**6. Future developments**

A highly promising solvent-based CO2 capture process, named the mixed-salt technology, is being currently developed, as reported by Jayaweera et al. [43]. This technology adds potassium carbonate to the system in order to exploit the advantages of both ammonia-based and potassium carbonate-based technologies. The simplistic representation of the CO2 absorption and removal reaction is as follows:

$$\mathrm{K}\_{2}\mathrm{CO}\_{3}\cdot\mathrm{NH}\_{3}\cdot\mathrm{H}\_{2}\mathrm{O}\cdot\mathrm{x}\mathrm{CO}\_{2} \Leftrightarrow \mathrm{K}\_{2}\mathrm{CO}\_{3}\cdot\mathrm{NH}\_{3}\cdot\mathrm{H}\_{2}\mathrm{O}\cdot\mathrm{y}\mathrm{CO}\_{2}\tag{6}$$

**5.** The mixed-salt technology is a promising evolution of the process to further reduce the

Chemical Absorption by Aqueous Solution of Ammonia http://dx.doi.org/10.5772/intechopen.78545 121

The authors gratefully acknowledge Mr. Stefano Lillia of Politecnico di Milano for his help in

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absorption by aqueous NH3

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specific heat duty and the load for the water washing on top of the absorber.

investigating carbon capture alternatives as well as in reviewing this chapter.

**Acknowledgements**

**Author details**

**References**

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Gianluca Valenti\* and Davide Bonalumi

Politecnico di Milano, Milano, Italy

\*Address all correspondence to: gianluca.valenti@polimi.it

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where the CO2 loading is the numerical difference between *y* and *x*. The left and right side of the equilibrium represent the lean and rich solutions, respectively. Despite the system being characterized by the presence of several ionic species that could form a solid phase, precipitation is avoided by operating the absorber at relatively high temperatures and at concentrations below the solid-forming conditions. The expected advantages are a limited heat duty at the regenerator and a limited load for the water wash on top of the absorber.
