High-pressure ATEX multistage pump for green hydrogen energy plant

The most popular types of renewable energy include solar, wind, hydro, tidal, geothermal and biomass. These are in abundant supply and usage is on the increase. However, dirty sources of power, such as fossil fuels (gas, oil and coal) and nuclear energy, still account for the largest proportion and it will take many years for them to become obsolete.

Hydrogen types, production & energy density

A new source of power that is increasing in popularity is
hydrogen, which is the most abundant element on Earth. It is an energy carrier that does not normally exist naturally, it must be produced from other materials. There are no harmful emissions from hydrogen once used; however, it is the process of producing it that determines if it is considered to be a clean energy or not. There are many uses for hydrogen, including fuel cells, vehicle engines, powering commercial buildings and even spacecraft propulsion – making
it a very exciting alternative source of power.

It has a far higher energy density than any other fuel currently used, meaning far less is required to generate large amounts of energy. 

The main types of hydrogen are blue hydrogen, grey hydrogen, and green hydrogen. Blue and grey hydrogen are the most common and involve splitting hydrogen from fossil fuels, mainly natural gas. This is achieved by either steam methane reforming (SMR) or auto thermal reforming (ATR);
both methods produce carbon dioxide (CO2) as a by-product, which is harmful to the environment. The CO2 is released into the atmosphere during the production of grey hydrogen, whereas it is captured and stored during the production of blue hydrogen – making it a cleaner and safer option.

The most promising and cleanest is green hydrogen. This is produced by splitting the hydrogen from water by electrolysis. The only components produced are hydrogen and oxygen; there are
no harmful emissions or by-products. In addition to this, to be classed as green, the electricity used to power the equipment during production must be derived from renewable sources, such as wind or solar. This makes the entire production and end use zero emission and carbon free. Due to the potential use, abundant supply and clean nature of green hydrogen, it is likely to become one of the main sources of energy in years to come...

Read the full article in DPA's November issue