A two-step process for removal of carbon dioxide and production of desalinated water using ammoniated saline water OMAR CHAALAL MD. MONWAR College of Engineering United Arab Emirates University Address P.O, Box !5551 Al Ain COUNTRYUNITED ARAB EMIRATES chaalal@scientist.com Abstract: - The emission of CO2 has been increasing steadily and reached the critical concentration of 400 ppm in 2013 for the first time. CO2 removal from the sources such as fossil-fuel power plants and similar sources is of paramount importance to these industries and to reduce the effect on global warming. A two-step process is investigated experimentally to remove CO2 from a synthetic mixture of natural gas containing it. The first-step of the process is based on the modified Solvay process and involves the chemical reaction between CO2 and ammonia in saline solution. This process can reduce CO2 by about 99% and at the same time it can reduce water salinity by 40%. The process produces sodium bicarbonate and ammonium chloride which are at high concentrations. The second step uses a membrane extraction method to reduce the concentration of ammonium chloride to produce treated water that can be used for irrigation purposes. This combined process is potentially more effective and less harmful than the conventional amine scrubbing process. This innovative process has been applied to the sweetening of natural gas in the laboratory and can be extended to treat similar sources. Simultaneous reduction of salinity to produce treated water is an additional benefit of this process. Key-Words: - removal, carbon dioxide reduction, desalinated water, ammonia, extraction. 1 Introduction Power plants, oil refineries, desalination plants, steel mills, paper mills, cement factories and other facilities create megatons of manmade CO2 emissions that are beyond the earth’s ability to absorb and neutralize. The emission of CO2 has been increasing steadily and with the increasing demand of desalinated water (especially in GCC countries) this is expected to increase at a faster rate (Dawoud and Al Mulla, 2001). Saline water is also coproduced during oil and gas exploration. Further, the produced gas contains up to 10% carbon dioxide. The huge amount of saline water, which is discharged, rejected or dumped back in the oil and gas fields, is a real production problem(Jibri and Abrahim, 2001; Abdel-AAl, 1997). Carbon dioxide is very corrosive in presence of water, it has no heating value and is a major contributor to the greenhouse effect. The co- existence of carbon di-oxide and saline water in oil and gas extraction industries are creating problems and require urgent solution. Therefore, the available commercial processes are being evaluated and new processes are being investigated for complete or partial removal of CO2 preferably using the huge amounts of saline water around (or produced in) the GCC countries. There are processes available for carbon dioxide capture (David and Kishore, 1999; Ritter and Ebner, 2007; Washim Uddin and Hagg, 2012; Scholes et al., 2008; Madsen, 2011). They are effective, but have disadvantages in large-scale applications. Furthermore, CO2 absorbed in these processes cannot be released and require additional handling systems. Amine scrubbing is successful but expensive and has corrosion problems. Carbon dioxide capture by cryogenic distillation requires large amounts of energy and have problems dealing with high temperature gases. Various membrane- based processes are being investigated in last two decades (Mohshim et al., 2013; Strathman, 2001; Recent Advances on Environmental and Life Science ISBN: 978-1-61804-332-0 80