Patent RU-2342402-C2 (RU)
Inventor: SANDELL DEJVID DZH
IPC: C08F210/16
Filed: 2004-09-30
Granted: 2008-12-27
Abstract: FIELD: chemistry, pharmacology. 
     SUBSTANCE: current invention relates to methods of quick monitoring and regulation of polymerisation reactions. Described is a method of monitoring and regulating polymerisation of olefin, the method involves: (a) determining FR 1 , constituting of the actual value of the flux ratio in the reactor or the ratio of comonomer/ethane or the actual value of the ratio of hydrogen/ethane, expressed in the form of exponentially weighted moving average (EWMA) in the moment of time T; determining GR 1 , constituting of the actual value of the concentration ratio of comonomer/ethane or actual value of the concentration ratio of hydrogen/ethane in the moment of time T in the reactor, by a specific method of analysis of the recycle flow, (b) obtaining functions determining an indicator, Li, determined in the following way:   , where GR 1  denotes the actual values of the concentration ratio of comonomer/ethane or actual value of the concentration ratio of hydrogen/ethane in the moment of time T in the reactor, by a specific method of analysis of the recycle flow; where FR 1  denotes the actual values of the concentration ratio of comonomer/ethane or actual value of the concentration ratio of hydrogen/ethane, expressed in the form of exponentially weighted moving average (EWMA) in the moment of time T; where FR 2  denotes instantaneous value of flux ratio for td a minute till the moment of time T; where FR 3  denotes EWMA, obtained using the stay period of comonomer or hydrogen for td a minute till the moment of time T-1; where β = 1-exp(-T/(stay period of comonomer)= exp(-Δt/τ); where Δt = time step, selected for refreshing the computation LI; where τ = time step of comonomer or hydrogen, usually used with the computation LI, on condition that comonomer dissolved in polymerised olefin is included in the specified comonomer, used in computation of LI; where td = the last gap in time or delay time; (c) a correlation between LI and the target value determining the indicator, which is the function of the liquidity index of the polymer; and (d) changing of at least one parameter of the reactor in reply to deviation of LI from the target value. Also described is the method of maintaining regulation of the determinative indicators in gas-phase polymerisation reactions in the polymerising reactor including: a) computation of functions of the determinative indicator, (LI) to p. 1, the specified LI includes a numerator and denominator, in such a way that the numerator and the denominator had the same dynamic response to changes in the process; b) correlation of LI with the target value of the determinative indicator, which is the function of the liquidity index of the polymer; c) selection of at least one sensitive process parameter changing it in order to regulate the specified determinative indicator (LI); d) changing the sensitive process parameter; and e) removing the polymeric product. 
     EFFECT: faster and more accurate method of monitoring and/or predicting changes in characteristics of polymers or changes in relative activity of catalysts 
     10 cl, 4 dwg, 3 tbl, 5 ex