Going Beyond Gas Carriers

Lloyd’s Register (LR) has strengthened the case for LPG as a marine fuel, arguing that its established technology, global supply chain and lower capital costs give owners a practical route to near-term emissions reductions.

LPG, or liquefied petroleum gas, consists mainly of propane and butane, stored as a liquid under pressure, with the precise blend affecting its storage and handling characteristics rather than fundamentally determining engine efficiency.

The classification society’s updated Fuel for Thought: LPG report, published with the World Liquid Gas Association in May 2026, stops short of presenting fossil LPG as a zero-carbon solution. Instead, it describes a transition pathway that is already proven aboard gas carriers and could eventually extend into container ships, bulk carriers and other sectors.

Constantinos Chaelis, LR’s Global Gas Segment Director, said LPG combined “mature infrastructure, a growing dual-fuel fleet and clear emissions advantages” with a route to compliance today. He argued that renewable LPG, wider retrofit options and onboard carbon capture could extend its usefulness, although all three elements remain at differing stages of commercial and technical maturity at present.

LR says fossil LPG produces about 97% less sulphur oxides, 90% less particulate matter and approximately 20% less carbon dioxide than heavy fuel oil. On a well-to-wake basis, greenhouse gas emissions may be up to 17% below marine gas oil, although performance will vary with production and supply chain.

The practical case rests heavily on scale. Global seaborne LPG trade rose 5% to a record 145 million tonnes in 2025. LR counted 1,758 LPG carriers in service at December 2025 and identified about 500 terminals that could potentially support bunkering for other vessel types, subject to local regulation, safety assessment and sufficient demand.

Commercially, the LR report estimates that converting a conventional engine to LPG dual-fuel operation could cost between US$9.5 million and US$27 million, compared with US$12 million to US$33 million for LNG. LPG storage also requires less space than LNG, although about 1.5 times the tank volume of marine diesel oil.