02099nas a2200253 4500008004100000022001400041245007600055210006900131260000800200300001400208490000700222520131000229653001501539653001901554653001601573653001301589653003301602100002601635700002201661700001901683700002301702700001901725856010101744 2016 eng d a1875-510000aEffect of the amino acid L-histidine on methane hydrate growth kinetics0 aEffect of the amino acid Lhistidine on methane hydrate growth ki cSEP a1453-14620 v353 a

In the present study, the effect of a polar amino acid, L-histidine on methane hydrate growth kinetics has been investigated. Methane hydrate formation experiments were carried out in a stirred tank reactor setup at pressure and temperature conditions of 274.15 K and 5.0 MPa respectively. Two different concentrations (0.1 and 1 wt %) of L-histidine were studied. Hydrate growth through molecular dynamic (MD) simulation was also studied; pressure and temperature conditions for the simulations were set at 10.0 MPa and 270.0 K, while the concentration of L-histidine was kept fixed at 0.94 wt %. Hydrate formation runs using MD simulation were carried out with optimal concentration of methane in water. The presence of L-histidine in the system was found to significantly enhance methane hydrate growth kinetics as compared to pure water for both experimental and MD simulation runs. Final gas consumption with 1 wt % L-histidine was found to be comparable to that with 1 wt % SDS, the most commonly used additive for hydrate promotion studies. L-histidine is a benign additive which offers considerable enhancement in methane hydrate formation kinetics and can be utilized for various hydrate based technologies such as methane storage and transport. (C) 2016 Elsevier B.V. All rights reserved.

10aAmino acid10aCrystal growth10aGas hydrate10akinetics10aMolecular dynamic simulation1 aBhattacharjee, Gaurav1 aChoudhary, Nilesh1 aKumar, Asheesh1 aChakrabarty, Suman1 aKumar, Rajnish uhttps://library.ncl.res.in/content/effect-amino-acid-l-histidine-methane-hydrate-growth-kinetics02056nas a2200253 4500008004100000022001400041245017300055210006900228260000800297300001200305490000800317520116300325653001301488653001601501653001301517653002001530653001301550653002401563100002601587700002001613700002401633700001901657856012601676 2018 eng d a0021-961400aKinetic promotion of methane hydrate formation by combining anionic and silicone surfactants: scalability promise of methane storage due to prevention of foam formation0 aKinetic promotion of methane hydrate formation by combining anio cFEB a248-2550 v1173 a

Methane storage in its solid hydrate form has recently come up as a rather attractive and low risk option for large scale storage of the gas owing to its mild storage conditions, high gas retention capacity and benign (non-explosive) character. However, it has its fair share of limitations with the slow rate of hydrate formation being one of the most prominent. The addition of surfactants like Sodium dodecyl sulfate (SDS) to the hydrate forming system significantly speeds up the process of methane hydrate formation but the large amount of foam generated by these surfactants during the process of hydrate formation and dissociation stands as a major roadblock towards the scaling up of the technology. In the current work, a small amount of a silicon based surfactant has been proposed to be used as antifoam in conjunction with an anionic surfactant SDS to eliminate the foam generation while at the same time promote the kinetics of methane hydrate formation. The idea is simple, cost effective and can be a potential game-changer in the quest to develop a commercially scalable hydrate based methane storage technology. (C) 2017 Elsevier Ltd.

10aAntifoam10aGas hydrate10akinetics10aMethane storage10ascale-up10aSilicone surfactant1 aBhattacharjee, Gaurav1 aBarmecha, Vivek1 aKushwaha, Omkar, S.1 aKumar, Rajnish uhttps://library.ncl.res.in/content/kinetic-promotion-methane-hydrate-formation-combining-anionic-and-silicone-surfactants02708nas a2200313 4500008004100000022001400041245011000055210006900165260000900234300001100243490000800254520170900262653001601971653001301987653001902000653002002019653002102039653002402060653001202084100002602096700002202122700002002144700002402164700002102188700002002209700001502229700001902244856013102263 2019 eng d a0306-261900aMethane recovery from marine gas hydrates: a bench scale study in presence of low dosage benign additives0 aMethane recovery from marine gas hydrates a bench scale study in cNOV  a1135660 v2533 a

