Creating a Circular Carbon Economy: Methanol as a Liquid Hydrogen Carrier

We are on the cusp of a great energy transition. 

Economic development, changes in human behavior, and improvements in technology usually determine our energy sources. Humans previously experienced two great energy transitions: from wood to coal in the 18th century, and from coal to oil and natural gas in the 20th century. Soon, we will enter the third great energy transformation: from fossil fuels to renewable energy. I believe green hydrogen is our next revolutionary energy carrier.

Hydrogen: Advantages and Disadvantages

In 2025, 87% of the world’s energy came from fossil fuel combustion, which contributes to climate change by releasing carbon dioxide (CO2) into the atmosphere. Through collaborations such as the historic 2015 Paris Agreement, countries around the world are working together to transition to non-fossil fuel energy sources that emit less or no CO2. Hydrogen gas is one such option: it produces water when it combusts, and releases no CO2. 

Especially when coupled with renewable energy sources such as wind and solar, hydrogen can be a solution for a sustainable and fossil fuel-free energy market. The U.S. government recognized this potential by providing incentives for the hydrogen economy through the 2021 Bipartisan Infrastructure Law. This landmark bill set aside up to $8 billion for hydrogen hubs. 

In 2022, the Inflation Reduction Act added a tax credit of up to $3 per kilogram of clean hydrogen produced. Though the fate of these incentives is uncertain in today’s U.S. political climate, global momentum in this space has not slowed down.

Researchers are also exploring hydrogen fuel cells, which can convert the energy stored in hydrogen’s chemical bonds into electrical power. They are more efficient than traditional combustion processes, produce less noise pollution, and require minimal space. However, the hydrogen must be free of contaminants, such as carbon monoxide and CO2, which can reduce the fuel cell’s output.

Hydrogen does have some key challenges. It has to be stored and transported as either a gas or a liquid. Pressurizing hydrogen into a gas requires costly compressors and reinforced tanks for safe storage. When hydrogen gas is transported through standard pipelines, chemical reactions between the hydrogen and the pipe materials can make the pipes brittle, leading to high maintenance costs. 

On the other hand, cooling hydrogen to its liquid state requires a temperature of -253°C and expensive equipment. Many researchers are working to develop new pipe materials or more efficient cooling systems, but work is still needed to make a large-scale hydrogen economy economically feasible.

Methanol: the Potential Solution

Liquids that contain hydrogen, such as methanol, are a potential solution. These liquids can “carry” the hydrogen to a location where the hydrogen can be produced for use. In fact, methanol is already used as fuel for large shipping vessels, and some Indian companies are exploring methanol-blend fuels for shipping vessels.

Methanol is a promising candidate partly because it is richer in hydrogen by weight than other potential carriers. It can also be manufactured using CO2 captured from our atmosphere and H2. As outlined in The Methanol Economy by USC Nobel Laureate George Olah and Dr. Surya Prakash, methanol can then be chemically converted back to hydrogen and CO2 on-site or used directly as a drop-in fuel like gasoline. The released CO2 can then be used to help produce more methanol, creating a circular, carbon-neutral energy economy that does not add CO2 to our atmosphere.

Finally, methanol can help overcome key logistical problems for hydrogen transport. It does not react with existing pipeline materials and does not have to be compressed for transport, so it can be moved using existing infrastructure. 

Here’s how the process works: at site A, methanol is created by combining carbon dioxide and hydrogen. Once created, methanol is easily transported to site B, where it can be converted back into hydrogen and CO2. The hydrogen can then be used for energy, and the CO2 can be recaptured to help create more methanol.

My Work on Methanol

As a 4th-year Ph.D. candidate in the Prakash Lab at USC’s Loker Hydrocarbon Research Institute, I develop new chemical technologies for the creation of methanol and its conversion into hydrogen or other energy sources. I also explore new materials that can be used to capture CO2 and convert it into a hydrogen carrier, all with the goal of building a circular carbon economy. 

Supported by the Wrigley Institute Graduate Fellowship, I’ve been exploring the production of clean, ultra-high-pressure hydrogen gas from methanol. My new process involves adding a base to the reaction to improve the capture of CO2 and produce more hydrogen overall. A base is like a sponge for acids: when CO2 is dissolved in water, it is slightly acidic, and some bases can grab onto the CO2 to prevent it from escaping into the air. 

By scaling up this reaction, I can potentially produce hydrogen gas at pressures that are suitable for use in fuel cells that can power cars. Notably, the hydrogen gas contains no carbon monoxide or CO2 that could reduce the fuel cell’s efficiency. That means there is no expensive purification step needed—a leap forward in minimizing the cost of using methanol for fuel cells.

Methanol has the potential to bridge today’s infrastructure and tomorrow’s hydrogen economy. Its compatibility with existing transport systems, potential for carbon neutrality, and ability to deliver high-pressure hydrogen make it a possible solution for scaling hydrogen technologies. 

Continued innovation in carbon capture materials, catalysts for producing methanol, and processes like those being developed at the Loker Hydrocarbon Research Institute, will be essential in making hydrogen not just a futuristic ideal, but an accessible and sustainable reality.

Zohaib Suhail is supported by the Diane Sonosky Montgomery and Jerol Sonosky Graduate Fellowship for Environmental Sustainability Research.