@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} } @article { ISI:000360026900051, title = {Role of metallic packing and kinetic promoter in designing a hydrate-based gas separation process}, journal = {Energy \& Fuels}, volume = {29}, number = {7}, year = {2015}, note = {2nd International Conference Biogas Science, Vienna, AUSTRIA, 2014}, month = {JUL}, pages = {4463-4471}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

In the present work, kinetics of the hydrate-based gas separation (HBGS) process has been studied employing an unstirred reactor configuration. Gas uptake measurements were carried out for studying hydrate formation kinetics and final water to hydrate conversion using fuel gas mixtures (mixture 1, 40.4\% CO2 + 59.6\% H-2; mixture 2, 40.9\% CO2 + 58.05\% H-2 + 1.05\% H2S). Silica sand and stainless-steel-structured packing (SSP) were used as contact media in the presence of an anionic surfactant sodium dodecyl sulfate (SDS) as a kinetic promoter. Experiments were conducted with three different concentrations of SDS in water to enhance hydrate formation kinetics. On the basis of induction time and rate of hydrate growth, 1 wt \% SDS was determined to be the best concentration for carbon dioxide capture at 7.0 MPa and 273.65 K from the CO2 + H-2 gas mixture. In comparison to silica sand packing, use of SSP was found to improve the final water to hydrate conversion (71.0 +/- 4.1\%). The addition of H2S impurity in the fuel gas mixture was also found to enhance the rate of hydrate formation in the presence of SDS at 7.8 MPa and 274.5 K. On the basis of the experimental results and our previous studies on separation efficiency, a continuous HBGS process is proposed to separate CO2 and produce CO2- and H2S-free H-2 stream from a fuel gas mixture.

}, issn = {0887-0624}, doi = {10.1021/acs.energyfuels.5b00664}, author = {Kumar, Asheesh and Kumar, Rajnish} } @article { ISI:000366878100001, title = {Role of surfactants in promoting gas hydrate formation}, journal = {Industrial \& Engineering Chemistry Research}, volume = {54}, number = {49}, year = {2015}, month = {DEC}, pages = {12217-12232}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Gas hydrates have been proposed as a potential technology for a number of applications, such as separation of gas mixtures, CO2 capture, transportation, and sequestration, methane storage and transport, and seawater desalination. Most of these applications will benefit from reduced induction time of hydrate nucleation, enhanced hydrate growth rate, and maximum water-to-hydrate conversion. The addition of surfactants to the gas-water system serves this purpose in a very effective manner. This review focuses on different surfactants that were utilized for gas hydrate formation studies; insights have been provided on the possible mechanisms of action through which these surfactants affect hydrate formation kinetics. A thorough analysis of the existing literature on surfactants suggests that enhanced rate of hydrate nucleation and growth kinetics may not be directly linked to micelle formation. Conversely, reduced surface tension in the presence of surfactants not only enhances the mass transfer but also changes the morphology of hydrate formation, which in turn enhances gas-water interactions for faster hydrate growth rate.

}, issn = {0888-5885}, doi = {10.1021/acs.iecr.5b03476}, author = {Kumar, Asheesh and Bhattacharjee, Gaurav and Kulkarni, B. D. and Kumar, Rajnish} } @article { ISI:000371560100018, title = {Rapid methane hydrate formation to develop a cost effective large scale energy storage system}, journal = {Chemical Engineering Journal}, volume = {290}, year = {2016}, month = {APR}, pages = {161-173}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

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.

