[ water treatment ]
5 x 100 m 3 / h EDI system by Pure Water Group
Electrodeionization processes for ultrapure water production in green hydrogen generation
It is well documented that all electrolysers require ultrapure water ( UPW ) as a feedstock for hydrogen production . Nine litres of water are required to produce 1 kg of hydrogen , and approximately 200 litres per hour of UPW are required per MW of electrolyser capacity . The importance of UPW is to ensure the efficiency and longevity of the electrolyser through the prevention of fouling or scaling . Electrodeionization ( EDI ) is an electrochemical membrane process that may be used as part of the UPW preparation . This article aims to explain the EDI process and highlight its advantages , especially for high capacities that will be needed as hydrogen generation scales up .
By Philip Bayley , Senior Sales Engineer , Pure Water Group
UPW for electrolysers
One of the main parameters used for defining water quality is the electrical conductivity , which is a measure of the ability of water to pass an electrical current as a result of dissolved salts and inorganic chemicals . Thus , the lower the conductivity , the lower the concentration levels of problematic species . Of course , the electrolyser manufacturer may also include parameters for specific ions such as silica or
30 Hydrogen Tech World | Issue 12 | October 2023