Gas to Liquids, or GTL, is a technology breakthrough to convert natural gas into high-performing, ultra-clean liquid fuels by means of Fischer-Tropsch (FT) reaction. A by-product of the FT reaction is process wastewater, generated in large volumes, 25% more than hydrocarbon products, on a weight basis. The process wastewater generated from GTL industries needs to be treated to comply with the standards set by Regulatory Agencies for effective reuse as well as for safe discharge into the sea or other water bodies. The treatment and management of wastewater for reuse and disposal is particularly important for Gulf countries, since they occupy one of the most arid regions in the world. This paper addresses treatment methodology for GTL process wastewater and the management of treated wastewater, including approaches to their reuse and alternate disposal options.
The first part of this paper identifies source of wastewater from the GTL industries and briefly describes typical contaminants found in process wastewater and extensively illustrates treatment technology. Process wastewater mainly contains dissolved hydrocarbons and acidic contaminants, such as, alcohols, acids, ketones, aldehydes, acetates and other oxygenates. The second part discusses the management of treated water for various applications and how they are reused or alternatively disposed off. In addition a number of recommendations, emphasizing in particular that more efforts are needed in GTL industries for the improvement of water reuse through an integrated, multi-disciplinary water management strategy.