Tham khảo tài liệu 'essentials of process control phần 4', ngoại ngữ, ngữ pháp tiếng anh phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | CHAPTER 5 Interaction between Steady-State Design and Dynamic Controllability 169 Reactor holdup lb-mol ZB mole fraction B Consecutive reactions. 170 PART one Time Domain Dynamics and Control Ternary reactor two-column process a 4 2 I RECYCLE Fo 100 2 172 F 324 -W zc FIGURE Ternary reactor two-column process a 4 2 1 . S 100 XB c DC2 Da D 224 xDị A cc xĐlfí cc V 578 O2 153 XDZ the reactor effluent requires a recycle of this component back to the reactor. Much higher yields can be obtained from this type of recycle system. However the reactor still encounters controllability limitations. Figure is a sketch of the plant under consideration. Fresh feed enters the reactor at a flow rate Fq and composition Z0 A 1 pure component A in the fresh feed . We assume that the relative volatilities of components A B and C are respectively so unreacted component A comes overhead in the first distillation column and is recycled back to the reactor at a rate and composition . . Reactor effluent is fed into the first distillation column. The rates of and vapor boilup in this column are T 1 and Vị. Bottoms Bị from the first column is fed into the second column in which components B and C are separated into product streams with about 1 percent impurity levels. Steady-state component balances around the whole system and around each of the units are used to solve for the conditions throughout the plant for a given recycle flow rate The reactor holdup and the reactor temperature necessary to achieve a specified ratio are calculated as part of the design procedure. The other fixed design parameters are the kinetic constants preexponential factors activation energies and heats of reaction for both reactions the fresh feed flow rate and composition the overall heat transfer coefficient in the reactor the inlet coolant CHAPTER 5 Interaction between Steady-State Design and Dynamic
