and potential exergies (𝐸𝑥 % ). However, kinetic and potential exergies may be neglected in the case of chemical reactions due to data shortage on the exact process layout, 14 rendering: We define the reference environment with mean concentrations of reference compounds in the surrounding environment specified by Szargut et al. Note that the reference state for all elements is not the actual natural environment, but a state that represents the most devaluated form of the elements. Standard chemical exergies for common and simple components, e.g. carbon dioxide, ethanol, nitrogen, have already been calculated in previous literature using Eq. ( ) and can be taken from tabulated works. For complex materials such as biomass, Δ𝐺 , ° is difficult to obtain. ) refers to the exergy destruction as a result of solution mixing and is analogous to the Gibb's energy change of mixing. In the case of ideal mixing, as is the case for the solids in the system, 𝛾 * is 1. For mixtures of gases, the molar fraction in the gaseous phase, 𝑦 0,/ and the fugacity coefficient, ϕ 1 are used instead of 𝑥 0,/ and γ 0 respectively.