The Gayley process, also known as the Gayley-Otto process, is an industrial method used for the production of chlorine and sodium hydroxide (NaOH) through the electrolysis of sodium chloride (NaCl) solution. It is a variation of the chlor-alkali process, which is commonly employed for the simultaneous production of these chemicals.
In the Gayley process, the electrolysis of brine occurs in a diaphragm cell, where a diaphragm or membrane separates the anode and cathode compartments. This prevents the mixing of chlorine gas, which evolves at the anode, and sodium hydroxide solution, formed at the cathode. The diaphragm allows the ions (sodium and chloride) to pass through, while blocking the gases and liquids.
The process operates at relatively lower voltages compared to alternative methods, reducing energy consumption. The electricity passes through the brine, causing sodium ions (Na+) to migrate to the cathode and chlorine ions (Cl-) to migrate to the anode. At the cathode, the sodium ions capture electrons and are transformed into sodium metal, which then reacts with water to produce sodium hydroxide. At the anode, chlorine ions capture the discharged electrons and are converted into chlorine gas.
The Gayley process is advantageous as it facilitates the production of chlorine and sodium hydroxide separately, allowing for optimal storage and handling of both chemicals. Moreover, the process contributes to the economic sustainability of various industries that heavily depend on chlorine and sodium hydroxide, such as chemical manufacturing, wastewater treatment, and pulp and paper production.
