summary
In Terneuzen, Evides Industriewater processes different raw materials into a variety of water qualities, such as industry water, cooling tower water, demineralised water and ultra-pure water. This water-on-demand water is supplied to the local production facility of Dow Chemical.
The treatment plants have been implemented according to the DBFO (Design, Build, Finance & Operate) concept: they have been designed, financed and constructed and are currently operated by Evides Industriewater. This leads to a long-tem partnership, assuring Dow of the reliable supply of its entire water portfolio without the need to invest in any assets and giving access to the water expertise and financial muscle of Evides Industriewater. As a result Dow has secured its water management at a competitive efficiency.
how mutual interests lead to water-partnering
During the mid-nineties, Dow Chemical - one of biggest powerhouses in the chemical industry - has expanded the capacity of its naphta crackers at its production site in Terneuzen. As a consequence of the expansion of the production capacity the expansion of the energy production and cooling water facilities were mandatory. This marked the moment to also replace some of the less efficient production plants for demineralised water. All of these modifications and expansions were driven by durability and sustainability.
The project had to be carried out in compliance with new environmental directives in the area of energy efficiency and atmospheric emissions (CO2/NOX) as well as surface water discharges (N, P, TOC, TDS). The energy requirements for the new cracker’s peripheral systems could be recovered from the high-value residual heat from the naphtha furnaces. By turning ultra-pure water into high-pressure steam, multi-stage turbines can be driven to generate direct axial power. A new cooling tower has been constructed to process the unusable residual low calorific heat. Finally the existing old seewater evaporation plant and various ion exchange lines have been replaced with new desalination technologies.
Dow’s substantial demand for water led to a re-evaluation of the supply side of water in the area. Due to the scarcity of fresh (surface) water in this area any use of these sources needs to be considered carefully. This prompted Evides Industriewater to explore the options for exploiting alternative water sources and the reuse of water. Among the many possibilities was the production of demi water from brackish groundwater, seawater, effluent from household waste water treatment and river water from the Maas river. Additionally, meeting the demand for cooling water by means of reuse of the final effluent of a waste water treatment plant was also examined.
The studies resulted in the construction of water treatment facilities that produce several different process water qualities using six different water sources. It should be noted that the Terneuzen site of Dow has sufficient backup capacity available from the common distribution network of industry water and Fresh water.
project details
In 1998 design and construction started on the various water treatment schemes. The process plants were commissioned in 2000. The design and construction took place as a joint venture. The plant is now 100% owned and operated by Evides Industriewater. The redundancy was expanded in 2004 by adding an extra ion exchange line.
The total water treatment facilities produce an aggregate of 750 m³/hour of demineralised water (demi water), 650 m³/hour of cooling tower suppletion water (cooling water) and 1,050 m³/hour ultra-pure water (polished water).
|
|
Water source |
Net capacity |
|
|
Ion exchange lines 1 & 2 |
River water |
600 |
m³/h |
|
Ion exchange line 3 |
Fresh water |
250 |
m³/h |
|
Membranes (MF/RO) |
Effluent WWTP Terneuzen |
250 |
m³/h |
|
Cooling water |
BIOX effluent/fresh water |
700 |
m³/h |
|
Polished water |
Condensate/Demi-water |
2,000 |
m³/h |
Until 2007 seawater was being used for the production of demi-water. The use of effluent of the municipal waste water treatment plant of the town of Terneuzen (WWTP De Drie Ambachten) as water source for the production of high-prized process water resulted in various domestic and international prizes in 2007 and 2008 for Dow and Evides. All of them acclaimed the fact that both companies keep on striving to achieve high levels of sustainability with respect to their water sources as well as their water use.
The final stepping stone of the transition of seawater to municipal effluent is the construction (2008-2009) of a MBR at the site of the WWTP DDA, which makes the MF pre-treatment of the RO redundant. This website closely monitors the construction of this biggest industrial MBR.