Effects of different water percentages in non-surfactant water-in-diesel emulsion fuel on the performance and exhaust emissions of a small-scale industrial burner

In a previous study, a device that combined two existing mixing methods to produce water-in-diesel emulsion fuel (W/D) without surfactant had been developed and tested on a small-scale engine by Ithnin et al. However, it is inapplicable for industrial burners with high fuel flow rate. Therefore, a device with a similar concept was developed in this study. W/D has been proven to improve combustion, but it was unknown if non-surfactant W/D made by the device can improve burner performance and exhaust emissions. The aim of this study is to analyse the fuel consumption, flame temperature and emissions of the industrial burner utilising Malaysian Diesel grade 2 (D2M) labelled as D2, surfactant-added W/D and non-surfactant W/D produced by the device. Both emulsion fuels tested contained 5%, 10% and 15% water by volume. Based on the comparative evaluation, the performance of non-surfactant W/D was comparable to surfactant-added W/D. Compared to D2, non-surfactant W/D reduced fuel consumption, nitrogen oxides, particulate matter, carbon monoxides and hydrocarbons emissions by up to 17%, 53%, 34%, 24% and 44%, respectively. Although the increase in water content decreased the flame temperature, W/D with 5% water had higher flame temperature and had better fuel consumption than D2. Graphic abstract: [Figure not available: see fulltext.]