Oxidação de etanol a acetaldeido sobre catalisador de cobre oxidado

AUTOR(ES)
DATA DE PUBLICAÇÃO

1984

RESUMO

During its initial stage of development Brazil, Ethanolchemistry will certainly be developed along the traditional chemical routes, as the conventional acetic acid and derivatives from aceta1gehyde. This work involves the kinetic study of ethanol oxidation to acetaldehyde over an oxidized copper catalyst, whose results are used in the simulation of an industrial fixed bed reactor. An experimental apparatus was designed an set-up to carry out gas-solid heterogeneous catalytic reactions in order to obtain accurate kinetic data. Data for the catalytic oxidation of ethanol with air were obtained in the range of catalyst 300 to 360ºC, using eletrolitic copper rods as particles. The rods present diameter and lenght of 1 mm, and were packed in an integral, isothermal fixed bed order to keep isothermal conditions, the reactor was fitted in a brass heat transfer case for operational temperatures from 300 up to 330ºC. The runs at 360ºC were carried out in a reactor immersed in a molten salt bath which showed to be more adequate to dissipate the high heat of reaction. The interpretation of the kinetic data in terms of a rate equation is accomplished through a reaction mechanism of the Temkin type. The proposed mechanism assumes that molecular oxygen is adsorbed in a single active site the resulting acetaldehyde being partially converted to carbon dioxide. It is found that the net conversion of ethanol acetaldehyde is strongly affected by the ethanol although being independent of reactor temperature. The kinetic model is applied to simulate a chemical reactor operating under industrial conditions to detect "hot-points". The tubular chemical reactor is assumed to be non-isothermal and non-adiabatic with unidimensional gas flow. The model shows parametric sensitivity when applied to a reactor with 7 mm I.D.. The effects of external wall temperature, air ethanol and molar ratio to superficial mass velocity were analysed for a 17 mm tubular reactor. Finally it is shown that a stable operation may be obtained through variations in the ethanol feed flow

ASSUNTO(S)

oxidação alcool

ACESSO AO ARTIGO

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