Method for directly producing methyl acetate and/or acetic acid from syngas

A method for directly producing acetic acid from syngas, whose reaction process is carried out in at least two reaction zones, the method comprising:

• a) feeding a raw material containing syngas into a first reaction zone comprising a copper-based metal catalyst and contacting and reacting the syngas with the copper-based metal catalyst in the first reaction zone to obtain an effluent containing methanol;
• b) feeding the effluent from the first reaction zone to a second reaction zone comprising a solid acid catalyst, either directly or after the addition of carbon monoxide to said effluent, and contacting and reacting the effluent from the first reaction zone with the solid acid catalyst in the second reaction zone to obtain an effluent containing acetic acid;
• c) separating the acetic acid product from the effluent obtained from the second reaction zone, and optionally returning a residual part of the effluent from the second reaction zone to the first reaction zone and/or second reaction zone as one or more recycle streams;
• wherein the volume content of syngas in the raw material is in a range from 10% to 100%, and the volume ratio of carbon monoxide to hydrogen in the syngas is in a range from 0.1 to 10;
• the reaction temperature in the first reaction zone is in a range from 190° C. to 230° C., and
• the reaction pressure is in a range from 1.0 MPa to 8.0 MPa;
• and the reaction temperature in the second reaction zone is in a range from 230° C. to 300° C., and the reaction pressure is in a range from 1.0 MPa to 8.0 MPa;
• wherein the solid acid catalyst in the second reaction zone comprises one or more zeolite molecular sieves selected from MTF and EMT zeolite molecular sieves, and wherein the zeolite molecular sieve may also be modified with pyridine or elements other than the framework constituent elements.