Acrylic acid BASF process

The important role Transmission Electron Microscopy (TEM) can play in this process is demonstrated on the development of an oxidation catalyst for the production of acrylic acid. Acrylic acid is produced by BASF in quantities of several 100.000 tons per year in a two step gas phase oxidation process starting from propene, which is oxidised to acrolein in the first step and then further oxidised to acrylic acid in a second step, each step requiring a special developed catalyst. Acrylic acid is used as a base material for the production of superabsorbents for nappies, dispersions and emulsions for adhesives and construction materials. 

B. Vollmert, Impact-resistant plastic compositions comprising a styrene polymer and a cross-linked acrylic acid ester polymer, and process for preparing same, US Patent 3 055 859, assigned to BASF AG, September 25,1962. 

The industrial catalytic Reppe process is usually applied in the production of acrylic acid. The catalyst is NiBr2 promoted by copper halides used under forcing conditions. The BASF process, for example, is operated at 225°C and 100 atm in tetrahydrofuran solvent.188 Careful control of reaction conditions is required to avoid the formation of propionic acid, the main byproduct, which is difficult to separate. Small amounts of acetaldehyde are also formed. Acrylates can be produced by the stoichiometric process [Eq. (7.20)], which is run under milder conditions (30-50°C, 1-7 atm). The byproduct NiCl2 is recycled ... 

This invention has its roots in Reppe chemistry. In the late 1930s, Reppe in Germany had developed a number of manufacturing processes for bulk chemicals, where acetylene was used as one of the basic building blocks. Even today BASF and Rohm Hass manufacture large quantities of acrylic acid and its esters by hydrocarboxylation of acetylene. This reaction, 4.12, is catalyzed by a mixture of NiBr2 and Cul. It involves high pressure (100 bar) and temperature (220°C), and mechanistically is not fully understood. 

Reppe s work also resulted in the high pressure route which was established by BASF at Ludwigshafen in 1956. In dais process, acetylene, carbon monoxide, water, and a nickel catalyst react at about 200°C and 13.9 MPa (2016 psi) to give acrylic acid. Safety problems caused by handling of acetylene are alleviated by the use of tetrahydrofuran as an inert solvent. In this process, the catalyst is a mixture of nickel bromide with a cupric bromide promotor. The liquid reactor effluent is degassed and extracted. The acrylic acid is obtained by distillation of the extract and subsequendy esterified to the desired acrylic ester. The BASF process gives acrylic acid, whereas the Rohm and Haas process provides the esters direcdy. 

Tlic major processes are the catalytic BASF process for acrylic acid (in Germany, the plant had a capacity of 130000 t/a). and the semicatalytic Rohm Haas process for acrylic acid (in the U.S.A., at Deer Park.Texas the plant had a capacity of 80000 t/a). 

The production of carboxylic acids via carbonylation catalysis is the second most important industrial homogeneous group of processes. Reppe developed most of the basic carbonylation chemistry in the 1930s and 1940s. The first commercial carbonylation process was the stoichiometric Ni(CO)4-based hydroxycarbonylation of acetylene to give acrylic acid (see Section 3.5 for details). This discovery has since evolved into a trae Ni-catalyzed process, used mainly by BASF. The introduction of rhodium catalysts in the 1970s revolutionized carboxylic acid production, particularly for acetic acid, much in the same way that Rh/PPhs catalysts changed the importance of hydroformylation catalysis. 

The Ni-catalyzed production of acrylic acid from acetylene produces 320 millionkg year. The BASF process operates at... 

Acrolein and acrylic acid are both made by vapor phase oxidation of propylene. U.S. 6,281,384 (to E. I. du Pont Nemours and Atofina) describes a fluidized bed process, while U.S. 5,821,390 (to BASF) describes an isothermal reactor cooled by heat transfer to a molten salt. U.S. 6,858,754 and U.S. 6,781,017 (both to BASF) describe alternative processes based on a propane feed. Compare the economics of acrylic acid production from propane with production from propylene. Is the conclusion different if the process is stopped at acrolein ... 

The synthesis of carboxylic acids by carbonylation of unsaturated hydrocarbons or alcohols was developed mainly by Reppe and his co-workers in the laboratories of BASF at Ludwigshafen. Many industrially important processes such as the synthesis of acrylic acid, propionic acid, and acetic acid were elaborated there in the period from the late 1930s to the mid-1950s [1, 2]. Reppe s introduction of metal carbonyls as catalysts for carbonylation reactions was of paramount importance and many processes, which are still industrially relevant today, were developed rapidly (eq. (1), [3]). 

