Ruhrchemie process converter

In the mid-1980s, Ruhrchemie (now Hoechst) converted its oxo capacity to a proprietary water soluble rhodium catalyzed process (27,28), a technology developed jointly with Rhc ne-Poulenc. Product separation in this process is by decantation. Isomer ratios of n- to isobutyraldehyde of about 20 1 are obtained. 

Aqueous, two-phase catalysis is also utilized industrially in a number of other processes apart from hydroformylation. The hydrodimerization of butadiene and water, a telomerization variant yielding 1-octanol or 1,9-nonanediol (cf. Section 6.9), is carried out at a capacity of 5000 tonnes per annum by the Kuraray Corporation in Japan. Rhone-Poulenc is operating two-phase, aqueous, catalytic C—C coupling processes (using TPPTS obtained from Ruhrchemie) for small-scale production of various vitamin precursors such as geranylacetones. Moreover, TPPTS-modified Ru catalysts have been proposed for the homogeneously catalyzed hydrogenation to convert unsaturated ketones into saturated ones. 

Hydroformylation is a very important industrial process. Olefins are converted to aldehydes, which can be further transformed into acids, alcohols or amines. The Ruhrchemie/Rhone-Poulenc hydroformylation process is an aqueous-organic biphasic process which uses an easily separable water-soluble rhodium... 

Commercially, the aqueous-phase concept was firstly applied in Ruhrchemie/Rhone-Poulenc s (RCH/RP) process (for the fundamentals, see Section 2.4.1.1). In several units the RCH/RP process has been converting propene to n-butyraldehyde and isobutyraldehyde (or butenes to valeraldehydes) since 1984 in the presence of HRh(CO)(TPPTS)3 (with TPPTS = m-trisulfonated triphenylphosphine or tris-(sodium-fn-sulfonatophenyl)phosphine as water-soluble ligand) according to Eq. (1). The output of the units mentioned is approximately890 000 tpy, which corresponds to roughly 13% of the world s total production. 

The process uses TPPTS from Ruhrchemie s production unit. Interestingly, in commercial operation supported aqueous-phase catalysis operation is more effective than the nonsupported catalyst version [2b]. Moreover, TPPTS-modified Ru or Pd catalysts have been proposed for the homogeneous catalyzed hydrogenation step for converting unsaturated into saturated ketones. It is not known how many of these proposals have been realized industrially [3]. 

Finally, the third generation, in which a liquid-liquid biphasic system is used, corresponds to the development of the Ruhrchemie/Rhone-Poulenc process. Olefins of the organic phase are converted by a rhodium complex maintained in an aqueous phase by adjunction of an hydrosoluble phosphine, the sodium salt of the meta-sulfonated triphenylphosphine [Na][TPPTS). The separation of aldehydes from the catalytic phase is then performed by a simple decantation. 

Oxo synthesis, or more formally hydroformylation, is an olefin/CO coupling reaction which in the presence of hydrogen leads to the next higher aldehyde. The process was discovered in 1938 by Otto Roelen at Ruhrchemie, where it was first commercialized [4]. This reaction is the most important industrial homogeneous catalysis in terms of both scale and value. The most important olefin starting material is propene, which is mainly converted to 1-butanol and 2-ethylhexanol via the initial product butyraldehyde (Eq. 3-1). 

In the late 1930s, Otto Roelen at Ruhrchemie discovered hydroformylation, sometimes called the 0x0 process, one of the first commercially important reactions to use a homogeneous catalyst. He found that an alkene can be converted to the homologous linear n) and branched iiso) aldehydes (eq. 20) by the addition of H2 and CO, catalyzed by Co2(CO)8 further reduction of the aldehydes to the alcohols is observed under some conditions. Today, 4 million ton of aldehydes are made annually in this way. 

Today the Ruhrchetme/Rhone-Poulene Process (RCH/RP) is successfully operated at two locations in the world. In the early 1980s a 100,000 ton scale process was developed and commercialized at the Oberhausen site of Ruhrchemie AG (now Celanese AG). The first unit was started up in 1984. In 1988 and in 1999 two additional lanes went on stream. The actual combined capacity of aU three units at Oberhausen (combined with the conversion of not reacted propylene in a hi -pressure hydroformylation set up) amounts to more than 500,000 tons of C4-products. The l b-C4-aldehydes produced are converted further to the corresponding C4-alcohols or after aldol condensation and hydrogenation to 2-ethyl- 1 -hexanol (2-EH). With an annual volume of 360,000 tons of 2-EH the Oberhausen facility became the world s largest 2-EH operating unit. 

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