The Elemental Unit has one inlet material stream and one outlet material stream. It copies the content of the inlet material stream to the outlet material stream. It performs a P-VF flash in case the feed is at a phase boundary, and the resulting temperature is less then 0.1 K from the feed temperature. Otherwise it performs a P-H flash for a stream that is near enough to pure, or a T-P flash.
The Elemental Unit measures elemental flow rates and elemental fractions of specified elements in the mixture.
For each of the compounds, the chemical formula must be known and correcly parsed. Chemical formula is automatically obtained from the simulation environment, if available.
Elemental mass flow rates use the atomic masses as given by "Atomic weights of the elements 2009 (IUPAC Technical Report)", M.E. Wieser and T.B. Coplen, Pure Appl. Chem., ASAP Article, doi:10.1351/PAC-REP-10-09-14.
For consistency, elemental mass fraction uses the ratio of the atomic mass and the total atomic mass calculated from the same source, over all elements in the mixture. The molecular weights of the compounds as exposed by the simulation environment are not used.