Study On The Effection Mechanics Of Surfactants In The Process Of Gas Hydrate Formation

Surfactants are widely used in gas hydrate technology experiments.When surfactants were added into the system of hydrate reaction,the interfacial tension between reactants was reduced,diffusion resistance between the guest molecular and water was decreased,solubility and super saturation of guest molecules in water were increased,the induction time of hydrate reaction was reduced and the speed of reaction was accelerated.In the research achievements of hydrate technology,most of them were concentrated in the application of surfactants in hydrate technology.They are concerning the kinetics of hydrate formation, decomposition and equilibrium conditions.In order to reveal the effects mechanism of surfactants on hydrate formation initially,this paper had done following quantitative researches.The surface tension of surfactant solution was reduced to the lowest when its concentration reached the CMC.So the interfacial tension of surfactants solution/ HCFC141b and H2O/ HCFC141b at 8.4-20℃were measured by interfacial tensionmeter,the effects of surfactants on the reduction degree of water/HCFC141b's interfacial tension were studied quantitatively.Experimental results:the effects of anionic surfactant SLS,SDS and SDBS on the interfacial tension of HCFC141b/water is obviously,the interfacial tension of HCFC141b/water can be reduced to 9-62%when surfactant was added into water, SDBS is the best one compared with SDS and SLS.It is very obviously that the effects surfactants on the interfacial tension reduction in preliminary experimental results.Temperature is an important influencing factor of surfactant's CMC.The temperature of HCFCH1b hydrate formation is different from the temperature of CMC determination experiments. Therefore,it is necessary to determine the value of surfactants' CMC near the temperature of gas hydrate formation.The surface tension of surfactants solution with different concentrations were measured at different temperatures by Surface Tension Meter,SDS and SDBS also as an example in this paper.The CMC of SDS and SDBS under the conditions of HCFC141b hydrate formation were confirmed basis the interfacial tension data.The CMC of SDS and SDBS is 1950 and 400ppm near the condition of HCFC141b hydrate formation,respectively.The surface tension of surfactant solution was reduced to a lower level when their concentration reached 500 and l00ppm,respectively.All of these experimental results are applicable for HCFC141b hydrate formation condition,in order to expand the applied range of experimental results in hydrate technology.The electric conductivity of SDS solution with different concentrations was measured by digital conductivity meter at different temperatures.The analytic relationship between the CMC and temperature of SDS at 1-40℃was obtained as follow.c_CM'＝-0.00014862t⁵+0.01482645t⁴-0.51139450t³+7.72226492t²-62.11395313t+2644.94421135 This result can be used in any experiment with surfactant at 1-40℃.There is a minimum of SDS'CMC in the temperature range,the minimum value of SDS' CMC is 2267ppm when the temperature reached 24.6℃.The originality innovation of this paper was listed as follow:(1)Surface tension of HCFCl41b was obtained at 8.4-20℃for the first time;(2) Analytic relationship between the CMC and temperature at 1-40℃was obtained.