Controllable Synthesis of Styrene-divinylbenzene Adsorption Resins

Subscriber access provided by Caltech Library

Separations

Controllable synthesis of styrene-divinylbenzene adsorption resins and the effect of textural properties on removal performance of fermentation inhibitors from rice straw hydrolysate Qianlin Huang, Hairong Zhang, Lian Xiong, Chao Huang, Haijun Guo, Xuefang Chen, Mutan Luo, Lanlan Tian, Xiaoqing Lin, and Xin-De Chen Ind. Eng. Chem. Res., Just Accepted Manuscript • DOI: 10.1021/acs.iecr.8b00545 • Publication Date (Web): 22 Mar 2018 Downloaded from http://pubs.acs.org on March 23, 2018

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60

Industrial & Engineering Chemistry Research

1

Controllable synthesis of styrene-divinylbenzene adsorption resins and the effect

2

of textural properties on removal performance of fermentation inhibitors from

3

rice straw hydrolysate

4

Qianlin Huang,†,‡,§,ǁ Hairong Zhang,†,‡,§,# Lian Xiong,†,‡,§,# Chao Huang,†,‡,§,# Haijun

5

Guo,†,‡,§,# Xuefang Chen,†,‡,§,# Mutan Luo,†,‡,§,ǁ Lanlan Tian,†,‡,§,ǁ Xiaoqing Lin,†,‡,§,£*

6

Xinde Chen,†,‡,§,#**

7

†

8

Nengyuan Road, Tianhe District, Guangzhou 510640, People’s Republic of China

9

‡

Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, No.2

CAS Key Laboratory of Renewable Energy, No. 2 Nengyuan Road, Tianhe District,

10

Guangzhou, 510640, People's Republic of China

11

§

12

Development, No.2 Nengyuan Road, Tianhe District, Guangzhou 510640, People’s

13

Republic of China

14

ǁ

15

People’s Republic of China

16

#

17

Energy Conversion, Chinese Academy of Sciences, Xuyi 211700, People’s Republic

18

of China

19

£

20

Technology, No.100 Waihuan Xi Road, Panyu District, Guangzhou 510006, People’s

21

Republic of China

22

S Supporting Information ○

Guangdong Provincial Key Laboratory of New and Renewable Energy Research and

University of Chinese Academy of Sciences, No. 19 Yuquan Road, Beijing 100049,

R&D Center of Xuyi Attapulgite Applied Technology, Guangzhou Institute of

School of Chemical Engineering and Light Industry, Guangdong University of

1

ACS Paragon Plus Environment

Industrial & Engineering Chemistry Research 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60

23

Abstract

24

The purification of lignocellulosic hydrolysate has great practical significance in

25

the field of bioenergy and biorefinery. In this study, the effects of textural properties

26

of styrene-divinylbenzene (St-DVB) adsorption resin prepared by oil/water

27

suspension polymerization method on its adsorption capacities of sugar, fermentation

28

inhibitors and pigments in rice straw hydrolysate were investigated. The results

29

showed that the Brunauer-Emmett-Teller (BET) surface area plays a pivotal role in the

30

adsorption of pigments, furan derivatives and acid soluble lignin (ASL), while the

31

pore diameter is critical for the adsorption of organic acids and sugars. High

32

distribution coefficient (22.80 mL/g, 22.64 mL/g, 7.26 mL/g, respectively) and

33

selectivity coefficient (10.46, 10.39, 3.33, respectively) with respect to ASL, furfural

34

and 5-hydroxymethylfurfural, were achieved for the St-DVB adsorption resin

35

obtained under the copolymerization conditions: mSt+DVB:mporogen=1:1, mSt:mDVB=1:1,

36

mtoluene:mliquid paraffin =1:1, moil:mwater=1:3. In summary, the research provides guidance

37

for choosing and designing adsorbent for the purification of lignocellulosic

38

hydrolysate.

39

Key words: adsorption resin; decolorization; detoxification; fermentation inhibitors;

40

rice straw hydrolysate.

