@article { ISI:000329552500027, title = {HBGS (hydrate based gas separation) process for carbon dioxide capture employing an unstirred reactor with cyclopentane}, journal = {Energy}, volume = {63}, year = {2013}, month = {DEC}, pages = {252-259}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

The effect of CP (cyclopentane) as a promoter/additive, in the HBGS (hydrate based gas separation) process for pre-combustion gas mixture was investigated by employing an unstirred reactor configuration. Gas uptake measurements were performed at two different temperatures (275.7 K and 285.7 K) and at an experimental pressure of 6.0 MPa to determine the kinetics of hydrate formation. Experiments were conducted with three different volumes (7.5, 15 and 22 ml) of CP and based on induction time and the rate of hydrate growth, 15 ml of CP was determined to be the optimal volume for carbon dioxide capture at 6.0 MPa and 275.7 K. In addition, the effect of a kinetic promoter, SDS (sodium dodecyl sulfate), was investigated. Surprisingly, no improvement in kinetic performance was observed at 6.0 MPa and 275.7 K in the presence of SDS and CP. From the study, it was found that at the optimal 15 ml CP (CP layer thickness of 1.8 mm), the average composition of carbon dioxide in the hydrate phase was 90.36 mol\% with a separation factor of 17.82. Furthermore, the unstirred reactor also yielded better kinetic performance over the stirred tank reactor with the unstirred reactor having a 2.28 times higher average gas uptake. (C) 2013 Elsevier Ltd. All rights reserved.

}, keywords = {Carbon dioxide capture, Cyclopentane, Gas hydrates, Gas separation, Pre-combustion, Unstirred reactor}, issn = {0360-5442}, doi = {10.1016/j.energy.2013.10.031}, author = {Ho, Leong Chuan and Babu, Ponnivalavan and Kumar, Rajnish and Linga, Praveen} } @article { ISI:000316432700037, title = {Pre-combustion capture of carbon dioxide in a fixed bed reactor using the clathrate hydrate process}, journal = {Energy}, volume = {50}, year = {2013}, month = {FEB}, pages = {364-373}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Hydrate based gas separation (HBGS) process with silica sand and silica gel as contact medium was employed to capture CO2 from fuel gas mixture. Gas uptake measurement at three different pressures (7.5, 8.5 and 9.0 MPa) and 274.15 K were conducted for hydrate formation kinetics and overall conversion of water to hydrate, rate of hydrate formation were determined. Water conversion of up to 36\% was achieved with silica sand bed compared to 13\% conversion in the silica gel bed. Effect of driving force on the rate of hydrate formation and gas consumption was significant in silica sand bed whereas it was found to be insignificant in silica gel bed. Hydrate dissociation experiments by thermal stimulation (at constant pressure) alone and a combination of depressurization and thermal stimulation were carried out for complete recovery of the hydrated gas. A driving force of 23 K was found to be sufficient to recover all the hydrated gas within 1 h. This study indicates that silica sand can be an effective porous media for separation of CO2 from fuel gas when compared to silica gel. (C) 2012 Elsevier Ltd. All rights reserved.

}, keywords = {Carbon dioxide capture, Clathrate hydrates, Gas separation, Global warming, Pre-combustion}, issn = {0360-5442}, doi = {10.1016/j.energy.2012.10.046}, author = {Babu, Ponnivalavan and Kumar, Rajnish and Linga, Praveen} } @conference { ISI:000375936100396, title = {Impact of pressure and temperature on tetra-n-butyl ammonium bromide semi-clathrate process for carbon dioxide capture}, booktitle = {International Conference on Applied Energy, ICAE2014}, series = {Energy Procedia}, volume = {61}, year = {2014}, note = {6th International Conference on Applied Energy (ICAE), Taipei, TAIWAN, MAY 30-JUN 02, 2014}, month = {MAY}, pages = {1780-1783}, publisher = {Elsevier Science BV}, organization = {Elsevier Science BV}, address = {Sara Burgerhartstraat 25, Po Box 211, 1000 AE Amsterdam, Netherlands}, abstract = {

The pre-combustion capture of CO2 in an IGCC power plant employing the hydrate based gas separation (HBGS) process is a novel method currently receiving attention around the world. Tetra-n-butyl ammonium bromide (TBAB) is a promoter that has been shown to improve the efficiency of hydrate formation. In this study, the effect of temperature and pressure on 0.3 mol\% TBAB solution is investigated. The induction time for the experiments conducted at 6.0 MPa and 274.8 K was found to be lower, while nucleation became increasingly random as temperature is increased and pressure is reduced. Total gas uptake and normalized rate of hydrate formation (NR5) is also the highest for the experiments conducted at 6.0 MPa and 274.8 K. However, it was found that the hydrate phase CO2 composition remains relatively constant at both reduced temperatures and pressures. (C) 2014 The Authors. Published by Elsevier Ltd.

}, keywords = {Carbon dioxide capture, Clathrate process, Gas hydrates, Gas separation, Promoters, tetra-n-butyl ammonium bromide}, issn = {1876-6102}, doi = {10.1016/j.egypro.2014.12.211}, author = {Babu, Ponnivalavan and Chin, Weng Inn and Kumar, Rajnish and Linga, Praveen}, editor = {Yan, J. and Lee, D. J. and Chou, S. K. and Desideri, U. and Li, H.} } @article { ISI:000355889800021, title = {Review of the hydrate based gas separation (HBGS) process for carbon dioxide pre-combustion capture}, journal = {Energy}, volume = {85}, year = {2015}, month = {JUN}, pages = {261-279}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

In this work, a systematic review of the literature work done so far on the use of hydrate crystallization as a basis to develop data for the hydrate based gas separation (HBGS) process for the capture of CO2 from fuel gas mixtures is presented. Such a gas mixture may arise in integrated gasification combined cycle (IGCC) power plants. A thorough assessment of the thermodynamic, kinetic factors and economic aspects of the HBGS process and critical comments are presented. Compared with competing technologies, high CO2 capacity and the use of water as a solvent are key advantages for the HBGS process for CO2 capture. Furthermore, in this review, a snapshot of the current state-of-the-art is presented and further research and development opportunities and pathways for commercializing the HBGS process for pre-combustion capture of CO2 from IGCC power plants are discussed. (C) 2015 Elsevier Ltd. All rights reserved.

}, keywords = {Carbon dioxide capture, Clathrate process, Gas hydrates, Gas separation, IGCC plants, Pre-combustion capture}, issn = {0360-5442}, doi = {10.1016/j.energy.2015.03.103}, author = {Babu, Ponnivalavan and Linga, Praveen and Kumar, Rajnish and Englezos, Peter} }