Hydrogen and heat transfer, an inseparable combination
We assume that you share our conviction that green hydrogen will play a significant role in the energy transition. Developments in the field of hydrogen are rapid, with the number of installations and electrolysers increasing rapidly worldwide. But the processes are not yet fully defined. Understandably so! People all over the world are looking for the optimum configuration to produce hydrogen as sustainably and efficiently as possible. In the field of heat transfer, Kapp knows the way; we have a suitable heat exchanger for every step in the production of hydrogen. This real edge benefits our customers. That said, knowledge and experience of other experts in the hydrogen sector are essential for us. Our approach in this market is therefore: “Here to teach, here to learn”. A philosophy that stems from the realisation that time passes quickly and that we can accelerate developments, especially together with other experts from the sector.
Our approach in this market is therefore: “Here to teach, here to learn”.JEROEN VAN RUITENBEEK – MANAGER NEW ENERGIES
WHAT WE PROMISE
Lower CAPEX and OPEX
With the cry for renewable energy come big challenges. Green hydrogen is a great development, but many processes require optimisation. The right technology is as sustainable and efficient as possible. In the field of heat transfer, we have the answers. And we promise lower CAPEX and OPEX.
Compact, safe, and efficient solutions
Kapp is well-versed in the risks and challenges involved in every stage of hydrogen production. The appropriate heat exchanger should be compact to allow ample space for other components, capable of withstanding the media, temperatures, and pressures involved to ensure safety, and highly efficient to minimize energy loss.
Best solution guaranteed
Due to our belief that hydrogen has immense potential to become the sustainable energy source of the future, particularly for industrial applications, we have extensively researched the hydrogen production process for a considerable time. Consequently, we possess the expertise to significantly enhance our clients’ processes and projects. During the offer phase, we devote considerable effort to scrutinizing your parameters, process, and installation. This ensures that we always propose the most optimal solution, providing you with a guarantee of our commitment to excellence.
We meet the strictest requirements
For more than 25 years, Kapp has been meeting the most rigorous standards and requirements while being well-versed in the critical factors that are prevalent in the industry. All our products adhere to the quality requirements and standards that are pertinent to the industry, such as PED, ASME VIII, EN13445, AD2000, API660, API661, API662, TEMA, ISO 9001, and ISO 14001.
This is how we can improve your hydrogen process
Sustainable generated electricity is a prerequisite for producing green hydrogen. Keeping this fundamental aspect in mind, we tackle every challenge that arises during the hydrogen production process. Heat exchangers play a crucial role in each step of this process. With our extensive experience and expertise, we are well-versed in the associated challenges and have the most suitable heat exchangers for every step. Furthermore, we possess a unique advantage in compression and purification sub-processes, with our highly compact heat exchangers. If you require further information, we would be delighted to provide it.
The process of electrolysis involves immersing two electrodes in water and connecting them to a direct current source. Oxygen is produced at the anode while hydrogen is produced at the cathode by splitting water. To maintain the process’s efficiency, it is essential to maintain a constant temperature. Following electrolysis, the hydrogen and oxygen generated are cooled and the electrolyte is recondensed. The waste heat produced during these processes can be utilized in other applications.
Significant improvements in process efficiency will be essential to make green hydrogen a viable alternative in the coming years. Another challenge is the need for almost daily start-up of processes particularly during periods of limited availability of renewable electricity. However, this often results in residual heat that we aspire to effectively utilize, such as for district heating or in other processes. Safety is also a crucial factor to consider since hydrogen and oxygen flows both entail inherent risks.
For electrolyte cooling, a Plate & Frame heat exchanger with stainless steel (PEM) or nickel plates (Alkaline) is a perfect fit. We also observe developments in which electrolyzers operate at higher pressures, such as in the cooling of KOH in an alkaline electrolysis process, with pressures ranging from 30-50 barg. In this case, a Plate & Shell heat exchanger with nickel plates is the optimal choice. Our engineers, with their extensive experience in similar projects, are skilled at striking the right balance between CAPEX and OPEX. Feel free to ask for references to verify our expertise.Electric heaters can be used during start-up and heating of the medium and serve as frost protection during shutdowns. For cooling hydrogen and oxygen streams and recondensing and recovering heat from electrolyte, semi-welded (LWC) plate exchangers or fully welded heat exchangers are a perfect fit.
During the production of green hydrogen, approximately 30-50% of the electrical energy is converted into heat, with a significant portion being generated by the electrolyser. Additionally, heat is produced during compression, deoxidation, and drying processes. Given the sustainable aspirations of the hydrogen sector, we strongly believe in the importance of effectively utilizing this heat.
While residual heat can be utilized in various ways within the hydrogen production process, such as for district heating, there are instances during warmer months when heat demand is lower, and excess low-grade heat must be cooled off. In choosing a suitable heat exchanger, it is crucial to consider local constraints such as space limitations, permissible noise levels, and the availability and quality of cooling water.
Many offshore hydrogen production sites are planned on new or existing production platforms and use existing infrastructure (pipelines), fed by renewable generated electricity from offshore wind farms. Cooling is especially challenging here because allowed weight and dimensions of components are very limited.
