The Unified Design method has evolved over the years. The original contribution [Siitonen & Sainio, 2015] was the first to show that batch chromatograpy and steady-state recycling chromatography can be described with operating parameters that are equivalent to those used in Triangle Theory for SMB chromatography. Later, Sainio [2016] introduced more systematic definitions, as well as a new notation, for the UD operating parameters. This enabled analysing and visualizing the feasible regions of various chromatographic single-column and multicolumn processes for binary and ternary separations.

More recently, Sainio [2021] applied the UD method to binary separations with arbitrary purity constraints. Also operating strategies where a waste fraction is collected and discarded were discussed. The Feasible regions section provides a free tool to calculate the boundaries for your own system and purity specification.

A key publication in the development of the tools available on this site is Siitonen and Sainio [2011] that provided an explicit method to calculate the position and height of the pure first component shock (binary separation, Langmuir isotherm). This problem had remained unsolved for 70 years. The Batch chromatograpy section provides a tool to calculate the chromatograms for your own system.