Combustion characteristics of nanofuels: A comprehensive review on diesel/biodiesel-based nanofuels

Abstract

Nanoparticles dispersed in liquid fuels are capable of creating colloidal mixtures with superior heat transfer and combustion properties. This approach has gain considerable attention from the internal combustion engine community to enhance the engine efficiency and reduce its pollutants emission. In the current study, a comprehensive review is performed on the recent findings on the effects of using various nanoparticles on the fuel properties and combustion characteristics in compression ignition (CI) engines. The experimental results on the Brake Thermal Efficiency (BTE), Brake Specific Fuel Consumption (BSFC), NOx, smoke and unburned hydrocarbon (UNBC) emissions are reviewed and summarized. The detailed specifications of the test rigs are also reviewed. The literature review showed that most of the nanoadditives can enhance BTE and BSFC and at the same time reduce smoke and UNBC emissions. Although reduction in NOx emission was reported is some studies, considerable increment in NOx emissions was also observed in several scholars. Most of the studies are performed in single-cylinder four-stroke naturally-aspirated engines with a rated power at full load in the range of 3.7–5.5 kW. Finally, some suggestions on using novel hybrid types of nanoparticles as additives in CI engines are provided for future research studies.