Process Economics Program Report 37C
Published: Dec-2001
This report appraises the current commercially dominant
methanol carbonylation technologies for acetic acid production based on the
recent developments in catalyst technology. In addition, two alternate but comparatively
newer technologies employing the oxidation of hydrocarbons
(ethylene and ethane) are evaluated. The following technologies are dealt with:
• BP CativaTM technology.
• Celanese Acid Optimization (AO) technology.
• Showa Denko Single-step Ethylene Oxidation technology.
• SABIC (Saudi Basic Industries Corporation) Ethane Oxydehydrogenation technology.
BP’s CativaTM, a methyl carbonylation technology, is
an improved version of the original Monsanto’s rhodium catalyzed acetic acid
technology which BP inherited from Monsanto in 1986.
Instead of rhodium, CativaTM employs BP’s proprietary
iridium (and iodides) based promoted catalyst. The new catalyst offers a higher
reactivity, increased catalyst stability, reduced byproducts and lower energy
consumption in product purification as compared to original rhodium catalysts.
Celanese also originally licensed the acetic acid technology
from Monsanto in the late 1970s. But now it is the sole owner. The AO technology
is a result of a number of improvements and optimizations in the original Monsanto
technology. AO technology is founded on proprietary rhodium (and iodide) based
catalyst materials, which impart a high stability to the catalyst system permitting
carbonylation at lower water concentrations. Some catalyst formulations use
iridium in combination with rhodium. By-product formation is much reduced and
optimized purification methodologies result in increased product purity. From
the capital investment viewpoint, Celanese, as our estimates indicate, has a
slightly higher capital intensity than that of BP.
SD’s (Showa Denko’s) ethylene route to acetic acid makes
acetic acid production independent of methanol and carbon monoxide (CO). This
process, which offers capability for a singlestep ethylene conversion to acetic
acid, is a more cost effective variance of the conventional twostep ethylene
oxidation process (via acetaldehyde). The (palladium catalyzed) process is useful
at small capacities to meet local requirement of acid. However, its economics
are not comparable with those of methyl carbonylation technology.
SABIC’s (molybdenum, vanadium and niobium/palladium/lanthanum
catalyzed) ethane based route to acetic acid is another alternative technology
for acetic acid which is being tested for commercialization. Like SD, this technology
may offer cost effective means for acid production for regionalized demand.
The technology has not been yet demonstrated even on a semi commercial scale
and bears of all kinds uncertainties typical to a new process. Ethylene and
CO2 are PEP’01 SNN the major by-products. CO2 may be an environmental concern
if it does not find an end user. Ethylene and acetic acid production need to
be balanced according to their demand.
Other PEP Related Reports
For more information contact:
| 
