Process and apparatus for treating a sulphur-containing off-gas from a sulphur recovery system

An apparatus for recovering sulfur (9), comprising:

• a sour gas scrubbing apparatus (S), which comprises a scrubbing part (SP), a regeneration part (RP), and a scrubbing agent circuit, in which sulfur components and carbon dioxide can be selectively removed from a crude synthesis gas (2) with the aid of a circulating scrubbing agent (3),
• a sulfur recovery system (SR) to which a sulfur-containing gas fraction (8) accumulating in the regeneration part (RP) of the sour gas scrubbing apparatus (S) can be supplied and from which an off-gas (10) comprising carbon dioxide and also sulfur components can be withdrawn,
• a hydrogenating apparatus (H) in which the off-gas (10) can be hydrogenated, and
• a scrubbing apparatus (Z) which is connected to both the hydrogenating apparatus (H) and the scrubbing agent circuit of the sour gas scrubbing apparatus (S) and in which hydrogenated off-gas (12) from said hydrogenating apparatus (H) can be subjected to a scrubbing operation with a scrubbing agent (13) supplied from said scrubbing agent circuit of the sour gas scrubbing apparatus (S).