Hydrated coefficient of clathrates and its applications in determination of aqueous inclusions with multivolatile components  

作　　者：刘斌 徐金明 

机构地区：[1]Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China [2]Department of Civil Engineering,Shanghai University,Shanghai 200072,China

出　　处：《岩石学报》2007年第1期105-112,共8页Acta Petrologica Sinica

基　　金：a grant from the Natural Science Foundation Committee of China under Grant （No.40572162.）

摘　　要：During the microthermometric measurement（cooling）of aqueous inclusions with multivolatile components,solid crystals of gas clathrates often occur with snow-flower-or soft-ice appearances.The structural formula of these solids is M·nH2O（where n≥5.67）.Many hydrocarbons,related compounds and their binary or multi-component mixtures may generate gas clathrates.This phenomenum is of fundamental importance to the study of inclusions with hydrocarbon aqueous solutions,because this is related to the determination of inclusion parameters and the computation of thermodynamic parameters. In the nature most aqueous inclusions contain not merely one volatile component but multi-volatile components.Therefore,the measurement of aqueous inclusions with multivolatile components is of universal significance and great importance.There have been many studies and available formula or figures about the computation of thermodynamic parameters for aqueous inclusions with one volatile component.Nevertheless,there are few studies concerning with muhivolatile components and it is very difficult to computate thermodynamic parameters for aqueous inclusions with these components. In this paper,hydrated coefficient K is introduced.Ki is the ratio of molar fraction of component i in the gas phase to that in the gas clathrate,or Ki=yi/xi.Because K is a function of temperatures and pressures,it can be used to evaluate the temperature-pressure conditions on the phase behavior with muhivolatile components. Based on the regression analysis of available experimental data,the authors have developed computational expression of hydrated coefficients in relation to temperature and pressure for most hydrocarbons and other volatile components,which is helpful to conveniently compute thermodynamic parameters on stability state for elathrates with volatile components.As aqueous inclusions with muhivolatile components are common in the nature,by the use of final melting temperatures of clathrates from mierothermometry and these formula,fluid densitDuring the microthermometric measurement （cooling） of aqueous inclusions with multivolatile components, solid crystals of gas clathrates often occur with snow-flower-or soft-ice appearances. The structural formula of these solids is M nH2O （ where n i〉 5.67 ）. Many hydrocarbons, related compounds and their binary or multi-component mixtures may generate gas clathrates. This phenomenum is of fundamental importance to the study of inclusions with hydrocarbon aqueous solutions, because this is related to the determination of inclusion parameters and the computation of thermodynamic parameters. In the nature most aqueous inclusions contain not merely one volatile component but multi-volatile components. Therefore, the measurement of aqueous inclusions with muhivolatile components is of universal significance and great importance. There have been many studies and available formula or figures about the computation of thermodynamic parameters for aqueous inclusions with one volatile component. Nevertheless, there are few studies concerning with muhivolatile components and it is very difficult to computate thermodynamic parameters for aqueous inclusions with these components. In this paper, hydrated coefficient K is introduced. K1 is the ratio of molar fraction of component i in the gas phase to that in the gas clathrate, or K, = y/x1. Because K is a function of temperatures and pressures, it can be used to evaluate the temperature-pressure conditions on the phase behavior with multivolatile components. Based on the regression analysis of available experimental data, the authors have developed computational expression of hydrated coefficients in relation to temperature and pressure for most hydrocarbons and other volatile components, which is helpful to conveniently compute thermodynamic parameters on stability state for clathrates with volatile components. As aqueous inclusions with muhivolatile components are common in the nature, by the use of final melting temperatures of clathrates from microthermometry

关 键 词：气水化合物 水合常数 水溶液包裹体 多组分挥发分 测定 应用 

分 类 号：O645.1[理学—物理化学]