Well-to-Tank Carbon Intensity Variability of Fossil Marine Fuels: A Country-Level Assessment

TL;DR

This study assesses the variability in well-to-tank carbon intensity of fossil marine fuels globally, highlighting significant differences across countries and supply chains, and providing insights for targeted emission reduction strategies.

Contribution

It offers the first comprehensive country-level assessment of well-to-tank carbon intensity for HSFO and LPG, incorporating upstream, refining, and transportation emissions worldwide.

Findings

HSFO well-to-tank CI varies 1-22.7 gCO2e/MJ

LPG well-to-refinery CI varies 2.8-13.9 gCO2e/MJ

Refining accounts for a large share of emissions

Abstract

The transition toward a low-carbon maritime transportation requires understanding lifecycle carbon intensity (CI) of marine fuels. While well-to-tank emissions significantly contribute to total greenhouse gas emissions, many studies lack global perspective in accounting for upstream operations, transportation, refining, and distribution. This study evaluates well-to-tank CI of High Sulphur Fuel Oil (HSFO) and well-to-refinery exit CI of Liquefied Petroleum Gas (LPG) worldwide at asset level. HSFO represents traditional marine fuel, while LPG serves as potential transition fuel due to lower tank-to-wake emissions and compatibility with low-carbon fuels. Using OPGEE and PRELIM tools with R-based geospatial methods, we derive country-level CI values for 72 countries (HSFO) and 74 countries (LPG), covering 98% of global production. Results show significant variation in climate impacts globally. HSFO upstream CI ranges 1-22.7 gCO2e/MJ, refining CI 1.2-12.6 gCO2e/MJ, with global volume-weighted-average well-to-tank CI of 12.4 gCO2e/MJ. Upstream and refining account for 55% and 32% of HSFO well-to-tank CI, with large exporters and intensive refining practices showing higher emissions. For LPG, upstream CI ranges 0.9-22.7 gCO2e/MJ, refining CI 2.8-13.9 gCO2e/MJ, with volume-weighted-average well-to-refinery CI of 15.6 gCO2e/MJ. Refining comprises 49% of LPG well-to-refinery CI, while upstream and transport represent 44% and 6%. Major players include China, United States and Russia. These findings reveal significant CI variability across countries and supply chains, offering opportunities for targeted emission reduction policies.