- Email: [email protected]
Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions
G Model
JIEC 3266 1–6 Journal of Industrial and Engineering Chemistry xxx (2016) xxx–xxx
Contents lists available at ScienceDirect
Journal of Industrial and Engineering Chemistry journal homepage: www.elsevier.com/locate/jiec
1 2
3 Q1 4 Q2 5
Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions Pradeep Kumara , Manish Varyanib , Praveen K. Khatrib , Subham Paula,** , Suman L. Jainb,* a b
Refinery Technology Division, CSIR-Indian Institute of Petroleum, Dehradun, 248005, India Chemical Sciences Division, CSIR-Indian Institute of Petroleum, Dehradun, 248005, India
A R T I C L E I N F O
Article history: Received 26 August 2016 Received in revised form 5 December 2016 Accepted 17 January 2017 Available online xxx Keywords: Ionic liquid CO2 capture and utilization Cyclic carbonate Amino acid ionic liquid Green chemistry
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
A B S T R A C T
The present work describes a simple, highly efficient and cost effective approach for efficient capturing of CO2 and its conversion into high value product by using amino acid derived task specific ionic liquids (AAIL). Among the three different kinds of amino acid (histidine, aspartic acid and glutamic acid) derived ionic liquids studied, histidine derived amino acid ionic liquid was found to be an efficient capturing medium for CO2 and its conversion to corresponding cyclic carbonates by reaction with epoxides under ambient reaction conditions at atmospheric pressure using dimethylcarbonate as reaction medium. The salient features of the developed methodology are the use of biocompatible amino acid derived ionic liquid, efficient capturing and conversion of carbon dioxide, metal free system, excellent product yields and atmospheric pressure condition. © 2017 Published by Elsevier B.V. on behalf of The Korean Society of Industrial and Engineering Chemistry.
Introduction Development of efficient approaches for capturing CO2 to minimize its accumulation into the atmosphere as well as to convert it into high value chemicals is an area of current research interest from both the environmental and economical point of views. Among the different capturing techniques developed for the removal of CO2 gas, solvent absorption using amine-based solvents has been widely studied and utilized for various technologies and processes [1,2]. However, these absorbents suffer from certain drawbacks such as equipment corrosion and high energy consumption which further make the process tedious and costly. Recently, ionic liquids (ILs) owing to their several fascinating properties such as higher thermal stability, exceptionally lower vapour pressure, inflammability and tunable physico-chemical properties have been established to be promising candidates for absorption of CO2 [3–9]. Hence ILs has extensively studied and a large number of reports have been published on the use of ILs as absorbents for the removal of CO2. So far a maximum CO2 absorption capacity of 0.75 in mol fraction of CO2 has been found for [C8MIm][PF6] at 40 C under high pressure (93 bar) [10].
* Corresponding author. Fax: +91 135 2660202. ** Corresponding author. Fax: +91 135 2660202. E-mail addresses: [email protected] (S. Paul), [email protected] (S.L. Jain).
However, the relatively week physisorption between CO2 and IL makes this process of limited applicability. Consequently, task specific ILs that can chemically bind CO2 to functionalized imidazolium-based ILs at ambient conditions or near ambient conditions have been utilized for CO2 absorption [11–15]. Recently Liu et al. reported the urea derivative based bi-functional ionic Q3 liquids containing imidazole moiety for CO2 capture and conversion [16]. Despite of these advancements, so far the captured CO2 is being deposited in underground reservoirs, which further makes the process cost ineffective. Hence, the ultimate goal should be to develop efficient, cost effective and biocompatible methodology for capturing the CO2 and possibly instead of storing the captured CO2 (which is cost inefficient), it would be better to convert it into value added products. Among the various known processes for CO2 conversion, formation of cyclic carbonates from the coupling of CO2 and epoxides has widely been studied due to their wide spread applications in the pharmaceutical and fine chemical industries [17–21]. Although the formation of cyclic carbonate via homogeneous as well as heterogeneous metal based and metal free catalysts has been well documented in the literature [22–38], in most of the cases the process requires either high temperature and pressure or a co-catalyst such as TBAB. Recently Liu et al. established the cycloaddition of CO2 with epoxides to give cyclic Q4 carbonates using hydroxyl/carboxyl task specific ionic liquids via hydrogen bond activation [39]. To the best of our knowledge there is only one report known which describes the capturing of Q5
http://dx.doi.org/10.1016/j.jiec.2017.01.022 1226-086X/© 2017 Published by Elsevier B.V. on behalf of The Korean Society of Industrial and Engineering Chemistry.
Please cite this article in press as: P. Kumar, et al., Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions, J. Ind. Eng. Chem. (2017), http://dx.doi.org/10.1016/j.jiec.2017.01.022
26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51
G Model
JIEC 3266 1–6 2 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70
P. Kumar et al. / Journal of Industrial and Engineering Chemistry xxx (2016) xxx–xxx
CO2 and its conversion to cyclic carbonates using metal functionalized conjugated microporous polymers as heterogeneous catalyst. However this method suffers from certain drawbacks such as the use of bimetallic Co/Al-salen based catalyst which involves multi-step tedious synthesis and need of co-catalyst (TBAB) during the reaction [40]. Thus, the development of a metal free, easily accessible and reusable capturing medium/catalyst for synthesizing cyclic carbonate under mild conditions such as at atmospheric pressure remains a challenge. Herein, we report a simple, highly efficient and cost effective approach for efficient capturing of CO2 with three different kinds of amino acid (histidine, aspartic acid and glutamic acid) derived ionic liquids (Fig. 1, IL 1–3) and its conversion to cyclic carbonates using histidine amino acid derived ionic liquid at atmospheric pressure using dimethylcarbonate (DMC) as solvent (Scheme 1). Q6 The developed methodology offers several advantages such as use of biocompatible amino acid as precursor for ionic liquid, metal free system, mild reaction conditions such as 1 atm and high product yields.
71
Experimental section
72
Material
73
79
CO2 (99.5% purity) and nitrogen (N2, 99.9% purity) were obtained from Gupta gases, Dehradun, India. Methanol, acetonitrile (99% purity) and sodium hydroxide (99% purity) were obtained from Merck, India. L-Histidine, L-aspartic acid and L-glutamic acid were purchased from Sigma Aldrich, USA and used without further purification. Tetrabutylammonium hydroxide (40% in water) was procured from Alfa Aesar and used as received.
80
Synthesis and characterization of ionic liquids (ILs)
74 75 76 77 78
81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
O N CO2 + O
HN
NH2 [N4444][His] IL 1
Bu Bu N Bu Bu
O
Temp.=80 oC
R
1 atm
Table 1 Elemental analysis data of synthesized ionic liquids. Ionic liquid
C
H
N
IL1 IL2 IL3
64.65 (63.64) 60.28 (64.07) 64.03 (64.85)
11.52 (11.09) 11.10 (11.21) 11.17 (11.32)
13.79 (13.15) 7.48 (7.47) 7.24 (7.21)
*Values in brackets are calculated.
O O
HO
O
DMC (3 ml)
Scheme 1. Conversion of epoxides to cyclic carbonates.
Fourier Transform Infrared (FTIR) Spectra were recorded on Perkin–Elmer spectrum RX-1 IR spectrophotometer using
O
O
IL 1
R=Aromatic, aliphatic alicyclic
Techniques used
O
Bu N Bu Bu
NH2
HN
R
Syntheses of ionic liquids were carried out by following the method published elsewhere [41]. In brief, an aqueous solution of tetrabutylammonium hydroxide (40 wt% solution in water) was added drop-wise to an amount of amino acid aqueous solution that was slightly in excess of equimolar. The reaction mixture was kept on stirring at room temperature for 12 h with the help of a magnetic bar. At the end of the reaction, water was removed under reduced pressure by rotary evaporation at 55 C. Further, to this Q7 concentrate were added 90 ml of CH CN and 10 ml of CH OH, and 3 3 the resulting mixture was stirred vigorously. Precipitated excess amino acid was filtered off and filtrate was concentrated to allow it to become pale yellow viscous liquid. The product was dried in vacuum for 2 days at 80 C. The synthesized ionic liquids were characterized by elemental analysis, FTIR and 1H NMR analysis. The characterization data of the synthesized ILs are given in the following Tables 1 and 2.
