Processes for removing contaminants from a dehydrogenation effluent

A process for removing contaminants from a reactor effluent of a catalyst dehydrogenation process, the process comprising:

• dehydrogenating a paraffin feed in a dehydrogenation reaction zone under dehydrogenation reaction conditions in the presence of a dehydrogenation catalyst to form a reactor effluent containing olefins;
• compressing the reactor effluent to provide a compressed effluent;
• removing chloride contaminants from the compressed effluent in a chloride removal zone to provide a treated effluent;
• removing water and hydrogen sulfide from the treated effluent in a dryer zone to provide a dryer output stream including olefins and unconverted paraffins, the dryer zone having at least one vessel comprising a regenerable adsorbent;
• separating the dryer output stream into a vapor stream and a liquid stream comprising an olefin product stream;
• regenerating the regenerable adsorbent in the dryer zone with a regenerant gas stream to produce a spent regenerant stream, the spent regenerant stream including water and hydrogen sulfide;
• wherein the regenerant gas stream comprises a portion of the reactor effluent;
• removing the hydrogen sulfide from the spent regenerant stream in a regenerant cleaning zone to provide a cleaned regenerant stream, the regenerant cleaning zone including at least two vessels having a sorbent to remove hydrogen sulfide from the spent regenerant stream;
• wherein two vessels are operated in a lead-lag configuration;
• wherein at least one vessel is used as a heat exchanger to remove heat from the cleaned regenerant stream to provide a cooled regenerant stream;
• removing contaminants form the cooled regenerant stream;
• and
• recycling the cooled regenerant stream to provide to the dryer as the regenerant gas stream.