GC Aromatic Composition

[vibhore]

I have detailed GC for for a gas condensate field by cryogenic distillation and it contains various aromatic compositions as well like Benzene, Toulene, Ethyl Benzene, O/M/P-Xylene.
I am trying to reduce these composition by adding the aromatic compounds with various Carbon Number, for example Benzene with C7, Toulene with C8, O/M/P-Xylene with C9.
Is this correct or do I need to follow some other combination?

This combinatin is for comparing various composition as compositional analysis by GC is done for Cryogeinc distillation and Single stage flash as well. SSF composition doen't have such detailed aromtic compositions.

Thanks.

[Javarga5691]

Do you mean you want to substitute these BTEX components with paraffinic equivalents (based on their identical carbon number) to make the compositional analyses comparable? What parameters of the streams do you want to compare?

[vibhore]

In the GC composition, C7 would represent all isomers including nC7. This is true for other Carbon Numbers as well. I have cryogenic flash composition data for some samples and they have BTEX compositions. Standard Single Stage Flash (SSF) composition for other samples doesn't include these BTEX composition. They have been reported as C7 total, C8 total...
So when I have to compare different samples to understand compositional variation, they have different composition scheme. I just proposed the above composition to make two different sets of compositions to have a unified composition scheme.
I would like to know whether I need to follow some other procedure.

[vibhore]

In the GC composition, C7 would represent all isomers including nC7. This is true for other Carbon Numbers as well. I have cryogenic flash composition data for some samples and they have BTEX compositions. Standard Single Stage Flash (SSF) composition for other samples doesn't include these BTEX composition. They have been reported as C7 total, C8 total...
So when I have to compare different samples to understand compositional variation, they have different composition scheme. I just proposed the above composition to make two different sets of compositions to have a unified composition scheme.
I would like to know whether I need to follow some other procedure.

[vibhore]

Solution-
CN is defined on boiling point criteria. Following are the boiling point range for C7, C8 and C9 (ref:Phase Behaviour of Petroleum Reservoir Fluids-Pederson)
from table 2.1
C7: 69.2-98.9 (degC)
C8: 98.8-126.1 (deg C)
C9: 126.1-151.3 (deg C)
and boling point for Benzene, Toulene, Ethyl Benzene, O/M/P-Xylene are as (ref: table 2.2- PEDERSON)
Benzene: 80.2 (deg C)
Toulene: 110.7 (deg C)
Ethyl Benzene: 136 (deg C) (source-Wikipedia)
m+p-Xylene: 138.8 (deg C)
o-Xylene: 144.5 (deg C)

So accordingly Benzene can be added to C7, Toulene to C8 and Ethyl Benzene, O/M/P-Xylene to C9.