A new report from Lloyd’s Register (LR) explores the current state of LPG as a fuel for shipping. LPG is already a widely available fossil fuel that offers emissions benefits compared to other fossil options.
In particular, “Fuel For Thought: LPG”, has found that the market for dual-fuel LPG engines will continue to grow based on a healthy orderbook, with LPG offering a cleaner, lower carbon emission marine energy source than many alternatives currently available.
According to the report, the use of LPG as a marine fuel combined with technology such as Onboard Carbon Capture and Storage (OCCS) can reduce a vessel’s emissions profile, with the added benefit of reducing the required CO2 storage capacity, due to the lower CO2 emissions from LPG combustion. This allows the technology to work more effectively and offers shipowners a pathway towards future regulatory compliance.
The report, however, outlines that technology readiness will need to improve for LPG to become a viable choice for shipowners and operators looking to transition their fleet to low and zero-carbon vessels. Although well established, the range of available engine technologies will need to be expanded to enable widespread adoption of LPG on multiple vessel types. Currently there is no four-stroke marine engine capable of using LPG, meaning auxiliary engines on vessels would need to be decarbonised through an additional fuel.
A safe bunkering framework must be also developed to encourage uptake of LPG. Regulations remain in their early stages, with interim guidelines recently published by IMO.
Panos Mitrou, Global Gas Segment Director, Lloyd’s Register, said: “The pace and scale of renewable production for LPG remains a critical factor in initiating the wider adoption of LPG as a marine fuel. Supportive energy-saving technologies, as along with potentially maturing onboard carbon capture and storage, will further assist in making LPG a viable low-zero carbon fuel. By ensuring this, LPG could offer attractive operating and capital costs compared to other alternative fuels as shipowners look to decarbonise their fleets in line with more stringent regulations.”
LPG stands as a unique and exceptional energy source, pivotal for decarbonising the shipping sector. Stored and transported as a liquid and consumed as a gas, it is well recognised for its lower emission benefits as a marine fuel. With a surge in orders for LPG-fuelled ships, it’s clear that LPG’s role in the shipping industry is expanding.
…Nikos Xydas, World Liquid Gas Association Technical Director said.
There are several potential hazards to the storage, use and transportation of LPG that need to be mitigated in all industrial scenarios:
- LPG is approximately twice as heavy as air when in gas form and will tend to sink to the lowest possible level and accumulate there.
- LPG forms a flammable mixture with air in concentrations of between 2% and 10%. It can, therefore, be a fire and explosion hazard if stored or used incorrectly
- At very high concentrations when mixed with air, vapour is an anaesthetic and subsequently an asphyxiant by diluting the available oxygen.
- LPG in liquid form can cause severe cold burns to the skin owing to its rapid vaporisation. Vaporisation can cool equipment which may also be cold enough to cause cold burns if not properly insulated.
- Vapour/air mixtures arising from leakages may be ignited some distance from the point of escape and the flame can travel back to the source of the leak.
- A storage vessel that has contained LPG is nominally empty but may still contain LPG vapour and be potentially dangerous.
Maritime safety regulations
While the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGC Code) covers the construction and equipment of ships carrying liquified gases as bulk cargoes, including the use of such cargoes as fuel, the use of gases or other low-flashpoint fuels like LPG as fuel onboard for non-gas carriers is governed by the International Code of Safety for Ships using Gases or other Low-flashpoint Fuels (IGF Code).
As explained, considering the nature of the fuels involved, the codes indicate the necessary prerequisites for the equipment, machinery, other systems and their arrangement on board in order for the vessel to run safely on gas or low-flashpoint fuels in a way that minimises the risk to the ship, its crew and the
environment. In addition to goals, functional requirements, risk assessment and prescriptive requirements, the IGF Code also addresses operational requirements and crew training requirements.
Process assurance for LPG bunkering operations
Using guidelines on LNG bunkering as a basis – including ISO 20519 for LNG bunkering in ports, SGMF/EMSA guidelines and standards, as well as several countries’ national legislation – an equivalent roadmap for LPG should focus on the following pillars:
- Systems and equipment, including transfers, connections, insulation, emergency shutdown/release, maintenance, facilities, etc.
- Processes and procedures; including mooring, communication protocols, preparation/operation, risk assessment (safety zones, navigation, and traffic simulations), emergency preparedness and response, simultaneous operations protocol, etc.
- Management systems and quality assurance; including procedures, auditing, sustainability, records, port procedures manual, etc.
- Personnel training, responsibilities and familiarisation; including programs and procedures, timetable, matrices and organograms, documentation, etc.
- Checklists, including for authorisation, preparation/pre-meetings, during and after operations, documentation and records, etc.
- Safety and compatibility studies; safety zones assessment and implementation, hazard identification workshops/studies for specific receiving/bunkering vessels, site evaluation at port/compatibilities, etc.
