The recent growth of studies about the properties and behavior of clathrate hydrates leads to the need of obtaining experimental results which are reliable, consistent and comparable, given also the inherently stochastic nature of the phenomenon of enclathration. Therefore, experimental devices used therefor should be designed to match the above criteria. To overcome those problems, we developed a novel apparatus and approach which can measure several sensitive parameters in a single formation and/or decomposition experiment.[1] By means of the subject apparatus, we were able to obtain data sets which are definitely self-consistent. With this approach we can improve the variable control strategies, by the introduction of PID control loops for pressure, temperature and fluid flow, that allow us to get - from the same experiment - data that can give both thermodynamic and kinetic insigths. Moreover, we have implemented in our apparatus a constant-volume, fluid transfer system, that allows to modify the amount and/or composition of solution subject to hydrate formation, under hydrate-forming conditions. The constant-volume fluid transfer feature of our apparatus ensures a constant pressure during fluid transfer, thus providing for the ability of studying - under a constant pressure - critical phenomena related to the amount of solution or the concentration of additives in the same. To measure the concentration of additives (inhibitors, promoters, etc.) added to the hydrate-forming solution, we have designed and fabricated a conductometric probe able to withstand high pressures and resistant to several organic solvents. By combining, e.g., the features of constant-volume fluid addition and conductometric measurements under an elevated pressure (i.e., up to 300 bar) we carried out investigations on several colloidal properties of the solution subject to hydrate formation, such as, e.g., critical micelle concentration and so on.[2,3] We have also provided our apparatus with a videocamera with digital recording, and an internal cool lighting system, which allow a remarkable size reduction as compared to a conventional video monitoring system. Finally, our apparatus is designed to implement such analyses as, e.g. fiber-optic Raman, light scattering and UV-Vis spectroscopies to offer a more complete and characterizing data set. References [1] S. Arca P. Di Profio, R. Germani, G. Savelli “Apparatus for preparing and studying clathrate hydrates” Int'l. Pat. Appl. PCT/IT/2006/000274. [2] S. Arca P. Di Profio, R. Germani, G. Savelli “Novel Nanostructured Media for Gas Storage and Transport: Clathrate Hydrates of Methane and Hydrogen” Journal of Fuel Cell Science and Technology, Feb. 2007 Issue. [3] P. Di Profio, S. Arca, R. Germani, G. Savelli, “Surfactant promoting effects on clathrate hydrate formation: are micelles really involved?”, Chem. Eng. Sci., 60 (2005) 4141-4145.
Novel apparatus for investigating clathrate hydrates
DI PROFIO, Pietro;
2006-01-01
Abstract
The recent growth of studies about the properties and behavior of clathrate hydrates leads to the need of obtaining experimental results which are reliable, consistent and comparable, given also the inherently stochastic nature of the phenomenon of enclathration. Therefore, experimental devices used therefor should be designed to match the above criteria. To overcome those problems, we developed a novel apparatus and approach which can measure several sensitive parameters in a single formation and/or decomposition experiment.[1] By means of the subject apparatus, we were able to obtain data sets which are definitely self-consistent. With this approach we can improve the variable control strategies, by the introduction of PID control loops for pressure, temperature and fluid flow, that allow us to get - from the same experiment - data that can give both thermodynamic and kinetic insigths. Moreover, we have implemented in our apparatus a constant-volume, fluid transfer system, that allows to modify the amount and/or composition of solution subject to hydrate formation, under hydrate-forming conditions. The constant-volume fluid transfer feature of our apparatus ensures a constant pressure during fluid transfer, thus providing for the ability of studying - under a constant pressure - critical phenomena related to the amount of solution or the concentration of additives in the same. To measure the concentration of additives (inhibitors, promoters, etc.) added to the hydrate-forming solution, we have designed and fabricated a conductometric probe able to withstand high pressures and resistant to several organic solvents. By combining, e.g., the features of constant-volume fluid addition and conductometric measurements under an elevated pressure (i.e., up to 300 bar) we carried out investigations on several colloidal properties of the solution subject to hydrate formation, such as, e.g., critical micelle concentration and so on.[2,3] We have also provided our apparatus with a videocamera with digital recording, and an internal cool lighting system, which allow a remarkable size reduction as compared to a conventional video monitoring system. Finally, our apparatus is designed to implement such analyses as, e.g. fiber-optic Raman, light scattering and UV-Vis spectroscopies to offer a more complete and characterizing data set. References [1] S. Arca P. Di Profio, R. Germani, G. Savelli “Apparatus for preparing and studying clathrate hydrates” Int'l. Pat. Appl. PCT/IT/2006/000274. [2] S. Arca P. Di Profio, R. Germani, G. Savelli “Novel Nanostructured Media for Gas Storage and Transport: Clathrate Hydrates of Methane and Hydrogen” Journal of Fuel Cell Science and Technology, Feb. 2007 Issue. [3] P. Di Profio, S. Arca, R. Germani, G. Savelli, “Surfactant promoting effects on clathrate hydrate formation: are micelles really involved?”, Chem. Eng. Sci., 60 (2005) 4141-4145.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
