What’s the role of flow control in producing hydrogen?

March 3, 2021 Arjan Bikkel

Hydrogen has become a hot topic recently. Besides application in the traditional industry, we see more and more applications in the sustainable energy sector. Flow meters play an important role in producing hydrogen, as reliable and precise flow measurements are essential to the process. For many years now, we have been supplying flow meters to HyGear in Arnhem (NL), which they use in their steam reforming units.

We talked to Ellart de Wit, CTO of HyGear, to find out more about this interesting market, the steam methane reforming units they develop and the role that our flow meters play in this process.

HyGear steam methane reforming unit with flow meters

What does HyGear actually do with hydrogen?

‘HyGear is essentially a company that builds chemical installations, with the focus on hydrogen. That’s how we started out in 2002. At that time, hydrogen was seen as a highly promising option for car fuel, and we took advantage of this idea. Hydrogen has many positive properties, but transporting it can be tricky. After all, the gas is very light, and you can’t liquefy it under pressure.

So, the challenge is to limit transport as much as possible. This can be done by producing the gas locally as much as possible. In the early years, we did this by supplying turnkey systems to our customers, so they could produce hydrogen themselves. More recently, we have been positioning ourselves more as a true gas supplier, which means that customers buy hydrogen per kilogramme on a gas-as-service basis, accompanied by the entire service package.’

More about Hygear

Do you also supply hydrogen for sustainable energy applications?

‘The majority of our customers are operating in the traditional industry sector:

  • Flat glass manufacturers and metal companies who use hydrogen mainly as a shielding gas in processes where oxygen must be eliminated. 
  • The food industry uses hydrogen in the hydrogenation or “hardening” of oil to create fats. 
  • Hydrogen vehicles are now on the rise as a customer group, but this is still relatively new.
In all these cases, the hydrogen must be very clean, without any impurities.’

Hydrogen Fuel Cell explained

‘We’re seeing an increasing demand for hydrogen in various areas. Traditional industry, for example, requires ever more high-quality hydrogen. In addition, there’s a growing number of sustainable energy solutions involving hydrogen, such as powering fuel cells for cars.’

‘Hydrogen is also increasingly being used in new areas, in inland areas, for instance, far from the coast and hence far from chemical clusters where hydrogen is released as a residual product.’

The service provided by Bronkhorst is outstanding! -  Ellart de Wit, CTO HyGear

And what’s the situation with hydrogen cars?

‘At the moment, we still see several challenges when it comes to powering hydrogen cars. Industrial processes have a fairly regular and even gas consumption, but powering vehicles is trickier. This involves very high pressures and flow rates in a short period, especially at the start, after which it slows down more and more. The quantity of hydrogen filled in the tank needs to be constantly and precisely monitored, so that the customer pays the right price at the fuel pump.’

Hydrogen Car

What are steam methane reforming units?

‘One of HyGear’s solutions for producing hydrogen locally is by means of steam methane reforming units that can be moved from location to location. In steam methane reforming, methane (derived from natural gas) reacts at high pressure and temperature with steam to form a mix of mainly hydrogen and carbon dioxide. This is used to make the required hydrogen by means of pressure swing adsorption (PSA). The good thing about this form of local hydrogen production is that there are natural gas pipelines all over the world – meaning it’s cheap to transport this raw material. You can choose to use natural gas, biogas or green gas, with or without CO2 capture. So the customers themselves can decide whether they want grey, blue or green hydrogen.

  HyGear HyGEN process flow
HyGear 'HyGEN' process flow

The outstanding feature of these steam methane reforming units is that all the required modules for the cracking installation, the steam forming and the purification steps are integrated and can continue to function without external intervention. This applies when starting them up and also when keeping them running.

The system doesn’t need an operator, is fully self-managing and can switch quickly. It works just like a tube trailer with hydrogen cylinders, where all you need to do is open the tap to supply hydrogen. In a fast-changing world with ever shorter supply contracts, a relocatable stationary system provides the right degree of flexibility.

Flow meters for reliable and precise measurements

‘Ever since we began developing these units, we have been using flow meters from Bronkhorst. These flow meters are used at two points in the process. When we let methane react with steam, we need to know how much we are adding. We use Bronkhorst thermal mass flow controllers for methane, with a flow range of 500 litres of methane per minute. We handle things differently with steam. At the outlet of the system, we measure the hydrogen output quantity, for which we use Bronkhorst thermal mass flow meters with a flow range of 90 to 250 Nm3 hydrogen per hour. Since the system is installed locally – and possibly in a very remote location – it’s important that the flow meters and flow controllers are reliable. We need to be able to rely on the measured value. When it comes to measurement, it’s important to be reliable as well as precise, because the customer ultimately has to pay the bill based on the quantity of supplied hydrogen.’

Bronkhorst supplies the flow ranges we need with a high level of reliability. -  Ellart de Wit, CTO HyGear

Bronkhorst flow meters for hydrogen applications

Bronkhorst regularly supplies flow meters and vapour generation systems for a range of processes in the hydrogen sector. These include flow solutions for humidification of fuel cells, leak testing of fuel cell stacks, power-to-gas application, hydrogen storage in metal hydride and hydrogen storage with liquid organic hydrogen carriers (LOHC).

Our thermal mass flow meters and CEM vapour generation systems are used widely in all these areas.

Hydrogen applications with Bronkhorst flow meters
Hydrogen applications where Bronkhorst flow meters can be used

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