Characterization of solar-powered non-asbestos diaphragm cells for the production of caustic soda

An experimental study was performed using an array of solar panels to power three non-asbestos diaphragm type electrochemical cells whose anodes consisted of carbon rods and cathodes made up of stainless steel plate for the electrolysis of a 25% w/w sodium chloride solution, with the aim of producing caustic soda. The non-asbestos diaphragms served to hinder the formation of unwanted substances as well as permit reasonable production of the desired products. Quantitative analysis showed that the quantity and concentration of caustic soda produced varied with the current and voltage obtained from the solar panels which were dependent upon the intensity of the sun on any particular day and the length of time the panels were exposed to sunlight. The three non-asbestos diaphragm cells exhibited various characteristic performances, which are reflections of their design, fabrication, composition and operational parameters. The non-asbestos diaphragm D3 with composition of 60 % w/w Portland cement, 20 % w/w silica and 20 % w/w polyvinyl chloride (PVC) indicated the highest yield of caustic soda per d.c Watt with specific electrical energy supplied. The research served as an encouraging inquisitive foundation into the possibility of producing caustic soda directly from solar powered electrolytic diaphragm cells as well as investigating key factors that affects cell performance in view of present conventional modes of electrochemical production.