1 Issues with the decimal separator in Compound Creator (CC) We have DWSIM 4.0 installed in the computer classrooms, since we do the installation once in a semester (starting in February), so we haven’t updated the software in the classroom (though I have 4.3 in my desktop). With version 4.0, a team of students “created “ succinic acid with CC. They used the comma as decimal separator in Windows and in DWSIM, including CC. They used the experimental boiling point of succinic acid (they introduced 508,15 K, probably unnecessary decimal figures). However, when they added the database and created a stream of pure succinic acid, the model gave an error, failing to calculate the VLE in the stream (NRTL Nested Loops). When we edited de CC file, the boiling point in the General properties tab was shown as 5015: The comma had disappeared. And this seemed to be the source of the error. We fixed it by defining the dot as decimal separator in Windows and introducing 508.15 K in CC. Then it worked. I tried to reproduce the error some days later in DWSIM 4.3, but all worked perfectly: comma in Windows and comma in DWSIM including CC. Just an example of how the use of comma or dot can be a bit confusing for the user. Also, it seems that Compound Creator in DWSIM 4.3 allows to use the comma as decimal separator. I attach a PDF with the details of “everything apparently OK” with the comma in CC in 4.3. DWSIM Comma on Windows Comma in DWSIM 4.3: no problem The decimal separator in Windows 7 is seta as “,” (the comma). Create new Compound Creator Study for Succinic Acid. UNIFAC structure: Identification: molecular weight is OK. 2 Create new database ‘Succ_comma_on_comma_DB.xml’ Opening the ‘General Properties’ Tab: DWSIM displays decimal commas everywhere (as well as dot as thousands separator): Introducing the experimental boiling point (235 C, 508 K). I enter 508,15 K in order to test the comma compatibility with CC. Other properties recalculated: 3 Save project as “Succ_comma_on_comma” (Compund Creator Study), save compound to database, exit CCS. Using the compound in a material stream in a simulation project Creating new steady‐state simulation Adding Succ_comma_on_comma_DB.xml Adding Succinic acid to the simulation: Basis: NRTL and Nested Loops VLE. Creating a material stream: (100% succinic acid, 1 atm, bubble point. Resulting temperature is ~normal builing point (508,63 K). It seems it works properly. 4 A mixture with water (30% water) and a flash evaporation from (400 kPa, bubble point) to 100 kPa (just to try something involving LVE calculations): The properties and composition of the final Vapor stream: .