Investigation and comparative evaluation of a hybridized marine engine powered by eco-friendly fuels including hydrogen

International trade volumes have grown due to acceleration of marine transportation of goods between continents. However, there is a concomitant increase in fossil fuel consumption and adverse environmental impact. This paper presents a new design of marine engines comprising of gas Brayton cycle, solid oxide fuel cell, and two organic Rankine cycles to replace two-stroke internal combustion engines. Hydrogen, methane, dimethyl ether, ethanol, and methanol are potentially selected as green fuels. In addition, liquified natural gas is used for cooling processes. This integrated hybridized marine engine is thermodynamically analyzed using the Aspen Plus software to assess its performance energetically and exergetically. It is found that the engine's total power is boosted by 33% to an average of 15758 kW with average energetic and exergetic efficiencies of 38% and 46%, respectively. The maximum power is fulfilled using all sustainable fuel blends to reach 16087 kW with a maximum carbon emission reduction of 83% and minimum specific fuel consumption. The proposed engine has better performance and less environmental impact, which is a more convenient choice than traditional engines.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This paper presents a new design of marine engines that replace two-stroke internal combustion engines with a combination of gas Brayton cycle, solid oxide fuel cell, and two organic Rankine cycles. Sustainable fuels such as hydrogen, methane, dimethyl ether, ethanol, and methanol are used, along with liquified natural gas for cooling processes. The thermodynamic analysis shows that the integrated hybridized marine engine has improved performance with a total power boost of 33% and average energetic and exergetic efficiencies of 38% and 46% respectively. The proposed engine achieves maximum power with sustainable fuel blends, resulting in an 83% reduction in carbon emissions and minimum specific fuel consumption.