Apparatus for the small-scale manufacture of chlorine and sodium

Abstract

Presented is an apparatus and method for producing small quantities of chlorine and sodium hydroxide or sodium hypochlorite, useful in many applications where the major investment of a full-blown chemical plant capable of producing tons of product per day is not economically feasible. The apparatus of the invention includes the use of an electrolytic cell embodying an anode chamber charged with an acidic, concentrated sodium chloride solution and a cathode chamber charged with a basic aqueous solution and through which an electric current may be passed under controlled conditions to initiate and maintain a reaction that produces chlorine gas in the anode chamber and hydrogen gas and a solution of sodium hydroxide in the cathode chamber. The anode and cathode chambers are separated by a chemically-resistant ion-exchange membrane permeable only to positively charged ions. Anolyte and catholyte feed tanks are arranged in association with appropriate anolyte and catholyte surge tanks connected to the electrolytic cell in such a way that the reaction proceeds continuously without the need for mechanical pumps. The chlorine and the sodium hydroxide solution may leave the apparatus as separate product streams, or, in a second aspect of the invention, may be combined to form (as yet another product) a solution of sodium hypochlorite.