Blue, green, gold — what do all the colors of hydrogen even mean? Photo via Getty Images

Repeated association of specific colors in defined contexts deeply reinforces themes in the human brain. It’s why most students and alumni of Texas A&M University scoff at the sight of burnt orange, and you’d be hard-pressed to find the home of a Longhorn adorned in shades of crimson or maroon.

The color-coding of hydrogen energy production exemplifies one such ambiguous classification methodology, as the seemingly innocuous labeling of hydrogen as green (for hydrogen produced from renewable sources) and black (for hydrogen produced from coal) initially helped to quickly discern which sources of hydrogen are environmentally friendly or not.

But the coding system quickly became more complicated, as the realization that hydrogen extracted from natural gas (aka grey hydrogen) or coal (again, black hydrogen, or sometimes, brown hydrogen, depending on the carbon content and energy density of the source coal) could be extracted in a less harmful way, by introducing methods of carbon capture and storage.

These cleaner methods for hydrogen extraction earned the lofty color coding of blue, just one shade away from green in the rainbow spectrum and a safe distance from the less delightful and inspiring colors grey, brown, and black.

Then along came pyrolysis — a method for producing hydrogen through methane cracking, plainly, the decomposition of methane, CH4, into solid carbon and hydrogen gas, without the introduction of oxygen. This method results in significantly less (if any) creation of carbon dioxide as a by-product. Logic would lead one to categorize this process with a color that lies further away from black than exalted cousin, green hydrogen.

However, the solid carbon that remains after pyrolysis retains over one-third of the original energy available from methane and could tip the GHG scales negatively if not utilized in an environmentally responsible manner, so it’s not a clear-cut winner in the game of lower-carbon energy production. Thus, it is nestled between green and blue and often referred to as “turquoise hydrogen” production.

Other hydrogen production methods — pink, purple, and red — defy rainbow logic as they have all proven to result in higher GHG emissions than the original “clean” queen, green hydrogen, despite following a similar electrolysis process to separate hydrogen and oxygen from one another in its original composition as water. The source of electricity used in the electrolysis process determines the color-code here, as pink hydrogen is generated from nuclear power, red hydrogen is generated from nuclear thermal power, and purple hydrogen is generated from a combination of nuclear power and nuclear thermal power.

Yellow hydrogen seems to not yet have found a clear definition. Some argue it refers to green hydrogen produced exclusively from solar-powered electrolysis, while others claim it to be the child of mixed green/gray hydrogen. Artists should probably keep a far distance from this conversation, unless the energy produced from the steam coming out of their ears could perform electrolysis more cleanly than any of the green hydrogen solutions.

Finally, we have white hydrogen, the naturally occurring, zero-carbon emitting, plentiful element found in the earth’s crust – which is also the least understood of all the hydrogen extraction methodologies.

Remember, hydrogen is the first element in the periodic table, meaning it’s density is very low. Hydrogen knows no bounds, and once it escapes from its natural home, it either floats off into outer space or attaches itself to another element to form a more containable compound, like water.

Many believe white hydrogen to be the unquestionable solution to a lower-carbon energy future but there is still much to be understood. Capturing, storing, and transporting white hydrogen remain mostly theoretical, despite recent progress, which includes one recently announced Houston lab dedicated to hydrogen transport. Another Houston company, Syzygy has raised millions with its light-based catalyst for hydrogen production.

For example, Cemvita, a local Houston chemical manufacturing company, predicts a future powered by gold hydrogen: white hydrogen sourced from depleted oil and gas wells. Many wildcatters believe strongly in a new era of exploration for white hydrogen using techniques refined in oil and gas exploration, including reservoir analysis, drilling, and fracking.

Without a doubt, investigating further the various hydrogen extraction theories is surely a craveable new challenge for the sciences. But perhaps the current color-coding nomenclature for hydrogen needs refinement, as well.

Unless used in the scientific context of wavelength, color-based labels represent an ambiguous classification tool, as the psychology of color depends on modern societal norms. The association of colors with the various hydrogen production methodologies does very little to distinguish the climate impact each method produces. Additionally, the existing categorizations do not consider any further distribution or processing of the produced hydrogen — a simple fact that could easily negate any amount of cleanliness implied by the various production methods — and a topic for a future article.

For now, hydrogen represents one of the front-running sources for a lower-carbon energy future, but it’s up to you if that’s best represented by a blue ribbon, gold medal, white star, or cold-hard greenbacks.

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Lindsey Ferrell is a contributing writer to EnergyCapitalHTX and founder of Guerrella & Co.

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Rice researchers' quantum breakthrough could pave the way for next-gen superconductors

new findings

A new study from researchers at Rice University, published in Nature Communications, could lead to future advances in superconductors with the potential to transform energy use.

The study revealed that electrons in strange metals, which exhibit unusual resistance to electricity and behave strangely at low temperatures, become more entangled at a specific tipping point, shedding new light on these materials.

A team led by Rice’s Qimiao Si, the Harry C. and Olga K. Wiess Professor of Physics and Astronomy, used quantum Fisher information (QFI), a concept from quantum metrology, to measure how electron interactions evolve under extreme conditions. The research team also included Rice’s Yuan Fang, Yiming Wang, Mounica Mahankali and Lei Chen along with Haoyu Hu of the Donostia International Physics Center and Silke Paschen of the Vienna University of Technology. Their work showed that the quantum phenomenon of electron entanglement peaks at a quantum critical point, which is the transition between two states of matter.

