Study on characteristics of marine heavy fuel oil and low carbon alcohol blended fuels at different temperatures

Abstract

The current study proposes heavy fuel oil (HFO)-methanol/ethanol blends as sustainable way shipowners can limit their emissions to acceptable levels. However, the blends of HFO- methanol/ethanol present miscibility problems, and little has been reported about the improvement of this situation within the existing literature. Hence, the primary aim of the current study is to prepare a blend of HFO- methanol/ethanol in the presence of n-butanol, tetrahydrofuran (THF), and polyoxymethylene dimethyl ethers (PODE), that can be kinetically stable for at least 48 h. Also, the ternary systems’ viscosity, corrosivity, and sulfur content relative to that of neat HFO were ascertained. Finally, an economic feasibility of using the proposed ternary systems in comparison to an HFO + scrubber system, as two different pathways of meeting SOx emission standards is conducted. The ternary blends were undisturbed at an experimental temperature (20 °C, 40 °C, and 50 °C) for at least 48 h to observe their mutual solubility. After maintaining a 2-day single-phase solution, the best co-solvent for methanol-containing blends was PODE, and that of ethanol was THF. The oxygenated fuels decreased the kinematic viscosity well below that of a preheated/unheated HFO; reducing preheating cost and energy. The corrosivity of the ternary systems were extremely low and negligible. The HFO blend at 1:1 ratio showed a significant decrease in sulfur content of neat HFO. The study promotes the wide use of oxygenated fuels in the shipping industry; a positive step towards decarbonizing this transportation sector.