Acetex Chimie

Acetex (cyprus) Limited

Daniel Marcel Thiebaut

Carl Patois

Kenneth Ebenes Vidalin

Lise Layeillon

Daniel Marchand

Robert M Perron

Philippe J Kalck

Philippe Serp

Carole Le Berre

A method for the production of syngas from methanol feedstock is disclosed. The methanol feed () is supplied to a partial oxidation reactor () with oxygen () and optionally steam () to yield a mixed stream () of hydrogen, carbon monoxide, and carbon dioxide. The carbon dioxide () is separated out and the hydrogen and carbon monoxide mixture () is fed to a cold box () where it is separated into hydrogen-rich and carbon monoxide-rich streams (). The separated carbon dioxide () can be recycled back to the partial oxidation reactor () as a temperature moderator if desired. The carbon monoxide-rich stream () can be reacted with methanol () in an acetic acid synthesis unit () by a conventional process to produce acetic acid () or an acetic acid precursor. Optionally, an ammonia synthesis unit () and/or vinyl acetate monomer synthesis unit () can be integrated into the plant.

Preparation of syngas for acetic acid synthesis by partial oxidation of methanol feedstock

An integrated process for making methanol, acetic acid, and a product from an associated process is disclosed. Syngas () is produced by combined steam reforming () and autothermal reforming () of natural gas () where a portion () of the natural gas bypasses the steam reformer () and is blended with the steam reformer effluent for supply to the autothermal reformer (ATR) () with CO2 recycle (). A portion of the syngas is fed to CO2 removal () to obtain the recycle CO2 and cold box () to obtain a hydrogen stream () and a CO stream (). The remaining syngas, hydrogen stream () and CO2 from an associated process are fed to methanol synthesis (), which produces methanol and a purge stream () supplied to the CO2 removal unit. The methanol is supplied to an acetic acid unit ()with the CO () to make acetic acid, which in turn is supplied to a VAM synthesis unit (). Oxygen for both the ATR and VAM synthesis can be supplied by a common air separation unit (), and utilities such as steam generation can further integrate the process.

Integrated process for acetic acid and methanol

The invention relates to a continuous process for the manufacture of acetic acid and/or methyl acetate, characterized in that, during the continuous operation of the installation for a continuous industrial process, called the initial process, for the carbonylation of methanol or a carbonylatable derivative of methanol such as dimethyl ether, methyl halides or methyl acetate, in the homogeneous liquid phase and under carbon monoxide pressure, in the presence of a catalyst system comprising a rhodium-based homogeneous catalyst and a halogenated promoter, and in the presence of a concentration of water greater than or equal to 14% in the reaction medium, the composition of said homogeneous catalyst is modified gradually by adding an iridium compound over time. This process makes it possible on the one hand to modify the composition of the catalyst system so as to change from a homogeneous catalyst based on rhodium alone to a catalyst based on rhodium and iridium, or even iridium alone, without stopping the installation, and on the other hand to reduce the water content of the reaction medium once the iridium additions have been effected.

Modification of the catalytic system in an industrial process for making acetic and/or methyl acetate acid

The invention relates to a process for the preparation of acetic acid and/or methyl acetate in the liquid phase by the carbonylation of methanol and/or the isomerization of methyl formate in the presence of water, a solvent, a homogeneous catalyst system comprising iridium and a halogen-containing promoter, and carbon monoxide, wherein said catalyst system also comprises platinum.

Method for preparing acetic acid and or methyl acetate in the presence of iridium and platinum

An integrated large capacity, single-train process for making 1,00020,000 MTPD methanol and 3006,000 MTPD acetic acid is disclosed. Syngasis produced by autothermal reformingof natural gaswhere the feedof the natural gas is supplied with oxygen and CO2 recycleto the autothermal reformer (ATR). A portion (5-50%) of the syngas is fed to CO2 removalto obtain the recycle CO2 and cold boxto obtain a hydrogen streamand a CO stream. The 50-95% remaining syngas, hydrogen streamand optionally any CO2 from an associated process are fed to methanol synthesis, which produces the methanol. The methanol is supplied to an acetic acid unitwith the COto make the acetic acid, which in turn can be supplied to a VAM synthesis unit. Oxygen for the ATR and any VAM synthesis can be supplied by a single common air separation unit, and utilities such as steam generation can further integrate the process.

The retrofitting of an existing methanol or methanol/ammonia plant to make acetic acid is disclosed. The existing plant has a reformer ( ) to which natural gas or another hydrocarbon and steam (water) are fed. Syngas is formed in the reformer ( ). All or part of the syngas is process to separate out carbon dioxide ( ), carbon monoxide ( ) and hydrogen ( ), and the separated carbon dioxide ( ) is the existing to the existing methanol synthesis loop ( ) for methanol synthesis, or back into the feed to the reformer ( ) to enhance carbon monoxide formation in the syngas ( ). Any remaining syngas ( ) not fed to the carbon dioxide separator ( ) can be converted to methanol in the existing methanol synthesis loop ( ) along with carbon dioxide ( ) from the separator ( ) and/or imported carbon dioxide ( ), and hydrogen ( ) from the separator ( ). The separated carbon monoxide ( ) is then reacted with the methanol ( ) to produce acetic acid ( ) or an acetic acid precursor by a conventional process. Also disclosed is the reaction of separated hydrogen ( ) with nitrogen ( ), in a conventional manner, to produce ammonia. Also disclosed is the reaction of a portion of the acetic acid ( ) in a conventional manner with oxygen ( ) and ethylene ( ) to form vinyl acetate monomer ( ). The nitrogen for the added ammonia capacity in a retrofit of an original methanol plant comprising an ammonia synthesis loop ( ), and the oxygen ( ) for the vinyl acetate monomer process ( ), are obtained from a mew air separation unit ( ).

