Dynamics and control of an industrial front-end acetylene converter

• Published in: Computers & chemical engineering Vol. 18; pp. S355 - S359
• Main Authors: Schbib, N.S., Errazu, A.F., Romagnoli, J.A., Porras, J.A.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Oxford Elsevier Ltd 1994; Elsevier
• Subjects: Applied sciences; Chemical industry and chemicals; Exact sciences and technology; Industrial chemicals; Organic industry; Tubular reactor; Hydrocarbon; Simulation; Dynamics; Process control; Fixed bed reactor; Adiabatic; Dynamic model; Mathematical model; Hydrogenation; Modeling; Acetylene
• ISSN: 0098-1354; 1873-4375
• DOI: 10.1016/0098-1354(94)80059-6

The dynamic simulation of a frontal industrial acetylene converter and its closed-loop performance under three different control strategies are discussed in the present work. The reactor is used for the selective hydrogenation of acetylene in the presence of large amounts of ethylene. It consists of a condenser followed by three catalytic beds with intermediate cooling. In the first step, the steady-state and the open-loop dynamic modeling and simulation of the converter are described. An analysis of the closed-loop behavior follows, starting with the existing control scheme, i.e. three conventional feedback loops located at the condenser and at the two intermediate heat exchangers respectively. The second control configuration studied is formed by adding feedforward scheme, which acts on the set points of the feedback loops. This configuration proves to diminish the peaks in the reactor temperature produced by changes in the total reactants flowrate and/or in the CO or the C 2H 2 concentration. The last scheme studied is the previous one plus an external feedback composition loop. To keep the acetylene concentration in the final ethylene below 3 ppm, this controller should ensure around 1 ppm C 2H 2 at the reactor outlet (approximately 1.4 10 −4 wt% for a typical process stream composition).