Cleaner Technology Projects in Denmark 1996
Cleaner Technology and Recycling at Frigodan, Orehoved and Frigodan, Svendborg
Renere teknologi og genbrug på Frigodan, Orehoved og Frigodan, Svendborg
Arbejdsrapport nr. 32, 1996, Miljøstyrelsen
There is a tradition that the process water from the vegetable food industry is eliminated by ejection or by purification in biological purifying plants. Both solutions are connected with technical and practical problems. This projects aims at clarifying - by means of physical and chemical processes - whether it is possible to purify the process water to an extent that it can be recycled in the firms.
The food industry is characterised by seasonal production with a large water consumption, which means that a purifying plant should be able to manage varying loads. Moreover, the purifying plant has to be made ready for the season by adding a substance with another composition than that of the actual process wastewater. As the firms in the food industry are often large, the load will be heavy and rather varying. This fact will require large investments in machinery.
The results of the project are illustrated in figures that are enclosed as appendix in the project.
The water consumption, defrosting of freezers, and refrigerating plants are described for Frigodan, Orehoved and Frigodan, Svendborg. Suggestions to water-saving measures are made. Where it was possible, the expected profit is stated.
The energy consumption of electricity and gas in Svendborg is revised for all products and consumption places. Apart from the total annual energy consumption, the electricity and gas consumption per ton-finished goods is also stated and commented on. As regards to Orehoved, the total consumption of electricity, gas and oil is revised.
Considering the limitations of upgrading the results of the test plant to a full-scale plant, the following conclusions can be made:
 | It is possible to evaporate an average water flow from the firms so that the condensation can be recycled in the production. |
| With a number of process-water flows it is possible to achieve a water quality, which complies with the water requirements. |
| Ejection or recycling in selected parts of the production is very likely to take place immediately; if the evaporation occurs in a plant specifically constructed for the purpose. |
| The content of bacteria and embryo in the condensate was always situated below the drinking water requirements. |
| Tests with flotation/sifting/RO filtration resulted in an out-flow from the RO filtering, which can neither comply with the drinking water requirements nor be drained of. |
| Concentrate from the above processes can be used as fertiliser in the agriculture, and, in some cases, as feed. |
| The estimated costs of the above solutions are higher than the traditional solutions. However, audits of draining taxes or green taxes can change this picture. In addition, the firms’ possibilities of increasing the production, while avoiding a corresponding increasing environmental impact, and the social value of the solutions must be taken into account. |
| Especially at Frigodan, Svendborg there was a possibility of reducing water and energy consumption considerably. In some cases, the measures were relatively simple, and, in others, significant changes in the existing productive equipment had to be made. This picture is likely to be general for this type of firm. |
Author/ institution
Hedeselskabet
This report is subsidised by the National Council for Recycling and Cleaner Production
ISSN no. 0908-9195
ISBN no. 87-7810-599-4