Decision support system on optimized waste collection by vacuum technology with simultaneous production of bioenergy from wastes

The Biosuck project: Decision support system on optimized waste collection by vacuum technology with simultaneous production of bioenergy from wastes is an ERAnet project. The project has been coordinated by Fraunhofer Umsicht in Germany and has had industry partners from Norway (NTNU), Poland (Institute for Ecology of Industrial Areas) and two industry partners form Germany (Bilfinger Water Technologies ? now Aqseptence group and Ingenieurbüro für Wasserwirtschaft und Ressourcenmanagement GmbH). The main aim of the BioSuck project has been to establish a decision support system (DSS) that promotes optimization of collection and utilization of waste streams in the food processing industry. This shall be done by the use of vacuum technology to reduce the water consumption and thereby lead to upconcentration of the waste streams. The concentrated waste streams can then be used for ie production of bioenergy (biogas, bioethanol, hydrothermal carbonization) or recycling of nutrients. The vacuum technology is developed by Bilfinger/Aqseptence for use in for instance municipal sewage systems, but more knowledge is needed about industrial side streams to be able to adapt and start to use the system in the food industry. NTNU?s part of the project has been to characterize the waste streams, both using conventional chemical methods (lipid, protein etc.) and analysis of pollution parameters including chemical oxygen demand, total organic carbon, total nitrogen and total phosphorous. In addition, the samples have been characterized using NMR (nuclear magnetic resonance). This is a method that can be used to determine a range of different substances and metabolites in the waste water. As part of the project, an overview of which methods that are used today for characterization of waste water have been compiled. The overview includes advantages and disadvantages with these methods. Waste water from the fish industry as well as rest raw material from different fish species have been analysed during the project. To study how the composition of the waste water would change by the use of vacuum technology, a model system was generated. Use of vaccum technology may reduce the amount of water used maybe by up to 60% which may make it possible to isolate valuable components from the waste water. The data generated in the Norwegian part of the project will be part of the basis for a decision support system that can be used by the industry to decide what it will be profitable to use different sidestreams and waste water for. The sustainability of the different scenarios has been evaluated by the Polish partner. In order to send samples from different food industries to NTNU it was necessary to freeze the samples that were taken. Comparison of freshly generated waste water and frozen stored samples of the same waste water showed that freezing influence the values for the pollution parameters chemical oxygen demand, total nitrogen, total phosphorous and total organic carbon. To what degree the values were influenced depended both on the sample type and on which parameter that was determined. The effect of freezing on the determination of this type of parameters should therefore by studied further. In the last part of the project, samples received from two plants in Germany, one protein producer and a dairy was analyzed. In order to send these samples from Germany the samples had to be frozen. The samples were taken from different parts of the production process. The results will be used to see how water from different parts of the process can be used in a more optimal way. Waste water with a low content of nutrients and a low organic load can ie be used in other parts of the process. Alternatively, this water could be mixed with water that is more polluted to obtain specific requirements or maximum permissible emission. Waste water with different pH could also be mixed to prevent corrosion in tanks and tubes etc. Use of standard cuvette tests to determine pollution parameters worked well with the exception of determination of biological oxygen demand. This requires use of bacterial cultures adapted to each different waste water. The cuvette tests are relatively easy to use, are standardized with instructions and equipment making it easy to carry out these measurements also in the industry. NMR has been shown to be a very good tool for characterization of metabolites in waste water ? NMR can be used both for determination of different metabolites such as amino acids, but also for determination of metabolites that can give information on the freshness of the raw materials nad use of detergents etc. Two student projects have been carried out in relation to the project.

The project BioSuck aims at establishing a decision support system (DSS) that forces a redesign of the food processing industry with regard to an optimized waste collection system. This shall work via vacuum lines and subsequent processing of concentrated waste into bioenergy or recycling of nutrients. The redesign will save a significant quantity of water, because it requires considerably less water for cleaning purposes when waste is sucked off. This will accordingly decrease the disposed wastewater and thus reduce costs. The concentrated waste (high organic load fraction) can further be used for a self supply with nutrients (fertilizer, food or feeding purposes) and/or bioenergy generated by subsequent processes (biogas, bioethanol, hydrothermal carbon ization). The DSS will need sufficient input data to enhance the combination of solutions for the opitmal redesign within the different sectors of the food processing industry (beverage, dairy, meat, seafood?). Therefore, various waste streams will be cha racterized by conventional and innovative spectral measurements to find new efficient solutions for waste categorization (e.g. bioactive compounds). Additionally, a summary of waste compositions will be made by literature research. The resulting database will supplementary contain the kind of waste accumulation and relevant characteristics of the food sector where it accumulates (possibility for nutrient recycling, etc.). A sustainability analysis of the technologies and processes will be carried out by a n LCA and an environmental impact assessment. A conducted case study will reveal real life data to integrate this data into the DSS. Therefore a small test pilot system for concentrating waste via vacuum lines will be designed and built. The project outco me will be an MS-Excel® based decision support system with a complementary guideline for the redesign of the food processing industry and for closing loops regarding energy and nutrient supply.