Reliable Ceramic Membrane Filter &Green Process for Brine Filtration in the Chlor -Alkali Industry

Most of modern chloralkali plants are now using ion exchange membrane for caustic soda production. It's high efficiency and power saving. However, the electrolyzer has high requirement for high quality brine supply. Raw salt NaCl is first dissolved in dissolver at concentration 280-300g/L at high temperature. After reaction with NaOH & Na2CO3, Mg2+ and Ca2+ will be transformed into sediments Mg(OH)2 and CaCO3 .Other organic solids like alga, humic acid will be decomposed to small fragments by oxidant NaClO. All those impurities have micron particle size,and are difficult to be removed. Traditional purification process are Dorr Clarifier . To control the concentration of Suspended solid and Ca+Mg down to a low level, many steps of filtration should be applied, which cause complicated maintenance and high cost.?

Ceramic membrane has been widely used in strict and harsh liquid environment in process industry due to its nano pores, stable chemical performance. 15 years ago, Ceramic membrane were successfully applied for primary brine refining. Nowdays, most of China caustic soda industry are using this advanced membrane technology for brine purification. It have been proved to be more economical, stable, reliable than normal clarifier.

After reaction, crude brine will be pumped into a prefilter by feed pump to remove the fibers and sand. Circulation pump will increase high velocity for the brine, to flow across the membrane layer. Driven by pressure, clean NaCl solution will pass through the ceramic membranes, which is called permeation stream and goes to secondary refining process-Chelating resin.The micron solids like Mg(OH)2 , CaCO3 ,fragments, mud will be rejected into the retentate stream, and then go to Filter Press to remove the sludge. The flowrate ,operating pressure, and VCF (volume concentrated factor) can be automatically controlled by remote DCS or PLC system. Backpulsing will be automatically applied to increase the flux. Chemical cleaning in space can also be very effective to remove deep scaling inside the porous structure. By optimized process design and high quality membrane, CRBR system can keep on running with stable performance for many years.

The filtrated brine from CRBR can reach high and stable quality:

SS(Suspended Solid): ≤0.5mg/L?,Ca2++Mg2++≤ 0.5mg/L

Process Advantages by Ceramic Membranes?

● High and stable quality of refined brine

● One -step filtration

● Less thermo Loss

● No use of flocculant agent

● Reliable and stable performance on long period

● Low operating cost

● No need of precoating process

● Wide adaptability to all raw salts

● Long membrane worklife

● Benefit for post chelate resin and electrolyzer system

● Low labor and maintenance cost

● Compact design with small foot print

TFT company provides you different models of CRBR systems to fit your different requirements either for existing plant or newly designed plant. We can also make a machine customization to meet your special capacity from 5KTa to 400Kta.

Ceramic membrane have been widely applied for primary brine purification and refining in chloride alkali industry for caustic soda production in many countries like China, India,Turkey, Russia,Mexico,Thailand...If you need more details about ceramic membrane process for CRBR technology in chloride alkali industry ,please do not hesitate to contact with us or send email to us. TFT is willing to communicate and share information with you on engineering process issues. We are looking forward to developing more market and more applications with your help, bring this new technology to end users, create more values and benefits for all parties.