2


Page 2 of 35

Page 3 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


41

1.Introduction

42

Owing to increasing concern about environmental pollution and shortening

43

availability of fossil resources, the searching for alternative and renewable resources

44

has drawn global attention 1. Lignocellulosic biomass, particularly agricultural

45

residues, has become attractive raw material to produce bio-chemicals and bio-fuels

46

due to its potential advantages of low cost, widely availability, and renewability 2.

47

Rice straw is one of the most abundant agricultural residues and its annual global

48

production is more than 730 million tons 3. Meanwhile, with increasing demand for

49

rice in many countries, the production of rice straw will also be gradually increased 4.

50

Unfortunately, excess rice straw in many underdeveloped or developing countries is

51

often subject to be abandoned in fields or burned directly, and thus will cause

52

economic cost and serious environmental problems 5. The better solution is utilizing

53

these straws to produce bio-fuels or high value chemicals by pretreatment,

54

hydrolysis and fermentation processes.

55

Several hydrolysis methods can be performed to convert lignocellulosic

56

biomass into monosaccharide, such as enzymatic hydrolysis, dilute acid hydrolysis

57

and concentrated acid hydrolysis 6. Comparing with other methods, dilute acid

58

hydrolysis is the most promising hydrolysis method with respect to industrial

59

implementation, possessing characteristics of fast, convenient and low cost 7.

60

However, during dilute acid hydrolysis of lignocellulose, in addition to fermentable

61

reducing sugars, it is inevitable to generate a series of fermentation inhibitory

62

compounds including organic acids (formic acid, acetic acid and levulinic acid), 3



63

furan derivatives (furfural and 5-hydroxymethylfurfural (HMF)) and acid soluble

64

lignin (ASL), which can inhibit fermentation microorganism growth and strongly

65

interfere with fermentation efficiency 8, 9.

66

To improve the fermentability of dilute acid hydrolysates into bio-fuels or

67

bio-chemicals, several treatment methods have been proposed to remove these

68

inhibitors from the lignocellulosic hydrolysate, including physical methods

69

(extraction, evaporation and adsorption), chemical methods (overliming, alkaline

70

detoxification and reducing agents), biological methods (enzymatic and microbial

71

detoxification), and combined treatment 8, 10. Among these methods, adsorption has

72

been deemed to be one of the most convenient and effective methods due to its

73

energy-saving, environmentally friendly, high efficiency and easy handing 11.

74

Furthermore, adsorption resins have drawn extensively attention to remove the

75

fermentation inhibitors from the lignocellulosic hydrolysate, because of its unique

76

structure and outstanding adsorption properties 12-15. Styrene-divinylbenzene

77

(St-DVB) adsorption resins were used to effectively adsorb small organic molecules

78

such as furfural, 5-HMF and ASL from the lignocellulosic hydrolysate 16-19. However,

79

the textural properties of the St-DVB adsorption resins often vary from the synthetic

80

variable including the synthesis conditions (initiator, temperature, time of

81

polymerization, etc.), and the type and amount of the main chemical compounds

82

(monomers, crosslinker and porogen), which have been deemed to the most

83

important factors 20, 21. To our knowledge, there is no published work that specially

84

focused on the effect of textural properties on the fermentation inhibitors and 4


Page 4 of 35

Page 5 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


85 86

pigments removal, as well as the sugar loss by St-DVB adsorption resin. The aim of this research was to investigate the effect of the type and amount of

87

porogen and crosslinker on the textural properties and the removal capacity of

88

fermentation inhibitors and pigments of St-DVB adsorption resin. A series of resins

89

were synthesized by oil/water (O/W) suspension polymerization technique. The

90

St-DVB adsorption resin was characterized by Fourier transform infrared (FTIR)

91

spectroscopy, scanning electron microscopy (SEM) and N2 adsorption-desorption

92

isotherms. The removal capacity fermentation inhibitors of St-DVB adsorption

93

resins were tested in batch experiments. The regeneration and reusability of the resin

94

was also investigated.

95

2. Material and methods

96

2.1.Materials

97

Styrene (St), cyclohexane, toluene (Tol), n-heptane, liquid paraffin (LP) and

98

methylene blue were purchased from Sinopharm Chemical Reagent Co., Ltd., China.