As already mentioned, the processes for the homogeneously catalyzed carbony-lation of acetylene have opened up the way for acrylic acid to become a mass product for which worldwide production capacities are currently two million tonnes per annum. Acrylic acid and its esters are important monomers for polymer dispersions, whose use is widespread. Since the mid-1960s, however, the availability of propene, a less expensive feedstock than acetylene, has led to the development of an even more advantageous production process the heterogeneously catalyzed gas-phase oxidation of propene [21, 22]. Nowadays, acrylic acid is produced almost exclusively by this process (cf. Chapter 1). The Reppe acrylic acid plant at BASF is now the only one left in the world which still uses acetylene as feedstock. 

The BASF process is recommended, e.g., for acrylic acid, adipic acid nitril, and /3-naphtol. According to Ritner and Steiner (1985), this process has not been used on a commercial scale. 

The carbonylation of acetylene with carbon monoxide and water to make acrylic acid is of historical interest, as it was the first carbonylation reaction carried out by Reppe. Until the mid-1980s, BASF operated an acrylic acid plant based on this technology to produce 110,000 metric tons per year at Ludwigshafen, Germany. The plant has been replaced with a propylene oxidation process. Today, the production of acrylic acid worldwide is exclusively by the propylene oxidation route. 

Walter Reppe also used his new base to expand the chemistry of acetylene. His first major breakthrough, in the summer of 1939, was the addition of carbon monoxide to acetylene in the presence of alcohols (or water) and a nickel catalyst to form acrylates. Carbon monoxide had attracted attention for many years as a readily available, cheap and reactive carbon compound. I.G. Farben employed it in the Pier methanol synthesis, Ruhrchemie used it in the Fischer-Tropsch synthetic petrol process, and Du Pont had carried out research on the addition of carbon monoxide to olefins at very high pressure and temperatures. Additional impetus for the use of carbon monoxide in acetylene chemistry was provided by the introduction of covered carbide furnaces at I.G. Farben s Knapsack plant in 1938, which permitted the collection of by-product carbon monoxide. The polymers of acrylic esters were already used for treating leather and for paint, but acrylic acid was made from ethylene oxide, and consequently was rather expensive. Reppe s process reached the pilot plant stage by 1945, and was subsequently used on a large scale by BASF and its American partners. 

Acrylic acid represents a 4.5 million metric ton per year global market with BASF, Dow, and Arkema being major manufacturers [15]. AcryUc acid is manufactured by the oxidation of propylene. The reaction is a two-step process with oxidation to acrolein followed by further oxidation of the aldehyde to the carboxylic acid. Acrolein is a raw material for cosmetics, flavors, and pharmaceuticals. The major use of acrylic acid is as a monomer to make acrylic acid polymers and conversion to acrylate esters which are also used to make polymers. 

Currently, the main capacity for acrylic acid production is in the United States (38%), followed by Western Europe (28%), Japan (14%), the Asia/Paciflc region (16%), and the rest in smaller factories in Mexico, Brazil, and Eastern Europe [3]. The main manufacturers are BASF, Celanese, Dow Chemical, Rohm and Haas, Americal Acryl, and Stockhausen. The commercial process for making acrylic acid is a two-step process, starting frompropene via acrolein as follows [5] ... 

The polymerization is mainly processed with acrylic acid, as mentioned before. This monomer has very fast reaction kinetics and is successfully tested in spray polymerization processes. In addition the salts of the acrylic acid, acrylates, are investigated. Four different acrylates have been generated by neutralization of the acid. These are lithium, sodium, potassium and ammonium acrylate by adding their hydroxides. Because of the limited solubility in water the maximum weight fraction of lithium, sodium, potassium and ammonium is 27.0, 32.2, 59.6 and 42.2%. Acrylic acid has been made available by BASF SE and was received by Sigma Aldrich. To increase the storage stability an inhibitor, hydroquinone monomethylether (MEHQ), with a mass fraction of 180-220 ppm had been added before shipping. 

A variety of processes have been used for the production of esters of acrylic (propenoic) acid, including the solvolysis of acrylonitrile with c. H2SO4 and an alcohol. The Reppe process, commercialized by BASF and associated companies, is based on the reaction of acetylene with carbon monoxide, nickel carbonyl and an alcohol. However, the last U.S. operator of this process commissioned a propylene oxidation plant in October, 1982. 

Actual operating capacities of Reppe carbonylation processes are difficult to estimate since only a few data are available in the literature. However, it is known that some of the syntheses are carried out on an industrial scale, e. g. the synthesis of acrylates from acetylene, carbon monoxide and alcohols (BASF) [1004, 1005], the acetic acid synthesis from methanol and carbon monoxide and the synthesis of higher molecular weight saturated carboxylic acids from olefins, carbon monoxide and water. Propionic acid (30,000 tons/year) and to a smaller extent heptadecanoic dicarboxylic acid are manufactured via the carbonylation route at BASF. Butanol is made from propylene in Japan [1003, 1004]. 

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