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Title: Isochoric p-{rho}-T and heat capacity C{sub v} measurements on {l_brace}xC{sub 3}H{sub 8} + (1 {minus} x)i-C{sub 4}H{sub 10}, x {approx} 0.7, 0.3{r_brace} from 200 to 400 K at pressures to 35 MPa

Abstract

The p-{rho}-T relationships and constant volume heat capacity C{sub v} were measured for binary hydrocarbon mixtures containing propane (C{sub 3}H{sub 8}) and isobutane (i-C{sub 4}H{sub 10}). Temperatures ranged from 200 K to 400 K for p-{rho}-T and from 203 K to 342 K for C{sub v} with pressures up to 35 MPa for both measurements. Measurements of p-{rho}-T and C{sub v} were conducted on liquid samples with the mole fraction compositions {l_brace}xC{sub 3}H{sub 8} + (1 {minus} x)i-C{sub 4}H{sub 10}{r_brace} for x = 0.7006 and x = 0.2979. Determinations of saturated-liquid densities were made by extrapolating each isochore to the saturated-liquid pressure and determining the temperature and density at the intersection. Published p-{rho}-T data are in good agreement with this study. For the p-{rho}-T apparatus, the uncertainty of the temperature is 0.03 K, and for pressure it is 0.01% at p > 3 MPa and 0.05% at p < 3 MPa. The principal source of uncertainty in density is the cell volume ({approximately}28.5 cm{sup 3}) with a standard uncertainty of 0.003 cm{sup 3}. When all components of experimental uncertainty are considered, the expanded relative uncertainty (with a coverage factor {kappa} = 2 and thus a two-standard-deviation estimate) of the densitymore » measurements is estimated to be 0.05%. For the C{sub v} apparatus, the uncertainty is 0.002 K for the temperature rise and 0.2% for the change-of-volume work, which is the principal source of uncertainty. The expanded relative uncertainty of the heat capacity measurements is estimated to be 0.7%. Hydrocarbon mixtures are considered to be leading candidates to replace chlorofluorocarbon refrigerants, which will be phased out under the terms of the Montreal Protocol.« less

Authors:
;  [1]
  1. National Inst. of Standards and Technology, Boulder, CO (United States)
Publication Date:
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
697122
Resource Type:
Journal Article
Journal Name:
Journal of Chemical and Engineering Data
Additional Journal Information:
Journal Volume: 44; Journal Issue: 5; Other Information: PBD: Sep-Oct 1999
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; 40 CHEMISTRY; REFRIGERANTS; PROPANE; 2-METHYLPROPANE; SPECIFIC HEAT; BINARY MIXTURES; DENSITY; CHLOROFLUOROCARBONS; MATERIAL SUBSTITUTION

Citation Formats

Duarte-Garza, H.A., and Magee, J.W. Isochoric p-{rho}-T and heat capacity C{sub v} measurements on {l_brace}xC{sub 3}H{sub 8} + (1 {minus} x)i-C{sub 4}H{sub 10}, x {approx} 0.7, 0.3{r_brace} from 200 to 400 K at pressures to 35 MPa. United States: N. p., 1999. Web. doi:10.1021/je990090r.
Duarte-Garza, H.A., & Magee, J.W. Isochoric p-{rho}-T and heat capacity C{sub v} measurements on {l_brace}xC{sub 3}H{sub 8} + (1 {minus} x)i-C{sub 4}H{sub 10}, x {approx} 0.7, 0.3{r_brace} from 200 to 400 K at pressures to 35 MPa. United States. doi:10.1021/je990090r.
Duarte-Garza, H.A., and Magee, J.W. Wed . "Isochoric p-{rho}-T and heat capacity C{sub v} measurements on {l_brace}xC{sub 3}H{sub 8} + (1 {minus} x)i-C{sub 4}H{sub 10}, x {approx} 0.7, 0.3{r_brace} from 200 to 400 K at pressures to 35 MPa". United States. doi:10.1021/je990090r.
@article{osti_697122,
title = {Isochoric p-{rho}-T and heat capacity C{sub v} measurements on {l_brace}xC{sub 3}H{sub 8} + (1 {minus} x)i-C{sub 4}H{sub 10}, x {approx} 0.7, 0.3{r_brace} from 200 to 400 K at pressures to 35 MPa},
author = {Duarte-Garza, H.A. and Magee, J.W.},
abstractNote = {The p-{rho}-T relationships and constant volume heat capacity C{sub v} were measured for binary hydrocarbon mixtures containing propane (C{sub 3}H{sub 8}) and isobutane (i-C{sub 4}H{sub 10}). Temperatures ranged from 200 K to 400 K for p-{rho}-T and from 203 K to 342 K for C{sub v} with pressures up to 35 MPa for both measurements. Measurements of p-{rho}-T and C{sub v} were conducted on liquid samples with the mole fraction compositions {l_brace}xC{sub 3}H{sub 8} + (1 {minus} x)i-C{sub 4}H{sub 10}{r_brace} for x = 0.7006 and x = 0.2979. Determinations of saturated-liquid densities were made by extrapolating each isochore to the saturated-liquid pressure and determining the temperature and density at the intersection. Published p-{rho}-T data are in good agreement with this study. For the p-{rho}-T apparatus, the uncertainty of the temperature is 0.03 K, and for pressure it is 0.01% at p > 3 MPa and 0.05% at p < 3 MPa. The principal source of uncertainty in density is the cell volume ({approximately}28.5 cm{sup 3}) with a standard uncertainty of 0.003 cm{sup 3}. When all components of experimental uncertainty are considered, the expanded relative uncertainty (with a coverage factor {kappa} = 2 and thus a two-standard-deviation estimate) of the density measurements is estimated to be 0.05%. For the C{sub v} apparatus, the uncertainty is 0.002 K for the temperature rise and 0.2% for the change-of-volume work, which is the principal source of uncertainty. The expanded relative uncertainty of the heat capacity measurements is estimated to be 0.7%. Hydrocarbon mixtures are considered to be leading candidates to replace chlorofluorocarbon refrigerants, which will be phased out under the terms of the Montreal Protocol.},
doi = {10.1021/je990090r},
journal = {Journal of Chemical and Engineering Data},
number = 5,
volume = 44,
place = {United States},
year = {1999},
month = {9}
}