Method for preparing acetic acid through carbonylation of methanol

Abstract

The present invention provides a method for preparing acetic acid through carbonylation of methanol, wherein raw materials such as methanol, carbon monoxide and water pass through a reaction zone carrying an organic amine adsorbing acidic molecular sieve adopted as a catalyst, and a reaction is performed under a certain condition to produce acetic acid. According to the present invention, the method has characteristics of high acetic acid selectivity and good catalyst stability; and the catalyst does not contain noble metals such as rhodium or iridium, does not require iodine-containing auxiliary agents, and does not produce strong corrosive hydroiodic acid and the like.

Description

technical field

[0001] The invention relates to a method for preparing acetic acid by carbonylation of methanol. Background technique

[0002] Acetic acid, also known as acetic acid, is an important chemical raw material, mainly used to produce vinyl acetate, acetic anhydride, acetate, etc., with an annual global output of nearly 10 million tons. At present, acetic acid is mainly passed through Monsanto or Cativa TM The process is a representative methanol carbonylation route for industrial production, and the catalyst system is a rhodium or iridium complex (Adv.Catal.53, 2010, 1.). These two processes still have the following deficiencies, which need to be further improved to improve economic efficiency: first, there is highly corrosive HI in the catalytic cycle, and the reactor needs to use very expensive and strong corrosion-resistant materials; second, the existing There are industrial processes using homogeneous catalysts, and the separation of products and catalysts ...

Examples

Embodiment 1

[0065] One kilogram of sodium mordenite with Si / Al=7 was exchanged three times with 0.8 mol / L ammonium nitrate aqueous solution at 80°C to obtain ammonium mordenite. Calcining at 500° C. for 4 hours in an air atmosphere to obtain hydrogen-type mordenite, and then tableting, crushing, and sieving to prepare 5-10 mesh particles. Then it is loaded into a stainless steel fixed-bed reactor with a diameter of 32mm, and at 280°C, under normal pressure, it is treated with 500ml / min of 0.3% molar concentration of pyridine and nitrogen gas mixture for 6 hours to adsorption saturation, and then at 280 ℃, purged with 500ml / min nitrogen for 3 hours under normal pressure, and then lowered to room temperature to prepare the acidic mordenite molecular sieve adsorbed by pyridine. As catalyst A, its composition is shown in Table 1.

Embodiment 2

[0067] One kilogram of sodium mordenite with Si / Al=30 was exchanged three times with 0.8 mol / L ammonium nitrate aqueous solution at 80°C to obtain ammonium mordenite. Calcining at 500° C. for 4 hours in an air atmosphere to obtain hydrogen-type mordenite, and then tableting, crushing, and sieving to prepare 5-10 mesh particles. Then it is loaded into a stainless steel fixed-bed reactor with a diameter of 32mm, and at 280°C, under normal pressure, it is treated with 500ml / min of 0.3% molar concentration of pyridine and nitrogen gas mixture for 6 hours to adsorption saturation, and then at 280 ℃, purged with 500ml / min nitrogen for 3 hours under normal pressure, and then lowered to room temperature to prepare the acidic mordenite molecular sieve adsorbed by pyridine, as catalyst B, whose composition is shown in Table 1.

Embodiment 3

[0069] One kilogram of sodium ZSM-35 with Si / Al=3 was exchanged three times with 0.8 mol / L ammonium nitrate aqueous solution at 80° C. to obtain ammonium ZSM-35. Calcined at 500°C for 4 hours in an air atmosphere to obtain hydrogen ZSM-35, and then pressed into tablets, crushed and sieved to prepare 5-10 mesh particles. Then it is loaded into a stainless steel fixed-bed reactor with a diameter of 32mm, and at 280°C, under normal pressure, it is treated with 500ml / min of aniline and nitrogen gas mixture containing 0.3% molar concentration for 6 hours until adsorption saturation, and then at 280 °C, purged with 500ml / min nitrogen for 3 hours under normal pressure, and then lowered to room temperature to prepare the acidic ZSM-35 molecular sieve adsorbed by aniline, as catalyst C, whose composition is shown in Table 1.

technical field

[0001] The invention relates to a method for preparing acetic acid by carbonylation of methanol. Background technique

[0002] Acetic acid, also known as acetic acid, is an important chemical raw material, mainly used to produce vinyl acetate, acetic anhydride, acetate, etc., with an annual global output of nearly 10 million tons. At present, acetic acid is mainly passed through Monsanto or Cativa TM The process is a representative methanol carbonylation route for industrial production, and the catalyst system is a rhodium or iridium complex (Adv.Catal.53, 2010, 1.). These two processes still have the following deficiencies, which need to be further improved to improve economic efficiency: first, there is highly corrosive HI in the catalytic cycle, and the reactor needs to use very expensive and strong corrosion-resistant materials; second, the existing There are industrial processes using homogeneous catalysts, and the separation of products and catalysts ...

Examples

Embodiment 1

[0065] One kilogram of sodium mordenite with Si / Al=7 was exchanged three times with 0.8 mol / L ammonium nitrate aqueous solution at 80°C to obtain ammonium mordenite. Calcining at 500° C. for 4 hours in an air atmosphere to obtain hydrogen-type mordenite, and then tableting, crushing, and sieving to prepare 5-10 mesh particles. Then it is loaded into a stainless steel fixed-bed reactor with a diameter of 32mm, and at 280°C, under normal pressure, it is treated with 500ml / min of 0.3% molar concentration of pyridine and nitrogen gas mixture for 6 hours to adsorption saturation, and then at 280 ℃, purged with 500ml / min nitrogen for 3 hours under normal pressure, and then lowered to room temperature to prepare the acidic mordenite molecular sieve adsorbed by pyridine. As catalyst A, its composition is shown in Table 1.

Embodiment 2

[0067] One kilogram of sodium mordenite with Si / Al=30 was exchanged three times with 0.8 mol / L ammonium nitrate aqueous solution at 80°C to obtain ammonium mordenite. Calcining at 500° C. for 4 hours in an air atmosphere to obtain hydrogen-type mordenite, and then tableting, crushing, and sieving to prepare 5-10 mesh particles. Then it is loaded into a stainless steel fixed-bed reactor with a diameter of 32mm, and at 280°C, under normal pressure, it is treated with 500ml / min of 0.3% molar concentration of pyridine and nitrogen gas mixture for 6 hours to adsorption saturation, and then at 280 ℃, purged with 500ml / min nitrogen for 3 hours under normal pressure, and then lowered to room temperature to prepare the acidic mordenite molecular sieve adsorbed by pyridine, as catalyst B, whose composition is shown in Table 1.

Embodiment 3

[0069] One kilogram of sodium ZSM-35 with Si / Al=3 was exchanged three times with 0.8 mol / L ammonium nitrate aqueous solution at 80° C. to obtain ammonium ZSM-35. Calcined at 500°C for 4 hours in an air atmosphere to obtain hydrogen ZSM-35, and then pressed into tablets, crushed and sieved to prepare 5-10 mesh particles. Then it is loaded into a stainless steel fixed-bed reactor with a diameter of 32mm, and at 280°C, under normal pressure, it is treated with 500ml / min of aniline and nitrogen gas mixture containing 0.3% molar concentration for 6 hours until adsorption saturation, and then at 280 °C, purged with 500ml / min nitrogen for 3 hours under normal pressure, and then lowered to room temperature to prepare the acidic ZSM-35 molecular sieve adsorbed by aniline, as catalyst C, whose composition is shown in Table 1.

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