Abstract: A method for adjusting the concentration of starting materials, comprising adjusting the starting material concentration in a gas fed to a reactor in a gas phase contact reaction process having a recycling system, wherein the concentration of a starting material in a gas in the process is measured, the starting material is fed by setting the feed amount of the starting material newly added to the process based on the measured value, and thereby the starting material concentration in the gas fed to the reactor is controlled; and a method for controlling a reaction process using the above-described adjusting method.

Abstract: The method and apparatus for startup control of a polyolefine polymerization reactor of the present invention determines an olefine feed rate based on a reaction amount set by the heat balance within the polyolefine polymerization reactor, a reaction balance amount calculated from its unreacted amount and dynamic compensation amount, and the olefine concentration within the polyolefine polymerization reactor. Due to this, model errors are reduced, and the practical application of feed-forward control is possible.