The specific heats, Cs, and Cv, of compressed and liquefied methane

Abstract

The specific heats, C u , of saturated liquid meth ane ha ve bee n meas ured at 66 te mperatures in th e temperature ran ge 95-187 K. Th e s pecific heats at constant volume , C 1', have been measured at 20 dens iti es ran ging from 0.8 to 2.8 times the c ritical de nsity, a t temperatures betwee n 91 and 300 K , and a t pressures to 330 bar (at 280 PVT states in all). Th e un ce rtainty of most of th e meas ureme nts is es t;mated to be less than 0.5 perce nt , except near th e c riti cal point. These meas ure me nts were pe r· form ed prim aril y to provide input data for accurate th e rmod ynam ic pro pe rti es data ca lc ul at io ns for liquid meth a ne. Th ey are beli e ved to be th e most co mpre he nsive s pecifi c heat meas ure me nts avai lable for pure co mpressed gaseous a nd liquid methan e .

The VIM theory of molecular thermodynamics: Part I: Analytic equation of state of nonpolar fluids

“…These computations, Figures 2 and 3, show a very good agreement with the experimental (Younglove, 1974) data Another test of an equation of state is its accuracy in predicting the critical properties P,, p , and T,. According to the comparisons made with the experimcmtal thermodynamic data, the VIM equations of state is an analytic equation of state based on the statistical mechanical grounds which can be used for accurate prediction of therrnodynarnic proprties of nonpolar liquids and vapors.…”

Rarefied Natural Gas Transport

“…Then you can use the formulas and the properties to present further properties of other hydrocarbons, such as ethane, propane, butane, etc., to calculate further physical properties of natural gases in most common operating states, and to conduct further analyses of theoretical and experimental researches. Various tests have been conducted to determine  , k , p c , and  of methane at different working pressures or temperatures (Mann & Dickins 1931;Johnston & McCloskey 1940;Clarke & Smith, 1969;Jansoone et al, 1970;Vennix et al, 1970;Younglove, 1974;Gammon & Douslin, 1976;Kerley, 1980;Kurumov et al, 1988;Friend et al, 1989;Jin et al, 1992;Pátek & Klomfar, 2002;Hurly et al, 2003;Schley et al, 2004;Viswanathan, 2007). Except for density, temperature was found to be a relatively important factor in the gaseous state.…”

Crossover equation of state for the thermodynamic properties of mixtures of methane and ethane in the critical region

“…As mentioned earlier, the coefficient rio(() is determined implicitly by Eqs. (32) and (34). In the equation for fil(~) fil(~') ~-(l --~')/~I) =b" ~fi]2)oc film) ,dZc(~" ) (39) we arbitrarily took fi]l)= 0 for methane, but the coefficient fi~2) for ethane and the mixing coefficient fi~'~ were left as adjustable parameters.…”

“…Specifically, we used experimental Cv data obtained by Younglove [32] as corrected by Roder [33], experimental Cv data obtained by Anisimov et al [34] with temperatures shifted by 0.114 K as discussed by Kiselev and Sengers [ 35 ], and experimental speed-of-sound data obtained by Gammon and Douslin [36], by Straty [37], and by Trusler and Zazari [38]. In addition we used Cv values calculated from the global equation [27] [29,30] and by Trappeniers and co-workers [31 ] for methane from values calculated with the crossover equation of state.…”

“…This computer program is based on a classical principle of extended corresponding states and, hence, does not (0) Experimental Cv data [32][33][34] and Cv values calculated from the global equation [27].…”