Wärtsilä MeOH engine experiences

ZA40-MD Sum-Up Pros Cons Methanol-Diesel MD engine Methanol is burnt according to diesel process Methanol is injected close to TDC and ignited by a small amount of diesel pilot fuel Pros Cons + no knocking (diesel combustion) + no power reduction + good load acceptance + cost effective adaption + low THC, CO (and formaldehyde) levels + good back-up fuel performance - NOx higher than for DF concept NOx depends on pilot fuel for ignition High pressure Methanol injection - 600bar Three needles for Methanol injection 1 needle for standard & pilot diesel injection to ignite the methanol

Tests on Methanol – Initial testing of Wärtsilä MD concept Engine: Wärtsilä Vasa 32 Optimal heat release Lower Exhaust Temperatre Same efficiency as diesel Reduced NOx CO, THC acceptable ( < 1 g/kWh) Formaldehyde emissions low ~ much below TA-luft No Formic acid detected in exhaust gases

Tests on Methanol – Recent testing of Wärtsilä Sulzer Z40S-MD NOx Smoke Tier II 10,5 g/kWh Tier III 2,6 g/kWh Temp Repeated tests on Sulzer Z40S-MD show same trends as the pre-tests on Wärtilä Vasa 32: Reduced NOx / PM Reduced exhaust temperature Same (or better) efficiency Dry package hfo

Conclusions Methanol One of the most promising candidates for low cost, high efficiency and low emissions operation Neat methanol combustion is soot-free Direct Injection and Compression Ignition MeOH op. Dual fuel with direct injected diesel and port injected alcohols is established but lead to high emissions Wärtsiläs concept with double late direct injected dual fuel is functional and associated with reduced emissions PPC High efficiency, low emissions and high load op. Fuel flexible. Still some immaturities as research concept: Low load - cold start issues, high combustion noise PPC-MeOH is possible

Observations & Research opportunities Late direct injection reduces formaldehyde and formic acid emissions – Something to pursue further in SI, DICI and PPC PPC-MeOH is possible – but needs much more research: is 60% gross efficiency within reach? Methanol has high sensitivity and high heat of vaporization – Is this combination a key feature in managing both high and low loads in compression ignition of neat methanol (for instance PPC)?