Methanol as a catalyst for energy transition

Introduction

Methanol is currently considered as one of the best options in the search for alternatives to fossil fuels in the energy transition, which implies a shift towards renewable and sustainable energy sources in order to reduce greenhouse gas emissions without compromising economic viability.

Traditionally derived from fossil fuels, methanol is a low-carbon chemical compound and represents an alternative solution in sectors such as shipping. In the following, we will cover the concept of methanol as a driver towards energy transition, as well as innovations in sustainable production processes, highlighting its role in reducing emissions and independence from fossil fuels.

What is methanol?

It is a chemical compound of industrial use due to its multiple applications, one of the most important being the production of synthetic fuels. In its natural state, it is a light liquid at room temperature, which facilitates its transport and storage¹.

Most of the production comes from natural gas, and the one from renewable sources, known as green methanol, represents a viable solution to reduce the carbon footprint in industries such as shipping². In addition, its liquid form and low carbon footprint position it as a promising fuel in the energy transition to cleaner alternatives.

This short video explains why methanol represents a safe and environmentally friendly solution for the energy transition. Source: Methanol Institute.

Uses of methanol in the energy industry

• Alternative fuel: It is used as a fuel in internal combustion engines and fuel cells, as well as in blends with gasoline due to its high octane rating. Its combustion generates fewer greenhouse gas emissions and air pollutants, making it a cleaner option compared to conventional fuels.
• Energy storage: When produced from renewable energy sources, it can be stored as a form of energy in case of excess, it can be converted back into electricity or used as fuel. In addition, it can be used in ethanol fuel cells to generate electricity through electrochemical processes, being useful for portable applications, transportation, and stationary power generation.
• Biodiesel production: In the transesterification process, methanol is an essential component to convert triglycerides from vegetable oils, animal fats, or recycled fats into biodiesel. This process produces fatty acid alkyl esters (biodiesel) and glycerin as a by-product.

Impact of methanol on carbon emission reductions

Green methanol represents a key solution in the reduction of greenhouse gas (GHG) emissions. This chemical compound, which is traditionally produced from natural gas, can be generated through sustainable processes using biomass or renewable electricity. This new production model contributes to the decarbonization of highly polluting industries, and also has a number of practical advantages that facilitate its adoption on a large scale.

The problem of maritime transport and fossil fuels

Maritime transport is one of the main sources of GHG emissions, with 1,076 million tons emitted annually, representing about 14% of the total emissions of the transport sector³. Most large cargo ships use fuel oil, a highly polluting fuel that contributes significantly to the increase in carbon dioxide (CO₂) and other pollutants, such as black carbon and sulfur oxides. This situation has led to maritime transport being the third largest emitter of polluting gases, behind only land and air transport.

With the advent of regulations and increasing consumer expectations, the maritime sector is exploring alternatives to fossil fuels, such as green methanol, a viable and promising option. This low-carbon fuel has a lower environmental impact in terms of direct emissions and also facilitates the energy transition due to its physical properties and the infrastructure already in place for storage and distribution.

Green methanol: a solution to maritime emissions

Unlike other alternative fuels, such as liquefied natural gas (LNG), methanol is liquid at room temperature, which simplifies handling and storage. While LNG requires special tanks capable of maintaining extremely low temperatures, methanol can be stored in conventional tanks with minimal modifications. Of the top 100 international ports, 88 already have the infrastructure in place to supply methanol, which greatly facilitates its adoption⁴.

Companies such as A.P. Moller – Maersk have led the way in the implementation of green methanol. In 2023, the company launched its first feeder vessel powered by this fuel, representing a major milestone in the transition to more sustainable shipping. Maersk plans to build and operate a plant for the production of green fuels to explore opportunities to produce green shipping fuels in search of sustainable solutions worldwide that will enable it to achieve its decarbonization target by 2040, thus contributing to the energy transition in line with the Paris Agreements, the company added.

Impact on the life cycle of emissions

To assess its real impact on emissions reduction, it is necessary to analyze the life cycle, from the production of the fuel to its combustion in the engine. This approach, known as “well-to-wake”, allows a comprehensive view of the emissions generated by a fuel, including both those associated with its production and its final use.

According to studies by the International Council on Clean Transportation (ICCT), GHG emissions associated with methanol depend largely on the source from which it is derived. Methanol produced from natural gas (gray methanol) and methanol produced from natural gas in conjunction with carbon capture and storage technology (blue methanol) generate a high level of emissions. However, when methanol is produced from biomass (biomethanol) or its conversion with renewable electricity (e-methanol), emissions are drastically reduced, becoming competitive with cleaner fossil fuels. Green methanol, in its life cycle, has the potential to be one of the liquid fuels with the lowest carbon footprint.

