Page 36 - AW MayJune 19

MAKING WAVES

Successfully proven brine treatment

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

34 MARCH/APRIL 2019 Asian Water