| abstract |
A process of continuously controlling at least one characteristic of a simulated moving bed para-xylene separation process has been developed. The characteristics controlled may be the purity or the recovery of the para-xylene. The process involves measuring the concentrations of the para-xylene, meta-xylene, ortho-xylene, and ethylbenzene in the pumparound or pusharound stream, calculating the value of the characteristic, and making required adjustments to operating variables according to an algorithm which relates changes in the value of the characteristic to the changes in the concentrations of the components resulting from changes in the operating variables. The process is unique in that the necessary quantity of data to control the separation is rapidly generated, thereby providing increased efficiency, precision, and accuracy. |