfilling nature. The foremost limitations in the biobutanol development are lower yield rate, unavailability of feedstock and inhibitor formation. These obstacles are easily exterminated by the appropriate selection of waste biomass resources, few advanced metabolic engineering techniques and recent developments on integrated bioprocessing strategies with effective solvent recovery and purification methods. This review has been made to elaborate the various production techniques that have been enriched on biobutanol production from all the existing waste resources in last one decade and the highlights the research progress on biobutanol suitability in automotive applications. An elaborative discussion are undertaken on selection of waste feedstocks, superior pretreatment processes, selection of optimum strain, metabolic pathways of various microbes and separation techniques to enhance the economical biobutanol fermentation process. In a second phase of the review, the properties assessment of biobutanol and its technical suitability in spark ignition and compression engine are discussed in terms of performance, combustion and emission aspects. In the end, techno-economic analysis on biobutanol production is also provided to improve the commercial eminence on developing advanced techniques. Finally, the review report provided the route map towards the importance of developing efficacy integrated production techniques, research emphasis on flex fuel operation of biobutanol in hybrid configuration vehicles to meet the global demand in future. [ABSTRACT FROM AUTHOR]