}, keywords = {Energy storage, Enhanced kinetics, Gas hydrates, Natural gas storage, Tetrahydrofuran, Unstirred tank reactor}, issn = {1385-8947}, doi = {10.1016/j.cej.2016.01.026}, author = {Veluswamy, Hari Prakash and Wong, Alison Jia Hui and Babu, Ponnivalavan and Kumar, Rajnish and Kulprathipanja, Santi and Rangsunvigit, Pramoch and Linga, Praveen} } @conference {45823, title = {Role of Rhamnolipid: A biosurfactant in methane gas hydrate formation kinetics}, booktitle = {Proceedings of The First International Conference on Recent Advances in Bioenergy Research}, year = {2016}, month = {FEB}, publisher = {Sardar Swaran Singh Natl Inst Bio-Energy}, organization = {Sardar Swaran Singh Natl Inst Bio-Energy}, address = {7th Floor, Vijaya Building, 17, Barakhamba Rd, New Delhi, 110 001, India}, abstract = {

Naturally occurring methane gas hydrate is a vast source of methane gas which is trapped in crystalline ice-like structure present in permafrost regions and under the sea in outer continental margins. It is purposed that total amount of carbon in the form of methane hydrates is almost twice the carbon content in all the fossil fuel reserves put together, and hence these are supposed to be the future potential energy resource. This paper investigates the laboratory investigations on effect of a biosurfactant rhamnolipid on methane hydrate formation kinetics. Rhamnolipid was produced by Pseudomonas aeruginosa strain A11. The presence of P. aeruginosa has been reported in Gulf of Mexico gas hydrate samples. Biosurfactant reduced the surface tension of water from 72 to 36 mN/m with CMC of 70 mg/L. The biosurfactant dose is studied at two different concentrations in the solution at 100 and 1000 ppm. Kinetic of hydrate formation and growth is compared at 0, 100, and 1000 ppm of rhamnolipid showing that rhamnolipid acts as a hydrate promoter at these concentrations. Thus, small dosages of rhamnolipids produced by P. aeruginosa strain A11 must clearly affect the gas hydrate formation kinetics in natural sites (as in Gulf of Mexico).

}, keywords = {Induction time, methane hydrate, Potential energy resource, Pseudomonas aeruginosa, Rhamnolipid}, isbn = {978-81-322-2773-1; 978-81-322-2771-7}, doi = {10.1007/978-81-322-2773-1_25}, author = {Arora, Amit and Cameotra, Swaranjit Singh and Kumar, Rajnish and Singh, Anil Kumar and Kumar, Pushpendra and Balomajumder, Chandrajit and Laik, Sukumar}, editor = {Kumar, S and Khanal, SK and Yadav, YK} } @article {47051, title = {Rhamonolipids produced by Pseudomonas aeruginosa promotes methane hydrates formation in fixed bed silica gel medium}, journal = {Marine Geophysical Research}, volume = {42}, year = {2021}, month = {MAR}, pages = {5}, type = {Article}, abstract = {

Natural gas hydrates are seen as an alternative future energy source. They have also been valued for their carbon dioxide capturing capability, gas separation, desalination, natural gas storage and transportation. Developing economical and viable gas hydrate based technology is one of the most promising research areas of present decade. Successful commercialization of gas hydrate based technology is often curtailed due to slow formation rate. The present study evaluates biosurfactant as a kinetic promoter of methane hydrates formation in a fixed bed C type silica gel medium. Biosurfactant was produced by growing Pseudomonas aeruginosa strain A11 in glycerol supplemented mineral salt medium. Biosurfactant characterization with FTIR, NMR and MALDI-TOF spectroscopy reveled it to be a glycolipids type biosurfactant namely rhamnolipids. Saturating C type silica gel with of 100 ppm rhamnolipids solution enhanced the rate of methane hydrates formation by reducing the induction time. Mole of methane consumed and percentage of water to hydrate conversion was observed to be more in 1000 ppm rhamnolipids saturated C type silica gel as compared to quiescent water system and water saturated silica gel system. Overall results suggest that rhamonolipids produced by strain A11 in combination with silica gel can be utilized as environmentally safe kinetic promoter for methane hydrate formation.

}, keywords = {Biosurfactant, Energy, Glycolipids, Induction time, Kinetic promoter}, issn = {0025-3235}, doi = {10.1007/s11001-020-09426-6}, author = {Arora, Amit and Cameotra, Swaranjit Singh and Balomajumder, Chandrajit and Kumar, Rajnish and Singh, Anil Kumar and Santhakumari, B. and Kumar, Pushpendra and Laik, Sukumar} }