Patent ID: 9340440
Filing Date: 2016-05-17
CPC Classification: C02F,Y02W

Claim Text:
1. A method for the treatment of waste water from a plant for the hydrothermal carbonization of feedstocks (HTC plant), wherein process water is partly evaporated, the process steam thus obtained is condensed, the process steam condensate thus obtained is discharged from the HTC plant at least as partial quantity of waste water, and the waste water is biologically treated, characterized in that the steps of one of the following alternatives (A) or (B) are carried out, namely either: the steps of alternative (A) that: (A-1) a minimum quantity of process water is discharged from the HTC plant as waste water, which is required to raise the ash melting behavior of the carbonized feedstocks in such a way that an increase of an ash softening temperature to at least 1000° C. is achieved, and (A-2) in addition to step (A-1), either (a) the water content of the feedstocks is limited to such an extent or (b) the evaporative capacity of a thermal drying of the carbonized feedstocks in a steam atmosphere is increased to such an extent that the residual process water to be discharged from the HTC plant as waste water is evaporated in steam atmosphere in the thermal drying, or the steps of alternative (B) that: (B-1) so much additional process steam condensate is obtained by the evaporation of process water in an evaporation plant and its subsequent condensation and is discharged from the HTC plant as waste water, as results from the difference between the quantity of waste water and the quantity of process steam condensate from a thermal drying of the carbonized feedstocks in a steam atmosphere, and (B-2) in addition to step (B-1), from a concentrate of the process water evaporated in the evaporation plant such a quantity is discharged from the HTC plant as waste water or as waste as is required to adjust the ash melting behavior of the dry carbonized feedstocks in such a way that the ash softening temperature does not fall below a defined minimum, and (B-3) in addition to carrying out steps (B-1) and (B-2), in case additional concentrate is present in this concentrate: is introduced into the hydrothermal carbonization or admixed to the carbonized feedstocks before mechanically dewatering the same or is supplied to the thermal drying of the carbonized feedstocks.