Analysis of energy saving for ammonium sulfate solution processing with self-heat recuperation principle

As an important production process, the evaporative concentration of the inorganic salt solution is extensively applied in the industry, and it is significant to investigate the energy saving potential of such evaporation systems. In the paper, taking the ammonium sulfate solution for example, the self-heat recuperation technology (SHRT) is utilized to design two mechanical vapor recompression (MVR) systems, and the relevant energy saving performance is analyzed. It is found that the designed systems, which are satisfied with SHTR, enable the recovery of the sensible and latent heat of the emission solution without any additional heat, and compared to the conventional three-effect evaporation system, the energy saving performance are more prominent. However, in view of the existence of the boiling point elevation (BPE) for the inorganic salt solution, a maximum reduction amplitude of 40% of the energy saving performance for the double-stage MVR system is obtained compared with the single-stage MVR system. As a result, it is concluded that the only satisfaction to the SHRT is not enough, and the pattern of the MVR system should also be considered to ensure a prominent energy saving performance.