N
Bu
O
NH2 O
potassium bromide window. 1H and 13C NMR spectra of the AAIL’s were recorded using Bruker Advance-II 500 MHz instrument using DMSO-d6 solvent. Thermal stability of samples was evaluated by thermo gravimetric analyses (TGA) using a thermal analyser TA-SDT Q-600. Analysis was carried out in the temperature range of 40–800 C under nitrogen flow with heating rate of 10 C/min.
100
CO2 capture experiments
107
The experiments were carried out at batch absorption cell containing solvents with continuous flow of synthetic gas mixtures. The schematic of the gas absorption set-up is shown in Fig. 2. The jacketed reactor cell consists of a gas distributor at the bottom with a mesh size of 4 micron. Temperature in the cell was maintained by flowing thermostated water by refrigerated-heating circulator (Julabo) through the jacket. All the absorption experiments were carried out at 313 K temperature. The gas was introduced at the bottom of the reaction chamber and it flew upwards through the reaction chamber thereby allowing absorption of carbon dioxide in the solvent. The total flow rate of gas was usually in the range 1.20 105 3 1 m s . The partial pressure of carbon dioxide was typically between 0.05 and 0.15 atmosphere. Unlike many other studies carried out in this area which mainly concentrated to examine the absorption capacity with pure CO2 [42,43], this study was carried out to investigate the capacity of the ionic liquids to absorb CO2 with concentration typical in the range of flue gas composition. Desired gas mixtures were prepared by flowing gasses through mass flow controllers (Brooks 5850) and CO2 concentration in the feed and off gas mixtures were measured using non-dispersive infrared (NDIR) CO2 probes (VAISALA CARBOCAP GMT 221).
108
Bu Bu N Bu Bu
NH2 O
[N4444][Asp] IL 2
OH O
O
Bu Bu N Bu Bu
[N4444][Glu] IL 3
Fig. 1. Structure of synthesized ionic liquids.
Please cite this article in press as: P. Kumar, et al., Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions, J. Ind. Eng. Chem. (2017), http://dx.doi.org/10.1016/j.jiec.2017.01.022
101 102 103 104 105 106
109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130
G Model
JIEC 3266 1–6 P. Kumar et al. / Journal of Industrial and Engineering Chemistry xxx (2016) xxx–xxx
3
Table 2 Characterization data of synthesized ionic liquids. Ionic liquid
Yield (%)
1
H NMR (CDCl3, ppm)
13 C NMR (CDCl3, ppm)
FT-IR (cm1)
IL1
98.2
13.69 (CH3), 19.62 (CH3CH2), 23.52 (CH3CH2CH2), 39.20 (COCH2CO), 57.91 (CH2N), 116.3, 132.96, 177.88 (C¼O)
3371 (NH stretch), 2966, 2862 (CH2 stretch), 1715 (C¼O stretch), 1585 (C¼C and C¼N stret), 1474 (CH2 bending)
IL2
96.8
IL3
97
0.85–0.91 (m, 12H, CH3), 1.41–1.46 (m, CH3CH2), 1.57–1.61 (m, CH3CH2CH2), 2.35–2.40 (m, CH3CH2CH2CH2), 2.54 (d, CH2COO), 3.2 (t, CHCH2COO), 4.1–4.7 (broad s, NH, OH), 6.8 (s, 1H, Ar–CH), 7.5 (s, 1H, Ar–CH) 0.94 (t, CH3), 1.35 (sex, CH3CH2), 1.60 (quin, CH3CH2CH2), 2.38 (t, CH3CH2CH2CH2), 2.54 (d, CH2COO), 3.16 (t, CHCH2COO), 3.77 (m, CHNH2) 0.98 (t, CH3), 1.40 (m, CH3CH2), 1.65 (quin, CH3CH2CH2), 2.05 (q, CHCH2CH2COO), 2.40 (t, CH3CH2CH2CH2), 2.49 (t, CHCH2CH2COO), 3.25 (t, CHCH2CH2COO), 3.54 (m, CHNH2)
13.68 (CH3), 19.78 (CH3CH2), 24.48, 35.28 (CH2C¼O) (CH3CH2CH2), 56.69 (CH2N), 173.88 (C¼O) 13.65 (CH3), 19.80 (CH3CH2), 24.54, 35.31 (CH2C¼O) (CH3CH2CH2), 57.69 (CH2N), 173.56 (C¼O)
2966, 2862 (CH2 stretch), 1702 (C¼O stretch), 1590 (C¼C and C¼N stretch), 1470 (CH2 bending) 2960, 2850 (CH2 stretch), 1705 (C¼O stretch), 1588 (C¼C and C¼N stret), 1472 (CH2 bending)
Fig. 2. Schematic of gas absorption set-up.
131 132 133 134 135 136 137 138 139 140 141 Q8 142 143 144 145 146
When the absorption achieved equilibrium, the loaded solvent was collected from the bottom of the absorption cell and the CO2 loading in the liquid was estimated by titration using methanolic NaOH (UOP method 829-82).
was purified by column chromatography over silica gel using ethyl acetate: hexane (2:3) as eluent to afford the pure cyclic carbonate.
147
Results and discussion
149
Typical procedure for synthesis of cyclic carbonate from epoxide and CO2
Synthesis and characterization of IL
150
Ionic liquids were synthesized from the reaction of equimolar amounts of corresponding amino acid and tetrabutylammonium hydroxide in water at ambient temperature. After the reaction, the solvent was evaporated under reduced pressure and the ionic liquid so obtained was dried under vacuum. The successful synthesis of ionic liquids (IL 1–3) was confirmed by elemental analysis, FTIR and 1H NMR spectral analyses as described in the experimental section. Thermal stability of the synthesized ILs was determined by thermogravimetric analysis (Fig. 3). All the synthesized ILs 1–3 were found to be thermally stable upto 180 C and afterwards a sharp decomposition was observed in the
151
In a typical reaction, epoxide (10 mmol), IL1 (5 mol%), dimethyl carbonate (DMC; 3 ml) were placed in a Schlenk flask covered with a rubber cap and equipped with a stirring bar. Further, the resulting mixture was charged with CO2 with the help of a balloon. The reaction was carried out at 80 C for 5 h under stirring and continuous supply of CO2 at 1 atm. After completion of the reaction, the reaction mixture was extracted with diethyl ether to isolate the crude product. The recovered DMC layer contacting IL was recycled for subsequent runs. The diethyl ether layer was concentrated under reduced pressure. The concentrate so obtained
Please cite this article in press as: P. Kumar, et al., Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions, J. Ind. Eng. Chem. (2017), http://dx.doi.org/10.1016/j.jiec.2017.01.022
148
152 153 154 155 156 157 158 159 160 161
G Model
JIEC 3266 1–6 4
P. Kumar et al. / Journal of Industrial and Engineering Chemistry xxx (2016) xxx–xxx
Fig. 3. TGA curves of synthesized ionic liquids. 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185
temperature range of 180–250 C as shown in Fig. 3. Specifically ionic liquids synthesized from histidine IL 1 and aspartic IL 2 amino acids exhibited higher stability in comparison to IL derived from glutamic acid IL 3. CO2 capture studies using ILs 1–3 Absorption of CO2 was carried out in 5 wt% aqueous solutions of three different amino acid ionic liquids e.g., [N4444][His] IL1 derived from histidine, [N4444][Asp] IL2 derived from aspartic acid, [N4444][Glu] IL3 derived from glutamic acid i.e. 50 ml of aqueous solution containing 2.5 g of ionic liquid in absorption cell was examined for CO2 capture. The intension was to screen those ionic liquids for CO2 absorption capacity and the best among them would be selected as catalyst for further investigation related to CO2 conversion. The solvents were screened based on two criteria, e.g., absorption capacity of the solvent in terms of CO2 loading and rate of absorption of CO2 in the solvent. Fig. 4 shows the absorption of CO2 in three different ionic liquid solvents with respect to time and thus facilitates screening of solvents based on rate of absorption. Fig. 5 shows the absorption of CO2 at different partial pressures of CO2 which actually describes the capacity of the various solvents. Based on the study depicted in Figs. 4 and 5, [N4444][His] was found to be best among all the investigated ILs during this study.
