We can assist you with correct water treatment regardless of electrolyzer technology you use:
Our standard units cover all water treatment steps from raw water to ultrapure water.
The water source and the electrolyzer technology determine the choice of water treatment being used for green hydrogen production. Depending on your location and size of project you may have different water sources available and each will come with different requirements for your water treatment system. We help you choose the right water treatment solution based on your raw water and electrolyzer technology.
Ultrapure water is the central feedstock for production of green hydrogen. Furthermore cooling water may be required in the process and system.
But how much water does it take to produce green hydrogen? In the table we give you a rule of thumb.
9 L ultrapure water per kg H2
1 Nm3/h H2 = 1 L/h ultrapure water
1 MW electrolyser = 200 L/h ultrapure water
1 MW electrolyser = 400 L/h cooling water*
*Cooled using standard evaporative cooling tower
We offer a broad selection of standard units - from groundwater treatment to polishing of ultrapure water. All units are supplied with documentation and instructions.
How much water do I need for my electrolysis process?add
The amount varies depending on the efficiency of your electrolyser, but a good rule of thumb is around 200 L/h per MW electrolysis capacity. This does not include water for cooling.
How much hydrogen can I produce from my water?add
Water contains two atoms of hydrogen and one oxygen atom. Because oxygen is 16 times heavier than hydrogen, it takes up most of the mass in a water molecule. 89% of the mass is oxygen and 11% is hydrogen. This means that to produce 1 kg of hydrogen, 9 kg of water are required. In reality, 10-13 kg of water are required due to losses and inefficiencies.
What quality of water do I need for my electrolysis process?add
The quality depends on the type of electrolysis equipment you use, alkaline or PEM, and from which manufacturer the equipment is supplied. From a conductivity perspective, values can vary from 0.056-5 µS/cm, but many constituents affect the electrolysis process depending on the specific technology used.
What is ASTM water quality?add
ASTM Type I, II, II and IV are a set of international standards for water quality often used to describe water quality requirements for electrolysers. They cover conductivity/resistivity, sodium, chloride, TOC and silica, but in reality, they are often insufficient to properly describe the water quality needs for electrolysers.
Where do I need water treatment?add
Both PEM and alkaline electrolysis requires make-up water treatment. PEM also requires continuous polishing of the water once it has entered the electrolysis cell.
Should I use EDI or mixed bed in my polishers?add
Whether to use EDI or mixed bed depends on whether you need it for make-up water polishing or internal polishing. Also, EDI tends to have higher CAPEX, but allows you to avoid regeneration of spent resins.
Which resin should I use for polishing water for electrolysis?add
The choice of resin is very important to ensure a stable electrolysis process. Use of the wrong type of resin can lead to irreversible damage to your electrolysis stack.
Can I use seawater or treated wastewater as feed water for electrolysis?add
Yes. Each source of water requires special attention to specific constituents in the water and you need to take variations in the inlet water quality into account. In general, we can say that wastewater requires special attention to nutrients and microorganisms that can cause biofouling, as well as the load of organics, while seawater requires focus on high retention of ions.
How does water quality affect lifetime of electrolysers?add
The lifetime stated by electrolyser manufacturers is completely dependent on compliance with water quality requirements. Even small amounts of unwanted ions and molecules in the water can cause irreversible damage to the electrolysers.
How do I achieve the required water quality for electrolysis?add
Typically, we need first to bring the raw water to a state similar to drinking water quality. From here the water most be conditioned to avoid scaling, after which a RO process is used to remove the bulk of the ions, organics, and colloids. A targeted process is also required to remove dissolved gasses. Finally, a polishing step can be implemented depending on the specific needs of the electrolyser.
What size of projects can Eurowater cover?add
Our equipment covers the range from small 1-10 MW installations to large scale GW installations.