Case Study Successfully Proven Brine Treatment
Lanxess ion exchangers are being used for brine purification in chlor-alkali electrolysis in India. The Lewatit MDS TP 208 ion exchanger protects highly sensitive electrolysis membranes and its fine beads enhance the brine treatment process.
A leading producer of chlor-alkali products in the Indian market benefits from the improved efficiency of his chlor-alkali electrolysis by applying the new Lewatit MDS TP 208 as ion exchange resin from Lanxess, states the Lanxess firm. The finely dispersed polymer beads reduce the energy input effectively by preventing damage to the ion exchange membranes used for electrolysis and thus extending their lifespan. Consequently, this new generation of finely dispersed resins is being successfully introduced alongside the Mono Plus types, adds the company.
The chemical plant in the south of India has a production capacity of approximately 190 metric kilo tonnes of caustic soda a year requiring a quantity of around 400 cubic meters of sodium chloride brine per hour. The brine used for electrolysis needs to be pretreated to protect the electrolysis membranes from high levels of impurities. Otherwise precipitations can harm the membranes, for example, resulting in a less efficient process.
According to the company, the new finely dispersed ion exchange resin is being used in one of the three filters of one brine treatment line to optimise brine purification. The resin reduces the hardness of the brine from an incoming level of 2 mg/l to below 10 µg/l (Ca2+, Mg2+). The chemical plant also has an effective process for removing barium and strontium levels to a concentration of below 100 µg/l, opines the firm.
The use of the chelate resin from Lanxess enables effective economic advantages for the plant operator, in particular in terms of significant energy cost savings. Further advantages include a longer lifetime for the membranes and the resin. Additionally reduced quantities of regeneration agents are required and a reduction of wastewater is expected to lower operating costs. The resin type used is capable of achieving longer cycle times, which in turn generates a higher brine treatment throughput. Based on the positive results, the Indian producer decided to switch the other two resin filters of this line to Lewatit MDS TP 208 as well.
Since installation of the resins in 2016, the customer has enhanced the capacity of this brine treatment line by 53 per cent in two years. The use of the ion exchange resin has increased the throughput from 3,035 BV (bed volumes) to 4,662 BV, concludes the firm.