Conventional packed beds are traditionally used for acid gas enrichment processes. Rotating packed beds (RPBs) are unique, compact and effective technology, which can easily replace conventional packed beds for process intensification purposes. Two scenarios are used to substitute Khangiran natural gas refinery enrichment column with a couple of specially designed RPBs. The first scheme mirrors the exact existing process, while the second scenario provides an additional rich solvent stream directly delivered to amine regeneration unit. Aspen Custom Modeler software is employed to perform the entire simulations. As expected, replacing conventional packed bed with RPBs can drastically reduce the geometries of the packed beds and leads to considerable decrease in lean amine consumption. The second scenario performs more adequately and reduces the lean methyl-diethanolamine (MDEA) flow rate entering the enrichment section from 6069 kmole/hr to 5100 kmole/hr. The required enrichment equipment volume is also reduced from 235 m3 to 7.7 m3 (<3% of original value) and the packing volume collapses about 78 folds (from 59 m3 to 0.75 m3). A thorough discussion is also provided on sensitivity analysis of the entire enrichment process versus various input variables (i.e.: RPBs rotational speeds, their operating pressures and the lean amine rate entering enrichment tower). Finally, the results of cost estimation revealed that using the second more optimal RPB scenario reduced both operating costs and captital investments by 15.4% and 85.4%, respectively.

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