Methods of monitoring and controlling the melt index of a polyolefin product during production

Methods for producing polyolefin polymers may use a predictive melt index regression to estimate the melt index of the polyolefin during production based on the composition of the gas phase and, optionally, the concentration of catalyst in the reactor or reactor operating conditions. Such predictive melt index regression may include multiple terms to account for concentration of ICA in the reactor, optionally concentration of hydrogen in the reactor, optionally concentration of comonomer in the reactor, optionally the catalyst composition, and optionally reactor operating conditions. One or more terms may independently be represented by a smoothing function that incorporates a time constant. 生产聚烯烃聚合物的方法可使用预测性熔融指数回归估计生产期间的聚烯烃的熔融指数，其基于气相的组成，并且任选地基于反应器中的催化剂的浓度或反应器操作条件。此类预测性熔融指数回归可包括多个项以考虑所述反应器中的ICA的浓度、任选地所述反应器中的氢气的浓度、任选地所述反应器中的共聚单体的浓度、任选地催化剂组成和任选地反应器操作条件。或多个项可独立地由并入时间常量的平滑函数表示。