A new potential environmentally friendly treatment that purifies wastewater whilst producing energy Casanelles, Elisenda

What is REWAGEN?

Project Manager at KIM

Portolés, Ana External Communications at KIM

Funded by the European Union (EU), the REWAGEN project was developed to alleviate one of the greatest environmental problems at stake today: pollution from effluents produced by the dairy industry. Besides being an effective treatment for contaminated water, this solution reduces the user company’s water and energy consumption and, as a result, lowers their costs. A REWAGEN pilot test is currently underway at a farm in Vic (Barcelona).

REWAGEN is a collaborative project funded by the EU, which features the participation and commitment of 11 companies from 6 European countries for the creation of the first energy-efficient wastewater treatment plant in the dairy industry. PROJECT NAME

REWAGEN

ORIGIN OF THE NAME

REWAGEN is an acronym of Electrochemical WAter treatment system in the dairy industry with hydroGEN REcovery and electricity production.

SECTOR

Eco-innovation / Food Industry

COMPANIES INVOLVED

Frauhofer (Germany), LEITAT (Spain), HYGEAR (the Netherlands), AQON (Germany), Knowledge Innovation Market - KIM (Spain), IDROPAN (Italy), CTR (Spain), C-TECH (UK), ISA (Portugal), EUT (Germany) and ISA Energy (Portugal)

Objective REWAGEN’s objective involves developing a wastewater treatment system which: firstly, achieves dramatic savings in water consumption for the user company; secondly, recycles waste extracted from effluents for other needs in the dairy product production process; and thirdly, recovers hydrogen to generate reusable electricity for the maintenance of the system itself. As a result, REWAGEN will save the food industry millions of euros.

How does it work The REWAGEN project mainly works based on the sequential combination of three technologies with well-defined objectives, as shown in the following image: 1. Separation of water and fat residues. In the first phase, whey and wastewater are subjected to a process called electrocoagulation, which separates fats and oils from water. 2. Sludge filtration. After removing the fat, the wastewater passes through electrocoagulation (EC) and electrooxidation (EO) processes, which facilitate the removal of organic compounds from the water. During this electrochemical process, hydrogen is recovered which is

then used to power a fuel cell, so that the entire treatment process requires less energy. 3. Desalination. Finally, the water is deionised with electric currents to remove any dissolved salts. This produces purified water that can be reused for different purposes, including the production of dairy products themselves. It should be noted that, while still in the testing phase, this is the first documented project that combines all of these technologies with a view to reduce energy consumption during the water purification process by 10%, with an annual water saving of 30%, whilst 80% to 95% of the effluents generated by companies in the food industry can be recycled.

“El Canadell”: the pilot farm that has already started purifying water and making savings European funding has not only been used for research purposes, but the REWAGEN project has also enabled the creation of a pilot plant on a farm where scientists have been able to develop an innovative prototype for an energy-efficient wastewater purification system. The farm in question is “El Canadell”, situated in the town of Vic, in the Barcelona province. Although the results are pending official assessment,

“Most of the energy in dairy is used for heating and cooling” -Dr. Christoph Glasner, Fraunhofer Institute (Germany) according to Dr. Thomas Michael Scherer of the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, it is now possible to suggest that “the system’s operating principle has been proven” and that it has been possible to electrochemically generate hydrogen in the EO unit for later use in electrically powered water treatment facilities. Nevertheless, Scherer warns that the “system is still too small to achieve industrial efficiency” and to suggest a date by which any interested company could use this innovation would, for now, “be mere speculation”.

“Any resources of added value that can be recovered must be recovered, such as lactose, for example.” -Dr. Thomas Michael Scherer

The problems The need for projects like REWAGEN stems from current industrial requirements. This specifically applies to the food industry, which is one of the largest industries in Europe in terms of turnover, and is currently facing several environmental challenges, of which this report highlights two: 1. On the one hand, there’s the energy consumption: each year, around 140 million tonnes of raw milk are produced across Europe, which requires an average energy input of 18,400 GWh1 for equipment sterilisation, lighting, heating, cooling and transport, etc. 2. On the other, the industry consumes huge quantities of water, which in turn become effluents and whey contaminants. In short, the industry produces between 2 to 5 times more effluents than the volume of milk produced2, due to leaks, spills, the cleaning of equipment and facilities, and the disposal of drained brine. With a high 1. Horizon Magazine: Green milk – making dairy more environmentally friendly. 2. 2014 Conama Report: REWAGEN: Electrochemical water treatment system in the dairy industry with hydrogen recovery and electricity production.

concentration of fats, as well as nitrogen and phosphorus, these effluents generated by the dairy industry primarily lead to organic contamination (high COD and BOD levels).

“The system’s flexibility with regard to Industry 4.0 will be crucial for future modifications and optimisations.” -Dr. Thomas Michael Scherer As such, one of the main problems in the food industry lies in the prevention and treatment of effluents. An environmentally friendly, resource-saving treatment is therefore necessary in order to reduce its environmental impact and turn it into a more sustainable business.

KIM Recommendations Knowledge Innovation Market - KIM is involved in the REWAGEN project, which seeks to solve two of the dairy industry’s main sustainability problems (high energy consumption and wastewater pollutants) by adopting the following measures:

1. Implementing a circular economy By keeping water within the dairy industry’s production system many litres of water are saved, and the quantity of wastewater that ends up in rivers or the sea – causing a severe environmental impact – is considerably reduced. In addition, a process such as REWAGEN not only recycles water but also reuses other processed components. For example, whey can be concentrated and used as fertilizer, proteins can be fractionated (separated) and sold, and hydrogen can be used as an energy source within the same system, which not only reduces pollution but also the company’s expenditure.

2. Avoid combining effluents

3. Harnessing the system for other industries Fortunately, the latest innovations in wastewater management – such as the REWAGEN project – are increasing in number, but they pose significant yet realistic challenges for the industry. This does not only apply to the dairy industry, but the solution proposed by the REWAGEN project could also be unfolded across other industries, such as in the production of biodiesel and olives, or in abattoirs.

Autors Knowledge Innovation Market KIM would like to thank Dr. Thomas Michael Scherer, Head of the Physical Process Technology Department at the Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, and Group Manager Physico-chemical Water Technologies, whose participation and collaboration have made this report possible.

Layout by: Ricardo Bermúdez Piñeiro

Water is used for various processes in a dairy plant. It is mixed with certain chemicals that are used to add flavour or consistency to cheese, or with acids to clean machines. Part of the water used in this type of industry does not even need to be treated and can be handled like any other common municipal wastewater. However, all these different water types often end up in a common tank, creating contaminated wastewater that is very difficult to treat. Experts agree that by preventing effluents from being combined, water purification is cheaper and more efficient.