Ongoing Project: Pneumatic Propulsion
This compressed air energy storage system can be used to propel maritime vessels, such as ferries by using the air power to rotate an impeller.
This project introduces a novel approach to maritime propulsion, focusing on the use of pneumatic systems, particularly for ferry boats. Unlike most existing literature with focus on electrical or hybrid propulsion, this project explores benefits of pneumatic motors, known for their rapid response, durability, and ease of adoption into existing vessels. An experimental rig is constructed to compare the performance of this setup to an electrical propulsion system, drawing its power from electrochemical batteries.
The main objective is to compare thrust forces produced by either system through a loadcell. This study reports on effect of varying pressurized air tanks capacity, pressure, and discharge rate on said thrust force. Additionally, a life cycle analysis is conducted to examine the environmental impact and energy consumption of both propulsion systems, thereby computing any reduction in carbon dioxide emissions achieved using the pneumatic system. This work paves the way for the adoption of renewable and sustainable maritime transportation systems, positioning pneumatic motors as a practical, effective, clean, and sustainable alternative to traditional propulsion systems.
The figure shows the carbon footprint analysis for the pneumatic vs electrical motors. This analysis accounts for each system鈥檚 lifetime and the material, manufacturing, use, and end-of-life phases. It emphasizes the level of impact the material extraction and use phases have. Having two different lifetimes does have a certain bias in showing both the energy consumption and carbon footprint behaviors. As a result, normalizing these parameters and averaging the previously presented values over a single-year basis can provide a basis for a fair comparison between these two systems. This next phase will involve rigorous testing and optimization to meet safety regulations for a more sustainable and environmentally friendly maritime transportation option in Dubai.
Table 1 provides the RMS thrust force for both pneumatic propulsion systems. Where it can be noticed that the Pneumatic propulsion system has a comparable performance to that of the electrical propulsion system, even resulting in a higher thrust force.
| Case | RMS Thrust Force (N) | Operational Time (Sec) |
Electrical Propulsion
| EM | 99.083 | 1001 |
Pneumatic Propulsion
| PM | 104.994 | 950 |
The project will be taken forward by equipping commercial boats with pneumatic motors and storage tanks. This would be particularly suitable and successful for vessels with predetermined routes and pace, such as ferry boats. There was a collaboration with Finnish ferry maker K. J. Marine Consulting Ab to determine the technical and economic feasibility of equipping their ferries with pneumatic motors and storage tanks.
Although diesel engines are the de facto propulsion option at sea, the benefits of utilizing pneumatic power are numerous and have been proven feasible.
The next step is to build air storage tanks into the structure of the vessel. One of the most interesting vessels to start are the Tritoon or Pontoon boats.
The structure of the boat lend itself to allow compressed air storage in the lower structure that has to be made to withstand the required elevated operational pressures.