An inside look at methanol as fuel
Methanol, also known as methyl alcohol, is one of the most widely produced chemicals on earth, with nearly 100 million tons currently being made per year worldwide, nearly all produced from natural gas or coal.
It offers a firm foundation for its use as an alternative marine fuel for the shipping world, thanks to the ability to store it onboard in liquid form at ambient temperature and atmospheric pressure. Additionally, methanol handling and power conversion technologies are mature, and there is a strong level of infrastructure already existing in ports. Furthermore, methanol’s comparatively low pollutant emissions make it a good fuel choice for owners looking to meet environmental targets.
However, methanol presents a handful of challenges for ship owners and managers, notably in terms of availability, the cost of sustainably produced methanol, and onboard safety assurance. Overcoming these challenges will require ongoing collaboration between the marine and chemical industries, with an emphasis on advancing production of carbon-neutral methanol (bio-methanol or e-methanol) when considering well-to-wake greenhouse gas (GHG) emissions.
Putting sustainability and safety first
Safety is the first concern when using methanol as fuel. While methanol may be stored as a liquid at ambient temperatures and under normal pressure, it is a toxic and flammable substance. Particular attention must be paid to the high toxicity of its vapors. For shipowners looking to use methanol as fuel, this first means that specific arrangements for ventilation systems must be arranged onboard to ensure safe working conditions for crew. Second, methanol tanks must be maintained with inert atmosphere at all times during normal operations, avoiding the risk of dangerous chemical reactions. Finally, personnel must be trained to properly handle methanol, undergoing safety management training to minimize risk.
The second concern is sustainability. Methanol does hold a sustainability advantage over heavy fuel oil (HFO) and low sulfur fuel, containing no sulfur and producing limited nitrous oxides (NOx) and minimal particulate matter when burnt. However, its tank-to-wake GHG emissions remain high, typically reported as averaging only a 7% decrease in CO2 emissions as compared to HFO – markedly less than the theoretical 22% reduction possible with liquefied natural gas (LNG). This makes decarbonizing methanol production a must for the long-term sustainability and viability of methanol as marine fuel.
Different ways of producing methanol
Not all methanol is produced using the same materials or via the same processes. This leads to variations in the sustainability of methanol as fuel when considering well-to-wake GHG emissions.
- Brown methanol is produced from coal and may not significantly reduce well-to-wake carbon dioxide emissions.
- Grey methanol is produced from natural gas and may not significantly reduce well-to-wake carbon dioxide emissions.
- Blue methanol is produced using blue hydrogen in combination with carbon capture technology, vastly reducing well-to-tank carbon dioxide emissions.
- Green methanol may be bio-methanol produced from biomass or e-methanol produced from green hydrogen, captured CO2 and renewable electricity. Both ways may be considered as enabling neutral well-to-wake carbon dioxide emissions.
Managing the costs of methanol as fuel
As with all alternative fuels, there is the question of how much shipowners will need to spend to use blue or green methanol as fuel and regularly refuel. There are certain CAPEX costs associated with ships’ fuel storage, handling and power conversion systems. However, the key question is OPEX costs with methanol pricing.
To achieve effective CO2 emissions reduction, shipowners will need access to blue or green methanol, which is significantly more expensive than brown/grey methanol or HFO, and is currently in limited availability.
Additionally, because methanol has a lower energy density than HFO – about 15 MJ/L, as compared to 35 MJ/L – more volume will have to be stored onboard for the same amount of stored energy. This makes minimizing the costs of green methanol non-negotiable if marine stakeholders plan to make methanol-powered ships a viable long-term solution for decarbonization.
Director of Environment & Technologies Department
Bureau Veritas Marine & Offshore
What is encouraging about methanol is that the major changes to come are largely on the production side. The infrastructure and technology needed to safely store, transport and burn methanol are already proven and available. This will put shipowners in a strong position once there is a cost-efficient way to produce green and blue methanol.
Relying on mature infrastructure and technology
Methanol does nonetheless benefit from two crucial advantages when compared to other alternative fuels.
First, it has long been transported as marine cargo and it is already used as fuel by some chemical carriers, meaning that onboard technology for methanol-powered ships already exists. From onboard storage tanks, to handling and transfer systems, to power conversion systems, the marine technology that enables the use of methanol as fuel is available and proven in an operational environment.
Second, shipowners may benefit from well-developed infrastructure at ports, with methanol reportedly available in over 100 major ports today.
This is a significant mark in methanol’s favor, particularly when compared to alternative fuels that require extensive infrastructure expansion and the development of new technology.
Providing classification support for methanol as fuel
As a classification society dedicated to advancing the energy transition, Bureau Veritas is helping support shipowners in a move toward using methanol as fuel. Our NR 670 classification rules cover methyl- and ethyl-alcohol-fueled ships, providing requirements for methanol-powered vessels. Our rules integrate requirements from IMO’s most recent interim guidelines on methyl/ethyl alcohol as fuel, published in December 2020, helping ensure that methanol-powered ships are safe and compliant. Vessels that are constructed or converted in accordance with these rules may be granted our METHANOL FUEL notation.