Hydrogenation of oleic acid over ruthenium catalysts

Highly efficient Cu–Zn–Al catalyst for the hydrogenation of dimethyl adipate to 1,6-hexanediol: influence of calcination temperature

“…Precisely, the hydrogenation process is based on the adsorption on catalytically inactive ZnO sites, followed by its transition to the adjacent catalytically active copper sites, where it is further hydrogenated to alcohol by atomic hydrogen activated in neighboring Cu 0 sites. According to the heterogeneous catalytic theories and the studies done by Toba [1], Mendes [29], Pengbo Guan [30] and Ruixiang Li [26], the hydrogenation process is speculated as Fig. 7: (1) chemisorption and molecular hydrogen activation; (2) carboxylic group polarization, adsorption, migration to active sites and activation; (3) surface reaction, including hydrogenolysis and hydrogenation; (4) chemical desorption.…”

Preparation and characterization oF Ru-Sn/Al2O3 catalysts for the hydrogenation of fatty acid methyl esters

“…Because the oils and fats which are used as raw materials are a mixture of fatty acids of different chain lengths, alcohols of variable carbon number are obtained as products. 4 The C 12 -C 14 fraction is used to obtain detergents, and as in the case of FAME, there are few uses for the fractions C 8 -C 10 and C 16 -C 18 . In contrast, in the case of fatty acids there are applications for all fractions.…”

“…With reference to the latter, and depending on the desired quality of the final fatty alcohol (which usually tolerates a maximum of 1-5 ppm of aldehydes), it must have an additional stage of selective hydrogenation to eliminate these compounds. Other steps that normally are used at high production scales, is the distillation of fractions (C 6-10 , C 12-14 , C [16][17][18] ) or other technical fractionation suitable for separation by carbon atoms number. The hydrogenation of fatty acid methyl esters for the production of long chain fatty alcohols is a process with well established technology, which has remained virtually unchanged in the last decades.…”

“…[5][6][7] There have been attempts to reduce the pressure and temperature of the process by replacing the catalysts of Cu by others based on noble metals. 8 These have an increased activity at low temperature but in its pure form (i.e., without modifying the function of metal) have low selectivity. The obtention of fatty alcohols from fatty acid methyl esters requires the selective hydrogenation of carbonyl group and the hydrogenolysis of C-O methoxy group.…”

“…17 However, there are no reports about the effects of catalytic ensembles on activity and selectivity. On the other hand, there is a controversy between different research groups as some have reported the formation of oleyl alcohol from oleic acid or methyl oleate 16,18,19 using Ru-Sn/Al 2 O 3 catalysts while others just reported the formation of methyl stearate using the same reagents, operating conditions and catalysts. 20 This paper presents a study of the activity of Ru-Sn/Al 2 O 3 catalysts in the methyl oleate hydrogenation reaction.…”