Industrial process water

Industrial process water is highly industry- and company-specific in terms of its composition, characteristics and the required treatment objectives. Their treatment often requires complex combinations of technologies. Fraunhofer IKTS offers a wide range of services from process and requirements analysis to experimentally supported process development and the pilot transfer of treatment systems into practice. The institute draws on extensive project experience from the chemical, petroleum, food, ceramics, textile and paper industries as well as other processing sectors.

Production processes in the chemical and pharmaceutical industries can generate contaminated organic solvents that need to be purified for reuse. Furthermore, the recovery of homogeneous catalysts is becoming increasingly interesting due to their scarcity and the high price of precious metals. Both processes are currently implemented using distillation methods. As these processes are associated with high energy costs, ecologically and economically sustainable alternatives are needed.

A filtration stage with organophilic nanofiltration membranes can be used as an alternative or supplementary process. This enables the recovery of a large proportion of the valuable substances via a pressure-driven, physical process and therefore without external heating or cooling energy. Due to their resistance in organic solvents, ceramic membranes are an ideal basis for the development of such processes. One advantage of Fraunhofer IKTS is the ability to develop and modify customer-specific membranes.

Advantages:

• Energy-saving alternative to crystallization and rectification
• No phase change necessary
• Side reactions and decomposition reactions significantly reduced (low thermal load)
• No need for additives
• High chemical and thermal resistance of the ceramic membrane

The efficiency of an industrial cleaning step always depends on the degree of purity of the medium used. It therefore makes sense to separate the impurities absorbed by the cleaning agent in order to keep the cleaning effect at a consistently high level. One of the most important cleaning media in industry, certainly with a focus on the food and beverage industry, is hot lye. During caustic cleaning, impurities such as color, COD and particles as well as carbonates must be removed. With the help of the process stage proposed here, caustic recycling can be improved and the addition of additives minimized.

Due to the high chemical and thermal requirements, ceramic membranes offer an advantage here compared to polymer membranes. In addition, ceramic membranes can also be used to realize more compact systems, as they offer a higher filtration performance than polymer membranes with the same surface area. Fraunhofer IKTS offers customized membrane developments and modifications.
 

Advantages:

• Reduction of fresh caustic and saving of additives
• Minimization of carryover into downstream process stages
• Increased membrane service life when using ceramic membranes
• Possibly minimized space requirement (compared to polymer membranes) when using ceramic membranes
  

Based on the extensive technological expertise available, processes are developed for recovering valuable materials from wastewater and liquid process media as well as from secondary and non-conventional raw material sources. Fraunhofer IKTS covers the entire wet-chemical process chain from extraction (leaching) from solids to enrichment using membrane-supported extraction processes through to the pure metal or target product. Electrochemical processes are preferred, but process combinations with extraction processes are also used. Naturally, the portfolio also includes the corresponding chemical recovery and waste water treatment.

We have extensive experience in the extraction of rare earth concentrates from secondary raw material sources, in the purification of various rare earth compounds and in the extraction of special and precious metals (indium, gallium, tellurium, silver, palladium, platinum, rhodium) from scrap or tailings. A non-conventional resource is deep thermal water, from which many important raw materials can be extracted depending on the location.

Advantages:

• Comprehensive technological expertise in membrane and electrochemical processes
  
• Broad range of experience in terms of chemicals and materials (rare earths, special metals, precious metals)
  
• Pilot plants available at short notice for process development and optimization
  

In many areas of industry, radioactively contaminated wastewater is produced that must be treated to prevent the release of radioactive substances into the environment. In order to treat liquid organic waste containing C-14, which is difficult to handle, Fraunhofer IKTS has further developed a process for electrochemical total oxidation. This allows the radioactive carbon (C-14) bound in the organic materials to be converted into alkaline earth carbonates suitable for final disposal in a relatively simple process.

The electrochemical total oxidation process is also suitable for the removal of many other highly persistent organic pollutants, such as carcinogenic compounds like nitroaromatics or endocrine disruptors. With appropriate process control, it is superior to all currently established processes in terms of purification performance. The extraction of certain raw materials (rare earths, niobium/tantalum, coltan, etc.) and the use of geothermal energy also lead to the accumulation of naturally occurring radionuclides from the uranium and thorium decay series, which can be separated using appropriate electrochemical processes.

Advatages:

• Simple production of C-14 carbonates suitable for final disposal
  
• Treatment of flammable and/or aggressive organic waste
  
• Application for a wide range of substances
  
• Efficient separation of geogenic nuclides using electrochemical processes

Further areas of application

• Desalination
  
• COD/TOC reduction
  
• Nutrient recycling
  
• Removal of color, odor, taste and pollutants (pesticides, nitrite, phenols, CMC, complexing agents)
  
• Disinfection
  
• Deinking/decolorization
  
• Optimization of industrial wastewater treatment plants
  
• Removal of microplastics