Reaction And Extraction Solvent Design For Antioxidant RD Production

Antioxidant RD is one of the most important representatives of rubber additives.Due to easy application,low price and hypotoxicity,Antioxidant RD is considered as an effective antioxidant of vital practical importance.It was found that Antioxidant RD consists of oligomers of different polymerization degrees,mainly including dimers,trimers and tetramers.The performance of Antioxidant RD depends upon the content of dimers,which can be improved with the increase of dimer fraction in oligomers.So it is an essential task to improve the quality of Antioxidant RD products.In this paper,the computer-aided molecular design(CAMD)method is used to establish a solvent design model and design reaction solvents by maximizing the content of dimer in the reaction system in order to improve the quality of Antioxidant RD.The content of the body.The main content of this paper is as follows:(1)Researches on the kinetic data of Antioxidant RD synthesis reaction.The reaction kinetic data is an important parameter for the solvent design model.Currently there is a lack of relevant data in recent literatures and experiments.Therefore,the quantum chemistry calculation method is used to explore the reaction mechanism and kinetic data of the synthesis reaction of antioxidant RD.And the reaction mechanism is verified and analyzed by the electrostatic potential and the average local ionization energy to illustrate the feasibility of the results.(2)Solvent design framework and mathematical model are presented.A design framework for designing the reaction extraction solvent of antioxidant RD is proposed.According to product characteristics and target requirements,the solvent design framework is transformed into a Mixed-Integer Non-Linear Programming(MINLP)optimization model.The model includes structural constraints,property constraints and process constraints.The aliphatic and aromatic molecules are included based on structural constraints consider.The property constraints describe the target physical properties of the solvent.The process constraints include the reaction process and the solvent recovery process.Ordinary differential equations are formulated to solve the problem of simultaneous phase transfer equilibrium and chemical reaction and COSMO-SAC(Conductor-like Screen Model for Segment Activity Coefficient)is used to calculate the activity coefficient of the mixture components in the system.A decomposition algorithm is used to decompose the MINLP model into two sub-models for deceasing the difficulty of solving.First,all feasible solvent candidates are generated by only considering the structural and property constraints.After the generation of all feasible candidate solvents,the process model(which is often nonlinear and nonconvex)is included for all the generated solvents and the objective functions are used to evaluate and rank the solvents.Finally,the optimal solvents and all corresponding properties and process variables are obtained.It can improve more than 30% dimers.(3)Solvent evaluation method is proposed.In order to further take it into account that the advantages and disadvantages of the solvent design results,a multi-index evaluation method is applied to solvent screening.The FAHP(Fuzzy Analytic Hierarchy Process)method based on triangular fuzzy numbers is used to comprehensively consider all aspects of the solvent,including the percentage of dimer,energy consumption,the safety of the solvent,the hazard to the body and the impact on environment.Finally,the suitable solvent is selected.