The transition from conventional fossil-based energy supply to a sustainable gas economy is picking up pace, and technology suppliers are having to adapt to a rapidly changing energy environment.

Membrane specialist Evonik has committed to making this green revolution a reality by placing hydrogen front and centre of its long-term vision for a low carbon future. 

Considered one of the main cornerstones of decarbonisation, hydrogen still finds itself hampered by its association with steam methane reforming (SMR), a technique that produces so-called ‘grey’ hydrogen. 

One of the myriad colours of the hydrogen rainbow, grey hydrogen is produced through heat, pressure, and catalysts associated with fossil sources such as natural gas and – according to the International Energy Agency (IEA) – generates about 830m tonnes of CO2 emissions worldwide per year. 

Despite being one of the least sustainable methods of hydrogen production, SMR is responsible for more than 95% of the worldwide demand for hydrogen, but its time may be running out. 

Dr. Oliver Busch, Vice President Defossilation at Evonik, stated that industry needs to make the shift from grey hydrogen to clean ‘green’ hydrogen. 

“When we look at the chemical industry today for example in Germany the community industry needs more than one million tonnes of hydrogen every year,” said Busch.

“We have to transfer this from grey into green hydrogen to reduce the associated CO2 emissions.”

He added that, if the industry wants to fulfil all its energy needs of the future, it will need ‘much more’ than 1m tonnes per year. 

Source: Evonik

Green hydrogen and membranes 

Aside from SMR, hydrogen can be formed through a method called electrolysis. This involves a voltage being applied between two electrodes, which splits water into its constituent components of oxygen and hydrogen. 

Fuel cell technology utilises this concept, but in reverse. By combining hydrogen and oxygen, a reaction occurs that forms water and generates an electrical current. 

According to the International Energy Agency (IEA), green hydrogen makes up less than 0.1% of worldwide hydrogen production. Despite this, demand for hydrogen fuel cell technology has been increasing in recent years, with the IEA’s database registering more than 300 hydrogen projects since 2000.

To advance green hydrogen production, Evonik is developing an anion-conducting membrane that utilises anion exchange membrane (AEM) water electrolysis. 

By eliminating the need for expensive materials and metals for the cells, Evonik promises that this process will lower investment costs. 

“Evonik’s strategic focus is on so called next generation solutions with a strong positive environmental impact,” commented Janusz Berger, Head of Market Communications - Innovation Growth Fields High Performance Polymers at Evonik, who spoke to gasworld about the company’s drive towards a green hydrogen-rich future. 

“New product developments like our DURAION membrane for cost-efficient green hydrogen production are part of the whole movement.” 

Storage and transport 

Because true green hydrogen relies on renewable energy-generated electrolysis – and renewable energies are not entirely ubiquitous - to ensure that the clean fuel gets to where it needs to be, a suitable pipeline infrastructure needs to be put in place. 

To enable green hydrogen production, projects such as GET H2 Nukleus – Germany’s first publicly accessible hydrogen network – utilises Evonik’s polyamide 12, a high-performance material used in flexible pipelines which can be used for green hydrogen transportation. 

Another solution developed by Evonik and Linde uses pressure swing adsorption (PSA) technology and Evonik’s hollow-fibre membrane technology to deliver 99.9999% pure hydrogen. 

In addition to green hydrogen, Evonik has developed another alternative energy solution with its SEPURAN Green membranes. 

Source: Evonik

Having been used for biogas upgrading in one of Germany’s largest biogas plants, the technology enables the production of around 9,000 tonnes of biomethane per year.

”Evonik‘s gas separation membranes business aim to drive the transition towards sustainable gas economy based on green hydrogen and biomethane,” added Berger.

”We are strongly commited to move forward the energy transition!”