“Our findings reveal that strange metals exhibit a unique entanglement pattern, which offers a new lens to understand their exotic behavior,” Si said in a news release. “By leveraging quantum information theory, we are uncovering deep quantum correlations that were previously inaccessible.”

The researchers examined a theoretical framework known as the Kondo lattice, which explains how magnetic moments interact with surrounding electrons. At a critical transition point, these interactions intensify to the extent that the quasiparticles—key to understanding electrical behavior—disappear. Using QFI, the team traced this loss of quasiparticles to the growing entanglement of electron spins, which peaks precisely at the quantum critical point.

In terms of future use, the materials share a close connection with high-temperature superconductors, which have the potential to transmit electricity without energy loss, according to the researchers. By unblocking their properties, researchers believe this could revolutionize power grids and make energy transmission more efficient.

The team also found that quantum information tools can be applied to other “exotic materials” and quantum technologies.

“By integrating quantum information science with condensed matter physics, we are pivoting in a new direction in materials research,” Si said in the release.

Oxy subsidiary granted landmark EPA permits for carbon capture facility

making progress

Houston’s Occidental Petroleum Corp., or Oxy, and its subsidiary 1PointFive announced that the U.S Environmental Protection Agency approved its Class VI permits to sequester carbon dioxide captured from its STRATOS Direct Air Capture (DAC) facility near Odessa. These are the first such permits issued for a DAC project, according to a news release.

The $1.3 billion STRATOS project, which 1PointFive is developing through a joint venture with investment manager BlackRock, is designed to capture up to 500,000 metric tons of CO2 annually and is expected to begin commercial operations this year. DAC technology pulls CO2 from the air at any location, not just where carbon dioxide is emitted. Major companies, such as Microsoft and AT&T, have secured carbon removal credit agreements through the project.

The permits are issued under the Safe Drinking Water Act's Underground Injection Control program. The captured CO2 will be stored in geologic formations more than a mile underground, meeting the EPA’s review standards.

“This is a significant milestone for the company as we are continuing to develop vital infrastructure that will help the United States achieve energy security,” Vicki Hollub, Oxy president and CEO, said in a news release.“The permits are a catalyst to unlock value from carbon dioxide and advance Direct Air Capture technology as a solution to help organizations address their emissions or produce vital resources and fuels.”

Additionally, Oxy and 1PointFive announced the signing of a 25-year offtake agreement for 2.3 million metric tons of CO2 per year from CF Industries’ upcoming Bluepoint low-carbon ammonia facility in Ascension Parish, Louisiana.

The captured CO2 will be transported to and stored at 1PointFive’s Pelican Sequestration Hub, which is currently under development. Eventually, 1PointFive’s Pelican hub in Louisiana will include infrastructure to safely and economically sequester industrial emissions in underground geologic formations, similar to the STRATOS project.

“CF Industries’ and its partners' confidence in our Pelican Sequestration Hub is a validation of our expertise managing carbon dioxide and how we collaborate with industrial organizations to become their commercial sequestration partner,” Jeff Alvarez, President of 1PointFive Sequestration, said in a news release.

1PointFive is storing up to 20 million tons of CO2 per year, according to the company.

“By working together, we can unlock the potential of American manufacturing and energy production, while advancing industries that deliver high-quality jobs and economic growth,” Alvarez said in a news release.

Houston energy-focused AI platform raises $5M in Mercury-led seed round

fresh funding

Houston-based Collide, a provider of generative artificial intelligence for the energy sector, has raised $5 million in seed funding led by Houston’s Mercury Fund.

Other investors in the seed round include Bryan Sheffield, founder of Austin-based Parsley Energy, which was acquired by Dallas-based Pioneer Natural Resources in 2021; Billy Quinn, founder and managing partner of Dallas-based private equity firm Pearl Energy Investments; and David Albin, co-founder and former managing partner of Dallas-based private equity firm NGP Capital Partners.

“(Collide) co-founders Collin McLelland and Chuck Yates bring a unique understanding of the oil and gas industry,” Blair Garrou, managing partner at Mercury, said in a news release. “Their backgrounds, combined with Collide’s proprietary knowledge base, create a significant and strategic moat for the platform.”

Collide, founded in 2022, says the funding will enable the company to accelerate the development of its GenAI platform. GenAI creates digital content such as images, videos, text, and music.

Originally launched by Houston media organization Digital Wildcatters as “a professional network and digital community for technical discussions and knowledge sharing,” the company says it will now shift its focus to rolling out its enterprise-level, AI-enabled solution.

Collide explains that its platform gathers and synthesizes data from trusted sources to deliver industry insights for oil and gas professionals. Unlike platforms such as OpenAI, Perplexity, and Microsoft Copilot, Collide’s platform “uniquely accesses a comprehensive, industry-specific knowledge base, including technical papers, internal processes, and a curated Q&A database tailored to energy professionals,” the company said.

Collide says its approximately 6,000 platform users span 122 countries.