CONDENSATE POLISHING UNIT
WTE has enabled sugar & distillery factories to recycle 90-95% effluent water and achieve total water management through resource conservation, reutilisation, and recycling, wherein “Zero water intake” was achieved practically to meet the process demand.
Treatment of the Condensate
01. Physical Treatment
Physical Treatment is a process in which the pollutants are mechanically removed from the wastewater.Most common processes under physical treatment are screening, sedimentation, micro-, ultra- and nanofiltration, etc. Some other physical processes like adsorption and reverse osmosis can be used to treat the process condensate. Activated carbon and zeolite- based adsorption is widely used in water treatment to remove trace organic –inorganic substances, chemicals, microorganisms, odor and toxins. Reverse Osmosis (RO) is a process which uses a partially permeable membrane and is currently used by many sugar factories and other industries. RO may be used to treat the condensate as the process is effective for the removal of sugars, salts and metal ions. But organic acids present in the condensate may not be removed by RO process.
02. Biological Treatment
Biological wastewater treatment harnesses the action microorganisms using an effective system to clean water for proper disposal or recycle. Sugar mills can adopt aerobic treatment and lagoons for the treatment of process condensate. Lagoons, which use natural microbes from surroundings, typically occupy large area, have high retention time and less efficient. Furthermore, it leads to accumulation of sulfides which turn the water black. Aerobic treatment processes include aeration tanks, oxidation ditches, activated sludge, trickling filters, etc. The ‘activated sludge’ process, which may be suitable for treating low strength wastewater streams such as process condensate. An advantage of using biological treatment is that apart from reducing COD/BOD levels, it can simultaneously also remove other inorganic pollutants such as sulphates, nitrates, ammonia and chlorides
03. Chemical Treatment
Chemical methods include chemical separation such precipitation, coagulation, flocculation, solvent extraction, ion-exchange process and chemical oxidation, and other chemical reactions which destroy or remove the pollutants from wastewater. Most of the chemical separation process may not be techno-economically suitable for treatment of sugar mill process condensate due its inherent characteristics. Possibly, ion-exchange process can be used to treat the condensate although it is more suitable for water softening and metal ions removal.
Steam condensate will be recycled back as a boiler feed water to sugar factory.
Degeneration of the condensate increases microbial contamination. Due to these reasons, the condensate as such is not reusable in the mill. Currently many sugar mills face challenges in managing the process condensate due to lack of dedicated treatment solutions. Condensate polishing typically involves Ion Exchange technology for the removal of sugar traces, or traces of dissolved minerals and suspended matter.
Wastewater stream in sugar mill is the ‘process condensate’ which is a waste effluent from the syrup boiling and vacuum pan sections of the mill. The condensate consists of volatile organic-inorganic compounds and traces of sugar due to overloading of the evaporators, vacuum pans and extensive boiling of syrup, which further increases the pollutant ‘strength’ of the condensate.
The COD/ BOD is mostly due to sugars and organic acids, along with traces of other organic compounds such as phenolics. The condensate also consists of significant quantities of sulfides. Other parameters like hardness, alkalinity, chlorides, and total dissolved solids are generally found within the acceptable limits for reuse. After proper treatment, the condensate may be used for various unit applications. Major use of the recycled condensate can be as make-up water in cooling tower and for vapor cooling in injection channels.
- Finest outlet water quality
- Easy to handle organic varying load
- Easy to operate & maintain
- 100% treated water recycle & reuse
- Odourless treatment
- Continuous Improvement in quality of Steam results in increased Turbine Life
- Cooling tower make up water for distillery and co-generation
- Fermentation process in distilleries
- Co-generation DM inlet with suitable pre-treatment
- Used as a cooling media for mechanical parts of mills & turbines
- Other non–potable purposes
- Power plants
CONDENSATE POLISHING UNITS WE OFFER
Frequently Asked Question
A Condensate Polishing Unit (CPU) is a type of water treatment equipment used to remove dissolved impurities from the condensate generated by steam power plants, industrial boilers, and other similar process equipment. The purified condensate is then returned to the boiler feedwater system, where it can be used to generate steam again.
A CPU typically removes impurities such as dissolved salts, dissolved gases, particulates, and trace amounts of heavy metals.
There are several types of CPU's available, including ion exchange resins, mixed bed deionization, electro-deionization, and reverse osmosis. The type of CPU used will depend on the specific requirements of the application and the quality of the condensate.
CPUs require regular maintenance to ensure optimal performance. This includes regularly replacing resin beds, cleaning membranes, and monitoring system performance.
A CPU helps to improve the overall efficiency of a steam power plant or industrial boiler by returning high-purity condensate to the boiler feedwater system. This reduces the amount of makeup water required, which in turn reduces the amount of energy required to heat the water and generate steam. Additionally, reducing dissolved impurities in the condensate can reduce the corrosion and scaling inside the boiler and downstream equipment, which in turn can increase the life of the system.