Communication Multiscale Modeling Approach for Production of Perfume Microcapsules Microreactors are currently showing great promise as novel tools upon which new chemical technology can be built and for support process intensification in many industrial sectors. In this work, a modeling strategy is presented that inte- grates process units at multiple scales with microstructured elements to support the synthesis and characterization of perfume-containing microcapsules. The strategy concerns two interconnected modules: microreactor unit models, where microcapsules are produced (developed in MATLAB®), and normal scale unit op- eration models (performed in Aspen Plus®). Encapsulation of the microreactor model and integration of flows between micro and normal scale equipments are implemented within Aspen Plus. All former features are successfully presented to- gether in an integrated fashion with other key issues like recovery and reuse of solvents used for the minimization of environmental impacts. Keywords: Modeling, Microcapsules, Perfume, Production, Microtechnology, Industrial applications Received: April 2, 2008; revised: June 3, 2008; accepted: June 10, 2008 DOI: 10.1002/ceat.200800174 1 Introduction Sustainable development is a key concept and an issue to be considered in any current and future scientific and technologi- cal projects. However, sustainable development is not always easy to be met in industry. It requires radical innovation in production methods and implementation of completely new paradigms for industrial manufacturing. Intensified chemical process components, such as microreactors and other micro- devices, offer tremendous opportunities for substantially in- creasing material and energy efficiency, by using smaller vol- umes, reduced transport and inventories, and lower energy and solvent consumption as it has been shown in a significant number of recent research studies. See the discussions in Gav- riilidis [1], Roberge [2], and Hard [3]. However, microtechnology industrial applications are still in their infancy. So, the aspects to investigate (control of flow phenomena, heat and mass transfer, mixing, etc.) turn out to be additional challenges. Additionally, the current state-of-the- art in process model simulations does not offer models for this kind of devices. No commercially available process simulation package offers microdevice models. Also, the combination of microdevices with normal scale devices might be economically better for some situations leading to the challenge of a success- ful integration of multiscale unit operations. 2 Perfume-Containing Microcapsules (PlC) The industrial case studied is the synthesis and characteriza- tion of perfume-containing microcapsules (PlC). PlC are of great interest to the detergent industry and specialty chemicals industry as they offer a mechanism for the efficient deposition of perfumes as well as provide a long-lasting fragrance benefits. Perfume deposition on textiles is an inefficient process (≈ 90 % of perfume added to a detergent is lost during washing). In ad- dition, perfumes have to be fabric specific and this feature lim- its the possible applicable fragrances. Encapsulation of per- fume into a microcapsule helps deposition because, with careful control of the size, PlCs become entrapped into the cloth fibers during washing and resist being flushed away, thus, providing a long-lasting consumer-relevant benefit [4]. At present, PlCs are commercially made using interfacial polymerization with melamine-formaldehyde. The process is performed large reactors, with high long-drawn-out times and using environmentally dangerous materials. Capsule robust- ness is not ideal and storage stability of commercially PlC is marginal [4]. © 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim http://www.cet-journal.com Rodolfo V. Tona Vásquez 1 Laureano Jiménez Esteller 1 Aaron David Bojarski 2 1 Chemical Engineering Department, School of Chemical Engineering, University Rovira i Virgili, Tarragona, Spain. 2 Chemical Engineering Department, School of Chemical Engineering, University Politecnica de Catalunya, Barcelona, Spain. – Correspondence: Laureano Jiménez Esteller (laureano.jimenez@urv. cat), Chemical Engineering Department, School of Chemical Engineer- ing, University Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Spain. 1216 Chem. Eng. Technol. 2008, 31, No. 8, 1216–1222