The design and features of the pilot plant at Ulm University are described in detail in . Here, only the most important design aspects are briefly summarized. The configuration of the fourproduct mDWC pilot plant for the separation of a mixture ABCD, with A to D in the order of their boiling points, is shown in Fig. . It represents a simplified mDWC with two instead of three partitioning walls . This simplification can be carried out without an energy penalty, depending on the considered mixture to be separated . The resulting column design is called 2-2-4-a configuration . Sections C11 to C16 represent the so-called main column, sections C21 to C22 represent the middle column, and sections C31 to C33 represent the prefractionator. The name 2-2-4-a indicates the number of product streams leaving the prefractionator (= 2), the middle column (= 2) and the main column (= 4). The location of the second wall positioned in the upper half of the column is denoted by the letter a. All mentioned sub-columns are highlighted in Fig. and the different separation sections are labelled for better comprehensibility. The column scheme for the pilot mDWC that was built at Ulm University is shown in Fig. .