The purpose of this work is to investigate the effect that a solvent mixture has on the process-wide performance of the hydroformylation of 1-dodecene. A thermomorphic solvent mixture consisting of dimethylformamide and decane is used as a tunable solvent that ensures monophasic conditions during the reaction and that is also used to separate the homogeneous catalyst from the product through temperature controlled phase splitting in a decantation unit. So far reactor and process design for this reaction has been primarily based on a specific composition of the solvent mixture and without considering the economic impact of catalyst leaching. In order to reduce the complexity of the conceptual process design problem, linear regression models were used to accurately estimate the partition coefficients of the multicomponent mixture in the decanter. Using limited available experimental data from the literature, correlations were derived for catalyst loss based on the composition of the thermomorphic solvent system. Optimization results show that the catalyst loss has a significant effect on the total annualized cost of the process and that the frequently studied solvent composition should be altered to increase catalyst retention.