GALVANO-MD – Membrane distillation for energy-efficient treatment (concentration) of electroplating liquids

In the electro-plating industry the product has to be rinsed after the electro-plating or etching bath. This can be done directly above the bath or above a separate basin. The rinsing leads to the necessity of concentrating the electro-plating or etching bath or the rinsing water has to be treated in a way that, on the one hand electro-plating substances are concentrated and can be returned to the bath and on the other hand that the rinsing water has to be “cleaned” of the electro-plating substances and can be recycled as water. Conventional technologies for the concentration of electro-plating fluids are thermal evaporation or membrane separation technologies. To run these technologies a relatively high amount of thermal or electrical energy is needed.

Membrane distillation is an energy efficient, low temperature technology with low thermal and electrical energy consumption and enables the integration of waste heat and solar thermal energy as a heat source. For the usage of desalination and waste water treatment, membrane distillation has proven to be an energy efficient technology. For the application in the electro-plating industry only a few publications are available, hence research and development concerning suitable membranes and operating parameters are necessary.

The aim of this project is to reduce the energy demand of the bath treatments by the application of the membrane distillation and, due to the lower process temperatures, to enforce the integration of waste heat and solar thermal energy as heat source. In a first step a membrane module, which is adapted to the characteristics of the electro-plating fluids, will be developed and constructed using results from laboratory tests and simulations. This newly developed module will be then tested in a pilot scale facility, where ideal operating parameters (flow rates, feed and permeat temperatures) are identified. These parameters are optimized in terms of maximizing the transmembrane flow rate, minimizing the energy consumption as well as fouling of the membranes.

To be able to analyze the membrane distillation under realistic operating conditions, the pilot scale facility is installed and tested directly in an electro-plating plant. Furthermore, the long-term behavior can be analyzed extensively. In the scope of this project a concept for the integration of the membrane distillation facility into the electro-plating plant is developed and the potential for the integration of waste heat or solar thermal energy is pointed out. An essential part is also the calculation of the economic feasibility of this new technology.

The result of this project is an optimized pilot scale facility for the concentration of electro-plating and etching fluids with detailed knowledge about the operation parameters such as flow rates, temperatures, energy consumption etc. Based on these information, a scale up for large-scale facilities with an optimized membrane module and optimized operation parameters will be performed. This scale up concept should be economically feasible for the use in industry and should give the possibility for using waste heat or solar thermal energy as a heat source.

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Die Projektpartner AEE INTEC und ROTREAT Abwasser GmbH wurden am 3. Oktober 2016 für die Innovation mit dem ACR-Kooperationspreis 2016 ausgezeichnet. Der Preis wurde im Rahmen der ACR Enquete von Vizekanzler Dr. Reinhold Mitterlehner überreicht.

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Project management:
DI Christian Platzer