¿Qué es la clasificación de hidrógeno y por qué es útil?
Hydrogen plays a significant role in decarbonization as the world strives to limit global warming. With the increased spotlight on this critical clean energy source, colorful terms such as green hydrogen, blue hydrogen and grey hydrogen have entered the increasingly complex lexicon of sustainability buzzwords. But what does a system of color-coding mean, and why is it useful?
Hydrogen has been used as fuel for more than two centuries. Though thousands of vehicles and machines worldwide are powered by hydrogen fuel cells today, the complexities and cost of hydrogen production have hindered its wide-scale adoption in the past.
Hydrogen is the most abundant element in the universe, but it doesn’t occur naturally on its own. Hydrogen must be produced by separating it from other elements, such as water or fossil fuels. There are various ways to do this, and each process uses different amounts of energy and produces different greenhouse gas emissions.
As a clean energy source, it is crucial to differentiate hydrogen by the production method used to understand the full picture of its environmental impact.
Why a hydrogen "rainbow?"
El arco iris del hidrógeno es una forma sencilla para que las personas que no trabajan o no están familiarizadas con la industria de la energía limpia comprendan las opciones en torno a esta interesante solución energética. Vale la pena señalar que todo el hidrógeno es un gas invisible e incoloro. Desafortunadamente, ningún hidrógeno es realmente rosa, amarillo o turquesa en color visible.
En cambio, los colores son una herramienta útil para clasificar y recordar los tipos de hidrógeno.
The colors – while not reflecting scientific properties – used to label the production methods are meaningful in some cases and arbitrary in others. Green hydrogen, unsurprisingly, is the most sustainable option with the least environmental impact. Meanwhile, turquoise hydrogen gets its name because its production process is between green and blue. The hydrogen rainbow continues to expand as innovative new hydrogen production methods are introduced.
Hidrógeno verde
El hidrógeno verde no tiene emisiones de carbono y se crea utilizando fuentes de energía renovables como la solar, la eólica y la hidroeléctrica para electrolizar el agua. Los electrolizadores utilizan una reacción electroquímica. dividir el agua en sus componentes de hidrógeno y oxígeno.
Green hydrogen is the only hydrogen that emits zero harmful emissions during production. While the benefits of green hydrogen are significant, its production is more expensive and makes up a very small percentage of hydrogen production. As new advances and innovations in green hydrogen are made, prices will come down, and usage will grow.
Green hydrogen is the primary focus of Accelera™ by Cummins electrolyzer technologies. With proton exchange membrane (PEM) technology in its portfolio, Accelera electrolyzers actively produce green hydrogen in Bécancour, Canada, with a Sistema de 90 megavatios (MW). Most recently, Accelera announced a 100MW system commissioned in partnership with bp.
hidrógeno amarillo
Un subconjunto del hidrógeno verde, el hidrógeno amarillo, se produce mediante electrólisis generada por energía solar.
Hidrógeno gris
El hidrógeno gris se crea a partir de gas natural (normalmente metano) mediante un proceso llamado reformado de metano con vapor (SMR). The most common form of hydrogen production, grey hydrogen, makes up 95% of hydrogen production in the United States and has the lowest cost. The greenhouse gases made in the process are not captured.
Hidrógeno azul
Al igual que el hidrógeno gris, el hidrógeno azul se basa en el proceso convencional de SMR.
The key difference is the usage of carbon capture and storage (CSS). CSS traps the carbon dioxide from the reforming process and sequesters it underground. This technically lowers the emission threshold, but direct methane and hydrogen leakage from storage carbon pockets are a concern.
Al hidrógeno azul se le ha llamado bajo en carbono debido al CSS, pero todavía existe un debate sobre si el uso de SRM con CSS realmente puede considerarse un proceso "bajo en carbono".
Hidrógeno turquesa
Uno de los colores más nuevos que se une al espectro del hidrógeno es el hidrógeno turquesa. La turquesa, que se encuentra entre el hidrógeno verde y el azul, se produce mediante un proceso llamado pirólisis de metano. Se trata de un proceso de alta temperatura que convierte el metano en gas hidrógeno y carbono sólido (como carbón o biomasa) en presencia de un catalizador. No se crean emisiones de monóxido de carbono o dióxido de carbono.
While turquoise hydrogen has no proven impact at scale yet, it has potential as a low-emission solution if scientists can find ways to power the thermal process with renewable energy and adequately use or store the carbon byproduct.
Hidrógeno rosa
El hidrógeno rosa aprovecha la energía nuclear para alimentar la electrólisis necesaria para producirlo. Las altas temperaturas de los reactores nucleares brindan un beneficio adicional: el calor extremo produce vapor que puede usarse para electrólisis o reformado de metano con vapor a base de gases fósiles en otras formas de producción de hidrógeno.
Hidrógeno marrón y negro.
Black and brown hydrogen represents the traditional process for making hydrogen – the gasification of coal. Black coal (anthracite and bituminous coal) releases less CO2 per unit of energy produced than brown coal (lignite), but that doesn’t mean the gasification of black coal is desirable. It is still the most environmentally damaging hydrogen production process.
Hidrógeno blanco
White hydrogen is a naturally occurring, geological hydrogen found in underground deposits. Universities, companies, and research and policy organizations are exploring the potential of this hydrogen and its extraction impact.
El hidrógeno natural también ha sido llamado hidrógeno “oro”, pero el hidrógeno oro podría terminar pronto en su propia categoría. Si bien todavía hay debate al respecto, el hidrógeno dorado es la extracción de hidrógeno de microbios fermentadores que se encuentran en pozos petroleros agotados.
El impacto del arcoíris
Hydrogen can provide a clean fuel source and heat for homes, transport and industry. But its green credentials vary depending on how it is produced. Though the rainbow has been criticized in some places for oversimplifying the nuances of the production processes, it has undoubtedly helped people to learn about the options and their upsides and downsides. The colors have made it easy to remember these potentially complex messages, which options are the best, and to better understand an exciting new clean energy solution.
