Conceivable Applications

・Desalination and nitrate removal of groundwater for drinking water.
・This technology is applicable in areas where water resources depend on limited groundwater, not on sea water or river.
・Supply of drinking water in areas with insufficient power infrastructure.

 [Description of electrodialysis]
An electrodialyzer is composed of anion and cation exchange membranes stacked alternately with thin spacers between them and a pair of electrodes at both ends.
In an electrodialyzer, two types of chambers are placed between a pair of electrodes. One is a desalination (D) chamber partitioned with an anion-exchange membrane on the anode side and a cation-exchange membrane on the cathode side. The second is a concentration (C) chamber partitioned with a cation-exchange membrane on the anode side and an anion-exchange membrane on the cathode side.
Saline water is desalinated in the D chamber and is concentrated in the C chamber, as a result of the electrical potential (see Figure 1).

                                                 Figure 1. Cross section image of an electrodialyzer
 
                                                                Photo 1. Ion-exchange membranes
                               Left side: Cation-exchange membrane, Right side: Anion-exchange membrane

                                                      Photo 2. Example of an electrodialyzer

Competitive Advantage

1. High water reuse ratio
・The water reuse ratio of the ED (electrodialysis) process is higher than other technologies. Thus, this technology can contribute to the effective use of groundwater.
 
2. Energy saving
・The ED process requires less power compared with other water purification technologies.
・Although, there are no previous cases yet, because the ED process is powered by direct current, it can be used with solar panel systems, making it possible to install the system on sites with limited power sources.
・Ion exchange resin used in water-softening equipment loses performance as hard minerals build up during use. However the ED process requires no regeneration process to remove hard substances to recover performance, meaning that the amount of chemicals used can be cut significantly.

3. Low operational cost
 ・The operation cost is roughly the same or less than the conventional RO process since a high-pressure pump is not required. 

Performance

・The water reuse ratio of this method (electrodialysis method) is close to 90% (This value depends on the composition such as hardness component of water supplied and the target composition of water.)　

・The degree of desalination is adjustable.     

Technical maturity

In the late 1990’s, these systems were installed at more than 10 sites in the Middle East. These projects were related to well water.
We regularly replace membranes used in these systems even after installation. Membrane replacement frequency is roughly once every 4 years, but it depends on the usage situation. As annual maintenance can also serves as operational inspection, an option to replace 25% of the membrane every year is also available.

Conceivable risk

Without proper operation and maintenance (daily and regular), there is a possibility that the performance of the system can not be demonstrated to its full capacity.
In order to avoid this risk, we will work with local partner companies not only to install these systems, but also to build maintenance systems.
Part of maintenance and technical service will be conducted under the guidance of a local company, such as a water engineering company. The biggest risk is that users might operate the system without fully understanding the operation method resulting in damage to membranes. In order to avoid this risk, we also want to perform proper operation and maintenance locally.
The complexity of any electrodialysis water treatment system depends on its conditions and goals, so please make inquiries first.

Name	AGC Inc.
Address	Shin-Marunouchi Bldg., 1-5-1 Marunouchi Chiyoda-ku, Tokyo 100-8405 Japan
Capital	90,873 million JPY (As of the end of December 2016)
Contact person	Dr. Masaaki OKABE Phone: +81-80-2110-1391 e-mail: masaaki.okabe@agc.com HP: http://www.agc.com/en/index.html
Number of employees	50,963 (As of the end of December 2016)
Date of company foundation	September 8, 1907
The type of business	Manufacturing and sales of Glass, Electronics, Chemicals, Ceramics/Other

 

International operation

Number of employees for international operation		Close to 40,000 employees
Overseas offices	City, Country	Name of Company (if applicable)
	Singapore	AGC Asia Pacific Pte., Ltd., Regional headquarters for Southeast Asia
	India	AGC Asia Pacific (India) Pvt. Ltd
	Other Asia	35 bases
	UAE	AGC Middle East & Africa FZCO
	America	16 bases
	Europe	13 bases

 

Modality of business transaction

Partnership
Depending on the business environment, it may be possible to consider a partner contract with a local company and consider assembling of electrodialyzers, peripheral equipment, etc.
 
Export of product
Although it depends on the area, sales and maintenance will be the main exports from Japan.

Schematic  illustration of the technology

Product catalog
https://www.agec.co.jp/agec/pdf/selemion.pdf