Research Information System
Thesis Type: Postgraduate
Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey
Approval Date: 2011
Student: DUYGU UYSAL
Supervisor: ÖZKAN MURAT DOĞAN
Abstract:One of the most important problems of the world is global warming, which is caused by greenhouse gases emitted to atmosphere from all over the world. Preventing CO2 emission, especially from power plants by capturing and storing, is important to decrease the effect on global warming. Today, amine or ammonia like solutions are the mostly used chemicals to capture CO2. CO2, captured by these solutions in absorption columns, can then be sent to some underground geological formations or to deep parts of oceans in order to store it. This work is about capturing CO2 from flue gases. Firstly, CO2 capturing capability of sodium metaborate was investigated and it was proven that it can capture CO2. Then, in bubble column absorption with chemical reaction is carried out, which is one of the simplest liquid-gas contactors used in industry, operated batchwise with respect to liquid. As the next step of the work, kinetics of absorption of CO2 into sodium metaborate solution was studied; frequency factor and activation energy of rate constant of this reaction were found as 1,97x10-3 m3/mol.s and 18062 J/mol, respectively. Thirdly, absorption studies were performed with a bubble column operating continuously with respect to liquid and gas. Gas hold up for the system for different gas flow rates were obtained. Liquid side physical mass transfer coefficient was determined employing oxygen desorption method. Then, liquid side chemical mass transfer coeffient was obtained by experimentally employing CO2 absorption into sodium metaborate solution. Hereat, the enhancement factor for carbon dioxide absorption into sodium metaborate solution was determined. This enhancement factor can be used in design calculations of industrial applications. With this work, it was shown that sodium metaborate, which is the product of hydrogen generation from sodium borohydride process, can be used in a current issue like carbon dioxide removal. In addition to this, by drying of the solution obtained at the end of absorption process, a solid mixture of borax and sodium carbonate can be obtained and this has a great possibility of being used in several industries (especially in glass industry) is acquired.