Details

Autor(en) / Beteiligte

• Orme, Christopher J.
• Wilson, Aaron D.

Titel

1-Cyclohexylpiperidine as a thermolytic draw solute for osmotically driven membrane processes

Ist Teil von

• Desalination, 2015-09, Vol.371 (C), p.126-133

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The switchable polarity solvent (SPS) 1-cyclohexylpiperidine (CHP) was demonstrated as a viable draw solute for osmotically driven membrane processes. The SPS draw solution was formed from a heterogeneous mixture of water and water immiscible CHP was exposed to carbon dioxide to form concentrated aqueous ammonium bicarbonate solution with high osmotic pressure (>500atm). The free amine and ammonium bicarbonate solution has been demonstrated to be compatible with a polyamide thin film composite membrane through a variety of transport experiments. The reverse solute flux, Js, of CHP appears to occur by a different mechanism than the water flux Jw. This difference suggests that Js could be minimized in future membranes without impacting Jw. To demonstrate product water recovery, the solution was “degassed” removing carbon dioxide and converting the aqueous ammonium bicarbonate solute to a water immiscible CHP which can be decanted from water. Effective degassing ammonium bicarbonate solutions at low concentrations occurs at the lowest temperature of any SPS yet studied as a draw solute (70°C) and possibly at the lowest temperature of any thermolytic amine studied as a draw solute. [Display omitted] •CHP–H2CO3 is a high osmotic pressure thermolytic draw solute.•CHP–H2CO3 solutions produce relatively high forward osmosis water fluxes.•Low grade heat should be sufficient to degas CHP–H2CO3 solutions.•CHP–H2CO3 solutions display good material/membrane compatibility.•Water flux and reverse draw solute flux of CHP–H2CO3 occur by different mechanisms.