99

Benzoyl peroxide (BPO), poly (vinyl alcohol) (PVA, 87-89% hydrolyzed, average

100

Mw 124-186 kg/mol) were ordered from Aladdin. Divinylbenzene (DVB, 63%

101

mixture of isomers remaining ethyl vinylbenzene) was obtained from ZiAn

102

Chemical Co., Ltd., Jinan, China. All chemicals in the present research were used

103

without further purification.

104

The rice straw hydrolysate was amicably supplied by Zhongke New Energy

105

Technology Co., Ltd., Huaian, China. And the main components and concentrations

106

of rice straw hydrolysate have been determined to be ASL:6.08 g/L; D-glucose: 5



107

11.65 g/L; D-xylose: 23.98 g/L ; L-arabinose: 3.21 g/L ; formic acid: 0.99 g/L; acetic

108

acid: 1.77 g/L; levulinic acid: 1.67 g/L; HMF: 0.61 g/L; furfural: 0.72 g/L.

109

2.2.Methods

110

2.2.1. Synthesis of St-DVB adsorption resins

111

St-DVB adsorption resins were prepared by O/W suspension polymerization

112

technique. The dispersing agent PVA (0.6 g) and three drops of 1 wt% methylene

113

blue were dissolved in 240 g deionized water. Then, the aqueous solution was

114

injected into a 500 mL three-necked round-bottomed flask equipped with a reflux

115

condenser, a mechanical stirrer, and a thermometer, and then was heated to 50 oC.

116

Organic solution containing required amounts of porogen(cyclohexane, LP,

117

n-heptane and Tol), monomer (St), crosslinker (DVB) and initiator (BPO) was

118

transferred into the flask, and then nitrogen was bubbled through the mixture for 5

119

min. The mixture was suspended as spherical droplets with a suitable size in an

120

aqueous solution by stirring and then gradually heated to 80 oC within 3 h. The

121

suspension was carried out under stirring for approximately 5 h at 80 oC. After

122

copolymerization, the products were filtered out and washed with hot water and 95%

123

ethanol for several times. The resins were placed in a Soxhlet and extracted with 95%

124

ethanol for 24 h to remove porogen and residual reactants. Subsequently, they were

125

washed with deionized water and ethanol for several times, respectively, to ensure

126

complete removal of impurities. Finally, the resins were dried under vacuum at 60 oC

127

for 24 h until the weight was constant.

128

The St-DVB adsorption resins were numbered HQ-1 to HQ-5 with different 6


Page 6 of 35

Page 7 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


129

monomer/crosslinker ratios (w/w); HQ-6 to HQ-10 with different amounts of

130

porogen; HQ-11 to HQ-15 with different good/poor solvent ratios (w/w); HQ-16 to

131

HQ-18 with different types of poor solvent.

132

2.2.2. Characterization of St-DVB adsorption resins

133

To observe the shape and surface morphology of the resins, the prepared

134

samples were analyzed by a Hitachi SU70 scanning electron microscope (Hitachi,

135

Japan). FTIR spectroscopy of the resins were recorded on a TENSOR27 Fourier

136

transform infrared spectrophotometer (Bruker, Germany) using KBr pellets with a

137

range of 4000 to 400 cm-1. The pore structure of the resin was attained by N2

138

adsorption-desorption isotherms using an ASIQMO002-2 analyzer (Quantachrome,

139

USA). Before the measurement, the samples (∼80 mg) were degassed at 90 oC for 10

140

h to remove the adsorbed gases and others impurities in the samples 22. The specific

141

surface area and pore volume of the samples were calculated according to

142

Brunauer-Emmett-Teller (BET) mode , Langmuir mode, while pore size distributions

143

were calculated from N2 adsorption data using Barrett-Joyner-Halenda (BJH) model

144

22

145

2.2.3.Detoxification and decolorization of hydrolysate

.

146

Detoxification and decolorization of hydrolysate was performed in batch

147

process. Approximately 1 g of the resins were added into 50 mL hydrolysate in 100

148

mL conical flasks and kept at 160 rpm for 3 h at 25 oC. After equilibrium, the

149

solution was sampled with a syringe equipped with the Whatman Spartan 30/0.45

150

RC syringe filter (0.45 µm) to remove suspended solids, placed in an encapsulated 7



151

vial, and stored at 5 oC until analysis.