Fig. 5. CO2 absorption in solvents at different partial pressures.
Catalytic activity
186
As stated above, among all the three ILs 1–3, histidine derived IL1 was found to be best CO2 capturing agent; therefore it has been used as recyclable catalyst for conversion of epoxides to cyclic carbonates (Scheme 1). At first, a series of experiments were performed by varying the reaction conditions, including solvent, reaction temperature, reaction time, and the catalyst amount to optimize the yield of the cyclic carbonate (Table 3). The coupling of styrene oxide with carbon dioxide to afford styrene carbonate was selected as a representative reaction. The reaction was found to be very slow in the absence of any solvent and afforded poor yield of the product (Table 3, entry 1). Among a number of organic solvents such as acetonitrile, DMF, toluene and dimethylcarbonate (DMC) studied; DMC was found to be optimum and afforded almost quantitative conversion of the styrene carbonate selectively without any evidence for the formation of any by-product
187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202
Table 3 Results of the optimization experiments for the synthesis of styrene carbonate.a
O
O
CO2 IL (5 mol%)
O O
1 atm Solvent Time (h)
Fig. 4. CO2 absorption in ILs vs time.
Entry
Solvent
Temperature ( C)
Time (h)
Yield (%)b
1 2 3 4 5 6 7 8
None CH3CN Toluene DMF DMC DMC DMC DMC
90 80 90 90 90 25, 80 70 80
58 76 68 96, 74,c 68d 98.2 –, 98 92 55, 90, 98
9e 10f
DMC DMC
80 80
10 8 10 6 4.5 5 5 2, 4, 4.5 5 5
81 98.5
a Reaction condition: styrene oxide (10 mmol), IL 1 (5 mol%), DMC (3 ml) and CO2 under 1 atm. b Isolated yields. c using IL 2 as catalyst. d using IL 3 as catalyst. e 2 mol%. f 15 mol% catalyst IL 1.
Please cite this article in press as: P. Kumar, et al., Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions, J. Ind. Eng. Chem. (2017), http://dx.doi.org/10.1016/j.jiec.2017.01.022
Q12
G Model
JIEC 3266 1–6 P. Kumar et al. / Journal of Industrial and Engineering Chemistry xxx (2016) xxx–xxx 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248
(Table 3, entries 5–6). Similarly the reaction was found to be slow in acetonitrile and toluene and afforded poor product yield (Table 3, entries 2–3). Although DMF as solvent showed almost equal activity compared to DMC at atmospheric pressure (Table 3, entries 4–5), however, DMC is greener and environment friendly than DMF, thus, we choose DMC as the optimized solvent for this transformation. As suggested in a recent literature report that DMF being a Lewis base can activate CO2 species to facilitate the coupling reaction [44]. However in the suggested reference [44] the reaction has been carried out under extreme reaction conditions i.e. 150 C temperature and 3 MPa pressure. In order to evaluate the catalyzing/activating effect of DMF, we performed the coupling reaction of styrene oxide with CO2 in all three ILs (IL 1–3) using DMF as solvent under identical conditions (Table 3, entry 4). Among the three ILs studied histidine derived IL 1 was found to be most efficient and afforded best results. Thus we believe that DMF is not playing much significant role in the present investigation. If DMF had activation/catalyzing effect then we could get almost similar activity in three ILs. We assume that the structure of ILs is providing significant role. Among the three ILs, histidine derived IL (IL 1) contains imidazole ring which is already well known in literature to provide higher solubility/activation to absorbed CO2 for better conversion and absorption [13–16]. Thus, we believe that due to the presence of imidazole ring, ILs revealed better CO2 absorption/solubility and strong activation by combining with CO2 for coupling reaction. This is the reason due to that histidine containing ionic liquid showed excellent catalytic activity than other two ILs at ambient pressure conditions. Next, the effects of the reaction temperature, time and catalyst amount on the product yield were examined (Table 3, entries 6–10). The reaction did not proceed at room temperature whereas 80 C was found to be optimum for the reaction (Table 3, entries 6–7). Further increase in temperature did not provide any improvement in the results (Table 3, entry 5). Next, we performed the reaction at 80 C for different reaction times i.e. 2, 4 and 4.5 h under described reaction conditions (Table 3, entry 8). As shown in results, the reaction was found to be increased with time and at 4.5 h maximum conversion and product yield was obtained. Thus, we conclude that among the various reaction temperatures and time, the best result in terms of yield (98%) was obtained by carrying out the reaction at 80 C for 4.5 h using 5 mol% of catalyst at atmospheric pressure. However, by using the catalyst amount less than 5 mol%, the reaction was found to be less efficient and afforded lower yield (81%) of the product (Table 3, entry 9). However, by using more amount of catalyst 15 mol%, no significant enhancement in the product yield was obtained (Table 3, entry 10).
5
Next, we studied the recyclability of the developed catalyst in DMC solvent. After completion of the reaction, the reaction mixture was extracted with diethyl ether to isolate the crude product, which was subjected to usual workup to obtain the pure product. The recovered DMC containing IL was reused as such for subsequent experiments for six runs (Fig. 6). Interestingly, in all cases the conversion of the styrene oxide to cyclic carbonate with similar selectivity and reaction times, established the efficient recovery and recycling of the developed system. Next, we extended the scope of the reaction with a variety of epoxides under the above optimized reaction conditions. The results of these experiments are summarized in Table 4. All the epoxides either containing electron donating groups (entries 2–6) or electron withdrawing group (entry 7) could be transformed to the corresponding cyclic carbonates with almost quantitative yields (91–98%) within 4–6 h under 1 atm CO2 pressure at 80 C. We have also carried out the reaction of styrene oxide with CO2 in the absence of IL 1 as the catalyst under otherwise identical reaction conditions. No product was detected in the absence of IL catalyst as shown in Table 4, entry 1.
Table 4 IL 1 catalyzed cycloaddition of various epoxides with CO2.a Entry
Epoxide
1
Product
O
O
2
O
O
O
Yield (%)b
5.0 10c
98
5.0
97
5.5
95
5.5
94
5.5
92
4.5
98
6.0
94
6.0
91
O
3
O
O
O MeO
O
O O
MeO
4
O
5
O
O O
O
O
O Cl
8
O
O O
Cl
O O
O
7
O
O
O
6
O
O
O
O O
Fig. 6. Recycling of the IL1 in DMC for the synthesis of styrene carbonate.
O
O
Reaction time (h)
O
a Reaction conditions: substrate (10 mmol), IL 1 (5 mol%), DMC (3 ml) at 80 C under atmospheric pressure. b Isolated yields. c In the absence of IL catalyst in DMC solvent.