De-pressurization is one approach which has been found to be economically feasible for methane recovery from marine hydrates. Hydrate dissociation being an endothermic process suggests that de-pressurization alone would not be sufficient and some additional stimulation would be required for sustained production from one such reservoir. Thermal stimulation may overcome the challenge posed by the endothermic dissociation process; however, economically it may not be ideal. A possible way out is to use thermal stimulation, but at relatively low temperatures as compared to conventional practice. This would be economical and can be accomplished in the presence of small doses of additives mixed in with the water stream used for thermal stimulation. In the present study, a number of benign additives were identified which when used in low concentrations enhance the kinetics of methane hydrate dissociation compared to pure water. Additives were first shortlisted from a wide potential pool using quantum mechanical calculations. These additives were later tested for their efficacy in stirred tank reactor to quickly identify the best additives for the job and few selected additives were then studied in a larger bench scale setup (fixed bed configuration) where they were injected in the form of an additive-water stream to dissociate already formed hydrates. Factors such as toxicity of the additive, fluidity of additive-water stream, foam formation on mixing of additive with water, etc. were also taken into account. An energy and efficiency analysis revealed that reported additives enhance the energy ratio and thermal efficiency of the process as compared to pure water stimulation.

10aBench scale10akinetics10aMarine hydrate10amethane hydrate10aMethane recovery10aNatural gas hydrate10aProcess1 aBhattacharjee, Gaurav1 aChoudhary, Nilesh1 aBarmecha, Vivek1 aKushwaha, Omkar, S.1 aPande, Nawal, K.1 aChugh, Parivesh1 aRoy, Sudip1 aKumar, Rajnish uhttps://library.ncl.res.in/content/methane-recovery-marine-gas-hydrates-bench-scale-study-presence-low-dosage-benign-additives02177nas a2200301 4500008004100000022001400041245012500055210006900180260000900249300001100258490000800269520115900277653004601436653002701482653002401509653002201533653002001555653001601575653001301591653001301604653001501617100001601632700001901648700002601667700002901693700002201722856013101744 2021 eng d a0195-073800aHydrate-based carbon capture process: assessment of various packed bed systems for boosted kinetics of hydrate formation0 aHydratebased carbon capture process assessment of various packed cMAR  a0330050 v1433 a

The case for developing novel technologies for carbon dioxide (CO2) capture is fast gaining traction owing to increasing levels of anthropogenic CO2 being emitted into the atmosphere. Here, we have studied the hydrate-based carbon dioxide capture and separation process from a fundamental viewpoint by exploring the use of various packed bed media to enhance the kinetics of hydrate formation using pure CO2 as the hydrate former. We established the fixed bed reactor (FBR) configuration as a superior option over the commonly used stirred tank reactor (STR) setups typically used for hydrate formation studies by showing enhanced hydrate formation kinetics using the former. For the various packing material studied, we have observed silica gel with 100 nm pore size to return the best kinetic performance, corresponding to a water to hydrate conversion of 28 mol% for 3 h of hydrate growth. The fundamental results obtained in the present study set up a solid foundation for follow-up works with a more applied perspective and should be of interest to researchers working in the carbon dioxide capture and storage and gas hydrate fields alike.

10aair emissions from fossil fuel combustion10aCarbon dioxide capture10acombustion of waste10aFixed bed reactor10afuel combustion10aGas hydrate10ahydrates10akinetics10aSilica gel1 aArora, Amit1 aKumar, Asheesh1 aBhattacharjee, Gaurav1 aBalomajumder, Chandrajit1 aKumar, Pushpendra uhttps://library.ncl.res.in/content/hydrate-based-carbon-capture-process-assessment-various-packed-bed-systems-boosted-kinetics