Development of a new densimeter for the combined investigation of dew-point densities and sorption phenomena of fluid mixtures

Abstract

For the determination of dew-point densities and pressures of fluid mixtures, a new densimeter has been developed. The new apparatus is based on the well-established two-sinker density measurement principle with the additional capability of quantifying sorption effects. In the vicinity of the dew line, such effects cause a change in composition of the gas mixture under study, which can significantly distort accurate density measurements. The new experimental technique enables the accurate measurement of dew-point densities and pressures and the quantification of sorption effects at the same time.

Adsorption of CO2 on Gold Surfaces: Adsorbate Density Assumption Investigated Using Molecular Dynamics Simulations

“…Richter and Kleinrahm have shown that these sorption effects can lead to errors in gravimetrically measured vapor densities of about 0.1% . The results of the present study will support our current work utilizing two- and four-sinker densimeters and will also lead to application in density determination with single-sinker densimeters, i.e., gravimetric sorption analyzers.…”

“…In an earlier manufacturing step, the sinker was sandblasted with average particle sizes of 125 μm and plasma polished to remove about 2 μm. Later, it was galvanically gold-plated, which usually results in a layer thickness of several μm . A photograph of the sinker is shown in Figure .…”

“…Later, it was galvanically gold-plated, which usually results in a layer thickness of several μm. 10 A photograph of the sinker is shown in Figure 2.…”

“…In 2005, Keller and Staudt assumed the adsorbed phase to have the density of the liquid phase at the triple point . Moreover, a differentiation between subcritical and supercritical adsorption or between adsorption on porous and nonporous surfaces can be found in the literature. Based on these assumptions, the volume of the adsorbate is calculated and considered in the data analysis.…”

High-Pressure Gravimetric Measurements for Binary Gas Adsorption Equilibria and Comparisons with Ideal Adsorbed Solution Theory (IAST)

“…Implementing a pressure transducer with higher accuracy at low pressures and then carrying out a comprehensive force transmission error analysis could be a possible solution. Alternatively, adapting the two-sinker − or four-sinker , measurement techniques that incorporate a magnetic-suspension balance and inherently enable lower measurement uncertainties at pressures below 1.0 MPa could also achieve such a target.…”