Studying influence of different impurities on foaming of amine absorbents of sour gas treatment plants

Abstract

The article focuses on studying the foaming process in the amine solutions (diethanolamine (DEA) and methyldiethanolamine (MDEA)) on an example of the model mixtures containing different organic and inorganic impurities and their combinations: oxalic acid, formic acid, corrosion inhibitor, hydrocarbons, amine decomposition products, mechanical impurities. It has been found that the greatest influence on foaming in the DEA solution is exerted by its decomposition products containing the formic acid, and at a concentration of 3% by weight the foam height increased by more than 3 times, and the foam stability - by 20 times. Oxalic acid also has a significant effect on foaming: at a concentration of 1 g/l the foam height increased by 3 times, and the foam stability - by more than 5 times. The decomposition products of DEA containing oxalic acid have a rather noticeable effect - the height and stability of the foam increased by 2.8 and 6.8 times, respectively. The foam grew least in the presence of formic acid - by 2 times, at the same time the stability was enhanced by more than 4 times. It has been stated that hydrocarbons have the greatest influence on foaming of the MDEA solution - at a concentration of 0.5% vol. the foam height increased by more than 1.7 times, and the stability of the foam - by 5 times. Similarly, the decomposition products of MDEA made a significant impact – the foam height increased by more than 1.7 times, and the foam stability - by 11 times. Mechanical impurities caused an increase in the foam height by more than 1.6 times and in stability by 1.4 times. Introducing a corrosion inhibitor foaming gave the least result - the foam height decreased by 2.8 times, and the stability increased by 2 times. There has been found the mutual influence of impurities in the MDEA solution, which could be seen in the mutual suppression of foaming in the double and triple mixtures compared with the single-component solutions.