초록 ▼

An electrodialysis water splitting processes incorporates a chromatographic separation step using an amphoteric ion exchange resin to remove contamination salts from a salt solution feedstream and a base product solution. When the chromatographic column is subsequently eluted with water an effective

An electrodialysis water splitting processes incorporates a chromatographic separation step using an amphoteric ion exchange resin to remove contamination salts from a salt solution feedstream and a base product solution. When the chromatographic column is subsequently eluted with water an effective separation of the components is achieved. The separated pure salt stream is forwarded to an electrodialysis water splitter cell for conversion to acid and base. The base product solution (sodium hydroxide, potassium hydroxide) may be similarly purified by passing through a second chromatographic column also containing an amphoteric resin to separate the base from the salt (recovered salt). The process is also applicable in a chlor-alkali process for acidifying the brine feed to the electrolysis cell and for producing high purity caustic from salt.

대표청구항 ▼

1. A process for the a production of high purity alkali from salt, said process comprising the steps of:(a) processing a salt solution feedstream in an electrodialysis cell comprising bipolar membranes so as to produce an alkali solution containing a salt impurity; and (b) passing the solution of st

1. A process for the a production of high purity alkali from salt, said process comprising the steps of:(a) processing a salt solution feedstream in an electrodialysis cell comprising bipolar membranes so as to produce an alkali solution containing a salt impurity; and (b) passing the solution of step (a) through a chromatographic column containing an amphoteric ion exchange resin so as to recover a purified alkali solution and a second solution containing the salt.