Study On The Foaming Origin And Mechanism Of MDEA Natural Gas Desulphurization Solution

The methyldiethanolamine (MDEA) solution is widely used in the removalprocessof acid gas impurit ies such as H2S, but easy foaming defects in MDEA solution exists, which may cause entrainment, low efficiency of the desulfurization and shutdownof the desulfurization device. So the importance of inhibiting the foaming of MDEA increasingly reflected.In this article, measuring the foaming of MDEA equipment was built. The absorption temperature, absorption concentration, gas velocity, absorption volume, metal ions,organic matter and solid particles were investigated through single factor tests and multiple factors by taguchi method. The experimental results showed that the prominentfoaming factors of MDEA were the absorption temperature, Ca2+, Mg2+, Fe3+, FeS, isoctane and diethanolamine.The liquid deposition dropping method is adopted to investigate the metal ions and solidparticles and organic matter on the influence of the surface tension of MDEA solution. Resultsshow that:(1) With the increase of Ca2+, Mg2+, Fe3+, MDEA solution decreases, and thesurface tension of the foaming performance improvement;(2) The FeS, activated carbonpowder and other solid particles will adhere to the bubble surface, increases the bubblesurface viscosity and liquid membrane strength, significantly improve the stability of thefoam, greatly increase the foamability of MDEA solution;(3) The heavy hydrocarbonsfloating on the surface of MDEA solution can form gel layer, a significant decrease in thesolution surface tension, make it easier to foam.According to the actual production device of MDEA solution foaming problem easily,filtration and activated carbon adsorption of MDEA solution was put forward after filteringconcrete measures, such as to control the MDEA solution foaming advice. After activatedcarbon adsorption filtration solutions for the rich fluid, the experimental results than barrensolution defoaming effect is better, the method can effectively restrain the MDEA solutionfoaming; After activated carbon adsorption filtration, rich liquid foaming height of9.5cm,defoaming time reduced10.2s.