[ water treatment ] for chemicals for regeneration . This is significant for the hydrogen market since it offers a small footprint and significantly reduces health and safety risks , as well as operating costs associated with chemical storage , chemical handling , and waste neutralization . Another benefit is the reduced need for prolonged chemcial storage , which helps prevent corrosion in installed equipment .
Fig . 4 . 100 m 3 / h EDI system by Pure Water Group
• Very low operating costs . Typical energy requirement for EDI process is < 0.06 kwh / m 3 ;
• More susceptible to fouling / scaling and oxidation if pretreatment is not adequately designed ;
• Can operate at 60˚C continuously .
EDI differs from conventional ion exchange water purification technologies in that water purification is achieved without the requirement
About the author
Phil Bayley , PGCert in Water & Wastewater Engineering , has more than 30 years of experience in the field of potable and industrial water treatment with a strong focus on membrane and electrochemical membrane processes . He is considered a broad expert in the implementation of electrodeionization , with over 15 years of direct experience that includes business development , system design , and commissioning . He works as a senior sales engineer at Pure Water Group , which specialises in the design and fabrication of sustainable water solutions for industries requiring ultrapure water or the recovery of niche wastewaters .
Electrolyser refinement loop polishing
This loop has significantly higher capacity and operates at higher temperature than the make-up water . For a 1,000 MW PEM electrolyser , this may be in excess of 6,400 m 3 / h , with temperatures ranging from 60 – 80˚C . These loops are typically polished by means of a side stream , which is typically up to 6.0 % of the main flow . As hydrogen projects scale up in size , EDI may become the industry ’ s preferred choice for this application .
Summary
EDI is not a new technology ; commercial systems date back to early 1987 . Ongoing improvements and cost reductions have resulted in wider adoption across industries , including microelectronics , power , and pharma . Thousands of installations currently exist , with the largest exceeding 2,000 m 3 / h .
It is logical , therefore , that EDI technology , with its significant technical and environmental advantages , will become the technology of choice as part of the UPW preparation process for the hydrogen market .
Subject to ongoing trials and scale-up of the hydrogen market , it is anticipated that EDI will also offer significant advantages for the polishing of high-capacity refinement loops .
34 Hydrogen Tech World | Issue 12 | October 2023