BASF High-Pressure Process

As early as 1913, scientists from BASF pioneered a new route for acetic acid production by discovering the catalytic conversion of methanol and CO. The route became of economic interest in the 1920s, when methanol became available on a technical 

In the BASF carbonylation process, methanol and CO are converted in the liquid phase (solvent dimethyl ether, water) at 250 °C and 700bar. The reaction rate depends strongly on the concentration of methanol and the partial pressure of CO. The proposed mechanism for the Co-catalyzed carbonylation of methanol is presented in detail in Example 16.6.2. Acetic acid yields are typically 90% (based on methanol) and 70% (based on carbon monoxide). Selectivities are high, with the production of 100 kg of acetic acid affording 4 kg by-products (mainly CO2, CH4, ethanol, acetaldehyde, and propionic acid). 

---

Chemistry of the BASF High Pressure Acetic Acid Process. The chemistry for the BASF high pressure process is shown in Eqs. (14)-(19). The reaction takes place in the gas phase at 250°C (482 F) and 680 bars (10,000 psig). 

The yield achieved with the BASF high pressure process is 90% [141. 

Meanwhile, Wacker Chemie developed the palladium-copper-catalyzed oxidative hydration of ethylene to acetaldehyde. In 1965 BASF described a high-pressure process for the carbonylation of methanol to acetic acid using an iodide-promoted cobalt catalyst (/, 2), and then in 1968, Paulik and Roth of Monsanto Company announced the discovery of a low-pressure carbonylation of methanol using an iodide-promoted rhodium or iridium catalyst (J). In 1970 Monsanto started up a large plant based on the rhodium catalyst. 

An industrial process to produce methanol from carbon monoxide and hydrogen was developed by BASF in 1923 using a zinc oxide-chromia catalyst.361 362 Since this catalyst exhibited relatively low specific activity, high temperature was required. The low equilibrium methanol concentration at this high temperature was compensated by using high pressures. This so-called high-pressure process was operated typically at 200 atm and 350°C. The development of the process and early results on methanol synthesis were reviewed by Natta 363... 

In the 1960s, a new catalyst revolutionized the production of methanol, which had been made by the BASF high pressure or zinc oxide-chromia catalyst process since 1923. The new catalyst—copper, zinc oxide, and chromia or other oxide— had been known as a methanol catalyst for a considerable length of time. At ICI, researchers carried out a careful and systematic program of preparing and testing mixed catalyst systems. The new process operated under much milder conditions than the old one. Pressure was reduced from 200 to 50-100 atm and temperature dropped from 350 to 250°C. Virtually all methanol plants built after 1967 employed this technology (69). 

FIG. 25 Metallocene development for BASF high pressure tubular process. 

Two different high-pressure processes using autoclave or tubular reactors are applied for LDPE production. The autoclave process was developed by ICI, whereas the tubular reactor process was developed by BASF Aktiengesellschaft (predecessor of LyondellBasell s Lupotech T process). Monomer conversion rates of the adiabatic autoclave process can reach 25% compared to values up to 40% for tubular reactors, where the heat of polymerization can be partly removed through the jacketed reactor tubes via circulating cooling water. 

Sources Appl, M. 1986. Ammonia Synthesis and the Development of Catalytic and High-Pressure Processes in the Chemical Industry. H. L. Roy Memorial Lecture, Hyderabad, December 19, 1986, p. 8 Nagel, A. von, et al. 1991. Stickstoff. Ludwigshafen BASF, p. 56. 

Reppe s work also resulted in the high pressure route which was estabUshed by BASF at Ludwigshafen in 1956. In this process, acetylene, carbon monoxide, water, and a nickel catalyst react at about 200°C and 13.9 MPa (2016 psi) to give acryUc 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 hquid reactor effluent is degassed and extracted. The acryUc acid is obtained by distillation of the extract and subsequendy esterified to the desked acryhc ester. The BASF process gives acryhc acid, whereas the Rohm and Haas process provides the esters dkecdy. 

It has been known since the early 1950s that butadiene reacts with CO to form aldehydes and ketones that could be treated further to give adipic acid (131). Processes for producing adipic acid from butadiene and carbon monoxide [630-08-0] have been explored since around 1970 by a number of companies, especially ARCO, Asahi, BASF, British Petroleum, Du Pont, Monsanto, and Shell. BASF has developed a process sufficiendy advanced to consider commercialization (132). There are two main variations, one a carboalkoxylation and the other a hydrocarboxylation. These differ in whether an alcohol, such as methanol [67-56-1is used to produce intermediate pentenoates (133), or water is used for the production of intermediate pentenoic acids (134). The former is a two-step process which uses high pressure, >31 MPa (306 atm), and moderate temperatures (100—150°C) (132—135). Butadiene,... 

