Energy optimisation at Peka Kroef in Odiliapeel

Peka Kroef is a potato processing company producing fresh potato products. The company is supplying freshly packed pasteurised potato products to restaurants, professional kitchens and to retail companies. 

The potatoes are being peeled and processed into end products based on customer demands. Potatoes are being blanched or pasteurised and the heat for these processes is supplied by using steam. After the heat treatment the products are cooled down rapidly to guarantee the best quality. During the whole process the focus is on quality and hygiene aspects.   

Peka Kroef expects the demand for their products will increase further during the next years. For this reason the company is considering an expansion of the production capacity which seems to be the right moment to optimise the energy supply to all process lines. 

Epro Consult was asked to carry out a study to analyse the options for the optimisation of the energy supply side, mainly focussing on the heat supply. 

In relation to the production expansion plans a new boiler house will be build in order to meet the steam demand. Part of the steam generation will carried out by a wood fired steam boiler. The rest will be supplied by natural gas fired steam boilers. The steam demand is at two pressure levels, one is 7 bar(g) and the other is 14 bar(g). Part of the study was focussed on the selection of a steam net based on one or based on two steam pressure levels. 

Before drawing conclusions with respect to the stem generation Epro Consult has analysed the steam demand side. Steam consumption subdivision can be seen below.

 

                       

 

The company operates three air treatment units which have been installed mainly to reduce humidity and to avoid growth of micro organisms in the production areas. 

Apart from the steam demand shown there are smaller heat consuming units like the CIP (cleaning in place), hand operated washing equipment and during winter time also some heat supply to the anaerobic water treatment plant. Part of the water supply is coming from the water treatment plant and is further treated by reversed osmosis and then used as “technical water” mainly as boiler feed water. 

After having made the inventory of the steam demand Epro Consult has studied the options for waste heat recovery. Two options appeared to be interesting, one is heat recovery from pasteurisation vapours and the other one is heat recovery from the dryers. 

In total about 30 tonnes/h of steam will be needed to meet the future steam demand. Mainly because of the length of the piping it seemed not feasible to build two sepearte steam pipe lines for two pressure levels. 

By applying waste heat recovery and by installing a hot water loop about € 300.000,- can be saved yearly within a pay back time of about 1.5 years. The steam savings will be about 7% of the total steam demand.

 

 

Because more options for heat recovery seem feasible further study will be planned in order to optimise a waste heat recovery system (hot water loop). Waste heat recovery from the dryers still needs to be elaborated on since these vapours might cause contamination and might result in unwanted microbiological growth.