Division 2 Processing method

The high pressure hydrolysis biogas process shall be carried out according to the following processing standards:

1. (a)

   The animal by-products must be first processed using processing method 1 (pressure sterilisation) as set out in Chapter III in an approved processing plant;

2. (b)

   Following the process referred to in point (a), the defatted materials must be treated at a temperature of at least 220 °C for at least 20 minutes at a pressure (absolute) of at least 25 bar, heated in a two-step procedure, first by direct steam injection, secondly indirect in a coaxial heat exchanger;

3. (c)

   The process must be carried out in a batch or continuous system and the material is constantly mixed;

4. (d)

   The animal by-products must be treated in such a manner that the requirements regarding time, temperature and pressure are achieved at the same time;

5. (e)

   The resulting material must then be mixed with water and anaerobically fermented (biogas transformation) in a biogas reactor;

6. (f)

   In the case of starting material of Category 1, the entire process must take place on the same site and in a closed system and the biogas produced during the process must be combusted rapidly in the same plant at a minimum of 900 °C followed by rapid chilling (‘quenching’).