Hydrogen in the evolving energy market

With the inexorable rate of carbon emissions over the last two centuries, global warming has become an existential threat that demands action. The Paris Agreement set targets to stabilise the world temperature increase to below 2°C, but these aims require dramatic shifts in how we produce and source energy.

There is no panacea solution to this problem, but hydrogen has the potential to be a key initiative on the path to net zero. Hydrogen is multifaceted and used in various industrial processes, from chemical and steel production to transportation. The emissions produced by petrol and diesel are significant pollutants, while hydrogen only emits water and warm air.

The scaling up of hydrogen is increasingly becoming central for governments and industry energy policies. The security given by multiple energy sources also allows governments more freedom in case one source becomes unavailable for geopolitical or other reasons.

The hydrogen industry

Companies need to decarbonise to reduce their emissions and use low-carbon power sources to positively impact efficiency in industrial and domestic applications and global emission reduction. Using hydrogen and renewable energy is one of these approaches, alongside carbon capture and storage. All these efforts combine to have a substantive action on the necessary decarbonisation of the world. 

Currently, most hydrogen is produced by steam methane reforming (SMR). Without carbon capture, and storage (CCS), it is the least environmentally desirable option, known as “grey hydrogen”. When carbon emissions from this process are captured and stored (often underground), the resulting hydrogen is known as “blue hydrogen” and has a reduced environmental impact. 

An alternative process utilises electrolysis to produce hydrogen, where an electric current is passed through water to split it into oxygen and hydrogen. When the electricity is generated from renewable sources, it is called “green hydrogen” and, from nuclear power, “pink hydrogen”.

The production of green hydrogen is increasing rapidly, but not enough is currently being produced to satisfy demand. In the short term, the transition from grey to blue hydrogen can be considered technically and financially more accessible as it can use existing infrastructure. In 2021, governments and businesses began working together to promote the use of hydrogen, preferably green. 

Hydrogen is transported in compressed or liquid form using pipelines, rail or road. At its point of use, it can also be converted to ammonia and cracked (split back into hydrogen and nitrogen). The use of hydrogen to power long-haul transportation like trucks and lorries is likely to be a growth area.

Danny Nicholas, Business Development Manager, Hydrogen Equipment Global at Rotork, explains: “There is an argument that we should not simply be thinking in terms of colours of hydrogen production but in terms of the overall carbon footprint of each production method. For example, blue hydrogen might be a bigger pull in the short term because of the existing infrastructure assets. Green hydrogen, conversely, is in the process of scaling up, and we are not yet in a position where there is enough green hydrogen to cover our needs. We need to balance different ways of producing hydrogen, and this balance is something the industry is still working out."

Challenges

Danny Nicholas continues: “The two main challenges I currently see, are the issues of scaling up production of green hydrogen equipment and making the wider production/use of hydrogen cost-effective. The number of green hydrogen manufacturers is still relatively low and scaling up must be done cost-effectively (both in terms of investment in production and the final product price).”

Government grants and subsidies can accelerate adoption, which may offset the higher cost of production of grey and blue hydrogen. Valve and actuator suppliers must provide reliable, durable and accurate equipment for flow control within the production process. Rotork has extensive experience in the renewable energy sector and is now involved in the supply of process control equipment throughout the whole green hydrogen value chain.  

Hydrogen is an explosive and flammable substance, so explosionproof products (with approvals such as ATEX, CSA, and IECEx) must be used in its production, distribution, delivery and usage. As hydrogen is colourless, odourless and tasteless, leaks are hard to detect without accurate control and instrumentation.

Hydrogen transport is a challenge, with any risk of explosion or leakage affecting the public. Precise product flow and fail-safe operation are essential in converting hydrogen to/from its transport medium.

Importance of flow control

Correctly specified flow control equipment can provide a safe working environment, increase process efficiency (by moving quickly and precisely to a set position), reduce emissions, minimise maintenance, increase equipment lifetime and increase operators’ profitability. Hydrogen plants require emergency shutdown (ESD) procedures for control and safety needs.  

Rotork provides critical flow control solutions to hydrogen equipment and valve manufacturers throughout the complete hydrogen supply chain, from water flow into electrolysis skids to the flow of hydrogen to transport. Flow control products include electric, hydraulic, and pneumatic actuators and essential instrumentation such as solenoid valves, switch boxes, needle and ball valves, pressure regulators and filter regulators.

Rotork CVL process control electric actuators were installed on green hydrogen electrolysis skids for a French equipment manufacturer, where they play a critical role in the process control of the feedstock to the electrolyser. 

Each electrolysis skid has multiple CVL actuators which regulate the pressure and level of the water at the heart of the process. Hydrogen production through electrolysis requires precise control; any actuator installed would need to provide accurate control, a fail-safe action and a high-duty cycle. The CVL-500 actuators were chosen for their high movement frequency, quick reactivity, and ATEX IIC certification.

Conclusion

Green hydrogen has probably the greatest potential as a clean fuel to support the desperately needed global energy transition. However, this sits more on a medium-long-term timeline, and it’s evident that we must also consider other mechanisms to speed up this transition for many reasons. This includes the potential for blue, pink and other possible methods of producing low-carbon hydrogen for industry and all other emerging sectors. In each case, high-performing, critical flow control systems are required to provide safe operation, whilst allowing the equipment manufacturer to standardise, simplify and scale up their technology cost-effectively. This in turn will allow green and other low-carbon hydrogen to be produced cost-competitively in the market and will be the key to success.