Production of acetic acid with high conversion rate
A process for producing acetic acid comprising the steps of reacting carbon monoxide and at least one of methanol and a methanol derivative in a first reactor under conditions effective to produce a crude acetic acid product; separating the crude acetic acid product into at least one derivative stream, at least one of the at least one derivative stream comprising residual carbon monoxide; and reacting at least a portion of the residual carbon monoxide with at least one of methanol and a methanol derivative over a metal catalyst in a second reactor to produce additional acetic acid.
1. A process for producing acetic acid, comprising
reacting carbon monoxide and at least one of methanol and a methanol derivative in a first reactor under conditions effective to produce a crude acetic acid product;
separating, in a separation zone, the crude acetic acid product into at least one derivative stream, at least one of the at least one derivative stream comprising residual carbon monoxide; and
reacting at least a portion of the residual carbon monoxide with at least one of methanol and a methanol derivative over a metal catalyst in a second reactor to produce additional acetic acid.
2. The process of claim 1 , wherein a product stream exiting the second reactor comprises less than 40 mol % carbon monoxide.
3. The process of claim 1 , wherein the overall conversion of carbon monoxide is greater than 90%.
4. The process of claim 1 , wherein the at least one derivative stream comprising residual carbon monoxide, comprises:
from 10 mol % to 95 mol % carbon monoxide; and
from 5 mol % to 90 mol % at least one of methanol and a methanol derivative.
5. The process of claim 1 , wherein the metal catalyst comprises a solid catalyst.
6. The process of claim 5 , wherein the second reactor comprises a fixed bed reactor and the fixed bed reactor comprises the solid catalyst disposed in a catalyst bed.
7. The process of claim 5 , wherein the second reactor comprises a trickle bed reactor and the trickle bed reactor comprises the solid catalyst disposed in a catalyst bed.
8. The process of claim 1 , wherein the metal catalyst comprises a liquid catalyst.
9. The process of claim 1 , wherein, in the second reactor, the at least one of methanol and a methanol derivative are liquids and the metal catalyst is a solid.
10. The process of claim 1 , wherein, in the second reactor, the at least one of methanol and a methanol derivative, and the metal catalyst are liquids.
11. The process of claim 10 , wherein the metal catalyst is a homogeneous liquid.
12. The process of claim 1 , wherein, in the second reactor, the residual carbon monoxide and the at least one of methanol and a methanol derivative are vapors and the metal catalyst is a solid.
13. The process of claim 1 , wherein, in the second reactor, the residual carbon monoxide and the at least one of methanol and a methanol derivative are vapors and the metal catalyst is a liquid.
14. The process of claim 1 , wherein the reaction temperature in the second reactor ranges from 150° C. to 350° C.
15. The process of claim 1 , wherein the reaction pressure in the second reactor ranges from 0.1 MPa to 10 MPa.
16. The process of claim 1 , wherein the metal catalyst is a solid and comprises at least one metal selected from the group consisting of rhodium, iridium, ruthenium, nickel, and cobalt.
17. The process of claim 1 , wherein the at least one of methanol and a methanol derivative, in the second reactor is provided by a supplemental feed stream or another of the derivative streams.
18. The process of claim 1 , wherein the at least one of methanol and a methanol derivative is methyl acetate.
19. The process of claim 1 , wherein the at least one of methanol and a methanol derivative is dimethyl ether.
20. The process of claim 1 , wherein the separating comprises:
flashing the crude acetic acid product into a first vapor stream comprising acetic acid and residual carbon monoxide and a first liquid residue stream comprising catalyst which is recycled to the first reactor; and
separating the flashed vapor stream into a second vapor stream comprising carbon monoxide, a purified acetic acid product, and a second liquid residue stream.
21. The process of claim 20 , wherein the separating comprises:
decanting the second vapor stream to form a third vapor stream comprising residual carbon monoxide and a third liquid residue stream comprising methyl iodide, methyl acetate, acetaldehyde; and
scrubbing the third vapor stream to form a fourth vapor stream comprising residual carbon monoxide and a fourth liquid residue comprising methyl iodide.