Beschreibung
Absorption heat pumps enable the efficient utilization of waste heat in industrial processes. The commonly applied fluid pair consists of water and lithium bromide. However, lithium bromide has the drawbacks of crystallization and high corrosion at high lithium bromide mass fractions, i.e. at high desorber temperatures. Thus, research has focused on finding alternative sorbents for absorption heat pumps.The research project “AbSorbEnt” investigates ionic liquids and deep eutectic solvents as alternative sorbents to lithium bromide with water as the refrigerant. After a systematical compound screening to identify possible compounds for the formation of ionic liquids and deep eutectic solvents, the sorbents were produced and investigated regarding their ability to absorb water from air with a relative humidity of 96 % at ambient pressure and temperature. Subsequently, process-relevant sorbent properties were examined, such as melting point, viscosity, and density.
In the absorption experiments at ambient pressure and temperature, the sorbents showed a water absorption of up to 0.324 gwater/gsorbent within 24 hours; the reference sorbent lithium bromide resulted in an absorption of 0.239 gwater/gsorbent. In terms of process-relevant properties, the sorbents had a density of 1.0722-1.2521 g/cm³ at 10 °C and 1.0299-1.2048 g/cm³ at 80 °C. The dynamic viscosity of the sorbents was 0.044-5.194 Pa·s at 10 °C and 0.007-0.082 Pa·s at 80 °C. Viscosity measurements at different shear rates proved that the prepared sorbents exhibit a Newtonian behavior. In the next step, the best-performing sorbents are subject to hydrolytic stability and heat resistance analysis. Furthermore, to investigate the behavior under operation conditions, absorption and desorption experiments are conducted at 30 to 200 °C and pressures representative of water as the refrigerant.
| Zeitraum | 24 Sept. 2024 |
|---|---|
| Ereignistitel | 20. Österreichische Chemietage 2024 |
| Veranstaltungstyp | Konferenz |
| Ort | Graz, ÖsterreichAuf Karte anzeigen |