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 2025. 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 |
|---|---|---|---|---|---|
| 1101 |
QD SUMMER
IMO 9363845
|
19,994 | 2008 |
12.0
|
D |
| 1102 |
MISTRAL EXPLORER
IMO 9624770
|
21,323 | 2012 |
12.0
|
D |
| 1103 |
TRANS FJORD
IMO 9956939
|
12,576 | 2023 |
12.1
|
D |
| 1104 |
STOLT SURF
IMO 9168623
|
22,220 | 2000 |
12.1
|
D |
| 1105 |
MALBEC
IMO 9364928
|
38,603 | 2008 |
12.1
|
D |
| 1106 |
SLOMAN HESTIA
IMO 9776133
|
16,473 | 2017 |
12.1
|
D |
| 1107 |
EVA USUKI
IMO 9865532
|
19,808 | 2020 |
12.1
|
D |
| 1108 |
STOLT CONFIDENCE
IMO 9102071
|
37,090 | 1996 |
12.2
|
D |
| 1109 |
TERNFJORD
IMO 9722405
|
14,848 | 2016 |
12.2
|
D |
| 1110 |
DELONIX
IMO 9298387
|
20,610 | 2008 |
12.2
|
D |
| 1111 |
SCOT FLENSBURG
IMO 9365269
|
8,150 | 2008 |
12.2
|
D |
| 1112 |
JULIA THERESA
IMO 9837573
|
12,606 | 2019 |
12.2
|
D |
| 1113 |
SUN 9
IMO 9529645
|
19,992 | 2010 |
12.2
|
D |
| 1114 |
TRANS CHEMICA
IMO 9314715
|
12,430 | 2005 |
12.2
|
D |
| 1115 |
ERIN SCHULTE
IMO 9439814
|
16,716 | 2009 |
12.2
|
D |
| 1116 |
OCTONAUT
IMO 9340477
|
19,983 | 2007 |
12.2
|
D |
| 1117 |
AQUARIUS
IMO 9393008
|
19,928 | 2008 |
12.2
|
D |
| 1118 |
EDZARD SCHULTE
IMO 9439852
|
16,379 | 2011 |
12.2
|
D |
| 1119 |
SARIYAH
IMO 9858773
|
34,767 | 2021 |
12.2
|
D |
| 1120 |
BONITA AKI
IMO 9505974
|
14,701 | 2011 |
12.3
|
D |
| 1121 |
ATLANTIC MATE
IMO 9350745
|
18,000 | 2007 |
12.3
|
D |
| 1122 |
CHEMICAL FRONTIER
IMO 9940734
|
14,521 | 2022 |
12.3
|
D |
| 1123 |
ORIENTAL MARGUERITE
IMO 9407201
|
14,367 | 2008 |
12.3
|
D |
| 1124 |
ANDINO DELTA
IMO 9172210
|
16,028 | 1998 |
12.4
|
D |
| 1125 |
QIKIQTAALUK W.
IMO 9421221
|
19,998 | 2011 |
12.4
|
D |
| 1126 |
SOLAR NAAMA
IMO 9887396
|
24,621 | 2021 |
12.4
|
D |
| 1127 |
STELLA THERESA
IMO 9594145
|
12,601 | 2011 |
12.4
|
D |
| 1128 |
SLOMAN HEBE
IMO 9809784
|
16,432 | 2019 |
12.4
|
D |
| 1129 |
XT PROGRESS
IMO 9500144
|
17,427 | 2020 |
12.4
|
D |
| 1130 |
NQ FREESIA
IMO 9829772
|
13,029 | 2018 |
12.4
|
D |
| 1131 |
MALMO
IMO 9373242
|
19,992 | 2008 |
12.5
|
D |
| 1132 |
SAMU
IMO 9458054
|
14,355 | 2010 |
12.5
|
D |
| 1133 |
TRANS CATALONIA
IMO 9176694
|
19,715 | 2000 |
12.5
|
D |
| 1134 |
HAI GONG YOU 606
IMO 9301873
|
17,349 | 2006 |
12.5
|
D |
| 1135 |
PVT AURORA
IMO 9508938
|
19,991 | 2012 |
12.6
|
D |
| 1136 |
DANICA
IMO 9427976
|
14,368 | 2009 |
12.6
|
D |
| 1137 |
KOCATEPE
IMO 9274666
|
37,082 | 2005 |
12.6
|
D |
| 1138 |
CHEMICAL CONTENDER
IMO 9847140
|
15,945 | 2018 |
12.6
|
D |
| 1139 |
EVA MANILA
IMO 9918602
|
19,860 | 2021 |
12.6
|
E |
| 1140 |
ATLANTIC SPIRIT
IMO 9580974
|
19,131 | 2011 |
12.7
|
E |
| 1141 |
STOLT FLAMENCO
IMO 9391995
|
12,558 | 2010 |
12.7
|
E |
| 1142 |
STOLT VIKING
IMO 9196711
|
26,707 | 2001 |
12.7
|
E |
| 1143 |
NORTHERN SPIRIT
IMO 9580962
|
19,118 | 2011 |
12.7
|
E |
| 1144 |
OLYMPIC FLAME
IMO 9298375
|
20,635 | 2007 |
12.7
|
E |
| 1145 |
NQ MILLA
IMO 9261516
|
16,882 | 2003 |
12.8
|
E |
| 1146 |
MAGNOLIA THERESA
IMO 9384162
|
17,101 | 2007 |
12.8
|
E |
| 1147 |
GINGA MAYA
IMO 9339351
|
19,728 | 2005 |
12.8
|
E |
| 1148 |
TRANS ADRIATIC
IMO 9263928
|
12,503 | 2002 |
12.9
|
E |
| 1149 |
BONITA ANN
IMO 9422665
|
14,732 | 2010 |
12.9
|
E |
| 1150 |
TRANS IBERIA
IMO 9170597
|
19,733 | 1999 |
12.9
|
E |
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 2025 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.