A new innovation technology for primay brine purification for Chlor Alikali Plant

CRBR Process

CRBR - The New Generation Of Primary Brine Refining Process for Caustic Soda Production in Chlor-alkali Plant

A Reliable Membrane Cross-flow Filtration Technology, replacing the Dorr Clarifer and  sintered carbon filter. 

Raw salt is dissolved in Dissolver at concentration 280-300g/L at 55-600C. When reacted with NaOH & Na2CO3, Mg2+ and  Ca2+ will be tranformed 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.
After reaction, crude brine will be pumped into a prefilter by feed pump to remove the fibers and sand. Circulation pump will increase high velosity for the brine, to flow across the membrane layer. Driven by pressure, clean NaCl solution will pass through the 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 controled by remote DCS  or PLC system. Backpulsing will be automatically applied to increase the flux. Compressed air is fed into the Buffer tank, pushing the clean brine into the permeation side of membrane module from an opposite direction. The fouling cake will be blown away.  Chemical cleaning in space with 15% HCl can also be  very effective to remove deep scaling inside the porous structure. By crossflow filtration which is combined with backpusing and CIP, CRBR process can keep flowrate high and stable  for long time operation.

CRBR technology is suitable for rock salt, refined salt, sea salt, crude salt and brine, even for those salt with higher Mg++ than Ca++. 

crbr assembly

The CRBR machine skid has a M.O.C as titanium module and Al2O3 ceramic membrane, which can resist brine/caustic/acid corrosion and work stable in your system, feeding your resin tower a quality primary brine.

The full closed shell keeps the salt mist inside as well as protecting your steel frame and tank away from corrosion. It also feedback you a nice working environment.

You can customize different specifications models to fit your need.  TFT has a experienced and expert team for your service.


>>Stable and high quality of refined primary brine,with SS<0.5ppm (0.1NTU) ,Ca+Mg<0.5ppm.
>>Simple process for primary brine refining,which can reduce equipment investment.Total investment of CRBR process can be reduced by 30-50% compared with traditional Primary refining processes.
>>Wide adaptability to different crude brine,especially to brine with higher Mg2+ concentration than Ca2+ .
>>Benefits for better worklife of Chelating resin and Ionic membrane.
>>Less additives and chemical consumption,low running cost.
>>Less no-corrosion to piping&equipment without corrosive FeCl3.
>>Convenience for maintenance and operation,low labour cost.
>>Less floor space,convenience  for upgrating and capacity expansion. CRBR membrane filtration system can be modularly designed as a compact skid-mounted plant, which requires much less floor space. It can be installed on the first or second floor.The production capacity can be easily expanded based on current process. Most of the equipments can be reused after upgrated to new CRBR process.

excellent filtrate

Stable and high quality  primary brine after TFT Ceramic membranes:



[Ca++] + [Mg++]<0.5 mg/L

 Left to Right


2.Refined primary brine from Clarifier

3.Refined primary brine by CRBR

Low quality salt suitable

CRBR system can be used at very dirty and impurity salt.

Wide adaptability on different kind of raw salt from sea, well or other resources.


CRBR have many successful projects which use very dirty raw salt or brine to feed their caustic plants. The CRBR system is suitable for these kind of raw salt following:

1.Calcium and magnesium content are very high.

2.Dirty and dusty salt.

3.Magnesium content is higher than calcium's.

Reliable performance

Protect your resin towers and electrolyzers.

The full enclosed system protects your stell frames and tanks from salty mist and rust.


You need a stable and continuous production process of primary brine.

Most of the modern chlor alkali plants are using advanced Ionic membrane electrolyzer technology. It’s high efficiency and power saving. However, it needs high quality brine from resin tower.


The CRBR system provides a stable high quality primary brine, which will reduce the production load for the resin tower. The high quality of primary brine from CRBR can ensure the stability of the secondary brine.

DCS/PLC Automatic

CRBR automatic Control Operation interface of DCS system.

TFT company supplies a whole system including machine skid and automatic controller system - PLC/DCS, which can fit your need for saving labor and bring you a high efficient.

PROCESS Comparison

Based on 100Ktpa chlorine-alkaline plant.

Process & Cost

Dorr Clarifier

PTFE Filter

CRBR Ceramic

Process Brief

Dorr for clarification and carbon sintered filter for refined filtration after reaction.

Stepwise reaction ascent clarifier to remove Mg2+, organic membrane to remove Ca2+

Direct filtration to remove Mg2+,Ca2+


Sodium polyacrylate,α-cellulose



When Raw Salt Change

Dorr is muddy, carbon sintered filter

Ascnet clarifier is muddy, Primary brine flux is lowering.

No influence





Ca2+ & Mg2+ 








Operation Cost

$2.3/ton caustic soda

$1.9/ton caustic soda

$1.2/ton caustic soda

CRBR Development

Development and Capacity percentage. 

CRBR is a mature technology. After years of development, there have been many successful applications in China and parts of the world. Because its advantages of low investment, low cost, good and stable quality, low labor cost, good for environment, lots of chlor-alkali plant have accepted it. More and more CRBR systems are built in new plants and projects around the world.