Alcohols catalytic hydroformylation production

Atmospheric pressure hydroformylation of ethylene and propene was conducted at 373-453 K on reduced [Rh5]-NaY and RhFe-NaY. The results show that acetaldehyde is catalytically obtained as the hydroformylation product on [Rhg]-NaY (142). In contrast, it is of interest to find that the bimetallic RhFe-NaY catalyst gives much higher activities and selectivities for the normal alcohols, as compared to those on [Rhg]-NaY. In particular. 

The desired reaction in catalytic hydroformylation is the addition of carbon monoxide and dihydrogen to the olefin substrate usually to obtain aldehyde. To some extent, however, concurrent reactions of the olefin (substrate) such as hydrogenation, isomerization, and special carbonylations, and consecutive reactions of the aldehyde product such as hydrogenation to alcohol, aldol reaction, trimer-ization, and formate formation take place under the reaction conditions of hydroformylation, which affect both yield and selectivity of the aldehyde products. For an example of product composition obtained using an unmodified cobalt catalyst in the BASF process, see Table 3. 

Raffinate-II typically consists of40 % 1-butene, 40 % 2-butene and 20 % butane isomers. [RhH(CO)(TPPTS)3] does not catalyze the hydroformylation of internal olefins, neither their isomerization to terminal alkenes. It follows, that in addition to the 20 % butane in the feed, the 2-butene content will not react either. Following separation of the aqueous catalyts phase and the organic phase of aldehydes, the latter is freed from dissolved 2-butene and butane with a counter flow of synthesis gas. The crude aldehyde mixture is fractionated to yield n-valeraldehyde (95 %) and isovaleraldehyde (5 %) which are then oxidized to valeric add. Esters of n-valeric acid are used as lubricants. Unreacted butenes (mostly 2-butene) are hydroformylated and hydrogenated in a high pressure cobalt-catalyzed process to a mixture of isomeric amyl alcohols, while the remaining unreactive components (mostly butane) are used for power generation. Production of valeraldehydes was 12.000 t in 1995 [8] and was expected to increase later. 

In CO hydrogenation, the achvity and selechvity to C1-C5 oxygenates over the bimetallic samples are higher than those of the monometallic counterparts [187-190]. Bimetallic catalysts also showed improved activity in the hydroformylation of ethylene compared to either of the monometallic catalysts [191]. The promotion for higher alcohol production is proposed to be associated with the adjacent Ru-Co sites. However, the lack of an exhaustive characterization of catalysts does not allow a clear correlation to be established between the characteristics of the active sites and the catalytic behavior. A formyl species bonded to a Ru-Co bimetallic site has been proposed to be the intermediate in the alcohol synthesis in these systems. A subsequent reaction with an alkyl-surface group would lead to the C2-oxygenate production [187]. 

This preparation is an illustration of the hydroformylation of olefins (oxo synthesis). The reaction occurs in the presence of soluble catalytic complexes containing metals of Group VIII of the periodic system. Although the metal originally used by Roelen and still largely used in the industry for the production of aliphatic aldehydes and alcohols is cobalt, the most active and selective catalysts are rhodium-containing compounds. The catalytic activity of the other Group VIII metals is in... 

Hydrogenation Hydroformylation 100-300 edible oils hydrogasification hydrocracking desulfurization catalytic cracking naphtha hydroforming coal liquefaction fatty alcohols 1-6-hexanediol 1-4-butanediol hexamethylenedi amine C4 to Cl5 products... 

Supported aqueous-phase catalysts can also be used to advantage. These supported catalysts have a thin aqueous film adhering to silica gel that contains the water-soluble complex (131). These catalysts are particularly useful for the hydroformylation of substrates such as oleyl alcohol (132). Since these catalytic reactions occur at the phase boundary, characteristics such as the water content can cause changes both in the reactivity and in the linear branched chain ratio of the product aldehyde. 

An interesting catalytic system was described by Pinke in a patent of 1975 13). This system combines a complex of a group 8 transition metal with an aluminum hydride. Such catalysts can perform the hydroformylation of mixtures of terminal and internal alkenes to the corresponding linear aldehyde and alcohol. One example is related to the [RuCl2(PBu3)3] + AlHEt2 system which transforms, at 120 bar (Hj/ CO = 1/2) and 150°C over 24 hours, heptene into octanal and octanol. Linear products were detected exclusively. 

The catalytic addition of CO and H2 (synthesis gas) to olefins (hydroformylation or oxo-synthesis) is one of the major industrial applications of homogeneous catalysis. Over 6 million metric tons of aldehydes or alcohols (oxo-products) are produced worldwide per year. Commodities based on the C4 oxygenates currently have... 

Hydroformylation of various unsarurated alcohols with different catalytic systems has been investigated by two research groups. Ziolkowski et al. have reported the hydroformylation of l-buten-3-ol, 2-methyl-2-propen-l-ol and 2-buten-l-ol with a catalytic system containing Rh(acac)(CO)2 and the water-soluble phosphine Ph2PCH2CH2C0NHC(CH3)2CH2S03Li (PNS). In all cases, the main products of the hydroformylation were 2-hydroxytetrahydrofuran derivatives formed via a hydroxyaldehyde cyclization [Eq. (4)] [12]. 

A decline in catalytic activity with use was detected for reactions catalyzed by either species. Polymers 2 and 7 in the absence of cobalt both revealed excellent stability at 190 C (hydroformylation temperatures). This is illustrated by the TGA curves shown in Figure 4. Curve A shows an onset of decomposition for phosphinated polyphosphazene of 400 C, slightly better than that of phosphinated polystyrene (curve B, 20Z crosslinked curve C, 2Z crosslinked). Loss of phosphorus was observed over a period of 45 hours for a catalyst derived from 2 (2Z DVB crosslinked). The data depicted in Figure 5 reveal benzene, toluene, benzyl alcohol, diphenylphosphine and triphenyl phosphine as cleavage products. If one recalls the previously discussed homogeneous results it should be clear that the PPho is derived from a phosphide intermediate such as 8. ... 

A further example of practical catalyst development is the hydroformylation of long-chain a-olefins with various copper(i) complex catalysts [6]. Modification of the catalysts with tertiary phosphines and amines led to aldehydes as products in varying yields, with alcohols and alkanes as byproducts. It was foimd that defined copper complexes have only a low catalytic activity. Only after the introduction of tertiary amines as solvents and catalyst components were better results obtained. 

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