Fig. 2
From: Thermodynamic considerations in renal separation processes
The Gibbs energy flow in or out of the process streams for different urine volume production rates, at a constant solute excretion of 731 mmol/day, as in Table 2. Variables depicted on the graph include total change in Gibbs energy (ΔGtotal), pressure work (Wpres), separation work (Wsep) and friction losses (Wfric); these variables are described in Eqs. 2, 3, 4 and 5 respectively. Negative values for ΔGtotal indicate that there is excess or lost work, which implies the stream parameters are achievable without additional work applied to the system