Critical Review on Effects of Alcohols and Nanoadditives on Performance and Emission in Low-Temperature Combustion Engines: Advances and Perspectives

Abstract

This work reviews the numerous key parameters of each alcohol and their effect on CI engine characteristics. The second part of the review emphasizes the effect of nanoadditive addition on diesel and biodiesel owing to their physical and chemical features. A more detailed evaluation of the influence of nanoadditives on diesel engine behavior was done when diesel and biodiesel were doped at varying doses. According to the review, alcohols with a greater carbon concentration, such as butanol and pentanol, have superior miscibility and stability versus alcohols with lesser carbon elements. Additionally, the lower cooling impact and autoignition capability generated by high-alcohol concentrations would make this the optimum additive formulation for usage with diesel fuel. Nanoparticles have been added to fuels used in diesel engines to improve performance and reduce emissions in recent years. The utilization and preparation of fossil-based fuels increase environmental-related issues. Different nanomaterials assorted with fuels for compression ignition (CI) engines and their effects are reviewed in this work. Nanomaterials added to pure diesel and blends of diesel and biodiesel are considered for the study. The physiochemical properties of different fuels with nanoadditives are summarized. Performance characteristics such as brake-specific fuel consumption (BSFC), brake thermal efficiency (BTE), and exhaust gas temperature (EGT) are analyzed and compared for various fuel and nanoadditives combinations. Combustion characteristics and mass fraction burned are investigated. The values of various emissions from the engines fuelled with different combinations are examined. Among the various fuels and nanoadditives studied, 100 ppm TiO2 added diesel consumes the lowest BSFC of 0.3 kg/kWh. Hurdles faced in the current utilization of nanoadditives in diesel engines and the scope for future research are also highlighted.