*1.3. Reactor Arrangement*

Typically, the acetylene hydrogenation process contains four catalytic beds, namely Lead and Guard Beds. The philosophy of guard bed is the sensitivity of downstream units to acetylene and the decreasing acetylene concentration to the desired level [21]. The coke build-up on the catalyst surface decreases activity and increases acetylene concentration in outlet stream from Guard bed gradually. In this regard, two beds are in operation, while two other beds are in standby or regeneration modes. Dehghani et al. modified the reaction-regeneration cycles and the reactor arrangement in the acetylene hydrogenation process to decrease energy consumption, and improve catalyst lifetime [22]. The feasibility of the proposed configuration was proved based on a theoretical framework.
