National Taiwan University

National Science Council

China Petrochemical Development Corporation

Cheng-Ching Yu

Hsiao-Ping Huang

Jian-Kai Cheng

Ming-Jer Lee

Shih-Bo Hung

Ruei-Chiang Tsai

Yu-Chang Cheng

Yu-De Lin

Jyun-Hong Chen

A process for manufacturing esters from acid and alcohol and a system thereof are provided, wherein the system includes a reactive distillation column, a sidestream reactor packed with catalyst, and a decanter for conducting the method. The method is carried out by (a) extracting a first mixture of acid and alcohol from the reactive distillation column, for then feeding the first mixture to at least one sidestream reactor packed with catalyst to obtain a reaction product; (b) feeding the reaction product from the sidestream reactor to the reactive distillation column, allowing a second mixture of alcohol, ester and water to be separated from a top end of the reactive distillation column; (c) feeding the second mixture into the decanter to separate an organic phase from an aqueous phase; and (d) separating esters from the organic phase. The method and system allow the esters to be extracted without using a plurality of recovering columns and decanters, and are capable of improving packing/changing catalyst in a single reactive distillation column.

Method for manufacturing esters from acid and alcohol and system thereof

A separation system for a methyl acetate hydrolysis is provided. The separation system comprises a reactive distillation system, a reflux system, a first separation system and a second separation. The reactive distillation system allows the hydrolysis of a methyl acetate solution to generate a first mixture and a second mixture. The reflux system is packed with a heterogeneous catalyst and coupled to the reactive distillation system, which refluxes the first mixture to the reactive distillation system. The first separation system is coupled to the reactive distillation system, which directs the second mixture thereinto so as to isolate an acetic acid and a third mixture therefrom. The second separation system is coupled to the first separation system, which directs the third mixture thereintio so as to separate a methanol therefrom. The methyl acetate feeding system is coupled to, one of the reactive distillation system and the reflux system, which feeds the methyl acetate solution thereinto.

Separation process for methyl acetate hydrolysis and apparatus thereof

A transesterification process of methyl acetate is provided. The process comprises: (a) performing a first reactive distillation of a methyl acetate solution and a first alcohol to generate a first ester and a first mixture; (b) performing a first distillation of a first part of the first mixture to generate a second mixture; and (c) performing a second reactive distillation of a first part of the second mixture and a second alcohol to generate a second ester; wherein the respective one of the first and second alcohols is a limiting reagent. The transesterification process provided in the present invention could highly reduce the investing production cost of the transesterification of the by-product, methyl acetate, in the conventional polyvinyl alcohol plants.

Transesterification process of methyl acetate

In the present invention, a Smith predictor enhanced PID controller, SP-PID, is proposed. A tuning parameter Kis devised and the SP-PID controller would be gradually transformed from a PID controller to a Smith predictor as Kchanges from 0 to 1. Properties of the SP-PID are explored and the design procedure is given to ensure a certain degree of robustness. Simulation results clearly indicate that the SP-PID takes advantage of the SP when small modeling error is encountered and it is gradually detuned to a PID controller, a user-friendly controller, when the model quality degrades. Moreover, the controller and its design procedure can be implemented in current process control computers with virtually no extra hardware cost.

Method and apparatus for PID controller with adjustable deadtime compensation

A method and an apparatus are provided for autotuning a parameter of a PID controller which is employed in a transfer function. The method includes steps of (a) providing a first specific value for the transfer function; (b) computing a first ultimate parameter of the transfer function in response to the first specific value; (c) modifying the first specific value in response to the first ultimate parameter in order to obtain a second specific value; (d) generating a second ultimate parameter for a characteristic of the transfer function in a specified range in response to the second specific value; (e) obtaining a precise parameter of the PID controller in response to the second ultimate parameter. The autotuning apparatus includes; a controlled device outputting a first ultimate parameter and a second ultimate parameter, respectively in response to a first input signal and a second input signal; a nonlinear element connected to the controlled device, and outputting a first specific signal and a second specific signal in response to a first ultimate parameter; and a control unit connected to the nonlinear element, wherein the nonlinear element outputs the second input signal to cause the controlled device to output to the PID controller the second ultimate parameter for a specific characteristic of the controlled device in a specific range in order to obtain a precise parameter for the PID controller.

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Taipei, Taiwan

Cheng-Ching Yu