That's too bad

Speak to your licensor. Did you rip off this technology from a licensor? Then I guess that's out. Good luck figuring out what's wrong, then, but don't expect any help.

Is this for selective hydrogenation of propadiene and acetylene for the C3= cut from a naphtha cracker?

we contact with the licencor (stone & webster) and they said that there is no problems in the design of the reactor.
they told us that the problem may be from the catalyst (G-55 B).

yes, it is for selective hydrogenation of methyl acetylene and propadiene in the propylene stream.

we had contacted the catalyst vendor to investigate this problem. the vendor suspected poisons which would gradually reduce the activity of the catalyst. with permanent poisons, it is not possible to regenerate the catalyst in order to fully restore catalyst activity. the vendor had therefore proposed a sacrificial bed layer to be installed on top of the catalyst bed. this has not been implemented.

if any one know any reference book related to this subject please give me it's name or link.

thank you all

There is information on the net that palladium catalysts are very sensitive to poisons in the feed, and that in the past, the more rugged solution was to use presulfided Ni catalyst - the lower selectivity of the Ni catalyst is perhaps much more tolerable compared to the shorter run times and higher sensitivity for Pd catalyst.

Alternatives suggested on the net article indicate that extractive distillation with DMF ( dimethly formamide or some other high dipole moment / polar organic solvent) to remove MA and PD are also possible, but in a running plant, the modifications required may be impractical.

thank you georgeverghese
I will search about it