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-001987nas a2200265   4500008004100000022001400041245010200055210006900157260009000226300001000316490000700326520103300333653002701366653001701393653001901410653002201429653001901451653001901470100002301489700001501512700002901527700001901556700001901575856012701594       2013                        eng d  a0021-961400aHydrate phase equilibrium of ternary gas mixtures containing carbon dioxide, hydrogen and propane0 aHydrate phase equilibrium of ternary gas mixtures containing car  a24-28 OVAL RD, LONDON NW1 7DX, ENGLANDbACADEMIC PRESS LTD- ELSEVIER SCIENCE LTDcJUN  a58-630 v613 a<p>Hydrate phase equilibrium of the ternary guest mixtures containing carbon dioxide, hydrogen and propane at two different compositions were determined. Addition of mole composition of 2.5% propane to the fuel gas (CO2 (40%)/H-2 (60%)) mixture reduces the hydrate formation conditions by 66% at the temperature of 278.4 K. A Clausius-Clapeyron plot for the experimental results was plotted and from the slope, the enthalpy of hydrate dissociation was calculated. The enthalpy of dissociation of the mixed hydrate formed from a ternary gas mixture containing mole composition 38.1% CO2, 59.4% H-2 and 2.5% C3H8 was found to be 110 kJ.mol(-1) and hence it was concluded that the mixed hydrate formed structure II (sII) hydrates. Whereas for the ternary gas mixture containing mole composition 80.0% CO2, 18.8% H-2, and 1.2% C3H8, the enthalpy of dissociation of the mixed hydrate was found to be 78 kJ.mol(-1) and hence we believe the mixed hydrate formed structure I (sI) hydrate. (C) 2013 Elsevier Ltd. All rights reserved.</p>10aCarbon dioxide capture10aGas hydrates10aGlobal warming10aPhase equilibrium10aPre-combustion10aThermodynamics1 aBabu, Ponnivalavan1 aYang, Ting1 aVeluswamy, Hari, Prakash1 aKumar, Rajnish1 aLinga, Praveen  uhttps://library.ncl.res.in/content/hydrate-phase-equilibrium-ternary-gas-mixtures-containing-carbon-dioxide-hydrogen-and-002452nas a2200229   4500008004100000022001400041245014500055210006900200260009900269300001200368490000700380520154800387653002701935653001701962653001901979653001901998653001502017100002302032700001902055700001902074856012902093       2013                        eng d  a1750-583600aMedium pressure hydrate based gas separation (HBGS) process for pre-combustion capture of carbon dioxide employing a novel fixed bed reactor0 aMedium pressure hydrate based gas separation HBGS process for pr  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcSEP  a206-2140 v173 a<p>This work presents an effective medium pressure hydrate based gas separation (HBGS) process for pre-combustion carbon dioxide capture in a novel fixed bed column. 2.5 mol% propane was added to the fuel gas mixture as an additive to decrease the operating pressure of the HBGS process. Hydrate formation kinetics was investigated at three different pressures (4.5, 5.5 and 6.0 MPa respectively) and at 274.15 K. The performance of silica sand and silica gel as a medium was evaluated. In silica sand bed, multiple nucleation events were observed. In silica gel bed, the gas uptake and water conversion to hydrates was significantly low at any given driving force than that obtained in silica sand bed. Experiments at different water saturation levels (50, 75 and 100%) in silica sand bed were investigated at 6.0 MPa and 274.15 K. It was found that at 50% water saturation, gas consumed for hydrate formation and water conversion to hydrates was almost three times that at 100% saturation. Water to hydrate conversions of up to 64.3% was achieved after 4 h of hydrate formation for the 50% water saturated silica sand bed. Our study presents an opportunity to scale up the HBGS process for CO2 capture with enhanced kinetics by employing a fixed bed reactor configuration. Decomposition experiments at a driving force of Delta T of 10 K and 23K were carried out to recover the gas consumed for hydrate formation and it was found that Delta T of 23 K was sufficient to recover the hydrated gas. (C) 2013 Elsevier Ltd. All rights reserved.</p>10aCarbon dioxide capture10aGas hydrates10aGlobal warming10aPre-combustion10aSeparation1 aBabu, Ponnivalavan1 aKumar, Rajnish1 aLinga, Praveen  uhttps://library.ncl.res.in/content/medium-pressure-hydrate-based-gas-separation-hbgs-process-pre-combustion-capture-carbon-002291nas a2200253   4500008004100000022001400041245014900055210006900204260010600273300001200379490000700391520130600398653002701704653002201731653002201753653001701775653002701792653001401819100002301833700001801856700001901874700001901893856012501912       2014                        eng d  a0360-544200aEnhanced kinetics for the clathrate process in a fixed bed reactor in the presence of liquid promoters for pre-combustion carbon dioxide capture0 aEnhanced kinetics for the clathrate process in a fixed bed react  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcJUN  a664-6730 v703 a<p>In this work, we