Systematic design of blanket wash solvents with recovery considerations

The search for new solvents is driven by the needs of new applications and processing requirements, replacement of solvents whose continued use poses a threat to environmental health and safety, a response to changing environ mental regulations, and a response to market demands. Many cleaning solvent s (commonly referred to as blanket washes) used in the lithographic printin g industry are on the environmental hit list and are to be phased out withi n the next few years. This paper discusses the design of novel single compo nent solvents for this application. The simultaneous consideration of recov ery targets (and associated process constraints), physical property require ments, and environmental restrictions renders identification/selection of b lanket washes a complicated design problem. To address this, we present a f ramework for the design of novel blanket wash solvents. The framework aims at designing solvents that meet property requirements and the environmental restrictions while minimizing the operating cost associated with safe reco very and recycle operation. Molecular structural attributes are modeled by binary variables and the process variables are continuous variables. This f ramework is formulated as a mixed-integer non-linear programming problem (M INLP) and solved by an appropriate solver. To demonstrate the viability of the framework and the solution approach, blanket wash solvents are designed . (C) 2001 Elsevier Science Ltd. All rights reserved.