Commission Regulation (EC) No 92/2005 (repealed)Show full title

ANNEX I ALKALINE HYDROLYSIS PROCESS

1. Alkaline hydrolysis means treatment of animal by-products under the following conditions:

(a)

Either a sodium hydroxide (NaOH) or potassium hydroxide (KOH) solution (or a combination thereof) is used in an amount that assures approximate molar equivalency to the weight, type and composition of the animal by-products to be digested.

In the case of high fat in the animal by-products that neutralises the base, the added base is adjusted to the current fat content of the material.

(b)

The animal by-products and alkali mixture are heated to a core temperature of at least 150 °C and at a pressure (absolute) of at least 4 bars for at least:

(i)

three hours without interruption;

(ii)

six hours without interruption in case of treatment of animal by-products referred to in Article 4(1)(a)(i) and (ii) of Regulation (EC) No 1774/2002. However, material derived from animals referred to in Article 4(1)(a)(ii) may be processed in accordance with point 1(b)(i) provided that:

• the animals were below 24 months of age at the time they were killed, or

• the animals were subjected to laboratory testing for the presence of a TSE pursuant to Regulation (EC) No 999/2001 and the result of the testing was negative, or

(iii)

one hour without interruption in case of animal by-products consisting exclusively of fish or of poultry materials.

(c)

The process is carried out in a batch and the material in the vessel is constantly mixed; and

(d)

The animal by-products are treated in such a manner that the time-temperature-pressure requirements are achieved at the same time.

2. Animal by-products are placed in a steel alloy container. The measured amount of alkali is added either in solid form or as a solution as referred to in point 1(a). The vessel is closed and the content heated in accordance with point 1(b). The physical energy generated by a constant pumping action continually circulates the liquid material present in the vessel thereby aiding the digestion process until the tissues are dissolved and bones and teeth softened.

3. Following the treatment described above, resulting materials may be transformed in a biogas plant provided that:

(a)

Transformation in a biogas plant of material referred to in Article 4(1)(a) and (b) of Regulation (EC) No 1774/2002 and products derived therefrom takes place on the same site and in a closed system as the process described under points 1 and 2 above;

(b)

An appropriate gas clean-up system is in place to exclude contamination of the biogas with protein residues;

(c)

The biogas is combusted rapidly at a minimum of 900 °C, and followed by rapid chilling (‘quenching’).