Operational advantages of methanol in emission reduction

One of the main advantages of methanol is its compatibility with existing shipping infrastructure and systems. Unlike other alternative fuels that require completely new infrastructure, this compound can be stored and distributed using tanks and bunkering systems already in place, which significantly reduces adoption costs. In addition, dual-fuel engines allow for a gradual transition to the exclusive use of green methanol without the need for significant investments in propulsion technology.

Technological innovations driving the use of methanol

Direct Methanol Fuel Cells (DMFC)

These cells are a variant of polymer membrane fuel cells, similar to Proton Exchange Membrane (PEM) fuel cells, but with the difference that DMFCs use liquid methanol mixed with water. This aspect eliminates the need to reform this compound into hydrogen before introducing it into the system, simplifying operation and reducing costs.

DMFC operation is based on the direct oxidation of methanol at the anode, which produces carbon dioxide and protons. These protons migrate through a polymeric membrane that acts as an electrolyte, while the electrons generated in the electrochemical process flow through an external circuit, generating electricity. At the cathode, protons combine with oxygen from the air to form water. This process can be expressed by two key reactions: the reformation of methanol at the anode and the electrochemical reaction at the cathode.

DMFC technology has several advantages. The use of liquid fuel simplifies handling and storage compared to gaseous hydrogen, making it more viable for portable and automotive applications. In addition, due to its liquid nature, methanol is easy to transport, facilitating its integration into mobile power systems, such as portable electronic devices (laptops, cell phones) and, potentially, vehicles.

Carbon Capture and Storage Technology (CCS)

In the context of methanol production, Carbon Capture and Storage (CCS) technology is combined with Carbon Capture and Utilization (CCU) technologies, where CO₂ is captured from flue gases and used as feedstock to produce the desired compound. This process integrates three main stages⁵:

• Electrolysis to produce green hydrogen: Using a Polymer Electrolyte Membrane (PEM) electrolyzer, water is split into hydrogen and oxygen using renewable energy. The hydrogen produced is essential for the conversion of CO₂ to methanol.
• Post-combustion CO₂ capture: In this stage, CO₂ is extracted from the gases emitted by industries such as cement plants. A mixture of solvents (MDEA and piperazine) is used to absorb the CO₂, which is then compressed and purified by advanced absorption and regeneration processes.
• Catalytic CO2 conversion: Once captured, CO2 is combined with green hydrogen in a catalytic reactor and converted into methanol and water. This can be used as fuel or feedstock in various industries.

The use of CCS in methanol production helps to significantly reduce greenhouse gas emissions, turning CO₂ into a useful resource instead of a pollutant. This technology is an example of how carbon capture can be integrated into industrial processes to promote sustainability.

Conclusions

In the energy scenario, methanol represents an alternative solution to reduce carbon emissions and reduce the greenhouse effect. Production from renewable sources, such as biomass or through CO₂ capture, makes it a viable option compared to fossil fuels, one of the sectors being maritime, due to its ease of handling and storage, in addition to making use of existing infrastructure, facilitating large-scale adoption.

Its production from renewable sources positions it as a key catalyst in the energy transition to a more sustainable future in industrial and transportation sectors relative to fossil fuels. By integrating it into global decarbonization strategies, this compound can drive the development of more efficient technologies, leading the way to a low-carbon economy and fostering greater energy independence.

References

1. AIMPLAS – Instituto Tecnológico del Plástico. (2023, October 2). Metanol, el motor para alcanzar la transición energética. Accessed September 15, 2024 from https://www.aimplas.es/blog/metanol-el-motor-para-alcanzar-la-transicion-energetica
2. Iberdrola. (n.d.). Metanol verde: el combustible que puede acelerar la transición energética del transporte marítimo. Accessed September 15, 2024 from https://www.iberdrola.com/conocenos/nuestra-actividad/hidrogeno-verde/metanol-verde
3. GTA Ingeniería y Medio Ambiente. (2023, November 30). La producción de metanol verde, alternativa en la lucha para la descarbonización. Accessed September 16, 2024 from https://www.gtaingenieria.es/novedad/la-produccion-de-metanol-verde-alternativa-en-la-lucha-para-la-descarbonizacion/271
4. ECODES. (n.d.). Un paso adelante para el metanol “verde”. Accessed September 16, 2024 from https://ecodes.org/hacemos/cambio-climatico/incidencia-en-politicas-publicas/por-un-transporte-maritimo-limpio/un-paso-adelante-para-el-metanol-verde
5. Djettene, R., Dubois, L., Duprez, M., De Weireld, G., & Thomas, D. (2024). Integrated CO2 capture and conversion into methanol units: Assessing techno-economic and environmental aspects compared to CO2 into SNG alternative. Journal of CO2 Utilization, 85, 102879. https://doi.org/10.1016/j.jcou.2024.102879