Probleemstelling:

Global warming, a growing maritime transport, and the roadmap away from fossil fuels towards a CO2 neutral economy are driving innovations and technology developments in the marine sector. Given that the main marine propulsion is via compression ignition (CI) engines and with fossil fuels such as heavy fuel oil and diesel, the marine industry is looking for alternatives. Electric propulsion and fuel cells are looked at amongst others. However, fuel solutions that have a higher energy density are required for the longer distances, which are difficult to achieve with the low energy density of batteries and the low maturity of the fuel cell technology.

Fuel selection criteria such as sustainability, scalability and storability lead to the selection of methanol as a viable alternative for fossil fuels. It is a simple molecule, it is liquid at atmospheric conditions (a main advantage over LNG and H2), and it can be produced from a variety of feedstocks like natural gas, biomass and even from CO2. It is furthermore a top 5 worldwide shipped chemical which makes it readily available for commercial applications [1]. Methanol is a great engine fuel for spark ignition (SI) engines given its high octane number. If we want to use methanol in CI engines, the engine has to be operated with a dual-fuel combustion strategy where diesel has to ignite the methanol-air mixture, being as such a “liquid spark”.

The research group Transport Technology has retrofitted in its lab a high-speed marine Volvo Penta D7C-B TA to dual-fuel operation as part of the European Horizon 2020 financed project LeanShips [2,3]. The engine is equipped with a measurement system for acquiring a.o. mass flows, temperatures and pressures; and can operate with different operating strategies such as throttling, single and multiple point methanol injection. In 2019-2020 a system has been added to test hydrous methanol and in 2020-2021 two other systems are being added: an EGR system and an intake air temperature and pressure control system.

A general introduction to this research can be found on YouTube [4] and on URGENT.fm [5].

Doelstelling:

The research group has a close collaboration with a.o. engine manufacturers, vessel operators and shipbuilders. To enable full market uptake, low emissions and high efficiency are required, combined with a high substitution of diesel by methanol.

The research’s aim is therefore to understand the fundamentals that have an effect on engine performance in dual-fuel operation [6,7], like EGR and the effect of varying intake air temperature, and the combined effect of these engine modes. The effect of each mode on the amount of diesel that can be substituted by methanol is a key performance parameter: the amount of diesel that is substituted by renewable methanol equals the amount of saved (engine-out) CO2 emissions.

The goal of this experimental thesis is to exploit on the one hand the newly installed engine modes such as EGR and the intake air temperature & pressure control system, and on the other hand to investigate the combined effect of these modes. The engine has several operation modes and it is questioned what the interrelation is between modes.

The effect of these modes on (1) the maximum amount of diesel that can be substituted by methanol, (2) the overall efficiency, (3) the emissions such as NOx, CO and soot, are to be investigated. This thesis combines practical experimental work with analyzing the physics and chemistry of combusting methanol in a high speed marine dual-fuel methanol-diesel engine.

[1] J. Dierickx, “Waarom de verbrandinsmotor nog een rol zal spelen.” https://www.youtube.com/watch?v=e5s381P3Els&t=9s

[2] LeanShips website: http://www.leanships-project.eu/demo-cases/demo-case-05/overview/

[3] Verhelst et al., LeanShips video - Methanol as marine fuel: https://www.youtube.com/watch?v=ZcnhQxv95N4&t=19s

[4] J. Dierickx, Dag van de Wetenschap 2020 – Scheepvaart vervuilend? Hoe pakken we dat aan? https://youtu.be/_xj0A4FQpyE

[5] J. Dierickx, in radio program “Mensentaal” of URGENT.fm https://mensentaal.captivate.fm/episode/over-de-brandstof-van-de-toekomst-met-jeroen-dierickx

[6] S. Verhelst, CIMAC 2016 “Using alcohol fuels in dual fuel operation of compression ignition engines: a review”

[7] J. Dierickx, CIMAC 2019 “Efficiency and emissions of dual-fuel engines with methanol”