Eliminating 
between Eq. (3.125) and Eq. (3.126)
|
(3.127) |
The specific enthalpies in Eq. (3.127) can be determined knowing only the temperature T0 and the specific entropies can be determined knowing T0, p0 and the composition of the environment. For maximum work,
|
(3.128) |
Therefore, the chemical exergy 
can be expressed as
|
(3.129) |
The specific entropies for O2, CO2 and H2O are written from Eq. (1.104),
|
(3.130) |
where the first term on the right is the absolute entropy at T0 and p0 and xiis the mole fraction of component in the environment .Therefore ,Eq.(3.129) becomes,
|
(3.131) |
In terms of Gibbs function of respective substances,
|
(3.132) |
where
|
(3.133) |
