Method for preparing acetic acid by carbonylation of methanol

A method for preparing acetic acid by carbonylation of methanol, which comprises:

• passing a raw material containing methanol, carbon monoxide and water through a reaction region loaded with a catalyst containing an acidic molecular sieve with an adsorbed organic amine, and carrying out a reaction under the following conditions to prepare acetic acid;
• wherein the acidic molecular sieve is one or two molecular sieves selected from the group consisting of molecular sieves with MOR framework and molecular sieves with FER framework;
• the organic amine is one or more organic amines selected from the group consisting of pyridine, phenylamine, cyclohexylamine, piperidine, substituted pyridines with one or more substituents, substituted phenylamines with one or more substituents, substituted cyclohexylamines with one or more substituents and substituted piperidines with one or more substituents;
• and the substituents are independently selected from halogen or C1-3 alkyl group;
• the reaction region is constituted by one or more reactors which are connected in series and/or in parallel;
• the reaction conditions are listed as follows:
• the reaction temperature is in a range from 150° C. to 350° C.;
• and the reaction pressure is in a range from 0.5 MPa to 10 MPa;
• and the weight hourly space velocity of methanol is in a range from 0.01 h−1 to 10 h−1;
• and the molar ratio of monoxide to methanol is in a range from 1:1 to 100:1;
• and the molar ratio of water to methanol is in a range from 0.05:1 to 5:1;
• and
• wherein the acidic molecular sieve is an acidic mordenite molecular sieve.