The elementary isomerization A longrightarrowB is carried out at $20$atm in a fluidized CSTR containing $100kg$ of catalyst where $50\%$ conversion is achieved. It is proposed to replace the CSTR with a packed bed reactor. The entering pressure was $20$atm and the exit pressure was found to be $10$atm.

b$)$ What will the conversion be in the new PBR with pressure drop?