Energy technology innovations for sustainable climate protection
Vereinigte Fettwarenindustrie (VFI) is the result of a merger of three medium-sized companies based in Wels, Vienna and Innsbruck. The manufacturing facility in Wels was expanded and produces liquid oil and frying grease for consumers. Today, VFI supplies customers all over Europe from the site in Wels. At the moment, production takes place from Monday through Friday in 2-shift operation and is scheduled for extension to 4-shift operation.
Annual power consumption stood at roughly 4 GWh and heating oil consumption at around 5.5 GWh. The previous energy supply system was no longer state-of-the-art and broke down repeatedly due to technical defects. As a result, a more efficient and new supply system was discussed, followed by development of a new concept.
Measures implemented: The steam boiler (3t/h) consuming roughly 2.2 MW was exchanged. At the same time, the facility was converted from oil to natural gas. This conversion was the prerequisite of installing a cogeneration system, as a combined heat and power plant, mainly as the course of electricity demand was a strong argument for generating electricity internally. For the time being, only one CHP plant was installed, by now another CHP plant has been added. Electricity production now stands at 580 kW (2 x 290 kWel), covering almost two thirds of what previously had to be bought from outside.
While the CHP plant's high waste gas temperature (approx. 450-500°C) is directly fed into the gas boiler plant for optimal use, the waste heat from the cooling water and lubrication system is directed into a buffer storage system and slowly released again to consumers within the company premises (apart from high quantities of hot water, these are mainly heat processes for oils and heating purposes). The steam boiler base load can be maintained largely by the two CHP plants (steam maintaining operation mode), with one CHP plant providing basic thermal supply and electrical base load (also during night time), while the other one covers output peaks and is needed during daytime production anyway. Steam peaks are covered by the natural gas firing system.
Construction of a cogeneration plant for steam generation
VFI improves energy footprint
Vereinigte Fettwarenindustrie in Wels makes more of natural gas as energy supply source.
Gas is still, but more efficiently, used as an energy source and leaves open the option of using biogas. A cogeneration plant for conversion into electricity via two cogeneration plants is operated jointly with the gas-fired steam boiler plant in production.
Additionally, a buffer storage system has been set up for all heat recovery processes and optimal heat distribution. Measuring site data collection combined with an energy management system complete the plant.
The payback period for the sum invested is less than 5 years. Overall efficiency was improved by approx. 33 %.
As concerns climate protection, CO2 emissions are reduced by 755 t/a.
Buffer storage system serving as energy hub for heat
A generous buffer storage system accommodating any "heat surplus"
Cooling water heat and lubricant heat from the CHP plant,
waste heat from compressed air generation,
heat recovery from manufacturing processes during production,
serve as the hub for further energy utilisation and distribution within the company.
A sufficient number of measuring sites for capturing energy data ensure both a transparent internal energy balance and, in tandem with an energy management system, efficient operation of the system.
Results:
Energy cost reduction: 43 %
Payback period: < 5 years
Overall efficiency improvement approx. 33 %
Construction of the plant was started in April 2009. It has been in operation since December 2010 (followed by the second CHP plant in spring 2011).