Hydroformylation of methyl oleate with a recycled rhodium catalyst and estimated costs for a batch process

Methyl oleate was hydroformylated to methyl formylstearate at 120 C and 850–900 psig with a 1:1 mol mixture of hydrogen and carbon monoxide. In the presence of triphenylphosphite, an activated rhodium-on-alumina catalyst produced an essentially quantitative conversion in about 40 min. Filtration followed by distillation yielded methyl formylstearate. The solubilized rhodium catalyst was concentrated in the distillation residue. The residue was resupported on the spent support in a gas-fired rotary kiln. The process was repeated 9 times without significant loss of catalyst activity. Assuming the catalyst can be recycled repeatedly to the process without affecting the efficiency of operation, a preliminary estimate based on a hypothetical plant producing 2 million 1b of methyl formylstearate annually places the processing costs, not including cost for methyl oleate, at about 13.7 cents per pound.