Tapping Singular Middle Eastern Ultrasour Gas Resources Combining Membrane and Absorption Systems: Potential for Energy Intensity Reduction

A process design and techno-economic analysis is proposed for sweetening ultrasour natural gas containing over 20% H₂S and 30% total acid gases using a hybrid scheme approach. This type of gas resource is unique and can only be found in the Middle East. The hybrid scheme combines membrane and amine gas absorption systems. The study was made on the basis of process simulations and sensitivity analyses to find the most suitable process design and operating parameters using the software ProMax. A Pebax-based membrane module(s) is used as the primary sweetening method, whereas gas absorption is applied to meet the final gas product specifications. The hybrid scheme is benchmarked against the current stand-alone absorption system used to process this rare type of gas. It was found that the gas sweetening energy intensity can be substantially reduced using the hybrid scheme and be more cost-effective than conventional stand-alone absorption units for treating Middle Eastern ultrasour natural gas