Hydrate-based pre-combustion carbon dioxide capture process in the system with tetra-n-butyl ammonium bromide solution in the presence of cyclopentane

• Published in: Energy (Oxford) 2011-03, Vol.36 (3), p.1394-1403
• Main Authors: Li, Xiao-Sen, Xu, Chun-Gang, Chen, Zhao-Yang, Wu, Hui-Jie
• Format: Article
• Language: English
• Subjects: Air pollution caused by fuel industries; Ammonium bromides; Applied sciences; Carbon dioxide; CO 2 capture; Cyclopentane; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Gas uptake; Hydrate; Hydrates; IGCC; Induction time; Optimization; Pollution reduction; Reactors; Separation; Slurries; Stack gas and industrial effluent processing; temperature; Tetra-n-butyl ammonium bromide; Tetrahydrofuran; Uptakes
• ISSN: 0360-5442
• DOI: 10.1016/j.energy.2011.01.034

Effects of 0.29 mol% tetra-n-butyl ammonium bromide (TBAB) solution in conjunction with cyclopentane (CP) on the hydrate-based pre-combustion CO 2 capture are investigated by the measurements of the gas uptakes, CO 2 separation efficiencies and induction time of the hydrate formation at the different temperature–pressure conditions. The results show that the volume of the TBAB has an effect on the CO 2 separation and the induction time, and the addition of the CP into the TBAB solution remarkably enhances the CO 2 separation and shortens the induction time. The system with the CP/TBAB solution volume ratio of 5 vol% and TBAB solution/reactor effective volume ratio of 0.54 is optimum to obtain the largest gas uptake and the highest CO 2 separation efficiency at 274.65 K and 4.0 MPa. Compared to the results with tetrahydrofuran (THF) as an additive [1], the gas uptake is enhanced by at least 2 times and the induction time is shortened at least 10 times at the similar temperature–pressure condition. In addition, the CO 2 concentration in the decomposed gas from the hydrate slurry phase reaches approximately 93 mol% after the first-stage separation at 274.65 K and 2.5 MPa. The gas uptakes of more than 80 mol% are obtained after 400 s at the temperature range of 274.65–277.65 K and the pressure range of 2.5–4.5 MPa. ► Adding the CP into the TBAB-solution enhances the CO 2 separation and shortens the induction time. ► The optimum volume ratios of CP/TBAB-solution and TBAB-solution/reactor are submitted. ► The CO 2 concentration in the decomposed gas reaches 93mol% after the first-stage separation.