- A standard for Z-BaSICä software

The ‘cp’ file is the heart of Z-BaSIC^TM. The file contains a listing of the components of a process stream and their pure compound properties. There is a standard format for the ‘cp’ file, illustrated below, that contains for each component its ‘n’ and ‘z’ properties, its A, B, and C values of the Antoine vapor pressure equation, its critical temperature, its density and its weight fraction in the total process stream. The sum of the weight fraction column for any ‘cp’ file always equals 1.00. The information contained in the ‘cp’ file is sufficient to simulate distillation by first principles, and contains many other properties useful in determining the behavior of a process stream. The ‘cp’ file is the input file to all Z-BaSIC^TM programs. Z-BaSIC^TM simulator programs generate ‘cp’ files on product streams as their primary output file. The ‘cp’ file is, effectively, a surrogate for the process stream and anything that can be done with a process stream in the laboratory or in the refinery can, in principle, be processed similarly by the computer.