A hybrid approach using MLD (mixed logical dynamical) framework to handle infeasibility and constraint prioritization issues in MPC (model predictive control) based on input-output model is introduced. By expressing c...A hybrid approach using MLD (mixed logical dynamical) framework to handle infeasibility and constraint prioritization issues in MPC (model predictive control) based on input-output model is introduced. By expressing constraint priorities as propositional logics and by transforming the propositional logics into inequalities,the infeasibility and constraint prioritization issues are solved in the MPC. Constraints with higher priorities are met first, and then these with lower priorities are satisfied as much as possible. This new approach is illustrated in the control of a heavy oil fractionator-Shell column. The overall control performance has been significantly improved through the infeasibility and control priorities handling.展开更多
Elements including P, Sb, Ce, La, B, Sn, Ti, Bi and Mg that could passivate Ni and V were studied on their migration on FCC catalysts and carriers under simulated commercial FCC operating conditions.Test results had s...Elements including P, Sb, Ce, La, B, Sn, Ti, Bi and Mg that could passivate Ni and V were studied on their migration on FCC catalysts and carriers under simulated commercial FCC operating conditions.Test results had shown that P, Sb, B and Sn compounds exhibited migration activity. The effects of temperature, fluidizing medium and contact time on migration of antimony compounds were investigated,and the mechanism regarding antimony migration was proposed. Meanwhile, it was disclosed that Ni on catalyst could stimulate Sb contained in the metal passivator to move onto FCC catalyst in tandem with the interaction between nickel and antimony.展开更多
Synthesis of monoglycerides with Cinnamomum burmannii seeds oil and its application in moisturizing cream were studied. The results showed that the optimal transesterification conditions of synthesis of monoglycerides...Synthesis of monoglycerides with Cinnamomum burmannii seeds oil and its application in moisturizing cream were studied. The results showed that the optimal transesterification conditions of synthesis of monoglycerides with Cinnamomum burmannii seeds oil were as follows： the glycerol to oil molar ratio of 3 ： 1 ; NaOH catalyst dosage of 0.8% of the oil mass; reaction temperature of 180 ℃ for 3 hours; and the yield reached 62.6% . The crude product was purified by molecular distillation and the purity of the final product achieved 92.8%. Physicochemical properties of moisturizing cream prepared by using the final product can meet the requirements of China National Standard and the cosmetic product displayed good performance in application.展开更多
基金Supported by the 973 Program (No. 2002CB312200)National High Tech. Project of China (863/CIMS 2004AA412050).
文摘A hybrid approach using MLD (mixed logical dynamical) framework to handle infeasibility and constraint prioritization issues in MPC (model predictive control) based on input-output model is introduced. By expressing constraint priorities as propositional logics and by transforming the propositional logics into inequalities,the infeasibility and constraint prioritization issues are solved in the MPC. Constraints with higher priorities are met first, and then these with lower priorities are satisfied as much as possible. This new approach is illustrated in the control of a heavy oil fractionator-Shell column. The overall control performance has been significantly improved through the infeasibility and control priorities handling.
文摘Elements including P, Sb, Ce, La, B, Sn, Ti, Bi and Mg that could passivate Ni and V were studied on their migration on FCC catalysts and carriers under simulated commercial FCC operating conditions.Test results had shown that P, Sb, B and Sn compounds exhibited migration activity. The effects of temperature, fluidizing medium and contact time on migration of antimony compounds were investigated,and the mechanism regarding antimony migration was proposed. Meanwhile, it was disclosed that Ni on catalyst could stimulate Sb contained in the metal passivator to move onto FCC catalyst in tandem with the interaction between nickel and antimony.
文摘Synthesis of monoglycerides with Cinnamomum burmannii seeds oil and its application in moisturizing cream were studied. The results showed that the optimal transesterification conditions of synthesis of monoglycerides with Cinnamomum burmannii seeds oil were as follows： the glycerol to oil molar ratio of 3 ： 1 ; NaOH catalyst dosage of 0.8% of the oil mass; reaction temperature of 180 ℃ for 3 hours; and the yield reached 62.6% . The crude product was purified by molecular distillation and the purity of the final product achieved 92.8%. Physicochemical properties of moisturizing cream prepared by using the final product can meet the requirements of China National Standard and the cosmetic product displayed good performance in application.
