Infinite dilution activity coefficient measurements of organic solutes in fluorinated ionic liquids by gas-liquid chromatography and the inert gas stripping method

5.2.2. Trihexyltetradecylphosphonium bis (trifluoromethylsulfonyl) imide

Table 5-31: Experimental infinite dilution activity coefficients obtained by the inert gas
stripping method (IGSM) for six different organic solutes in the ionic liquid
Trihexyltetradecylphosphonium bis (trifluoromethylsulfonyl) imide, and comparison with
similar data obtained by the GLC method.

Results

Results from the IGST from GLC

T D D D Deviation#

K cm³/min cm³/min cm3/min (Average) %

n-hexane

303.15 7.55 1.087 15.05 1.084 20.98 1.083 1.085 1.089 -0.367

313.15 7.48 1.101 14.91 1.109 - - 1.105 1.096 0.821

323.15 7.52 1.116 15.65 1.121 - - 1.119 1.103 1.451

Hex-1-ene

303.15 7.51 0.895 15.32 0.899 19.87 0.890 0.895 0.900 -0.556

313.15 7.72 0.911 15.45 0.916 - - 0.914 0.907 0.772

T C

323.15 7.43 0.924 15.50 0.918 - - 0.921 0.913 0.876

? ? ? ?

13 1 ? 1

? Cyclohexane

303.15 7.53 0.801 15.29 0.815 21.52 0.803 0.806 0.794 1.511

3

313.15 7.52 0.813 14.82 0.821 - - 0.817 0.795 2.767

323.15 7.59 0.825 14.93 0.821 - - 0.823 0.796 3.392

Methanol

303.15 7.64 1.140 14.48 1.111 20.06 1.136 1.129 1.151 -1.911

313.15 7.62 1.105 15.08 1.094 - - 1.100 1.083 1.570

323.15 7.57 1.033 15.86 1.058 - - 1.046 1.048 -0.191

Benzene

303.15 7.61 0.391 15.11 0.399 20.15 0.387 0.392 0.381 2.887

313.15 7.55 0.406 15.72 0.400 - - 0.403 0.391 3.069

323.15 7.52 0.409 14.98 0.413 - - 0.411 0.398 3.266

Acetone

303.15 7.54 0.285 15.64 0.287 21.33 0.289 0.287 0.297 -3.367

313.15 7.66 0.303 14.89 0.308 - - 0.306 0.297 3.030

- 0.321 0.311 3.215

323.15 7.46 0.318 15.41 0.323 -

# Relative deviation given by

5.3.Separation potential of the investigated ionic liquids

From experimental data, equations (2-3) and (2-4) were used to calculate selectivities, and

capacities, at infinite dilution for seven different separation problems. Table 5-32 gives an

insight into the effectiveness of the ionic liquids investigated in this work as a separation solvent, as compared to other ionic liquids and some industrial molecular solvents such as sulfolane, NMP, dimethylsulfoxide and chlorobenzene.

Table 5-32: Selectivity and capacity at infinite dilution at T = 313.15 K of the ionic liquids
investigated in this work for different separation problems and comparison with industrial
separation agents as well as other ionic liquids

Benzene

n-hexane/ benzene

Methanol/ benzene

Ethanol/
benzene

Butan-2-one /benzene

Hexane/

hex- 1 - ene

Methanol/ acetone

Ethanol /

butan-2- one

Methanol

Hex- 1 - ene

Butan-2-one

Selectivity at infinite dilution, Limiting Capacity,

[EMIM][BF4]^a	38.65	0.17	0.31	0.65	2.02	0.39	0.47	0.41	0.02	2.33		0.62	[C16MIM][BF4]^b
3.10	1.52	1.94	1.32	1.35	1.28	1.47	1.27	0.55	0.83	0.96		[3C6C14P][BF4]^c
3.41	1.31	1.41	1.08	1.26	1.25	1.30	2.44	0.90	1.86	2.25		[3C6C14P][Tf2N]^c
2.80	2.77	3.25	0.81	1.21	3.85	4.00	2.56	1.10	0.92	3.15		[3C6C14P][PF6]^c
2.96	3.12	3.32	1.04	1.20	3.13	3.21	1.47	0.59	0.32	1.42		[3C6C14P][(C2F5)3PF3]^d
3.25	5.83	5.87	-	1.23		-	5.00	1.89	0.86	-		[3C1C4N][Tf2N]^e
13.94	1.07	1.38	-	1.89	3.33	-	0.75	0.10	0.70	-		[BMPyrr][Tf2N]^f
15.47	-	2.01	0.62	1.92		3.26	1.16	0.14	-	1.89		[C13C8N] [Tf2N]^c
3.77	2.68	2.82	0.82	1.33	3.13	3.44	2.27	0.80	0.85	2.78		[EMIM][TfO]^c,j
30.20	0.33	0.53	-	2.31		-	0.45	0.03	1.38	-		[MOIM][PF6]^c
11.27	1.88	2.35	-	1.72		-	1.04	0.16	0.55	-		[BMIM][SbF6]^c
22.25	1.41	1.89	0.50	2.08	4.35	3.74	0.79	0.07	0.56	1.56		Sulfolane^g
18.17	0.91	1.26	0.83	-	1.37	1.52	0.43	-	0.47	0.51		NMP^h
11.24	-	-	-	0.53		-	0.95	0.16	-	-		Chlorobenzene^i,k
-	-	-	-	-	0.17*	8.29	-	-	-	0.47		Dimethylsulfoxide^k
-	-	-	-	-	0.35*	0.20*	-	-	2.00*	0.35*

^aFoco et al. (2006), ^bMutelet and Jaubert (2007), ^cThis work, ^d Letcher et al. (2008, ^e Heintz et al
(2006b), ^f Kato and Gmehling (2005), ^gMöllmann and Gmehling (1997),^hKrummen et al. (2000),
ⁱKossack et al.(2008), ^jOlivier et al.(2010a); ^kDortmund Data Bank, DDB, * Data obtained at
298.15 K.