Please cite this article in press as: P. Kumar, et al., Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions, J. Ind. Eng. Chem. (2017), http://dx.doi.org/10.1016/j.jiec.2017.01.022
249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268
G Model
JIEC 3266 1–6 6 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287
P. Kumar et al. / Journal of Industrial and Engineering Chemistry xxx (2016) xxx–xxx
Conclusion We have developed an efficient but simple methodology for effective capturing and simultaneous conversion of captured CO2 to high value cyclic carbonates under very mild reaction conditions such as ordinary pressure and in the presence of a green solvent. Three amino acid derived ILs such as histidine, aspartic and glutamic acid derived ILs were synthesized and first tested for capturing of CO2. Among all the synthesized ILs histidine derived IL1 showed maximum capture efficiency and therefore used as reusable catalyst for chemical fixation of carbon dioxide in the form of cyclic carbonates by reacting with epoxides at atmospheric pressure. The notable advantages offered by this protocol are the efficient capturing of CO2 using biocompatible amino acid based Q9 ILs, use of green solvent like DMC, mild reaction conditions such as 1 atm, high selectivity, recyclability of the catalyst and high yield of products, which could make this procedure green and cost effective for the capturing and simultaneous fixation of CO2 to high value chemicals. Acknowledgements
288
Authors are thankful to Director, CSIR-IIP for his kind permission to publish these results. Analytical division of the 290 Institute is acknowledged for providing support in analysis of 291 the samples. Authors also thankfully acknowledge the financial 292 Q10 support of SERB, DST Govt. of India, through file No. SB/FTP/ETA293 0253/2013 for carrying out a part of experimental work. 289
294
295 296
References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
D.M. D’Alessandro, B. Smit, J.R. Long, Angew. Chem. Int. Ed. 49 (2010) 6058. D.M. D’Alessandro, B. Smit, J.R. Long, Angew. Chem. Int. Ed. 122 (2010) 6194. J.F. Brennecke, B.E. Gurkan, J. Phys. Chem. Lett. 1 (2010) 3459. Y. Zhang, S. Zhang, X. Lu, Q. Zhou, W. Fan, X.P. Zhang, Chem. Eur. J.15 (2009) 3003. P. Wasserscheid, W. Keim, Angew. Chem. Int. Ed. 112 (2000) 3926. P. Wasserscheid, W. Keim, Angew. Chem. Int. Ed. 39 (2000) 3773. J.L. Anderson, J.K. Dixon, J.F. Brennecke, Acc. Chem. Res. 40 (2007) 1208. J.F. Brennecke, B.E. Gurkan, J. Phys. Chem. Lett. 1 (24) (2010) 3459. M. Ramdin, T.W. de Loos, T.J.H. Vlugt, Ind. Eng. Chem. Res. 51 (2012) 8149. M.J. Muldoon, S. Aki, J.L. Anderson, J.K. Dixon, J.F. Brennecke, J. Phys. Chem. B 111 (2007) 9001. [11] S.N.V.K. Aki, B.R. Mellein, E.M. Saurer, J.F. Brennecke, J. Phys. Chem. B 108 (2004) 20355.
[12] M.B. Shiflett, D.J. Kasprazak, C.P. Junk, A.K. Yokozeki, J. Chem. Thermodyn. 40 (2008) 25. [13] M.S. Shannon, J.E. Bara, Ind. Eng. Chem. Res. 50 (2011) 8665. [14] A.S. Aquino, F.L. Bernard, M.O. Vieira, J.V. Borges, M.F. Rojas, F.D. Vecchia, R.A. Ligabue, M. Seferin, S. Menezes, S. Einloft, J. Braz. Chem. Soc. 25 (2014) 2251. [15] M.C. Corvo, J. Sardinha, T. Casimiro, G. Marin, M. Seferin, S. Einloft, S.C. Menezes, J. Dupont, E.J. Cabrita, ChemSusChem 8 (2015) 1935. [16] Mengshuai Liu, Lin Liang, Xin Li, Xiangxiang Gao, Jianmin Sun, Green Chem. 18 (2016) 2851. [17] E.D. Bates, R.D. Mayton, I. Ntai, J.H. Davis Jr., J. Am. Chem. Soc. 124 (2002) 926. [18] E. Torralba-Calleja, J. Skinner, D. Gutiérrez-Tauste, J. Chem. 2013 (2013) 16 Article ID 473584. [19] Z.F. Zhang, Y. Xie, W.J. Li, S.Q. Hu, J.L. Song, T. Jiang, B.X. Han, Angew. Chem. Int. Ed. 120 (2008) 1143. [20] Z.F. Zhang, Y. Xie, W.J. Li, S.Q. Hu, J.L. Song, T. Jiang, B.X. Han, Angew. Chem. Int. Ed. 47 (2008) 1127. [21] S.H. Kim, S.H. Hong, ACS Catal. 4 (2014) 3630. [22] V. Laserna, G. Fiorani, C.J. Whiteoak, E. Martin, E. Escudero-Adan, A.W. Kleij, Angew. Chem. Int. Ed. 53 (2014) 10416. [23] S.-S. Zhang, J.Q. Wu, Y.-X. Lao, X.-G. Liu, Y. Liu, W.-X. Lv, D.-H. Tan, Y.-F. Zeng, H. Wang, Org. Lett. 16 (2014) 6412. [24] A.W. Kleij, C.J. Whiteoak, ChemCatChem 7 (2015) 51. [25] Q. Chen, K. Gao, C. Peng, H. Xie, Z.K. Zhao, M. Bao, Green Chem. 17 (2015) 4546. [26] X.-D. Lang, L.-N. He, Chem. Rec. (2016), doi:http://dx.doi.org/10.1002/ tcr.201500293. [27] W.L. Dai, S.F. Yin, R. Guo, S.L. Luo, X. Du, C.T. Au, Catal. Lett. 136 (2010) 35. [28] H. Zhou, Y.M. Wang, W.Z. Zhang, J.P. Qu, X.B. Lu, Green Chem. 13 (2011) 644. [29] W.G. Cheng, X. Chen, J. Sun, J.Q. Wang, S.J. Zhang, Catal. Today 200 (2013) 117. [30] J.A. Kozak, J. Wu, X. Su, F. Simeon, T.A. Hatton, T.F. Jamison, J. Am. Chem. Soc. 135 (2013) 18497. [31] B. Zou, L. Hao, L.-Y. Fan, Z.-M. Gao, S.-L. Chen, H. Li, C.-W. Hu, J. Catal. 329 (2015) 119. [32] Y.A. Rulev, Z. Gugkaeva, V.I. Maleev, M. North, Y.N. Belokon, Beilstein J. Org. Chem. 11 (2015) 1614. [33] Q. He, J.W. O’Brien, K.A. Kitselman, L.E. Tompkins, G.C.T. Curtis, F.M. Kerton, Catal. Sci. Technol. 4 (2014) 1513. [34] C. Martín, G. Fiorani, A.W. Kleij, ACS Catal. 5 (2015) 1353. [35] J.W. Comerford, I.D.V. Ingram, M. North, X. Wu, Green Chem. 17 (2015) 1966. [36] A. Monassier, V. D’Elia, M. Cokoja, H.L. Dong, J.D.A. Pelletier, J.M. Basset, F.E. Kühn, ChemCatChem 5 (2013) 1321. ski, Y. Belmabkhout, A.J. Cairns, V. D’Elia, Ł. Wojtas, K. [37] V. Guillerm, Ł.J. Weselin Adil, M. Eddaoudi, Nat. Chem. 6 (2014) 673. [38] A. Barthel, Y. Saih, M. Gimenez, J.D.A. Pelletier, F.E. Kühn, V. D’Elia, J.-M. Basset, Green Chem. 18 (2016) 3116. [39] Mengshuai Liu, Kunqi Gao, Lin Liang, Fangxiao Wang, Lei Shi, Li Sheng, Jianmin Sun, Phys. Chem. Chem. Phys. 17 (2015) 5959. [40] Y. Xie, T.-T. Wang, X.-H. Liu, K. Zou, W.-Q. Deng, Nat. Comm. 4 (2013) 1960. [41] P.K. Khatri, G.D. Thakre, S.L. Jain, Ind. Eng. Chem. Res. 52 (2013) 15829. [42] B.E. Gurkan, J.C. de la Fuente, E.M. Mindrup, L.E. Ficke, B.F. Goodrich, E.A. Price, W.F. Schneider, J.F. Brennecke, J. Am. Chem. Soc. 132 (2010) 2116. [43] S. Sunmugavel, A.J. Kunov-Kruse, R. Fehrmann, A. Riisager, ChemSusChem 7 (2014) 897. [44] S. Zhong, L. Liang, B. Liu, J. Sun, J. CO2 Util. 6 (2014) 75.
