Composition Determination of Low-Pressure Gas-Phase Mixtures by ¹H NMR Spectroscopy.

ABSTRACT: ¹H NMR spectroscopy was used to analyze gas-phase mixtures of methane and propane at pressures near 0.1 MPa. The mixtures were prepared gravimetrically and had low uncertainty in their composition. The primary mixture used for this work had a methane mole fraction of x_methane,grav = (0.506875 ± 0.00019) and a propane mole fraction of x_propane,grav = (0.493125 ± 0.00019). NMR samples were prepared in two types of commercially available sample tubes that seal with a PTFE piston. Sample pressures ranged from 0.02 to 0.5 MPa. An analysis of measurement uncertainty for the NMR method resulted in combined standard uncertainties that decreased from 0.0082 x to 0.0010 x, as the pressure increased from 0.02 to 0.5 MPa. The larger uncertainties at lower pressures wer

SUBMITTER: Suiter CL 

PROVIDER: S-EPMC7008668 | biostudies-literature | 2019 Apr

REPOSITORIES: biostudies-literature