Method for cleaning tar-bearing waste water and apparatus for performing said method
AssigneeBabcock & Wilcox Volund APS
InventorThomas R Nissen
Life of this patent
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Abstract
In a method and an apparatus for cleaning tar-bearing waste water (17), a mixture of water and hydrocarbons, e.g. comprising polyaromatic hydrocarbons and phenols, the mixture is separated into a low-boiling-point part and a high-boiling-point part, bringing the low-boiling-point part on vapour form in a boiler (1), and the low-boiling-point part is cracked in vapour form at a high temperature in a reactor (2), providing light combustible gases, which can be utilised in e.g. gas engines, gas turbines or the like. Furthermore, the high-boiling-point part may be used for energy supply to the process or other processes or as an alternative be cracked for providing light combustible gases.
Claims18
Method for cleaning tar-bearing waste water (17) (a mixture of water and hydrocarbons, e.g. comprising polyaromatic hydrocarbons and phenols), characterized by comprising
- a) separating the mixture into a low-boiling-point part and a high-boiling-point part, bringing the low-boiling-point part on vapour form,
- b) cracking (2) the high molecular hydrocarbons from the low-boiling-point part in vapour form at a high temperature, thereby converting its contents of hydrocarbons to products that are on vapour form at atmospheric pressure and ambient temperature, which products are light combustible and can be utilised in e.g. gas engines, gas turbines or the like,
- c) condensation of the water contents of the cracked low-boiling-point part, thus separating the cracked low-boiling-point part in water and light combustible hydrocarbons.
Method in accordance with any of the preceding claims, characterized by comprising the burning of at least part of the high-boiling-point part for providing the high temperature for the cracking processes under b).
Method in accordance with any of the preceding claims, characterized by further comprising a heat exchange (3) between the cracked vapour and the vaporised low boiling-point part to be cracked.
Method in accordance with any of the preceding claims, characterized by at least part of the cracked vapour (4) being used to provide energy for the evaporation of the tar-containing water.
Apparatus for cleaning tar-bearing waste water (17), e.g. a mixture of water and hydrocarbons, e.g. polyaromatic hydrocarbons and phenols, characterized by comprising a boiler or evaporator (1) for evaporation of the mixture, a separator (7) for separating the high-boiling-point part of the mixture and a reactor (2) for cracking the remaining evaporated mixture, a heat exchanger (3) between the boiler (1) and reactor (2) for performing a heat exchange between the mixture flowing towards the reactor (2) and the mixture leaving the reactor (2), and a connection (4) feeding the mixture leaving the reactor (2) and heat exchanger (3) to the boiler (1), thereby extracting energy for the evaporation from this mixture.
Dependencies are inferred from the claim text.