Multi-objective optimization is used for the conceptual design of a new industrial process for the production of poly(oxymethylene) dimethyl ethers (OMEs), which are highly interesting environmentally benign fuel additives. A model based on infinity/infinity-analysis is used for the design. Quantitative measures for the separation effort are introduced in infinity/infinity-analysis and used as objectives. Pareto frontiers are determined for different choices of the design variables and objectives. The design point is chosen based on an exploration of Pareto frontiers. For the studied process the specifications of the product, which is a blend of OMEs of different chain length, are not known a priori. The optimization with the reduced model yields the optimal product composition. (C) 2013 Elsevier Ltd. All rights reserved.