MDEA Sweetening

Introduction

Sour gas from inlet separation and filtration is now divided into two equal flows for the two MDEA contactors. Flow to the contactors is controlled by individual flow control valves (FCVs). Gas enters the bottom of the contactor and flows upwards through 28 stainless steel trays coming into contact with lean amine (MDEA) flowing downwards. The lean MDEA absorbs the H2S and C02 from the gas flowing upwards through contactor through physical and chemical attraction. The MDEA leaves the contactor as rich amine to the regeneration section and the gas leaves sweet (no H2S or C02) to the TEG dehydration section. Lean amine is supplied by high pressure charge pumps described in module 8. Figure 1 block flow diagram highlights the amine location of the amine sweetening processes described in this module.

Raw Gas to Contactors

After the raw gas flow leaves the Inlet Gas Filter (FI-1105), the raw gas flow branches to feed the two, parallel Amine (PV-1101A/B) contactors (see Figure 2). The equipment numbering described below is for contactor A but contactor B is exactly the same. Refer to Amine Contactor A/B(PV-1101A/B) for more information.

Gas Cooling

After passing through the the hot amine and doing chemical reaction the gas is hot and needs to be cooled. The gas from the contactors passes through an air cooler. Refer to Sweet Gas Cooler(HT-1101).