Regeneration Of Chelated Iron Desulfurization Solution In Rotating Packed Bed

With the rapid development of natural gas purification, gas processing and oil fields, theremoval of H2S in the gas becomes more and more important. Among the numerousdesulfurization technologies, chelated iron desulfurization technology stands out with itsadvantages of high efficiency and clean. Whether the desulfurization solution can be normalrecycling is relevant to the regeneration of chelated iron desulfurization solution. As thetraditional regeneration equipment is the regeneration tower or the regeneration tank, existingthe disadvantages of poor mass transfer effect and long gas-liquid contact time. Such, it couldlead to the shortcomings of lower regeneration efficiency and more serious degradation ofchelating agent in the industrial application. In this paper, the new desulfurization solutiondeveloped by the research group were further optimized. A new technology of theregeneration of chelated iron desulfurization solution in rotating packed bed is proposed, andis studied in-depth.In the aspect of the optimization of chelated iron desulfurization solution, the influencefactors were investigated, which included the proportion of complexing agents, the proportionof complexing agent and iron, and the concentration of iron. A desulfurization solution with amore excellent performance was selected. At the same time, the crystal structure andmorphology of sulfur were studied by X-ray scattering techniques and scanning electronmicroscope. The results showed that the crystal type of the sulfur was rhombic. The content ofelemental sulfur reached as high as81.25%.In the aspect of the mass transfer of oxygen in desulfurization solution, the mechanism,of which the mass transfer of oxygen in desulfurization solution enhanced by high gravity technology, was analyzed by the double film theory. The calculation method of volumetricliquid phase mass transfer coefficient of oxygen mass transfer was established. The effects ofprocess parameters on the volumetric liquid phase mass transfer coefficient KLa were studied.The results showed that, KLa increased with the increase of the high gravity factor, gas flow,liquid flow and oxygen volume fraction, but decreased with the increase of temperature.Under the similar conditions, the KLa of rotating packed bed was increased by1order ofmagnitude than that of the traditional aeration, the effect of the enhancement of mass transferwas remarkable.Taking advantage of the superiority that the rotating packed bed could strengthen themass transfer of oxygen, it was applied to the regeneration of chelated iron desulfurizationsolution in this topic. Suitable process parameters in the range of experiment were determined.The results showed that, the regeneration rate first increased with the increase of the highgravity factor and gas flow rate, and then decreased. It increased with the increase of theregeneration temperature and oxygen volume fraction, and decreased with the increase ofliquid flow rate and initial concentration of Fe2+Ln-. When dealing with the desulfurizationsolution with an initial concentration of Fe2+0.02mol/L, the regeneration rate reached morethan60%, after the secondary regeneration, the regeneration rate reached more than90%. Theregeneration rate of the second level was71%, increasing by10%when compared with thefirst level. Compared with the traditional aeration regeneration, the regeneration in a rotatingpacked bed could alleviate the degradation of chelating agent. In this regeneration technology,the regeneration efficiency was improved, the degradation of complexing agent was alleviated,the volume of the equipment is reduced. It is with a broad prospects of development.