02238nas a2200253   4500008004100000022001400041245012400055210006900179260010600248300001200354490000700366520128200373653002701655653001701682653001701699653001901716653001901735653002201754100002101776700002301797700001901820700001901839856012601858       2013                        eng d  a0360-544200aHBGS (hydrate based gas separation) process for carbon dioxide capture employing an unstirred reactor with cyclopentane0 aHBGS hydrate based gas separation process for carbon dioxide cap  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcDEC  a252-2590 v633 a<p>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.</p>10aCarbon dioxide capture10aCyclopentane10aGas hydrates10aGas separation10aPre-combustion10aUnstirred reactor1 aHo, Leong, Chuan1 aBabu, Ponnivalavan1 aKumar, Rajnish1 aLinga, Praveen  uhttps://library.ncl.res.in/content/hbgs-hydrate-based-gas-separation-process-carbon-dioxide-capture-employing-unstirred-002922nas a2200265   4500008004100000022001400041245013800055210006900193260009900262300001200361490000800373520191900381653002102300653002402321653001902345653001502364653002002379653002202399100002902421700001802450700001902468700002602487700001902513856012402532       2016                        eng d  a0016-236100aEnhanced clathrate hydrate formation kinetics at near ambient temperatures and moderate pressures: Application to natural gas storage0 aEnhanced clathrate hydrate formation kinetics at near ambient te  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcOCT  a907-9190 v1823 a<p>SNG (solidified natural gas) technology via clathrate hydrates is a potential method for large scale stationary storage of natural gas. Clathrate hydrate formation kinetics in presence of methane and 5.6 mol% tetrahydrofuran (THF) was investigated in an unstirred reactor configuration at moderate pressure and temperature conditions. It is well known that the presence of THF generally improves the thermodynamic stability of the resulting hydrate. In order to study the scale-up potential of this approach, kinetics of hydrate growth at temperatures close to ambient conditions and moderate pressures is required. Hydrate formation experiments were performed at three different temperatures - 283.2 K, 288.2 K and 293.2 K and at experimental pressures of 7.2 MPa, 5.0 and 3.0 MPa. Further, we report a synergistic effect of kinetic promotion of mixed methane hydrate formation by coupling THF and sodium dodecyl sulfate (SDS) at 293.2 K. For the first time, we observe rapid mixed methane/THF hydrate formation kinetics at 293.2 K in presence of just 100 ppm sodium dodecyl sulfate surfactant with methane gas uptake of 3.45 (+/- 0.17) kmol/m(3) of water in 1 h. This is also the first study to demonstrate such rapid hydrate formation kinetics with significant methane storage capacity at temperature of 293.2 K (closer to the ambient temperature). Further, substantial methane gas uptake of 3.52 (+/- 0.13) kmol/m(3) of water is possible even at reduced experimental pressure of 3.0 MPa and 283.2 K in 2 h. Minimal energy requirement in an unstirred reactor for mixed methane/THF hydrate formation storage can propel the SNG technology for large scale commercial deployment. Further improvement in the process can be achieved by optimizing the cooling requirement through innovative reactor design and operating the process in a semi-batch or continuous mode. (C) 2016 Elsevier Ltd. All rights reserved.</p>10aMethane hydrates10aNatural gas storage10aRapid kinetics10asurfactant10aTetrahydrofuran10aUnstirred reactor1 aVeluswamy, Hari, Prakash1 aKumar, Sharad1 aKumar, Rajnish1 aRangsunvigit, Pramoch1 aLinga, Praveen  uhttps://library.ncl.res.in/content/enhanced-clathrate-hydrate-formation-kinetics-near-ambient-temperatures-and-moderate