present enhanced kinetics of hydrate formation for the clathrate process in the presence of two liquid promoters namely THF (tetrahydrofuran) and TBAB (tetra-n-butyl ammonium bromide) in a FBR (fixed bed reactor) for pre-combustion capture of CO2. Silica sand was used as a medium to capture CO2 from CO2/H-2 gas mixture by hydrate crystallisation. Experiments were performed at different temperatures (274.2 K and 279.2 K) and 6.0 MPa to determine the total gas uptake, induction time and rate of hydrate formation. The observed trends indicated that higher driving force resulted in higher gas consumption and significantly reduced induction time. For the same driving force, higher gas consumption and shorter induction time was achieved by THF as compared to TBAB. 5.53 mol% THF attained higher gas consumption than 1.0 mol% THF whereas 3.0 mol% TBAB attained lower gas consumption than 0.3 mol% TBAB. A highest gas uptake of 51.95 (+/- 5.183) mmol of gas/mol of water and a highest rate of 51.21(+/- 8.91) mol.min(-1).m(-3) were obtained for 5.53 mol% THF at 6.0 MPa and 279.2 K. Overall, this study indicated better hydrate formation kinetics with the use of THF in an FBR configuration for CO2 capture from a fuel gas mixture. (C) 2014 Elsevier Ltd. All rights reserved.</p>10aCarbon dioxide capture10aClathrate process10aFixed bed reactor10aGas hydrates10aPre-combustion capture10aPromoters1 aBabu, Ponnivalavan1 aHo, Chie, Yin1 aKumar, Rajnish1 aLinga, Praveen  uhttps://library.ncl.res.in/content/enhanced-kinetics-clathrate-process-fixed-bed-reactor-presence-liquid-promoters-pre-002258nas a2200229   4500008004100000022001400041245015800055210006900213260010600282300001200388490000700400520133500407653002701742653002201769653001701791653002001808100002301828700001701851700001901868700001901887856012201906       2014                        eng d  a0360-544200aImpact of experimental pressure and temperature on semiclathrate hydrate formation for pre-combustion capture of CO2 using tetra-n-butyl ammonium nitrate0 aImpact of experimental pressure and temperature on semiclathrate  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcDEC  a458-4640 v783 a<p>TBANO(3) (tetra-n-butyl ammonium nitrate) is a promising liquid phase promoter for capturing CO2 via HBGS (hydrate based gas separation) technology. In this study, the impact of experimental pressure and temperature on formation of mixed CO2-H-2-TBANO(3) semiclathrate hydrate for the optimum 1.0 mol% TBANO(3) reported by Babu et al. [1] was investigated. Experimental pressures of 3.0, 4.5 and 6.0 MPa and temperatures of 274.2, 276.2 and 278.2 K were employed. Irrespective of the experimental pressure, shorter induction time was observed for experiments conducted at 274.2 K when compared to the experiments at other temperatures. At a given pressure, the total gas uptake increased with increase in experimental temperature. Similarly at a given temperature, the total gas uptake increases with an increase in pressure. Higher rate of hydrate formation was observed at experimental pressure of 6.0 MPa than at 3.0 and 4.5 MPa irrespective of the experimental temperature. The CO2 composition in hydrate was between 87.5 and 93.2 mol%. Finally, the gas consumption for 1.0 mol% TBANO(3) as promoter was much higher than other promoters of quaternary salts like tetra-n-butyl ammonium bromide and tetra-n-butyl ammonium fluoride at comparable concentration and driving force. (C) 2014 Elsevier Ltd. All rights reserved.</p>10aCarbon dioxide capture10aClathrate process10aGas hydrates10aSemi-clathrates1 aBabu, Ponnivalavan1 aDatta, Stuti1 aKumar, Rajnish1 aLinga, Praveen  uhttps://library.ncl.res.in/content/impact-experimental-pressure-and-temperature-semiclathrate-hydrate-formation-pre-002022nas a2200313   4500008004100000022001400041245012300055210006900178260009900247300001400346490000700360520092100367653002701288653002201315653001701337653001901354653001401373653003501387100002301422700002001445700001901465700001901484700001201503700001601515700001701531700001701548700001101565856013201576       2014                        eng d  a1876-610200aImpact of pressure and temperature on tetra-n-butyl ammonium bromide semi-clathrate process for carbon dioxide capture0 aImpact of pressure and temperature on tetranbutyl ammonium bromi  aSara Burgerhartstraat 25, Po Box 211, 1000 AE Amsterdam, NetherlandsbElsevier Science BVcMAY  a1780-17830 v613 a<p>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.