Sugar Refineries use an Ion Exchange technology for decoloring sugar syrups. After the resin gets exhasuted, it has to be re-generated using caustic brine solutions. At present these effluents are sent to waste water station & fresh brine solution is prepared for every cycle.
- Colour Removal from Spent Caustic Brine in Sugar Refinery
Feature and Advantages
- Brine recovery is done without neutralizing, as was done in conventional systems.
- Minimal make‐up of caustic and salt is there, as no acid is required for neutralising the waste stream
- High flux and high temperature stability at high pH upto 13
- Membrine process recovers upto 85-90% Caustic brine back into the system.
- Colour concentrate further rejected as an option, making caustic brine recovery as high as 98%
- Low effluent loading as most of the colours are precipitated out in this new process
Raw sugar with high ICUMSA value has to be de-colorized. Two methods are used Activated Carbon and Ion Exchange resins. The carbon is regenerated in a hot kiln where the colour is burnt off from the carbon. This is a costly process in terms of the energy required. Ion Exchange method generates a lot of coloured spent caustic brine, which was difficult to manage. The new brine Recovery system developed by Diva Envitec Pvt Ltd, uses state of the art modified membranes to do the recycle efficiently.
Ion Exchange colour technology is catching up fast and many refineries are opting for the same. Although this removes less colour than GAC, but it additionally helps to remove of the inorganic contaminants as well. The Resin process uses the degree of charge on the colours to separate these from sugars by a absorption.
The Ion Exchange resin gets saturated after some usage and has to be regenerated. It is regenerated chemically using Caustic Brine solution at 12-13 pH. The cleaning is very efficient, but this gives rise to large quantities of coloured liquid effluents. This was a deterrent to the industry and various technologies are being employed to re-cycle this effluent water.
The RO process for Brine recovery was efficient but could only get 40-50% brine recovery and due to the neutralising process all caustic was lost. Poresep Membrine process to recover the Caustic Brine uses modified membranes to carry out the separation under most taxing environments.
The process comprises of series of pre-treatments followed by Modified Membrine process where the colours are removed from the effluents at high temperature and high pH. This process gives the saving in energy costs and also chemical consumption.
- Flow rates as high as 20-25 m3/Hour
- MOC – SS 316 or PP/FRP
- Full automation with Clean-in-place
- High degree of process control
- Design capability for different Caustic and brine concentrations