Hydrogen Sulfide Removal from Flare Gas

Flaring is necessary to prevent pressure buildup in the unit. Due to hydrotreatment processes at the refinery, flare gas can contain significant amounts of hydrogen sulfide. Combusting this gas can result in environmental and health issues. One method to reduce hydrogen sulfide is to replace the water in the seal drum with an amine solution. Honeywell UniSIM® process simulation was used to calculate the hydrogen sulfide removal efficiency with 45 wt% MDEA solution. Results show that removal efficiency depends on amine loading and pool height. Removal efficiency of up to 72.5% was achieved with a hydrogen sulfide-to-amine molar loading of 0.2 (4:20 ratio) and a pool effective height of 2.5 m.