Underwater Venting of Methanol Vapours: an Experimental and Numerical Study
conference paper
The use of methanol as an alternative fuel for ships is gaining traction, but its toxic vapours pose significant safety risks. Current interim guidelines recommend venting methanol vapours with a high vent pipe above deck, which creates a hazardous zone on the vessel around this pipe. This study investigates underwater venting as an alternative method, aimed at preventing methanol vapour accumulation on deck and thereby eliminating the need for a hazardous zone. Experiments were carried out with different vapour flow rates between 10 and 200 litres per minute, venting depths between 5 and 90 cm, and several nozzles. The results show that over 99% of the methanol vapour is absorbed at venting depths below 40 cm, even at the highest flow rate. Absorption is improved by increasing venting depth and by decreasing the bubble size. CFD simulations were carried out to model the absorption of underwater vented methanol. The simulations match the observed trends, but overpredict the absolute amounts of methanol absorbed, the reason for which is to be ascertained.
TNO Identifier
1019982
Source title
16th International Symposium on Practical Design of Ships and Other Floating Structures PRADS 2025
Ann Arbor, MI, USA, October 19th-23rd 2025
Ann Arbor, MI, USA, October 19th-23rd 2025
Pages
1-15
Files
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