Methanol plant retrofit for manufacture of acetic acid

A process for improving the stability and/or preventing the deactivation of catalyst in processes of continuous manufacture of acetic acid and/or methyl acetate includes a first, reaction step wherein at least one methyl formate isomerization reaction is carried out in a liquid phase reaction medium, in the presence of carbon monoxide and of a catalytic system including at least one halogenated promoter and at least one iridium-based catalytic compound, and, a second, flash step in which partial vaporization of a reaction medium originating from the first step is carried out in a flash separator. In a non-vaporized liquid fraction resulting from the partial vaporization in the flash separator, an overall content of formic acid and methyl formate is maintained at least equal to 1% by weight of said non-vaporized liquid fraction.

Process for improving the stability and/or preventing the deactivation of the catalyst during the manufacture of acetic acid and/or of methyl acetate

A continuous preparative process, including monitoring production, for acetic acid, methyl acetate or a mixture thereof, by carbonylation, in an industrial installation, of methanol or a carbonylatable derivative of methanol with carbon monoxide in a liquid phase in the presence of water and a homogeneous catalyst system. In a reaction zone I, the carbonylation is carried out in the liquid phase at a temperature of 150 to 250&deg; C., under a pressure of 5&middot;10 to 200&middot;10 Pa and with venting of part of a gaseous canopy above a liquid phase level in said reactor. Then, in a vaporization or flash zone II, a liquid originating from the zone I at a pressure below that of zone I is partially vaporized to form a liquid fraction which is recycled into the reactor, and in a purification zone III, a vaporized fraction originating from flash zone II is distilled on a distillation column. At an outlet of the column, the product is recovered, other constituents of the vaporized fraction being at least partially recycled into said reactor. In the process, the reactor temperature and feed rate of the methanol or carbonylatable derivative in said reactor are brought under control of the carbon monoxide feed rate and of at least one of the parameters defining the composition of the reaction medium, or of the venting or of both the reaction medium and of the venting.

Process for monitoring a continuous acetic acid and/or methyl acetate production

The present invention relates to process for improving the stability and/or preventing the deactivation of the catalyst in processes of manufacture of acetic acid and/or of methyl acetate according to which processes, in a first step, referred to as the reaction step, at least one methyl formate isomerization reaction is carried out in liquid phase, in the presence of carbon monoxide and of a catalytic system comprising at least one halogenated promoter and at least one iridium-based catalytic compound, and, in a second step, referred to as the flash step, the partial vaporization of the reaction medium originating from the first step is carried out in a separator referred to as the flash separator, characterized in that it consists in maintaining an overall content of formic acid and of methyl formate at least equal to 1% by weight of said liquid fraction, preferably between 1 and 50%, preferably between 1 and 30%, by weight with respect to said liquid fraction, in the non-vaporized liquid fraction originating from said flash separator. The invention also relates to a complete process of manufacture acetic acid and/or of methyl acetate which incorporates this improvement. The invention enables preparing acetic acid and/or methyl acetate with an increased stability of the catalytic system, even in the presence of contents of water which are particularly low, and of particularly low carbon monoxide pressures in the reaction zone, and is applied more particularly to processes of manufacture of acetic acid and/or of methyl acetate in which process the first step further comprises a methanol carbonylation reaction.

Method for preparing acetic acid and/or methyl acetate by isomerization and carbonylation

The retrofitting of an existing methanol or methanol/ammonia plant to make acetic acid is disclosed. The plant is retrofitted to feed carbon dioxide into a reformer to which natural gas and steam (water) are fed. Syngas is formed in the reformer wherein both the natural gas and the carbon dioxide are reformed to produce syngas with a large proportion of carbon monoxide relative to reforming without added carbon dioxide. The syngas is split into a first part and a second part. The first syngas part is converted to methanol in a conventional methanol synthesis loop that is operated at about half of the design capacity of the original plant. The second syngas part is processed to separate out carbon dioxide and carbon monoxide, and the separated carbon dioxide is fed back into the feed to the reformer to enhance carbon monoxide formation. The separated carbon monoxide is then reacted with the methanol to produce acetic acid or an acetic acid precursor by a conventional process. Also disclosed is the separation of hydrogen which is reacted with nitrogen, in a conventional manner, to produce ammonia. Also disclosed is the reaction of a portion of the acetic acid in a conventional manner with oxygen and ethylene to form vinyl acetate monomer. The nitrogen for the added ammonia capacity in a retrofit of an original methanol plant comprising an ammonia synthesis loop, and the oxygen for the vinyl acetate monomer process, are obtained from a new air separation unit.

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Lescar, France

Daniel Marcel Thiebaut