Please cite this article in press as: P. Kumar, et al., Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions, J. Ind. Eng. Chem. (2017), http://dx.doi.org/10.1016/j.jiec.2017.01.022
297
298 299 300
301 302 303
304 305
Q11 306
307 308 309 310
311 312 313 314
315 316
JIEC 3266 1–6 Journal of Industrial and Engineering Chemistry xxx (2016) xxx–xxx
Contents lists available at ScienceDirect
Journal of Industrial and Engineering Chemistry journal homepage: www.elsevier.com/locate/jiec
1 2
3 Q1 4 Q2 5
Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions Pradeep Kumara , Manish Varyanib , Praveen K. Khatrib , Subham Paula,** , Suman L. Jainb,* a b
Refinery Technology Division, CSIR-Indian Institute of Petroleum, Dehradun, 248005, India Chemical Sciences Division, CSIR-Indian Institute of Petroleum, Dehradun, 248005, India
A R T I C L E I N F O
Article history: Received 26 August 2016 Received in revised form 5 December 2016 Accepted 17 January 2017 Available online xxx Keywords: Ionic liquid CO2 capture and utilization Cyclic carbonate Amino acid ionic liquid Green chemistry
6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
A B S T R A C T
The present work describes a simple, highly efficient and cost effective approach for efficient capturing of CO2 and its conversion into high value product by using amino acid derived task specific ionic liquids (AAIL). Among the three different kinds of amino acid (histidine, aspartic acid and glutamic acid) derived ionic liquids studied, histidine derived amino acid ionic liquid was found to be an efficient capturing medium for CO2 and its conversion to corresponding cyclic carbonates by reaction with epoxides under ambient reaction conditions at atmospheric pressure using dimethylcarbonate as reaction medium. The salient features of the developed methodology are the use of biocompatible amino acid derived ionic liquid, efficient capturing and conversion of carbon dioxide, metal free system, excellent product yields and atmospheric pressure condition. © 2017 Published by Elsevier B.V. on behalf of The Korean Society of Industrial and Engineering Chemistry.
Introduction Development of efficient approaches for capturing CO2 to minimize its accumulation into the atmosphere as well as to convert it into high value chemicals is an area of current research interest from both the environmental and economical point of views. Among the different capturing techniques developed for the removal of CO2 gas, solvent absorption using amine-based solvents has been widely studied and utilized for various technologies and processes [1,2]. However, these absorbents suffer from certain drawbacks such as equipment corrosion and high energy consumption which further make the process tedious and costly. Recently, ionic liquids (ILs) owing to their several fascinating properties such as higher thermal stability, exceptionally lower vapour pressure, inflammability and tunable physico-chemical properties have been established to be promising candidates for absorption of CO2 [3–9]. Hence ILs has extensively studied and a large number of reports have been published on the use of ILs as absorbents for the removal of CO2. So far a maximum CO2 absorption capacity of 0.75 in mol fraction of CO2 has been found for [C8MIm][PF6] at 40 C under high pressure (93 bar) [10].
* Corresponding author. Fax: +91 135 2660202. ** Corresponding author. Fax: +91 135 2660202. E-mail addresses: [email protected] (S. Paul), [email protected] (S.L. Jain).
However, the relatively week physisorption between CO2 and IL makes this process of limited applicability. Consequently, task specific ILs that can chemically bind CO2 to functionalized imidazolium-based ILs at ambient conditions or near ambient conditions have been utilized for CO2 absorption [11–15]. Recently Liu et al. reported the urea derivative based bi-functional ionic Q3 liquids containing imidazole moiety for CO2 capture and conversion [16]. Despite of these advancements, so far the captured CO2 is being deposited in underground reservoirs, which further makes the process cost ineffective. Hence, the ultimate goal should be to develop efficient, cost effective and biocompatible methodology for capturing the CO2 and possibly instead of storing the captured CO2 (which is cost inefficient), it would be better to convert it into value added products. Among the various known processes for CO2 conversion, formation of cyclic carbonates from the coupling of CO2 and epoxides has widely been studied due to their wide spread applications in the pharmaceutical and fine chemical industries [17–21]. Although the formation of cyclic carbonate via homogeneous as well as heterogeneous metal based and metal free catalysts has been well documented in the literature [22–38], in most of the cases the process requires either high temperature and pressure or a co-catalyst such as TBAB. Recently Liu et al. established the cycloaddition of CO2 with epoxides to give cyclic Q4 carbonates using hydroxyl/carboxyl task specific ionic liquids via hydrogen bond activation [39]. To the best of our knowledge there is only one report known which describes the capturing of Q5
http://dx.doi.org/10.1016/j.jiec.2017.01.022 1226-086X/© 2017 Published by Elsevier B.V. on behalf of The Korean Society of Industrial and Engineering Chemistry.
Please cite this article in press as: P. Kumar, et al., Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions, J. Ind. Eng. Chem. (2017), http://dx.doi.org/10.1016/j.jiec.2017.01.022
26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51
G Model
JIEC 3266 1–6 2 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70
P. Kumar et al. / Journal of Industrial and Engineering Chemistry xxx (2016) xxx–xxx
CO2 and its conversion to cyclic carbonates using metal functionalized conjugated microporous polymers as heterogeneous catalyst. However this method suffers from certain drawbacks such as the use of bimetallic Co/Al-salen based catalyst which involves multi-step tedious synthesis and need of co-catalyst (TBAB) during the reaction [40]. Thus, the development of a metal free, easily accessible and reusable capturing medium/catalyst for synthesizing cyclic carbonate under mild conditions such as at atmospheric pressure remains a challenge. Herein, we report a simple, highly efficient and cost effective approach for efficient capturing of CO2 with three different kinds of amino acid (histidine, aspartic acid and glutamic acid) derived ionic liquids (Fig. 1, IL 1–3) and its conversion to cyclic carbonates using histidine amino acid derived ionic liquid at atmospheric pressure using dimethylcarbonate (DMC) as solvent (Scheme 1). Q6 The developed methodology offers several advantages such as use of biocompatible amino acid as precursor for ionic liquid, metal free system, mild reaction conditions such as 1 atm and high product yields.
71
Experimental section
72
Material
73
79
CO2 (99.5% purity) and nitrogen (N2, 99.9% purity) were obtained from Gupta gases, Dehradun, India. Methanol, acetonitrile (99% purity) and sodium hydroxide (99% purity) were obtained from Merck, India. L-Histidine, L-aspartic acid and L-glutamic acid were purchased from Sigma Aldrich, USA and used without further purification. Tetrabutylammonium hydroxide (40% in water) was procured from Alfa Aesar and used as received.
80
Synthesis and characterization of ionic liquids (ILs)
74 75 76 77 78
81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
O N CO2 + O
HN
NH2 [N4444][His] IL 1
Bu Bu N Bu Bu
O
Temp.=80 oC
R
1 atm
Table 1 Elemental analysis data of synthesized ionic liquids. Ionic liquid
C
H
N
IL1 IL2 IL3
64.65 (63.64) 60.28 (64.07) 64.03 (64.85)
11.52 (11.09) 11.10 (11.21) 11.17 (11.32)
13.79 (13.15) 7.48 (7.47) 7.24 (7.21)
*Values in brackets are calculated.
O O
HO
O
DMC (3 ml)
Scheme 1. Conversion of epoxides to cyclic carbonates.
Fourier Transform Infrared (FTIR) Spectra were recorded on Perkin–Elmer spectrum RX-1 IR spectrophotometer using
O
O
IL 1
R=Aromatic, aliphatic alicyclic
Techniques used
O
Bu N Bu Bu
NH2
HN
R
Syntheses of ionic liquids were carried out by following the method published elsewhere [41]. In brief, an aqueous solution of tetrabutylammonium hydroxide (40 wt% solution in water) was added drop-wise to an amount of amino acid aqueous solution that was slightly in excess of equimolar. The reaction mixture was kept on stirring at room temperature for 12 h with the help of a magnetic bar. At the end of the reaction, water was removed under reduced pressure by rotary evaporation at 55 C. Further, to this Q7 concentrate were added 90 ml of CH CN and 10 ml of CH OH, and 3 3 the resulting mixture was stirred vigorously. Precipitated excess amino acid was filtered off and filtrate was concentrated to allow it to become pale yellow viscous liquid. The product was dried in vacuum for 2 days at 80 C. The synthesized ionic liquids were characterized by elemental analysis, FTIR and 1H NMR analysis. The characterization data of the synthesized ILs are given in the following Tables 1 and 2.
