Velocys Technologies Limited

Graham Lea

Laura J Silva

Ivan Philip Greager

In a process for treating wastewater from a combined gasification and Fischer-Tropsch (F-T) process, feedstock derived from Municipal Solid Waste or the like is gasified in a reactor (R) and treated in a cleanup unit (C) which generates a first wastewater stream (1st WWT STREAM) containing salts and inorganic pollutants. The first wastewater stream is treated in a treatment unit (T) to remove inorganic pollutants derived from the syngas. The treatment comprises a) degassing, and subsequently b) neutralising the first wastewater stream before treatment in a Dissolved Air Flotation unit () and filtering in a moving sand bed or similar () to remove solids, and a stripping process to remove ammonia. A second wastewater stream (2WWT Stream) containing organic pollutants but being low in salts arises from the F-T process and is treated separately to allow recycling within the F-T process.

Gasification and Fischer-Tropsch process waste water treatment

The Fischer-Tropsch (FT) process creates significant amounts of water. The invention provides an aqueous composition comprising specified amounts of dissolved and suspended solids, low chemical oxygen demand and low chlorine demand, pH in the range of 6.5 to 8.0, where the aqueous composition comprises organic carbon derived from fossil sources.

Methods of making purified water from the Fischer-Tropsch process

The Fischer-Tropsch (FT) process creates significant amounts of water. This FT produced water contains significant amounts of organic impurities. The invention provides methods of treating FT produced water. Surprisingly, it was discovered that the FT produced water could be successfully treated in a membrane bioreactor (MBR) according to relatively simple and more efficient steps; for example, by adjusting the pH of the water in the range of 4.2 to 5.8 or treating the FT produced water in a stripper where the distillate product stream and a reflux stream returning to the stripper have the same composition. In a related aspect, water compositions are described.

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Oxford Cluny, United Kingdom

Graham Lea