SUSMILK - Re-design of the dairy industry for sustainable milk processing (2013-2016)
Industrial food production serves to satisfy basic human needs. The dairy industry accounts with 13% turnover for the total food and drink industry in Europe. The aim of the project SUSMILK is to initialize a change within the process chain for market milk and milk products to minimize energy and water consumption and establish the use of renewable energy resources. For the SUSMILK project, 21 partners from all over Europe joined in a consortium co-funded by the European Commission within the Seventh Framework Programme (FP7).
Milk processing is characterized by a large variety of heating and cooling processes. Main activities in the SUSMILK project are intended to substitute steam as heat transfer medium by hot water produced by means of renewable resources. The supply of heat and electricity shall be completely covered by combined heat and power generation, heat pumps, solar heat and, where appropriate, on-site produced biogas or other renewable fuels produced from waste. Since machines and equipment are often used over time periods up to 30 years in the food industry, such innovations will have an impact on energy consumption and CO2-emissions for the next decades.
To assure a sustainable supply of energy and raw materials over such a long time, the system change is to be implemented in an early stage. Closing water circuits, recycling of CIP solutions containing high organic load and recovery of the inherent heat is a second challenging part of the project.
As a further means to save water and energy, the pre-concentration of milk on the dairy farm will be investigated. This measure has the potential to reduce transport energy, to reduce the sizes of tanks and machines installed in the dairy and possibly increase the efficiency of production processes for cheese, yoghurt and other dairy products. The project includes the development of technical components, of which some were installed and tested at partner dairies of all sizes.
The whole project includes the development of technical components, their installation and testing at partner dairies of all sizes as well as a process simulation of a “green dairy” and the life cycle assessment (LCA) of these developments.
ESU-services is responsible for the LCA of the new technologies developed in the SUSMILK project. In the first step an LCA of a generic dairy was prepared. In the second step different improvement options are assessed. This work perfectly combines two of our main fields of expertise: food production and energy technologies.
The GreenDairyNet, is a platform that allows the private contact, meeting and knowledge sharing for experts and stakeholders in the European dairy sector that are interested in sustainable development and resource efficient processing technologies.
Life cycle assessment of improvement options for processing raw milk in dairies
Within the SUSMILK project, a detailed model for energy and material flows in a dairy was developed. The LCA conducted by ESU-services identifies the relevance of energy and water uses in different process stages in a dairy from an environmental point of view. It also shows the potential of improvement options to reduce the impact of heat, cooling and electricity demand. The LCA results including a description of the goal and scope are published in a public report. For the analysis of improvement options, data from project partners was collected. This life cycle inventory analysis is documented in a confidential deliverable.
The environmental impact of dairy processing from cradle to dairy gate was analysed with 15 environmental impact categories (recommended by European authorities) and with the cumulative exergy demand. In addition, these category indicators were summarized to a single score applying different approaches. All recommendations are based on both result types.
Raw milk production has the highest impact from cradle to dairy gate. Thus, the production systems used for the raw milk have a decisive role for the overall environmental impact of dairy products. Raw milk supply and a reduction of milk losses at the dairy should be given priority in environmental improvement strategies. Other important aspects are the choice of packaging, effluent treatment and raw milk transport. The impact of electricity and steam demand has to be considered as well, whereas the impact of the chemicals used for cleaning-in-place is very small.
Different improvement options that deliver heat, cooling and electricity were compared in this study. The best option is the reduction of the energy demand with a clever process design or the integration of heat exchangers.
The next best step is the replacement of existing technologies. For heating, a motor CHP (combined heat and power) plant driven by natural gas can be clearly recommended as a replacement of a natural gas boiler. If waste heat at high temperatures is available, a gas-engine driven heat pump can be recommended as well. Solar collector systems and a CHP plant driven by wood have higher environmental impacts in some environmental categories and lower in others, so that the recommendation depends on personal value choices. For solar collectors, an installation of solar collectors on flat roof is better than an installation on open ground. The share of heat delivered depends on available roof size and location (Southern Europe preferred) and thus the choice of the additional heat source is crucial. Pellet boilers cannot be recommended since they have higher environmental impacts in many environmental categories than the natural gas heating. Cooling with groundwater can clearly be recommended to replace electric cooling if no local environmental problem is affected (water temperature or scarcity). If waste heat is available, the integration of an absorption chiller can be recommended as well. If a co-generation plant was integrated for heat delivery, an absorption chiller driven by this heat can still be recommended, though the reduction potential is less high compared to the use of waste heat.
The detailed model of dairy processes can also be used to better understand the relevance of sub-processes in the dairy and to allocate environmental impacts of processing to single products.
- Keller R., Jungbluth N. and Eggenberger S. (2016) Milk Processing – Life cycle assessment of a detailed dairy model and recommendations for the allocation to single products. In proceedings from: The 10th International Conference on Life Cycle Assessment of Food (LCA Food 2016), University College Dublin (UCD), Dublin, Irland, 19th – 21st October 2016, retrieved from: http://lcafood2016.org/.
- Jungbluth N., Keller R., Doublet G., König A. and Eggenberger S. (2016) Report on life cycle assessment, economic assessment, potential employment effects and exergy-based analysis: Part I - LCA. Deliverable 7.3. SUSMILK - Re-design of the dairy industry for sustainable milk processing, Seventh Framework Programme: Project no. 613589. Funded by EC. Deliverable D7.3.
- Jungbluth N., Keller R., König A. and Eggenberger S. (2016) Life cycle inventory analysis. SUSMILK: Re-design of the dairy industry for sustainable milk processing. Project funded by the European Commission within the 7th Framework Programme. Project number n°613589. Deliverable D7.2 (confidential). ESU-services Ltd.
- Jungbluth N., Keller R. and Doublet G. (2014) Goal and scope definition for the life cycle assessment. SUSMILK: Re-design of the dairy industry for sustainable milk processing. Project funded by the European Commission within the 7th Framework Programme. Project number n°613589. ESU-services Ltd., Zurich.
The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement nº 613589.