Optimal control of process of pyrolysis of paraffinic hydrocarbons C2-C4 and their mixtures

This paper describes the scheme that has been developed for the optimal control of the process of pyrolysis for different types of hydrocarbon feedstock in the four-flow pyrolysis furnace at the Sumgait Ethylene-Polyethylene plant; the scheme is based on the use of a complex parameter of the process, i.e., the pyrolysis intensity function. The algorithm for this control has been constructed. In the paper, the results of optimal control of the process of propane pyrolysis, ethane pyrolysis, and pyrolysis of ethane together with the butane-butylene fraction are presented in accordance with the scheme being developed using the intensity function that corresponds to each process. Optimal values of the intensity function were found from the results of calculations carried out using the mathematical model of each process. The extended expression for the intensity function has been formulated and, with its use, it is possible to control the process both in the case of the change in the flows of feedstock and steam and the change in the inlet temperature, as well as in the case of the change in the feedstock composition.