In Kapp’s philosophy (and according to the ‘trias energetica’), waste heat should be reused. We have extensive experience with waste heat projects and therefore always have a suitable heat exchanger in our scope. If the heat demand is low, superfluous heat can still be cooled down. Cooling can be done with air, water, or a hybrid solution. For offshore installations, (titanium) plate heat exchangers or special offshore air coolers are very suitable, especially because of their compactness.
Making hydrogen suitable for storage and transport requires compression, from around 2 bar (alkaline) or 20-40 bar (PEM) to 30-100 bar. We often see this process step combined with deoxidisation and purification of the hydrogen. After compression, condensation takes place, during which a lot of water is already extracted from the hydrogen. The whole process again releases a lot of heat, which we do not want to lose.
Hydrogen is the smallest molecule. Leakage is therefore a major risk with concentrated hydrogen. The consequence of a leak can be disastrous because hydrogen is extremely flammable. Another challenge is the extremely low density of hydrogen, giving it a huge volume at low pressure. Due to electrolysis and deoxidation, the hydrogen contains a lot of water, which is condensed out after compression. This process constitutes a large part of the thermal load.
In these processes, you are dealing with start-ups of the installation on a regular base. This involves large temperature changes, a slight approach (especially with heat recovery) and, in the case of condensation, high capacities, so a lot of heat exchange surface is required.
Fully welded plate heat exchangers are well suited for hydrogen compression because they combine the compactness of a plate heat exchanger with the strength of a shell & tube heat exchanger. Our fully welded and gasket-free heat exchanger is also suitable for daily start-up. For offshore application, where cooling is typically done with seawater, we supply titanium plate heat exchangers.
Once the hydrogen comes out of the electrolyser, it must be made suitable for, for instance, fuel cells. The hydrogen is purified to around 99.99% by separating out the water and oxygen. The first step takes place in the deoxidiser: the deoxidiser contains a catalyst that reacts the little oxygen that comes with the hydrogen into water. After the deoxidiser, the hydrogen is dried, using PSA (pressure swing absorption) or TSA (temperature swing absorption).
At the start of the purification process, there is no residual heat available, so a heat input is needed to preheat the deoxidiser. In the step after, the drying process, we cool, condense and regenerate. The compressed hydrogen has a high pressure and therefore has the same risks as in the compression step.
For preheating and start-up of the deoxidiser, an electrical heater offers a solution, and this is also the ideal technique for regenerating. As pressures here are still very high due to compression, a fully welded plate heat exchanger remains a requirement for this step.
For transport, storage and filling tanks, the hydrogen will be compressed even further. In doing so, we are dealing with extremely high pressures, in some cases even > 700 bar. If tanks must be filled, this is done at low temperature and further cooling is required. After this, the hydrogen is suitable for use in industry, utilities, homes, and transport, among others.
Hydrogen weighs little and is a highly flammable gas. The pressures in this step are extremely high, so the risk also increases exponentially with it. Safety is always paramount. As with any other gas, it is important to handle it with care during production, transport, and use. If hydrogen is used in existing gas pipelines, it is important to further investigate the ‘behaviour’ of hydrogen in practice. This is because hydrogen is lighter than natural gas and can escape more easily at valves and valves. When filling tanks, the number of cycles is also very high. If the wrong material is chosen, material fatigue can occur, with all the risks that this entails. Components in the entire installation must therefore withstand regularly changing temperatures and pressures.
For applications up to about 100 bar (depending on the temperatures), a plate & shell heat exchanger is very suitable, but when pressures get even higher, this technology is no longer adequate. For those extremely high pressures, we have a printed circuit heat exchanger in our range. This type of heat exchanger is extremely strong due to the combination of two technologies: chemical etching and diffusion welding. The flow channels are chemically etched onto a metal plate. Etched plates are stacked and formed into a single block by diffusion welding.
WHERE WE ARE UNIQUE
Perfect fit for the hydrogen process
Hydrogen is the smallest molecule. In hydrogen production, it carries risks. In a number of processes in hydrogen production, pressures are high, and leakage can be disastrous; hydrogen and oxygen flows are explosive. In such critical processes, the right equipment is vital, even literally. For hydrogen processes, large, traditional tubular heat exchangers are still often considered because of their robustness. Sometimes this is a fine solution, but even more often other techniques are better suited. And there are plenty of examples where our all-welded plate heat exchanger is practically the only suitable solution. We see cases where our solutions weigh 70% less, cost 50% less, recover more heat and are at least as robust as the traditional tubular heat exchanger. For various processes in hydrogen production, a Plate & Shell heat exchanger is the perfect, and in some cases the only suitable, technology. A Plate and Shell heat exchanger is:
- Very compact – so a smaller plot size, less civil-work, insulation, piping, etc.
- Suitable for high pressures.
- Fully welded and therefore safe for hydrogen application and guaranteed leakproof.
- More profitable thanks to lower CAPEX and OPEX
Let’s discuss hydrogen and heat transfer!
Would you like to know more about heat transfer? Want to talk or need help making decisions regarding your hydrogen process? Make sure you get in touch with Jeroen.