INEDIBLE RENDERING BY MEANS OF THE WET PRESSING PROCESS - DEMONSTRATION PROJECT
The rendering of offal and waste materials from slaughtering and meat processing is based traditionally on batchwise dry rendering followed by separation of meat and fat by means of solvent extraction. The energy consumption in such a process is high, i.e. of the order of 75 kg fuel oil per tonne raw materials having an average water content of nearly 60 %. A new energy saving process has been developed based on a conditioning and prepressing of the new materials at temperatures of the order of 60 degrees C. The pressing procedure divides the materials into a solid phase with low fat content and a fluid phase containing more than 60 % of the total water and nearly all the fat. The solid phase is dried in an indirectly heated drier. The fat from the fluid phase is removed in a tricanter. 80-90 % of the water in the resulting liquid phase is removed in a three-stage vacuum evaporator using waste heat from the driers as heating medium. Pilot experiments have indicated that such a process is feasible and that the energy consumption in the process would be of the order of 35 kg fuel oil per tonne. The objective of the present project was to design and construct a full-scale production line using the wet pressing system, to demonstrate the feasibility of the process in full-scale operation and to obtain key figures for the energy consumption. The project was carried out at the Danish cooperation rendering plant KOFO in LOEsning. It was proven that the process - with minor modifications - is highly feasible in large scale operation. The measuring of energy consumption showed the following figures: (i) 33.2 kg oil per tonne offal or 60.1kg per tonne water evaporated, and (ii) 69.1 kWh per tonne offal or 125 kWh per tonne water evaporated. An annual energy saving of 1 632 toe was recorded for the wet pressing system compared to the conventional process formerly used at KOFO and based on a throughput of 50 000 t offal per year.
Bibliographic Reference: EUR 10652 EN (1986) FS, 21 P., BFR 200, EUROFFICE, LUXEMBOURG, POB 1003
Availability: Can be ordered online
Record Number: 1989124113200 / Last updated on: 1987-01-01
Available languages: en