Saving energy in plastics extrusion: from insulation to one's own combined heat and power plant
Troisdorf, 02.07.2013. Plastics extrusion produces every year tons of films, filaments and other products for the food industry, hygiene or medicine. In recent years the demand for sustainability has risen, especially for products in the consumer sector. If one considers the entire life cycle of the products, it quickly becomes clear: A transition to solely alternative raw materials is not a viable solution for the future. Those wishing to produce sustainably and reduce the energy consumption and CO2 immissions will have to begin with production processes: The respective solutions for greener plastics extrusion processes are already available. The Reifenhäuser Group, the worldwide leading manufacturer of plastics extrusion lines and components, is offering with its Blue Extrusion program a range from small measures such as insulation up to large measures such as made-to-order combined heat and power plants.
The Reifenhäuser Group recognized early on the necessity for sustainable production and has reacted accordingly. Ralf Pampus, responsible for the subject of Blue Extrusion within the Reifenhäuser Group, said: "We estimated our energy consumption earlier the way many continue to today. But we were no longer satisfied with this. Our specifications today are based on measurements. We know precisely how much energy we consume and crucially: We know where we consume energy. This way, we can target those areas where our measures have the greatest potential." The following examples of Blue Extrusion measures show how this strict approach has paid off, especially for the customers of the Reifenhäuser Group:
Heating: It does not always have to be electric
Reifenhäuser REICOFIL, specialist for nonwoven lines, offers its customers for instance an alternative heating concept. With conventional electric heating, the degree of efficiency is just about 31 percent. Those who instead use natural gas for the heating of melt-blown pressure hot air, calenders and dryers can increase the degree of efficiency up to 90 percent and thus save twice: The CO2 immissions for a 3.2 meter wide six-beam system can be sunk by approx. 14 percent with the alternative heating. At the same time, producers save energy costs. The large savings varies greatly from country to country due to the different prices for electricity and gas – but in all cases worthwhile.
Saving raw material through high level of automation and sophisticated features
Saving of raw materials allows a more sustainable and more economically efficient production. In plastics extrusion, raw material costs normally account for about 80 percent of the complete production costs. Thanks to a high level of automation of its lines, Reifenhäuser reduces set-up times and thus waste material. The start-up assistant from Reifenhäuser Kiefel Extrusion, for instance, reduces the start-up time after product changes by 50 percent. Producers producing 500 kgs/h on 300 days a year, and requiring about two new starts a week, can save 11,000 kgs per year, corresponding to 15,000 euro per year. They can even save more using the product change assistant which, thanks to pre-defined sequences, enables an automatic product change that is much faster than the manual mode. The change-over time can be reduced by up to 70 percent which corresponds to savings in raw material of 50,000 kgs per year.
Combined heat and power from one's own plant
If a part of the power is produced on one’s own, the arising waste heat can be used for operating the system. Combined heat and power plants, which can be laid out individually for each customer and their plastics extrusion lines, make this possible. Producers can thus achieve over 90 percent total degree of efficiency under optimum conditions, because the waste heat can be targeted for use at different temperature levels. In the case of nonwoven lines, high temperatures can be utilised for instance for generating melt-blown pressure hot air or for heating calenders and dryers. The waste heat from lower temperature levels is suited for pre-heating of process air or secondary air, for room heating or – when using absorption refrigeration – even for process cooling or the air conditioning of a building. By producing their own electricity, producers are prepared for the otherwise expensive load peaks.
Beyond fossil fuels such as heating oil or natural gas, combined heat and power plants can also be operated with renewable fuels such as plant oils or biogas. This makes producers more independent from fossil fuels and raises the local return on investment, depending on location. In combination with the high total degree of efficiency, the CO2 balance of the line can thus be significantly improved. Producers using combined heat and power produce not only with less resources and thus more sustainably, but can also cut their production costs. The possibilities for savings depend on many factors, such as price for the raw materials, the total energy need of the line or the government subsidisation of combined heat and power plants. The interplay with nonwoven lines allows the investment in a combined heat and power plant in many cases to be amortised within less than two years. The total annual savings potential is then more than 700,000 euro. The concept is generally transferable to all plastics extrusion lines.
Interested parties can find further information about Blue Extrusion and the concrete measures behind it at the K 2013. The Reifenhäuser Group will be there with all business units together at stand C22, hall 17.
Blue Extrusion:Selected sustainable measures of the Reifenhäuser Group
- An energy efficiency package such as:
- Additional insulation
- Down Gauging
- Development of systems technology for
- Processing renewable raw materials such as PLA and Lyocell
- Processing of 100% recycling material
- Concept for the utilisation of combined heat and power plants for supplying production lines with electricity and heat
- Heating with gas instead of electricity
- Use of energy efficient motors of highest energy efficient class
- Use of frequency-stabilized pumps
- Energy savings through optimized low-temperature screws for all kinds of polyolefins and barrier products
- Refitting cooling units with climate compatible refrigerating agents
- Recycling braking energy of rotating masses
- Heat recovery from exhaust air
- Stretching using initial heat
- Waste reduction, for instance with a high level of