Analysis of hydrocarbon solubility in amine solution used for natural gas processing

This Thesis comprises of experimental and the theoretical work done on the analysis of hydrocarbon solubility in amine solutions used for natural gas processing. The objective of this study is the solubility of hydrocarbons in different Amine solutions and the comparison of the results obtained, in order to understand their behaviour in applications related to Natural Gas processing. From solubility knowledge indeed several informations of interest could be obtained such as: i) quantification of possible losses of hydrocarbons during amine treatment ii) evaluation of the amount of these components reaching the stripper and iii) determination of the additional work to be done for purification of the amine solutions after the absorber. Data for the solubility of the different hydrocarbon and Amines are indeed important for proper modelling of absorption columns and the strippers. The peculiarity of the study is that in addition to the analysis of solubility on pure and mixed amine solution also the solubility of loaded amine solutions will be considered, i.e. Amine solution mixed with acid gas like CO2 and/or H2S. Indeed, while there had been previous measurements made on this project, but they were basically for the non-loaded amine solution, giving therefore only partial information on this topic. This experiment is carried out at the laboratories of the group of Chemical Engineering at Aalto School of Chemical Technology and written at the University of Bologna Italy. The chief apparatus for this study among others are BBQ apparatus with a capacity of 30 vials and GC Agilent 7890 B. The following Hydrocarbons were used: Benzene, Ethylbenzene, Toluene, Hexane, Cyclohexane and 2,2,4-Trimethylpentane and the following amines solutions: Diglycolamine (DGA), N-methyl-diethanolamine(MDEA), Monoethanolamine(MEA), Di-Ethanolamine(DEA), and Piperazine. Tests were carried out at (define T and P) and at H2S and CO2 loading level ranging from about 0.15 to 0.45