Method of and arrangement for continuous hydrolysis of organic material

Abstract

A method of and arrangement for continuous hydrolysis of organic material in the form of sludge with a dry solids content of 1-20% are described. The method includes the following steps: (a) heating a sludge containing the organic material with a low content of abrasive components and a dry solids content of 1-20%, to a temperature of approximately 100° C.; (b) mixing the sludge with steam at a pressure of 1-4 bar a; (c) leading the sludge/steam mixture to a preheating tank (4); (d) increasing the pressure of the sludge/steam mixture from 3 to 10 bar a; (e) leading the sludge/steam mixture to a reactor (7); (e) depressurising the sludge/steam mixture to 1-4 bar a in a depressurising tank (10); (f) separating sludge and steam, and possibly (g) cooling the sludge further. The arrangement includes: (i) a feed pump connected to a first heat exchanger (2) for heating the incoming sludge through heat exchange with the outgoing sludge; (ii) a mixing device (3) for mixing the sludge with steam, connected to the first heat exchanger (2); (iii) a preheating tank (4) connected to the mixing device (3); (iv) a pump (5) for increasing the pressure of the steam/sludge mixture by from 3 to 10 bar a, connected to the preheating tank (4); (v) a reactor (7) at a temperature of 130-180° C., connected to the pump (5); (vi) a depressurising tank (10) connected to the reactor (7), which depressurising tank (10) includes a nozzle (9) for depressurising the steam/sludge mixture to 1-4 bar a.

Dependencies are inferred from the claim text.