HydITEx - Colors of H2

Colors of hydrogen

colors of hydrogen

Types of Hydrogen Production Classified by "Color" Labels

Hydrogen production is classified using "color" labels to indicate the method of its creation and the associated environmental impact. It is crucial to understand that the color refers to the production process, not the hydrogen molecule itself. Here are types of hydrogen production, grouped by method.

How many types of hydrogen are produced currently, and what are the differences?

The term “produce” isn’t really right for hydrogen. Hydrogen is the most plentiful element in the universe (by far). You cannot really make hydrogen, only collect it from the environment (and separate it from compounds it may have formed).

It's important to note that the "color" classifications of hydrogen are a way to distinguish production methods and their associated environmental footprints, and the spectrum of colors is continually evolving as new technologies emerge.

The color label assigned to it relates to how the hydrogen is sourced or created and if the production process itself results in lesser carbon emissions than conventional methods of generating the gas.

Thresholds, Labels (Colors) are defined by public policies or by the market.

ISO/TS 19870:2023 is NOT defining what is acceptable in a given jurisdiction for the purpose of a specific public policy!

Hydrogen from Renewable and Low-Emission Sources

Green Hydrogen: Produced through the electrolysis of water using 100% renewable energy sources, such as solar or wind. This is the most environmentally friendly option.

Ultra-Green Hydrogen: This type is derived from biomass using renewable energy, and the process results in a net-negative carbon footprint.

Yellow hydrogen: Produced by the electrolysis of water using mixed-origin electricity, such as power purchased from an exchange, where a portion may not be renewable.

Pink Hydrogen/Purple Hydrogen/Red Hydrogen: Produced using the energy from nuclear reactors. Pink Hydrogen is made through electrolysis, Purple Hydrogen uses the reactor's high temperatures for steam reforming, and Red Hydrogen uses thermochemical processes.

Hydrogen Using Fossil Fuels with Carbon Capture

Blue Hydrogen: Produced through Steam Methane Reforming (SMR) of natural gas, with the application of Carbon Capture, Utilization, and Storage (CCUS) technologies, which significantly reduces emissions.

Turquoise hydrogen: Created through Methane Pyrolysis, which splits natural gas into hydrogen and solid carbon. This process is considered low-carbon because it does not release CO2 gas into the atmosphere.

Light-Blue Hydrogen: Obtained in situ (in the reservoir) from petroleum reservoirs using catalytic gasification.

Hydrogen with High Emissions

Grey Hydrogen: The most common type globally, produced by Steam Methane Reforming (SMR) of natural gas without CCUS. This process is associated with significant CO2 emissions.

Black Hydrogen: Produced by the gasification of black (bituminous) coal or oil. This is one of the least environmentally friendly production methods.

Brown hydrogen:: Created by the gasification of brown coal (lignite) or biomass without carbon capture.