N
Bu
O
NH2 O
potassium bromide window. 1H and 13C NMR spectra of the AAIL’s were recorded using Bruker Advance-II 500 MHz instrument using DMSO-d6 solvent. Thermal stability of samples was evaluated by thermo gravimetric analyses (TGA) using a thermal analyser TA-SDT Q-600. Analysis was carried out in the temperature range of 40–800 C under nitrogen flow with heating rate of 10 C/min.
100
CO2 capture experiments
107
The experiments were carried out at batch absorption cell containing solvents with continuous flow of synthetic gas mixtures. The schematic of the gas absorption set-up is shown in Fig. 2. The jacketed reactor cell consists of a gas distributor at the bottom with a mesh size of 4 micron. Temperature in the cell was maintained by flowing thermostated water by refrigerated-heating circulator (Julabo) through the jacket. All the absorption experiments were carried out at 313 K temperature. The gas was introduced at the bottom of the reaction chamber and it flew upwards through the reaction chamber thereby allowing absorption of carbon dioxide in the solvent. The total flow rate of gas was usually in the range 1.20 105 3 1 m s . The partial pressure of carbon dioxide was typically between 0.05 and 0.15 atmosphere. Unlike many other studies carried out in this area which mainly concentrated to examine the absorption capacity with pure CO2 [42,43], this study was carried out to investigate the capacity of the ionic liquids to absorb CO2 with concentration typical in the range of flue gas composition. Desired gas mixtures were prepared by flowing gasses through mass flow controllers (Brooks 5850) and CO2 concentration in the feed and off gas mixtures were measured using non-dispersive infrared (NDIR) CO2 probes (VAISALA CARBOCAP GMT 221).
108
Bu Bu N Bu Bu
NH2 O
[N4444][Asp] IL 2
OH O
O
Bu Bu N Bu Bu
[N4444][Glu] IL 3
Fig. 1. Structure of synthesized ionic liquids.
Please cite this article in press as: P. Kumar, et al., Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions, J. Ind. Eng. Chem. (2017), http://dx.doi.org/10.1016/j.jiec.2017.01.022
101 102 103 104 105 106
109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130
G Model
JIEC 3266 1–6 P. Kumar et al. / Journal of Industrial and Engineering Chemistry xxx (2016) xxx–xxx
3
Table 2 Characterization data of synthesized ionic liquids. Ionic liquid
Yield (%)
1
H NMR (CDCl3, ppm)
13 C NMR (CDCl3, ppm)
FT-IR (cm1)
IL1
98.2
13.69 (CH3), 19.62 (CH3CH2), 23.52 (CH3CH2CH2), 39.20 (COCH2CO), 57.91 (CH2N), 116.3, 132.96, 177.88 (C¼O)
3371 (NH stretch), 2966, 2862 (CH2 stretch), 1715 (C¼O stretch), 1585 (C¼C and C¼N stret), 1474 (CH2 bending)
IL2
96.8
IL3
97
0.85–0.91 (m, 12H, CH3), 1.41–1.46 (m, CH3CH2), 1.57–1.61 (m, CH3CH2CH2), 2.35–2.40 (m, CH3CH2CH2CH2), 2.54 (d, CH2COO), 3.2 (t, CHCH2COO), 4.1–4.7 (broad s, NH, OH), 6.8 (s, 1H, Ar–CH), 7.5 (s, 1H, Ar–CH) 0.94 (t, CH3), 1.35 (sex, CH3CH2), 1.60 (quin, CH3CH2CH2), 2.38 (t, CH3CH2CH2CH2), 2.54 (d, CH2COO), 3.16 (t, CHCH2COO), 3.77 (m, CHNH2) 0.98 (t, CH3), 1.40 (m, CH3CH2), 1.65 (quin, CH3CH2CH2), 2.05 (q, CHCH2CH2COO), 2.40 (t, CH3CH2CH2CH2), 2.49 (t, CHCH2CH2COO), 3.25 (t, CHCH2CH2COO), 3.54 (m, CHNH2)
13.68 (CH3), 19.78 (CH3CH2), 24.48, 35.28 (CH2C¼O) (CH3CH2CH2), 56.69 (CH2N), 173.88 (C¼O) 13.65 (CH3), 19.80 (CH3CH2), 24.54, 35.31 (CH2C¼O) (CH3CH2CH2), 57.69 (CH2N), 173.56 (C¼O)
2966, 2862 (CH2 stretch), 1702 (C¼O stretch), 1590 (C¼C and C¼N stretch), 1470 (CH2 bending) 2960, 2850 (CH2 stretch), 1705 (C¼O stretch), 1588 (C¼C and C¼N stret), 1472 (CH2 bending)
Fig. 2. Schematic of gas absorption set-up.
131 132 133 134 135 136 137 138 139 140 141 Q8 142 143 144 145 146
When the absorption achieved equilibrium, the loaded solvent was collected from the bottom of the absorption cell and the CO2 loading in the liquid was estimated by titration using methanolic NaOH (UOP method 829-82).
was purified by column chromatography over silica gel using ethyl acetate: hexane (2:3) as eluent to afford the pure cyclic carbonate.
147
Results and discussion
149
Typical procedure for synthesis of cyclic carbonate from epoxide and CO2
Synthesis and characterization of IL
150
Ionic liquids were synthesized from the reaction of equimolar amounts of corresponding amino acid and tetrabutylammonium hydroxide in water at ambient temperature. After the reaction, the solvent was evaporated under reduced pressure and the ionic liquid so obtained was dried under vacuum. The successful synthesis of ionic liquids (IL 1–3) was confirmed by elemental analysis, FTIR and 1H NMR spectral analyses as described in the experimental section. Thermal stability of the synthesized ILs was determined by thermogravimetric analysis (Fig. 3). All the synthesized ILs 1–3 were found to be thermally stable upto 180 C and afterwards a sharp decomposition was observed in the
151
In a typical reaction, epoxide (10 mmol), IL1 (5 mol%), dimethyl carbonate (DMC; 3 ml) were placed in a Schlenk flask covered with a rubber cap and equipped with a stirring bar. Further, the resulting mixture was charged with CO2 with the help of a balloon. The reaction was carried out at 80 C for 5 h under stirring and continuous supply of CO2 at 1 atm. After completion of the reaction, the reaction mixture was extracted with diethyl ether to isolate the crude product. The recovered DMC layer contacting IL was recycled for subsequent runs. The diethyl ether layer was concentrated under reduced pressure. The concentrate so obtained
Please cite this article in press as: P. Kumar, et al., Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions, J. Ind. Eng. Chem. (2017), http://dx.doi.org/10.1016/j.jiec.2017.01.022
148
152 153 154 155 156 157 158 159 160 161
G Model
JIEC 3266 1–6 4
P. Kumar et al. / Journal of Industrial and Engineering Chemistry xxx (2016) xxx–xxx
Fig. 3. TGA curves of synthesized ionic liquids. 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185
temperature range of 180–250 C as shown in Fig. 3. Specifically ionic liquids synthesized from histidine IL 1 and aspartic IL 2 amino acids exhibited higher stability in comparison to IL derived from glutamic acid IL 3. CO2 capture studies using ILs 1–3 Absorption of CO2 was carried out in 5 wt% aqueous solutions of three different amino acid ionic liquids e.g., [N4444][His] IL1 derived from histidine, [N4444][Asp] IL2 derived from aspartic acid, [N4444][Glu] IL3 derived from glutamic acid i.e. 50 ml of aqueous solution containing 2.5 g of ionic liquid in absorption cell was examined for CO2 capture. The intension was to screen those ionic liquids for CO2 absorption capacity and the best among them would be selected as catalyst for further investigation related to CO2 conversion. The solvents were screened based on two criteria, e.g., absorption capacity of the solvent in terms of CO2 loading and rate of absorption of CO2 in the solvent. Fig. 4 shows the absorption of CO2 in three different ionic liquid solvents with respect to time and thus facilitates screening of solvents based on rate of absorption. Fig. 5 shows the absorption of CO2 at different partial pressures of CO2 which actually describes the capacity of the various solvents. Based on the study depicted in Figs. 4 and 5, [N4444][His] was found to be best among all the investigated ILs during this study.
