Progress in commercial bipolar water splitting

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:567379

Salem, E; Chlanda, F P; Chiao, Y C ^[1]

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1. AQUALYTICS, Warren, NJ (United States)

Bipolar membrane water splitting has become an accepted method for electrically generating acids and bases from salts with a minimum of salt contamination. The benefit over electrolysis is potentially lower power costs and formation of acid and base without significant oxidation/reduction reactions. To date, AQUALYTICS has supplied 6 systems, the largest of which has effective cell size of about 7,500 square feet. This has been expanded to 10,000 square feet with an additional system. The sixth new system, with a value of 1.4 million dollars is currently in start-up recovering an organic acid and sodium hydroxide from an organic sodium salt. Figure 1 shows a schematic of a bipolar membrane in a salt solution. The bipolar membrane consists of bonded anion and cation permselective layers. When electric current is passed through the membrane the movement of salt ions through the membrane is inhibited by the selectivity of the layers. Any salt at the interface between the two layers is depleted soon after the current is started. This leaves only the hydrogen and hydroxyl ions form the dissociation of water to carry the current. As a result, hydrogen ions are produced on the cation side of the membrane and hydroxyl ions are produced on the anion side. The water splitting process is known to be an energy efficient route to acid and base production (1). Additionally, its use in organic acid isolation results in overall process simplification, through reduced capital costs and improved yields. These advantages have become recognized of late, as evidenced by the large number of publications and patents on this subject. In this paper we will discuss some of the experience gained to date on the application of this technology, especially at commercial plants.

• OSTI ID: 567379
• Report Number(s): CONF-961106--
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
40 CHEMISTRY
BASES
DISSOCIATION
ELECTROLYSIS
ENERGY EFFICIENCY
HYDROGEN
OXIDATION
SALTS
WATER