Pumps for the Hydrogen Production Industry

Michael Smith Engineers Ltd have been involved in green hydrogen generation applications for almost two decades. We have worked with many of the most innovative companies in this sector and worked with them as they developed into industry leaders.

Pumps for Alkaline Water Electrolysis for Hydrogen Generation production

In alkaline water electrolysis (AWE), the electrolyte is a strong solution of potassium (KOH) and/or sodium hydroxide (NaOH) Care is needed in selecting a suitable pump for the KOH or NaOH solution feed. It’s important to note that 316 stainless steel can stress-crack with high concentrations of KOH at temperatures above 65°C. In lower KOH concentrations, there is less chance of this, and stainless steel construction may be used.

The alkaline water electrolysis process usually requires temperatures up to 80°C and can often require high pressures up to 40 bar. For KOH supply and circulation on small demonstration units or R&D rigs, low-flow pumps such as Wanner Hydra-Cell pumps are ideal. For larger systems requiring higher flows, centrifugal pump units such as the Dickow NMB series may be suitable.

Wanner International  The Wanner Hydra-Cell pumps offer huge benefits for KOH and/or NaOH transfer and circulation.
Dickow Pumpen Dickow pumps are recognised world leaders in the field of high quality process pumps. For the high flow rates of KOH/NaOH electrolyte solutions required in larger green hydrogen production systems, a Dickow NMB series mag-drive centrifugal pump may be the best solution as it can tolerate system pressure of up to 40 bar.

 

Pumps for Proton Exchange Membrane Electrolysers for Green Hydrogen Production

In a Proton Exchange Membrane (PEM) electrolyser, the membrane is a solid polymer electrolyte that is extremely sensitive to any contamination. To deliver the deionised water feed, PEM electrolysers utilise non-metallic or electropolished pumps. This is to avoid any damage that could be caused to membranes by corrosion of pump casings or components.

Centrifugal pumps are generally suitable for the medium-high flow requirements with modest differential pressures. If the application demands non-metallic wetted materials, solutions such as the Finish Thompson seal-less mag-drive centrifugal DB Series and UC Series pumps are ideal. In applications where stainless steel wetted parts are acceptable, the Finish Thompson AC Series is suitable, or any of Dickow’s centrifugal pump range. SAWA pumps also offer electropolished centrifugal pumps for the hydrogen market.

Larger PEM systems also need a recirculating cooling system employing water or glycol at varying concentrations. These duties can be handled by metallic or non-metallic centrifugal pumps.

The Finish Thompson DB series leak-free magnetically coupled centrifugal pumps are an ideal choice for pumping deionised water for hydrogen generation. Typically supplied in polypropylene that is chemically resistant and will not leach chemicals into the deionised water. A feature that is essential for the proper operation of PEM electrolysers.
In arduous applications where a plastic pump is not suitable, the ultra durable UltraCHEM (UC) series from Finish Thompson Inc. is a good option. The UC pumps have a tough ductile iron construction, but are EFTE lined for chemical resistance and will not leach chemicals and contaminate the deionised water.
The Finish Thompson AC series stainless steel pumps are compact, easy to operate and economically priced. The range consists of 4 models available in horizontal or vertical configurations with a maximum flow rate of 58 m³/hr and a maximum differential head to 53 m. AC pumps are suitable for transferring fluids with a viscosity range of 0.2 - 200 cP, for example water (including RO, DI, waste) and cooling solutions.
For large scale hydrogen production applications where durability and reliability is paramount, pumps from Dickow Pumpen's from extensive range should always be considered. Dickow Pumpen offer a range of metallic single stage and multi-stage centrifugal pumps, side channel pumps and peripheral pumps that is second to none.
SAWA Pumpen are best known for food & drink pumps and pumps for the pharmacutical sector. However, their centrifugal magnetically driven stainless steel pumps have many potential applications within the green hydrogen production sector.