Collection of VLE data for acid gas-alkanolamine systems using Fourier transform infrared spectroscopy. Technical report, October 1, 1994--July 31, 1995

The industrial standard process for the purification of natural gas is to remove acid gases, mainly hydrogen sulfide and carbon dioxide, by the absorption and reaction of these gases with alkanolamines. The natural gas industry requires vapor-liquid equilibrium (VLE) data to develop more energy efficient amine mixtures. Some energy reductions have been realized in the past decade by applying such amine systems as hindered amines, methyldiethanolamine (MDEA), and MDEA based amine mixtures. However, the lack of reliable and accurate VLE data impedes the commercial application of these more efficient alkanolamine systems. The first objective of this project is to improve the accuracy of vapor-liquid equilibrium measurements at low hydrogen sulfide concentrations. The second objective is to make VLE measurements for amine mixtures. By improving the accuracy of the VLE data on MDEA and other amines, energy savings can be implemented in the many existing absorption units already in use. If about 25% of the existing 95.3 billion SCFD gas purification capacity is converted to these new amine systems, the energy saved is estimated to be 3 {times} 10{sup 14} BTU/yr. 14 refs., 31 figs., 12 tabs

Collection of VLE data for acid gas - alkanolamine systems using Fourier transform infrared spectroscopy. Final report, September 29, 1990--September 30, 1996

This report describes research from September 29, 1990 through September 30, 1996, involving the development a novel Fourier transform infrared (FTIR) spectroscopic apparatus and method for measuring vapor - liquid equilibrium (VLE) systems of carbon dioxide and hydrogen sulfide with aqueous alkanolamine solutions. The original apparatus was developed and modified as it was used to collect VLE data on acid gas systems. Vapor and liquid calibrations were performed for spectral measurements of hydrogen sulfide and carbon dioxide in the vapor and in solution with aqueous diethanolamine (DEA) and methyldiethanolamine (MDEA). VLE measurements were made of systems of hydrogen sulfide and carbon dioxide in 20 wt % DEA at 50{degrees}C and 40{degrees}C. VLE measurements were made of systems of hydrogen sulfide and carbon dioxide in 50 wt% and 23 wt% MDEA at 40{degrees}C and in 23 wt% MDEA at 50{degrees}C. VLE measurements were made of systems of hydrogen sulfide and carbon dioxide in 35 wt% MDEA + 5 wt% DEA and in 35 wt% MDEA + 10 wt% DEA at 40{degrees}C and 50{degrees}C. Measurements were made of residual amounts of carbon dioxide in each VLE system. The new FTIR spectrometer is now a consistently working and performing apparatus