An absorber apparatus for the reactive absorption of a gas composition comprising alkylene oxide, alkene, oxygen, carbon dioxide and water vapour comprising an absorption section containing vertically stacked trays and a sump,
- wherein the absorption section has
- i. an inlet for liquid lean absorbent at the top of the absorption section,
- ii. an inlet for the gas composition below the absorption section,
- iii. a tray for collecting fat absorbent above the sump and
- iv. an outlet for unabsorbed gas at the top of the absorption section;
- and
- wherein the sump has
- i. a sump inlet for fat absorbent from the absorption section and any liquid condensate,
- ii. a sump outlet for fat absorbent, and
- iii one or more baffles which are positioned in the sump to create a flow pathway that approximate plug flow between the sump inlet to the sump outlet between the one or more baffles.