Fig. 5. CO2 absorption in solvents at different partial pressures.
Catalytic activity
186
As stated above, among all the three ILs 1–3, histidine derived IL1 was found to be best CO2 capturing agent; therefore it has been used as recyclable catalyst for conversion of epoxides to cyclic carbonates (Scheme 1). At first, a series of experiments were performed by varying the reaction conditions, including solvent, reaction temperature, reaction time, and the catalyst amount to optimize the yield of the cyclic carbonate (Table 3). The coupling of styrene oxide with carbon dioxide to afford styrene carbonate was selected as a representative reaction. The reaction was found to be very slow in the absence of any solvent and afforded poor yield of the product (Table 3, entry 1). Among a number of organic solvents such as acetonitrile, DMF, toluene and dimethylcarbonate (DMC) studied; DMC was found to be optimum and afforded almost quantitative conversion of the styrene carbonate selectively without any evidence for the formation of any by-product
187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202
Table 3 Results of the optimization experiments for the synthesis of styrene carbonate.a
O
O
CO2 IL (5 mol%)
O O
1 atm Solvent Time (h)
Fig. 4. CO2 absorption in ILs vs time.
Entry
Solvent
Temperature ( C)
Time (h)
Yield (%)b
1 2 3 4 5 6 7 8
None CH3CN Toluene DMF DMC DMC DMC DMC
90 80 90 90 90 25, 80 70 80
58 76 68 96, 74,c 68d 98.2 –, 98 92 55, 90, 98
9e 10f
DMC DMC
80 80
10 8 10 6 4.5 5 5 2, 4, 4.5 5 5
81 98.5
a Reaction condition: styrene oxide (10 mmol), IL 1 (5 mol%), DMC (3 ml) and CO2 under 1 atm. b Isolated yields. c using IL 2 as catalyst. d using IL 3 as catalyst. e 2 mol%. f 15 mol% catalyst IL 1.
Please cite this article in press as: P. Kumar, et al., Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions, J. Ind. Eng. Chem. (2017), http://dx.doi.org/10.1016/j.jiec.2017.01.022
Q12
G Model
JIEC 3266 1–6 P. Kumar et al. / Journal of Industrial and Engineering Chemistry xxx (2016) xxx–xxx 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248
(Table 3, entries 5–6). Similarly the reaction was found to be slow in acetonitrile and toluene and afforded poor product yield (Table 3, entries 2–3). Although DMF as solvent showed almost equal activity compared to DMC at atmospheric pressure (Table 3, entries 4–5), however, DMC is greener and environment friendly than DMF, thus, we choose DMC as the optimized solvent for this transformation. As suggested in a recent literature report that DMF being a Lewis base can activate CO2 species to facilitate the coupling reaction [44]. However in the suggested reference [44] the reaction has been carried out under extreme reaction conditions i.e. 150 C temperature and 3 MPa pressure. In order to evaluate the catalyzing/activating effect of DMF, we performed the coupling reaction of styrene oxide with CO2 in all three ILs (IL 1–3) using DMF as solvent under identical conditions (Table 3, entry 4). Among the three ILs studied histidine derived IL 1 was found to be most efficient and afforded best results. Thus we believe that DMF is not playing much significant role in the present investigation. If DMF had activation/catalyzing effect then we could get almost similar activity in three ILs. We assume that the structure of ILs is providing significant role. Among the three ILs, histidine derived IL (IL 1) contains imidazole ring which is already well known in literature to provide higher solubility/activation to absorbed CO2 for better conversion and absorption [13–16]. Thus, we believe that due to the presence of imidazole ring, ILs revealed better CO2 absorption/solubility and strong activation by combining with CO2 for coupling reaction. This is the reason due to that histidine containing ionic liquid showed excellent catalytic activity than other two ILs at ambient pressure conditions. Next, the effects of the reaction temperature, time and catalyst amount on the product yield were examined (Table 3, entries 6–10). The reaction did not proceed at room temperature whereas 80 C was found to be optimum for the reaction (Table 3, entries 6–7). Further increase in temperature did not provide any improvement in the results (Table 3, entry 5). Next, we performed the reaction at 80 C for different reaction times i.e. 2, 4 and 4.5 h under described reaction conditions (Table 3, entry 8). As shown in results, the reaction was found to be increased with time and at 4.5 h maximum conversion and product yield was obtained. Thus, we conclude that among the various reaction temperatures and time, the best result in terms of yield (98%) was obtained by carrying out the reaction at 80 C for 4.5 h using 5 mol% of catalyst at atmospheric pressure. However, by using the catalyst amount less than 5 mol%, the reaction was found to be less efficient and afforded lower yield (81%) of the product (Table 3, entry 9). However, by using more amount of catalyst 15 mol%, no significant enhancement in the product yield was obtained (Table 3, entry 10).
5
Next, we studied the recyclability of the developed catalyst in DMC solvent. After completion of the reaction, the reaction mixture was extracted with diethyl ether to isolate the crude product, which was subjected to usual workup to obtain the pure product. The recovered DMC containing IL was reused as such for subsequent experiments for six runs (Fig. 6). Interestingly, in all cases the conversion of the styrene oxide to cyclic carbonate with similar selectivity and reaction times, established the efficient recovery and recycling of the developed system. Next, we extended the scope of the reaction with a variety of epoxides under the above optimized reaction conditions. The results of these experiments are summarized in Table 4. All the epoxides either containing electron donating groups (entries 2–6) or electron withdrawing group (entry 7) could be transformed to the corresponding cyclic carbonates with almost quantitative yields (91–98%) within 4–6 h under 1 atm CO2 pressure at 80 C. We have also carried out the reaction of styrene oxide with CO2 in the absence of IL 1 as the catalyst under otherwise identical reaction conditions. No product was detected in the absence of IL catalyst as shown in Table 4, entry 1.
Table 4 IL 1 catalyzed cycloaddition of various epoxides with CO2.a Entry
Epoxide
1
Product
O
O
2
O
O
O
Yield (%)b
5.0 10c
98
5.0
97
5.5
95
5.5
94
5.5
92
4.5
98
6.0
94
6.0
91
O
3
O
O
O MeO
O
O O
MeO
4
O
5
O
O O
O
O
O Cl
8
O
O O
Cl
O O
O
7
O
O
O
6
O
O
O
O O
Fig. 6. Recycling of the IL1 in DMC for the synthesis of styrene carbonate.
O
O
Reaction time (h)
O
a Reaction conditions: substrate (10 mmol), IL 1 (5 mol%), DMC (3 ml) at 80 C under atmospheric pressure. b Isolated yields. c In the absence of IL catalyst in DMC solvent.
