Most Emission-Efficient Chemical Tankers
Ships ranked by AER (Annual Efficiency Ratio) — grams of CO₂ emitted per tonne of deadweight carried one nautical mile (g CO₂/dwt·nm), the IMO carbon-intensity metric behind the CII rating — from official EU MRV emissions data for reporting year 2024. Lower is greener. Pick a segment and size class to see the greenest vessels first.
| # | Vessel | Size (DWT) | Built | Carbon intensity — AER (g CO₂/dwt·nm) | Grade |
|---|---|---|---|---|---|
| 1 |
ELANDRA WILLOW
IMO 9834349
|
49,999 | 2019 |
3.6
|
A |
| 2 |
STENA PRO MARINE
IMO 9899739
|
49,990 | 2022 |
3.8
|
A |
| 3 |
HAFNIA BEIJING
IMO 9856634
|
74,999 | 2019 |
3.8
|
A |
| 4 |
STI GALLANTRY
IMO 9712876
|
109,999 | 2016 |
4.0
|
A |
| 5 |
STENA PROVIDENT
IMO 9944637
|
49,990 | 2023 |
4.1
|
A |
| 6 |
CAPE TEMPEST
IMO 9407263
|
73,720 | 2008 |
4.2
|
A |
| 7 |
STENA PROGRESSIVE
IMO 9944649
|
49,990 | 2024 |
4.2
|
A |
| 8 |
STENA PROMISE
IMO 9923748
|
49,990 | 2022 |
4.2
|
A |
| 9 |
DORIC PIONEER
IMO 9637117
|
51,565 | 2013 |
4.2
|
A |
| 10 |
NORD JOY
IMO 9814179
|
49,874 | 2018 |
4.2
|
A |
| 11 |
CLEAROCEAN MARAUDER
IMO 9890446
|
49,999 | 2021 |
4.2
|
A |
| 12 |
STENA PROSPEROUS
IMO 9923750
|
49,990 | 2022 |
4.2
|
A |
| 13 |
CLEAROCEAN MELODY
IMO 9849265
|
49,995 | 2019 |
4.2
|
A |
| 14 |
AVAX
IMO 9953420
|
50,113 | 2021 |
4.3
|
A |
| 15 |
VICTORIA BAY
IMO 9974981
|
50,000 | 2024 |
4.3
|
A |
| 16 |
ISABELLA M II
IMO 9836440
|
49,999 | 2019 |
4.3
|
A |
| 17 |
CYPRESS SUN
IMO 9911551
|
49,999 | 2023 |
4.3
|
A |
| 18 |
AGIOS NIKOLAOS
IMO 9820283
|
49,988 | 2018 |
4.3
|
A |
| 19 |
MOSSEL BAY
IMO 9970375
|
49,999 | 2024 |
4.3
|
A |
| 21 |
AGIOI FANENDES
IMO 9798375
|
49,996 | 2019 |
4.3
|
A |
| 20 |
KK MARLIN
IMO 9835939
|
77,452 | 2021 |
4.3
|
A |
| 22 |
AHINOS
IMO 9328144
|
53,187 | 2007 |
4.4
|
A |
| 23 |
ISLA DE BIOKO
IMO 9767235
|
51,609 | 2016 |
4.4
|
A |
| 24 |
NORD OLYMPIA
IMO 9747132
|
49,995 | 2018 |
4.4
|
A |
| 25 |
DAT VENUS
IMO 9948293
|
49,801 | 2023 |
4.4
|
A |
| 26 |
CAPILANO SUN
IMO 9909584
|
49,999 | 2021 |
4.4
|
A |
| 27 |
CS HU BEI
IMO 9899480
|
47,495 | 2022 |
4.5
|
A |
| 28 |
SILVER MANOORA
IMO 9718844
|
49,897 | 2016 |
4.5
|
A |
| 29 |
HAFNIA PIONEER
IMO 9595632
|
74,999 | 2013 |
4.5
|
A |
| 30 |
ELDIA
IMO 9798351
|
49,996 | 2019 |
4.6
|
A |
| 31 |
HEROLDS BAY
IMO 9967251
|
49,999 | 2023 |
4.6
|
A |
| 32 |
EMMA GRACE
IMO 9694191
|
49,997 | 2015 |
4.6
|
A |
| 33 |
PS NEW ORLEANS
IMO 9919577
|
52,853 | 2022 |
4.6
|
A |
| 34 |
SOLAR KAREN
IMO 9907823
|
49,365 | 2021 |
4.6
|
A |
| 35 |
DEE4 KASTANIA
IMO 9933638
|
49,999 | 2020 |
4.6
|
A |
| 37 |
MRC NAZENDE
IMO 9419735
|
51,291 | 2009 |
4.6
|
A |
| 36 |
TP ENDEAVOUR
IMO 9835056
|
49,999 | 2020 |
4.6
|
A |
| 38 |
DEE4 NERIUM
IMO 9929821
|
49,990 | 2022 |
4.7
|
A |
| 39 |
CELSIUS PORTSMOUTH
IMO 9884837
|
50,299 | 2021 |
4.7
|
A |
| 40 |
LINDANGER
IMO 9725299
|
49,999 | 2016 |
4.7
|
A |
| 41 |
STI MYSTERY
IMO 9829461
|
49,999 | 2019 |
4.7
|
A |
| 42 |
DEE4 ILEX
IMO 9922093
|
49,999 | 2020 |
4.7
|
A |
| 43 |
ELAIA
IMO 9798363
|
49,996 | 2019 |
4.7
|
A |
| 45 |
MINDORO STAR
IMO 9441207
|
73,677 | 2009 |
4.8
|
A |
| 44 |
PACIFIC DEBBIE
IMO 9772058
|
73,500 | 2015 |
4.8
|
A |
| 46 |
ELANDRA STAR
IMO 9635767
|
49,999 | 2013 |
4.8
|
A |
| 49 |
GREEN SKY
IMO 9676515
|
50,879 | 2014 |
4.8
|
A |
| 48 |
ST NICHOLAS
IMO 9934149
|
50,226 | 2022 |
4.8
|
A |
| 47 |
PS ATENE
IMO 9831206
|
49,999 | 2018 |
4.8
|
A |
| 50 |
FPMC 36
IMO 9845180
|
49,721 | 2020 |
4.8
|
A |
Which engines power the greenest fleets?
The main engine is the single largest CO₂ source on board — typically well over 80% of a ship's emissions come from propulsion. We aggregated this ranking the other way around: every engine design is scored by the measured carbon intensity of the vessels carrying it, licensee-built units merged under their design brand. The verdict from the 2024 data — modern dual-fuel designs like MAN B&W's ME-GI and WinGD's X-DF families, together with EGR/SCR-abated and ultra-long-stroke G-type engines, consistently power the most emission-friendly ships in service.
AER (Annual Efficiency Ratio) = annual CO₂ emissions ÷ (deadweight × distance sailed), the IMO carbon-intensity metric used for CII ratings. It is built only from measured CO₂, distance and deadweight — not the self-reported cargo transport-work figure, which is unreliable. Implausible outliers (top 2% per segment) are excluded. Grade A–E reflects each vessel's rank within its segment. Source: EMSA THETIS-MRV.