Purification of exhaust air stream from rayon prodn. - using carbon absorption with double regeneration to remove carbon di:sulphide and hydrogen sulphide

摘要

Exhaust air stream from a rayon process contg. CS2 and H2S is fed into an adsorber contg. activated carbon as a moving bed. This adsorbs the H2S and CS2 having clean air to be exhausted to atmosphere while the carbon flows into a regeneration process. It irst enters a first desorber section where it is heated to release the CS2. It then enters a second desorber section where it is further heated to release the H2S and elemental S. It is then cooled and recycled back to the adsorber. Some carbon can bypass the second desorber. The temp. in the first desorber is pref. =200 (esp. 175) degrees C while that in the second is pref. >=340 (esp. 450) degrees C. Process eliminates liq. handling associated with prior processes.