Abstract
A multiscale strategy was used to conceptually design and economically analyze a scalable and sustainable process for dissolving and regenerating keratin from chicken feathers by using a sodium acetate-urea deep eutectic solvent as the reacting media. In this study, the recovery and recycling of the solvent were also considered. Moreover, molecular modeling of the solvent, keratin and its derivatives, property estimation of the corresponding mixtures, and simulation of the different process alternatives proposed, including the equipment sizing, estimation of energy needs, and economic analysis were presented. A quasi-planar cluster governed by H-bond interactions resulted in the most stable configuration of the deep eutectic solvent. Molecular models having molecular weights higher than 1.400 g/mol were created to represent the keratin species, where the most abundant amino acids in the feathers were included and conveniently ordered in the chain. Property estimations performed with the conductor-like screening model-real solvent succeeded in describing the main features of the interactions between the keratin derivatives and the solvents used. The process analysis performed on several alternatives showed that the process is technically and economically viable at the industrial scale, the costs being strongly dependent on the excess of both the solvent used to dissolve keratin and the water added for its regeneration. Several options to improve the process and reduce the costs are discussed.