METHOD FOR TREATMENT OF PROCESS WATER

摘要

Within the scope of hydrothermal carbonization of biomass, not only the main product, coal, but also the platform chemical 5-hydroxymethyl furfural, as well as furfural and levulinic acid, are formed. These are extracted from the process water of the carbonization reaction. However, in this connection, the problem exists that humic substances deposit on the container walls of the extraction column and can only be removed again by means of great cleaning effort. Furthermore, oligomers clearly worsen the purity of the product. This problem is solved by a filtration cascade through which the process water passes before extraction. In this connection, first the impurities mentioned are removed in a first filtration stage, and the remaining products and educts are separated from one another in a second filtration stage. Only the products are passed to extraction.

主权项

1. Method for treatment of process water (1) of a hydrothermal carbonization process, wherein, in a first filtration stage (2), the process water (1) is separated into a first retentate that essentially contains impurities (3) and a first permeate (4) that essentially contains products (7) and educts (6), and the first permeate (4) is passed to a second filtration stage (5), in which the first permeate (4) is separated into a second retentate (8) that essentially contains educts (6) and a second permeate (9) that essentially contains products (7), after which the second permeate (9) is passed to an extraction step for extraction of the products (7) or to an alternative further use.