Energy efficiency opportunities within the powder coating industry - Energy audit and pinch analysis

The powder coating industries in Sweden use about 525 GWh of energy every year. The need to reduce the energy use is increasing due to increasing energy prices but also due to demands from customers. Most plants uses LPG and electricity, which has an energy price that is expected to increase by 50-60 % until 2020 compared with the prices in 2010. This type of industry has had focus on environmental issues concerning hazardous chemicals and powder types. However, focus has not been on energy efficiency measures. In this project the powder coating company Quality Powder Coating AB was investigated. At the same time Sofie Osbeck from Linköping University conducted a parallel project at LaRay AB. The objective of the projects was to perform energy audits and calculate possible energy efficiency measures to see the energy efficiency potential within this type of industry. The project was separated into four main parts. These parts were fact and data collection, energy audit, calculations of energy efficiency opportunities and benchmarking with the project at LaRay AB. The energy audit showed that QPC AB uses approximately two GWh of energy each year distributed on LPG, electricity and district heating. The biggest consumers of energy within the plant are the cure oven, drying oven and pre-treatment unit. The largest consumer of electricity is the powder box due to its high ventilation. The heat exchange possibilities were investigated by the use of pinch analysis and three possible networks for heat exchange were compiled. These networks are either based on heat exchange for the ovens or with an additional cooling zone. In this project it was showed that the energy usage for QPC AB can be reduced with 420 MWh of energy per year which equals 21% of their total energy consumption. This energy reduction will also lead to cost savings of 24% compared with 2010 or 330 000 SEK per year and savings of carbon dioxide emissions of 157 tonne or 25%. The results for the project at LaRay AB were that the energy use can be decreased by 30%. Since powder coating industries is quite homogeneous the conclusion of these two projects is that the energy use within powder coating industries can be reduced by at least 20%, which responds to 105 GWh per year. Benchmarking between the two projects showed that heat exchange should be conducted within the same unit in the process