However, BASF developed a two-step process (25). After methyl formate [107-31-3] became available in satisfactory yields at high pressure and low temperatures, its conversion to formamide by reaction with ammonia gave a product of improved quaUty and yield in comparison with the earlier direct synthesis. 

Prior to 1975, reaction of mixed butenes with syn gas required high temperatures (160—180°C) and high pressures 20—40 MPa (3000—6000 psi), in the presence of a cobalt catalyst system, to produce / -valeraldehyde and 2-methylbutyraldehyde. Even after commercialization of the low pressure 0x0 process in 1975, a practical process was not available for amyl alcohols because of low hydroformylation rates of internal bonds of isomeric butenes (91,94). More recent developments in catalysts have made low pressure 0x0 process technology commercially viable for production of low cost / -valeraldehyde, 2-methylbutyraldehyde, and isovaleraldehyde, and the corresponding alcohols in pure form. The producers are Union Carbide Chemicals and Plastic Company Inc., BASF, Hoechst AG, and BP Chemicals. 

The carbonylation of methanol is currently one of the major routes for acetic acid production. The basic liquid-phase process developed by BASF uses a cobalt catalyst at 250°C and a high pressure of about 70... 

To convert N2 and H2 into ammonia at a reasonable scale, flow reactors are needed that can be operated at high pressures. Until then, high-pressure reactions were mainly carried out in batch processes. Carl Bosch at BASF developed the technology that enabled scaling up to several tons of ammonia per day at 300 bar. 

Pier-Mittasch A high-pressure, catalytic process for making methanol from carbon monoxide and hydrogen. Developed by M. Pier and A. Mittasch at BASF in the 1920s. 

Methanol process. BASF introduced high-pressure technology way back in I960 to make acetic acid out of methanol and carbon monoxide instead of ethylene. Monsanto subsequently improved the process by catalysis, using an iodide-promoted rhodium catalyst. This permits operations at much lower pressures and temperatures. The methanol and carbon monoxide, of course, come from a synthesis gas plant. 

The concept that acetic acid can be prepared by carbonylation originated in use of routine acids. Carbonylation of methanol was first practiced in a high temperature and pressure process using boron trifluoride or phosphoric acid. A carbon monoxide pressure of 10,000 psi at 300 C was needed for the reaction (10). Metal salts came to replace acids as carbonylation catalysts. Carbonylation of methanol using a metal carbonyl catalyst was first discovered by Reppe and practised later by BASF. However, the process again required high pressure, 7500-10,000 psi, and the selectivity was low (11-14). 

LDPE was occasionally found in 1933 by R.O. Gibson and E.W. Fawcett, when they tried to perform reactions with ethylene [1]. Based on their invention. Imperial Chemicals Ltd (ICI), Great Britain, developed a process with a stirred autoclave in which ethylene was radically polymerized under high pressure [2], Later, BASF AG in Germany designed a tubular reactor to produce LDPE under similar high-pressure conditions [3]. 

The most general commercial process for the manufacture of mono-and divinyl ethers, developed by Reppe m the 1930s at BASF, is by treating alcohols with acetylene under pressure of >6.8 atin (100 psi) at temperatures of 120-180 0 in the presence of catalytic amounts of the corresponding metal alcoholate, The danger of handling acetylene under pressure in concentrated form requires sophisticated equipment and should only be attempted experimentally in an appropriately barricaded high pressure autoclave,... 

Haber demonstrated that the production of ammonia from the elements was feasible in the laboratory, but it was up to Carl Bosch, a chemist and engineer at BASF, to transform the process into large-scale production. The industrial converter that Bosch and his coworkers created was completely revised, including a cheaper and more effective catalyst based on extensive studies in high-pressure catalytic reactions. This approach led to Bosch receiving the Nobel Prize in chemistry in 1931, and the production of multimillion tons of fertilizer per year worldwide, see also Agricultural Chemistry Catalysis and Catalysts Equilibrium Le Chatelier, Henri Nernst, Walther Hermann Ostwald, Friedrich Wilhelm. 

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. 

In the BASF process the 1,2-diacetate is the substrate for the hydroformylation step. It can be prepared either directly via oxidative acetoxylation of butadiene using a selenium catalyst or via PtCl4-catalyzed isomerization of the 1,4-diacetate (see above). The latter reaction affords the 1,2-diacetate in 95% yield. The hydroformylation step is carried out with a rhodium catalyst without phosphine ligands since the branched aldehyde is the desired product (phosphine ligands promote the formation of linear aldehydes). Relatively high pressures and temperatures are used and the desired branched aldehyde predominates. The product mixture is then treated with sodium acetate in acetic acid to effect selective elimination of acetic acid from the branched aldehyde, giving the desired C5 aldehyde. 

---