METHOD AND APPARATUS FOR CONTROLLING RATIO AMONG CONCENTRATIONS OF REACTANTS IN FEED STREAM FED TO REACTOR

摘要

In a process for manufacture of a chemical product, a reactive hydrocarbon feedstream, which varies in composition of the reactive component, is combined with a compatible but unreactive hydrocarbon feedstream to form a blended hydrocarbon stream which is then combined with a reactive alcohol stream of stable concentration of its reactive component, to form a complete feedstream to the reactor. A desired ratio of relative reactant concentrations in the complete feedstream to the reactor is maintained by a control system which maintains a stable concentration in the blended hydrocarbon stream by manipulating flow rate of the unreactive hydrocarbon feedstream responsive to a concentration measurement in the blended hydrocarbon stream. Flow ratio control is then applied to maintain a desired ratio of reactants in the complete feedstream for the reactor by calculating a flow ratio of the blended hydrocarbon stream to the reactive alcohol feedstream. The calculated flow ratio is the process variable input to a manually set ratio controller which manipulates the flow rate of the reactive alcohol feedstream responsive to the flow ratio.