</p>10aCarbon dioxide capture10aClathrate process10aGas hydrates10aGas separation10aPromoters10atetra-n-butyl ammonium bromide1 aBabu, Ponnivalavan1 aChin, Weng, Inn1 aKumar, Rajnish1 aLinga, Praveen1 aYan, J.1 aLee, D., J.1 aChou, S., K.1 aDesideri, U.1 aLi, H.  uhttps://library.ncl.res.in/content/impact-pressure-and-temperature-tetra-n-butyl-ammonium-bromide-semi-clathrate-process-carbon02012nas a2200229   4500008004100000022001400041245016100055210006900216260010600285300001200391490000800403520106200411653002701473653001701500653002201517653001701539653004301556100002301599700001901622700001901641856012201660       2014                        eng d  a0009-250900aUnusual behavior of propane as a co-guest during hydrate formation in silica sand: potential application to seawater desalination and carbon dioxide capture0 aUnusual behavior of propane as a coguest during hydrate formatio  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcSEP  a342-3510 v1173 a<p>We report an unusual behavior of hydrate formation in silica sand with gas mixtures containing propane as a co-guest. Based on morphology study we observed that propane as a co-guest has the ability to draw water dispersed in silica sand to the hydrate formation region and showed a tendency to result in drastic hydrate growth due to the migration of water molecules to the gas phase region. Hydrate nucleation occurred in the interstitial pore space between the silica sand particles and hydrate growth occurred in the gas phase above the silica sand bed and to sustain the hydrate growth, dispersed water was drawn towards the hydrate growth front. In addition, we elucidated the effect of sand bed height to maximize the growth rates utilizing this behavior that results in enhanced kinetics. We propose conceptual designs for utilizing this behavior of propane as a co-guest in sand for seawater desalination and an innovative approach to simultaneously capture carbon dioxide and desalinate seawater. (C) 2014 Elsevier Ltd. All rights reserved.</p>10aCarbon dioxide capture10aDesalination10aEnhanced kinetics10aGas hydrates10aPropane hydrate: pre-combusuon capture1 aBabu, Ponnivalavan1 aKumar, Rajnish1 aLinga, Praveen  uhttps://library.ncl.res.in/content/unusual-behavior-propane-co-guest-during-hydrate-formation-silica-sand-potential-001880nas a2200253   4500008004100000022001400041245010400055210006900159260010600228300001200334490000700346520093600353653002701289653002201316653001701338653001901355653001601374653002701390100002301417700001901440700001901459700002001478856012801498       2015                        eng d  a0360-544200aReview of the hydrate based gas separation (HBGS) process for carbon dioxide pre-combustion capture0 aReview of the hydrate based gas separation HBGS process for carb  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcJUN  a261-2790 v853 a<p>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.</p>10aCarbon dioxide capture10aClathrate process10aGas hydrates10aGas separation10aIGCC plants10aPre-combustion capture1 aBabu, Ponnivalavan1 aLinga, Praveen1 aKumar, Rajnish1 aEnglezos, Peter  uhttps://library.ncl.res.in/content/review-hydrate-based-gas-separation-hbgs-process-carbon-dioxide-pre-combustion-capture-002289nas a2200289   4500008004100000022001400041245009800055210006900153260006900222300001200291490000800303520126100311653001901572653002201591653001701613653002401630653002001654653002701674100002901701700002601730700002301756700001901779700002601798700002601824700001901850856013001869       2016                        eng d  a1385-894700aRapid methane hydrate formation to develop a cost effective large scale energy storage system0 aRapid methane hydrate formation to develop a cost effective larg  aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcAPR  a161-1730 v2903 a<p>Natural gas (NG) is the cleanest burning fossil fuel and its usage can significantly reduce CO2 emissions from power plants. With its widespread use, there is an ever increasing need to develop technologies to store NG on a large scale. NG storage via clathrate hydrates is the best option for a large scale storage system because of its non-explosive nature, mild storage conditions, high volumetric capacity and being an environmentally benign process. In this work, we demonstrate a new method to achieve rapid methane hydrate formation in an unstirred tank reactor configuration (UTR) at moderate temperature and pressure conditions employing tetrahydrofuran (THF) as a promoter. For the first time, THF is reported to act both as a thermodynamic and an excellent kinetic promoter for methane hydrate formation. We demonstrate a multi-scale experimental validation of our method to a volumetric sample scale-up factor of 120 and internal reactor diameter scale-up factor of 10. Further, new insights on the dissociation behavior of the hydrates are reported. There is a competitive edge for storing NG via clathrate hydrates compared to compressed natural gas storage both in terms of cost and safety. (C) 2016 Elsevier B.V. All rights reserved.</p>10aEnergy storage10aEnhanced kinetics10aGas hydrates10aNatural gas storage10aTetrahydrofuran10aUnstirred tank reactor1 aVeluswamy, Hari, Prakash1 aWong, Alison, Jia Hui1 aBabu, Ponnivalavan1 aKumar, Rajnish1 aKulprathipanja, Santi1 aRangsunvigit, Pramoch1 aLinga, Praveen  uhttps://library.ncl.res.in/content/rapid-methane-hydrate-formation-develop-cost-effective-large-scale-energy-storage-system-0