Grey, green or blue? What type of hydrogen is best for the environment?

The silver bullet of the energy sector is a fuel that offers zero emissions and reduces our impact on the environment. As the Royal Institute lectures noted in 2020, before humanity, the carbon in the atmosphere was 280 parts per million. Today, this stands at 415 parts per million, resulting in a temperature change of between 1.1 and 1.2 degrees. As a consequence, the climate is changing and governments are seeking solutions – especially when we can make connections between these emissions and the wildfires in Australia, for instance.

There are many that wonder why industry hasn’t looked to hydrogen more seriously. It is a fuel, when burned, that leaves nothing behind but water. There is no carbon emission, no noxious particles and no pollution.

There is a catch.

To be used as fuel, hydrogen must first be produced and this takes energy. The manufacture of hydrogen requires natural gas, coal, or biomass – and these create those unwanted emissions. There are more environmentally friendly approaches using electricity to split water, but it is expensive.

Here we explore grey, green and blue hydrogen, and which might offer a solution to the fuel issues of the future.

Grey Hydrogen

Grey hydrogen is perceived to be an improvement on brown hydrogen, which uses fossil fuels such as coal as a production method. Grey hydrogen instead uses natural gas as the feedstock and is produced through steam methane reformation (SMR). Yet, although this approach reduces the levels of methane emitted, it is not carbon-friendly and would not be the route to zero emissions.

Blue Hydrogen

Blue hydrogen is produced with natural gas but uses carbon capture and storage solutions. It is also created using steam methane reforming (SMR), but with mitigating strategies to increase the environmental credentials of the fuel.

Blue hydrogen is considered to be more environmentally friendly than grey hydrogen. However, the SMR process is not emission-free and would continue to pose energy companies issues into the future if they wanted to reduce emissions to zero. Some experts question whether this is a blind alley and companies and countries should be going further.

Yet, on the other hand, blue hydrogen is considered a step in the right direction even if it is not the ultimate solution. It is a way that Oil and Gas companies can transition to the fuels of the future, while the technologies for more environmentally friendly solutions are innovated.

Green Hydrogen

Green hydrogen allows you to marry the electrical production of renewable energies such as wind and solar, and the use of water electrolysers to separate the oxygen and hydrogen.

Renewable energy is problematic because the energy provided is inconsistent. Therefore, we need to find a way to store this energy. Storing it as hydrogen could be the answer if issues of combustibility can be resolved. One way to do this is to store hydrogen as a solid rather than a gas or liquid.

However, these current production methods are considered prohibitively expensive, which is why it is as yet not seen as the optimal solution. Future cheaper technological processes are being innovated that will capture the entire output range from the renewable energy source – even when intermittent.

In short, the expense of the water electrolysers is one problem requiring a solution. Companies are also exploring transportation, storage, as well as the use of fuel in practice.

The use of electricity from renewable sources to produce hydrogen fuel that, when burned, only produces water, is the only valid zero-emission alternative. Many experts predict that both blue and green hydrogen could be used to aid Oil and Gas companies in a quest to become zero carbon by 2050.

Ex~i Flow Measurement specialises in the manufacture of flow computers, which are compatible with the use of hydrogen. Contact us today to learn more about how we can help you reduce your environmental impact.