Page 392 - Multidimensional Chromatography

384 Multidimensional Chromatography

Figure 14.5 Chromatographic separation of (a) sulfur compounds, and (b) hydrocarbons,
obtained by using the system illustrated in Figure 14.4.

gas stream components is a prerequisite for achieving optimum control and quality
assurance. The refinery analyser configurations therefore have to cope with a wide
variety of gas compositions and concentrations.
A five-column configuration of such an analyser system is depicted in Figure
14.6. The first event in the process is the analysis of H 2 by injection of the contents of
sample loop 2 (SL2) onto column 5 (a packed molecular sieve column). Hydrogen is
separated from the other compounds and detected by TCD 2, where nitrogen is used
as a carrier gas. The next event is the injection of the contents of sample loop 1
(SL1), which is in series with SL2, onto column 1. After the separation of com-
pounds up to and including C 5 , and backflushing the contents of column 1, all com-
pounds above C 5 (C 6 ) are detected by TCD1. The fraction up to and including C 5 is
directed to column 2, where air, CO, CO 2 ,C 2 , and C 2 = (ethene) are separated from