Process for the purification of an aqueous stream coming from the Fischer-Tropsch reaction

摘要

Process for the purification of an aqueous stream coming from the Fischer-Tropsch reaction which comprises feeding said aqueous stream to one or more pervaporation units obtaining an aqueous stream enriched in oxygenated organic compounds (retentate side) and an aqueous stream enriched in water (permeate side), feeding said aqueous stream enriched in oxygenated organic compounds to a saturator obtaining a gaseous stream leaving the saturator, feeding said gaseous stream to a synthesis gas production plant. Said process allows at least a part of the aqueous stream coming from the Fischer-Tropsch reaction to be used as process water in a synthesis gas production plant, subsequently sent to a Fischer-Tropsch plant for the production of hydrocarbons.

主权项

1. A process for purifying a feed aqueous stream from a Fischer-Tropsch reaction, the process comprising:
feeding the feed aqueous stream to a pervaporation unit to obtain a first aqueous stream and a second aqueous stream; feeding the first aqueous stream and a process gas to a saturator to obtain a gaseous stream; and feeding the gaseous stream to a synthesis gas production plant; wherein: the feed aqueous stream comprises organic reaction by-products from the Fischer-Tropsch reaction; the pervaporation unit comprises a hydrophilic pervaporation membrane; the first aqueous stream is from a retentate side of the hydrophilic pervaporation membrane; the first aqueous stream is enriched in alcohols having from 1 to 20 carbon atoms relative to the feed aqueous stream; the first aqueous stream comprises organic acids having from 1 to 10 carbon atoms in an amount 0.5% by weight or less; the first aqueous stream optionally comprises volatile compounds; the second aqueous stream is from a permeate side of the hydrophilic pervaporation membrane; and the second aqueous stream is enriched in water relative to the feed aqueous stream.