Please cite this article in press as: P. Kumar, et al., Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions, J. Ind. Eng. Chem. (2017), http://dx.doi.org/10.1016/j.jiec.2017.01.022
249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268
G Model
JIEC 3266 1–6 6 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287
P. Kumar et al. / Journal of Industrial and Engineering Chemistry xxx (2016) xxx–xxx
Conclusion We have developed an efficient but simple methodology for effective capturing and simultaneous conversion of captured CO2 to high value cyclic carbonates under very mild reaction conditions such as ordinary pressure and in the presence of a green solvent. Three amino acid derived ILs such as histidine, aspartic and glutamic acid derived ILs were synthesized and first tested for capturing of CO2. Among all the synthesized ILs histidine derived IL1 showed maximum capture efficiency and therefore used as reusable catalyst for chemical fixation of carbon dioxide in the form of cyclic carbonates by reacting with epoxides at atmospheric pressure. The notable advantages offered by this protocol are the efficient capturing of CO2 using biocompatible amino acid based Q9 ILs, use of green solvent like DMC, mild reaction conditions such as 1 atm, high selectivity, recyclability of the catalyst and high yield of products, which could make this procedure green and cost effective for the capturing and simultaneous fixation of CO2 to high value chemicals. Acknowledgements
288
Authors are thankful to Director, CSIR-IIP for his kind permission to publish these results. Analytical division of the 290 Institute is acknowledged for providing support in analysis of 291 the samples. Authors also thankfully acknowledge the financial 292 Q10 support of SERB, DST Govt. of India, through file No. SB/FTP/ETA293 0253/2013 for carrying out a part of experimental work. 289
294
295 296
References [1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
D.M. D’Alessandro, B. Smit, J.R. Long, Angew. Chem. Int. Ed. 49 (2010) 6058. D.M. D’Alessandro, B. Smit, J.R. Long, Angew. Chem. Int. Ed. 122 (2010) 6194. J.F. Brennecke, B.E. Gurkan, J. Phys. Chem. Lett. 1 (2010) 3459. Y. Zhang, S. Zhang, X. Lu, Q. Zhou, W. Fan, X.P. Zhang, Chem. Eur. J.15 (2009) 3003. P. Wasserscheid, W. Keim, Angew. Chem. Int. Ed. 112 (2000) 3926. P. Wasserscheid, W. Keim, Angew. Chem. Int. Ed. 39 (2000) 3773. J.L. Anderson, J.K. Dixon, J.F. Brennecke, Acc. Chem. Res. 40 (2007) 1208. J.F. Brennecke, B.E. Gurkan, J. Phys. Chem. Lett. 1 (24) (2010) 3459. M. Ramdin, T.W. de Loos, T.J.H. Vlugt, Ind. Eng. Chem. Res. 51 (2012) 8149. M.J. Muldoon, S. Aki, J.L. Anderson, J.K. Dixon, J.F. Brennecke, J. Phys. Chem. B 111 (2007) 9001. [11] S.N.V.K. Aki, B.R. Mellein, E.M. Saurer, J.F. Brennecke, J. Phys. Chem. B 108 (2004) 20355.
[12] M.B. Shiflett, D.J. Kasprazak, C.P. Junk, A.K. Yokozeki, J. Chem. Thermodyn. 40 (2008) 25. [13] M.S. Shannon, J.E. Bara, Ind. Eng. Chem. Res. 50 (2011) 8665. [14] A.S. Aquino, F.L. Bernard, M.O. Vieira, J.V. Borges, M.F. Rojas, F.D. Vecchia, R.A. Ligabue, M. Seferin, S. Menezes, S. Einloft, J. Braz. Chem. Soc. 25 (2014) 2251. [15] M.C. Corvo, J. Sardinha, T. Casimiro, G. Marin, M. Seferin, S. Einloft, S.C. Menezes, J. Dupont, E.J. Cabrita, ChemSusChem 8 (2015) 1935. [16] Mengshuai Liu, Lin Liang, Xin Li, Xiangxiang Gao, Jianmin Sun, Green Chem. 18 (2016) 2851. [17] E.D. Bates, R.D. Mayton, I. Ntai, J.H. Davis Jr., J. Am. Chem. Soc. 124 (2002) 926. [18] E. Torralba-Calleja, J. Skinner, D. Gutiérrez-Tauste, J. Chem. 2013 (2013) 16 Article ID 473584. [19] Z.F. Zhang, Y. Xie, W.J. Li, S.Q. Hu, J.L. Song, T. Jiang, B.X. Han, Angew. Chem. Int. Ed. 120 (2008) 1143. [20] Z.F. Zhang, Y. Xie, W.J. Li, S.Q. Hu, J.L. Song, T. Jiang, B.X. Han, Angew. Chem. Int. Ed. 47 (2008) 1127. [21] S.H. Kim, S.H. Hong, ACS Catal. 4 (2014) 3630. [22] V. Laserna, G. Fiorani, C.J. Whiteoak, E. Martin, E. Escudero-Adan, A.W. Kleij, Angew. Chem. Int. Ed. 53 (2014) 10416. [23] S.-S. Zhang, J.Q. Wu, Y.-X. Lao, X.-G. Liu, Y. Liu, W.-X. Lv, D.-H. Tan, Y.-F. Zeng, H. Wang, Org. Lett. 16 (2014) 6412. [24] A.W. Kleij, C.J. Whiteoak, ChemCatChem 7 (2015) 51. [25] Q. Chen, K. Gao, C. Peng, H. Xie, Z.K. Zhao, M. Bao, Green Chem. 17 (2015) 4546. [26] X.-D. Lang, L.-N. He, Chem. Rec. (2016), doi:http://dx.doi.org/10.1002/ tcr.201500293. [27] W.L. Dai, S.F. Yin, R. Guo, S.L. Luo, X. Du, C.T. Au, Catal. Lett. 136 (2010) 35. [28] H. Zhou, Y.M. Wang, W.Z. Zhang, J.P. Qu, X.B. Lu, Green Chem. 13 (2011) 644. [29] W.G. Cheng, X. Chen, J. Sun, J.Q. Wang, S.J. Zhang, Catal. Today 200 (2013) 117. [30] J.A. Kozak, J. Wu, X. Su, F. Simeon, T.A. Hatton, T.F. Jamison, J. Am. Chem. Soc. 135 (2013) 18497. [31] B. Zou, L. Hao, L.-Y. Fan, Z.-M. Gao, S.-L. Chen, H. Li, C.-W. Hu, J. Catal. 329 (2015) 119. [32] Y.A. Rulev, Z. Gugkaeva, V.I. Maleev, M. North, Y.N. Belokon, Beilstein J. Org. Chem. 11 (2015) 1614. [33] Q. He, J.W. O’Brien, K.A. Kitselman, L.E. Tompkins, G.C.T. Curtis, F.M. Kerton, Catal. Sci. Technol. 4 (2014) 1513. [34] C. Martín, G. Fiorani, A.W. Kleij, ACS Catal. 5 (2015) 1353. [35] J.W. Comerford, I.D.V. Ingram, M. North, X. Wu, Green Chem. 17 (2015) 1966. [36] A. Monassier, V. D’Elia, M. Cokoja, H.L. Dong, J.D.A. Pelletier, J.M. Basset, F.E. Kühn, ChemCatChem 5 (2013) 1321. ski, Y. Belmabkhout, A.J. Cairns, V. D’Elia, Ł. Wojtas, K. [37] V. Guillerm, Ł.J. Weselin Adil, M. Eddaoudi, Nat. Chem. 6 (2014) 673. [38] A. Barthel, Y. Saih, M. Gimenez, J.D.A. Pelletier, F.E. Kühn, V. D’Elia, J.-M. Basset, Green Chem. 18 (2016) 3116. [39] Mengshuai Liu, Kunqi Gao, Lin Liang, Fangxiao Wang, Lei Shi, Li Sheng, Jianmin Sun, Phys. Chem. Chem. Phys. 17 (2015) 5959. [40] Y. Xie, T.-T. Wang, X.-H. Liu, K. Zou, W.-Q. Deng, Nat. Comm. 4 (2013) 1960. [41] P.K. Khatri, G.D. Thakre, S.L. Jain, Ind. Eng. Chem. Res. 52 (2013) 15829. [42] B.E. Gurkan, J.C. de la Fuente, E.M. Mindrup, L.E. Ficke, B.F. Goodrich, E.A. Price, W.F. Schneider, J.F. Brennecke, J. Am. Chem. Soc. 132 (2010) 2116. [43] S. Sunmugavel, A.J. Kunov-Kruse, R. Fehrmann, A. Riisager, ChemSusChem 7 (2014) 897. [44] S. Zhong, L. Liang, B. Liu, J. Sun, J. CO2 Util. 6 (2014) 75.
Please cite this article in press as: P. Kumar, et al., Post combustion capture and conversion of carbon dioxide using histidine derived ionic liquid at ambient conditions, J. Ind. Eng. Chem. (2017), http://dx.doi.org/10.1016/j.jiec.2017.01.022
297
298 299 300
301 302 303
304 305
Q11 306
307 308 309 310
311 312 313 314
315 316