The Studies On Hydroformylation Of Butene-1 And Mixture Of Butene-1 And Butene-2 In Biphasic Catalytic System

Two-phase catalytic system with water-soluble organometallic complexes as catalysis is one of the frontier fields in the "Green Chemistry" that is progressing quickly recently. The most important industrial development in this area is the so called Ruchrchemie/Rhone-Poulenc process whose econmical advantages are based on simple principle of catalyst recycling and the low-cost catalyst/product separation and enviromental protenctiong. Nowdays, There is increasing interest in n-valeraldehyde achieved by the hydroformylation of the available feedstock base of "Raffinate-II ",which is a mixture of isomeric butenes (usually composed of 1- and 2-butenes,and a small amount of butane) .In this paper, the hydroformylation of butenes catalyzed by water-soluble rhodium complex and hydrogenation of its products-aldehyde were studied. The main works include:1.Butene-1 hydroformylation catalyzed by water-soluble rhodium complex RhCl(CO)(TPPTS)2, with the water-soluble phophine TPPTS or BISBIS as ligand, in the presence of cationic surfactant CTAB was studied. The effect of the reaction conditions, such as concentration of surfactant and rhodium complex, temperature, syngas pressure and the mole ratio of phosphine to rhodium on the activity and selectivity of hydroformylation was investigated. The comparison between phosphine ligand TPPTS and diphosphine ligand BISBIS indicated that Rh-BISBIS catalyst system shows higher activity and selectivity for forming normal aldehyde than the Rh-TPPTS system and Rh-TPPTS-CTAB system. The cationic surfactants could obviously accerate the reaction rate.In butene-1 hydroformylation under the optimum reaction conditions: 130 ℃,2.0MPa, [Rh]=1.0×10-3mol/L,[BISBIS]/[Rh]=5, TOF and selectivity for forming normal valeraldehyde were 1498 h-1 and 98%, respectively. In the other optimum system which were 140℃,2. 5MPa, [Rh]=l. 0×10-3 mol/L,[TPPTS]/[Rh]=100, the conversion of butene-1 reached to 70 % for two hours and the mole ratio of normal/iso aldehyde was 7.3.2. Based on the hydroformylation of butene-1, the hydroformylation of the mixture of isomeric butenes (1- and 2-butene,and butane) in biphasic catalytic system was studied in datail. The Rh/TPPTS catalysts is only applicable in water to the hydroformylation of terminal olefins. Butene-2 doesn't react in the presence of butene-1. In this reaction, butene-1 is hydroformylated to n-valeraldehyde and 2-methyl butyraldehyde, and a part of butene-1 isomerized into butene-2 which decrease the formation of aldehyde. The results showed that higher CO partial pressure tend to suppress the isomerization of alpha olefin to internal olefine. Under the condition of 100℃, 2.0MPa, [Rh]=1.0×10-3mol/L,[TPPTS]/[Rh]=25, the conversion of the mixture of isomeric butenes and the selectivity for n-pentanal are 34.7% and 84.4%, respectively after four hours of reaction.3. Pentanal as the products of butene hydroformylation were hydrogenated in the RuCl3/TPPTS biphasic catalytic condition : [Ru]=6.0×10-3mol/L,[TPPTS]/[Ru] =3, 80℃,1.0MPa,the conversion of pentanals mixtures to pentanols was 95% and almost no by-products determined.