152

2.2.4. Reuse of St-DVB adsorption resins

153

After the batch experiment for the detoxification and decolorization of

154

hydrolysate, the resin was eluted by stirring with 95% ethanol in a thermostatic

155

shaker (160 rpm) at room temperature for 3 h to desorb fermentation inhibitors, and

156

then was filtered and washed with deionized water; finally the resin obtained was

157

used in reuse adsorption experiment. The adsorption and desorption processes was

158

repeated five times.

159

2.2.5.Analytical methods

160

The chemical compositions and concentrations of rice straw hydrolysate were

161

analyzed by high performance liquid chromatography (HPLC) (Waters 2695 systems,

162

Waters Corp., USA) equipped with a UV-detector (Waters 2489) and a refractive

163

index detector (Waters 2414). The analysis of monosaccharides, organic acids and

164

furan derivatives relied on an Aminex HPX-87H anion-exchange column (300×7.8

165

mm, Bio-Rad Corp., USA) using 0.005 mol/L sulfuric acid as mobile phase at a flow

166

rate of 0.5 mL /min and the column temperature was maintained at 55 oC. The

167

wavelength of the UV detector was set to 210 nm.The temperature of refractive

168

index detector was kept under at 50 oC.

169

The concentrations of ASL in the hydrolysate were determined according to the

170

National Renewable Energy Laboratory (NREL) analytical procedures 23. The

171

decoloration of the hydrolysate was analyzed using an UV-Vis spectrophotometer

172

(SP-752, Shanghai Spectrum Instrument CO., Ltd., Shanghai, China) according to 8


Page 8 of 35

Page 9 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


173 174

our previous study 24. All batch experiments in the present study were carried out at least three times

175

under identical conditions to ensure the repeatability and the averaged values of

176

three data sets were reported. The experiment standard deviations were found to be

177

less than ±10%.

178

2.2.6. Definitions and calculation

179 180

The adsorption capacity of fermentation inhibitors onto the resin was calculated according to Eq. (1):

qe = 181 182

(C0 - Ce)V m

(1)

The percentage loss of sugars and the decolorization ratio are represented as Eqs. (2) and (3), respectively.

Sugar loss =

C0 - Ce ×100% C0

Decolorization rate = 183 184

(2)

A0 - Ae ×100% A0

(3)

The distribution coefficient and selectivity coefficient are defined as Eqs. (4) and (5), respectively 25.

D=

(C0 - Ce)V Cem

β compound / sugar =

(4)

Dcompound Dsugar

(5)

185

where qe is the adsorption capacity at equilibrium (mg/g); C0 and Ce are the

186

concentrations of fermentation inhibitors or sugars in the aqueous phase at initial and

9



187

equilibrium conditions (g /L), respectively. V is the volume of aqueous solution (L);

188

m is the mass of the dry resin (g); A0 and Ae are the absorbances of the hydrolysate in

189

the 540 nm at initial and equilibrium conditions, respectively. D is the distribution

190

coefficient of inhibitors and sugar (mL/g) and β compound / sugar is selectivity

191

coefficient.

192

3. Results and discussion

193

3.1. Characterization of St-DVB adsorption resins

194

The FTIR spectra of the resin was recorded in the range of 4000–400 cm-1. As

195

shown in Fig. 1, the characteristic adsorption peaks appearing at 1600, 1499 and

196

1450 cm-1 corresponded to the stretching vibration of C=C bond of the benzene ring.

197

And the adsorption peaks at 3084, 3058 and 3022 cm-1 are attributed to the C-H

198

asymmetric and symmetric stretching vibration, which further provides an evidence

199

for the presence of benzene ring. In addition, it was obvious that there are

200

characteristic adsorption peaks of the asymmetric and symmetric stretching vibration

201

of –CH2– at 2927 and 2844 cm-1. The results indicated St and DVB

202

copolymerization reaction occurred successfully.

203

The shape and surface morphology of the resin was observed by SEM. It can be

204

seen from Fig. 2 that the resin presented a spherical form and a rough internal

205

surface. The rough internal surface brings about a large of surface area, which was

206

beneficial to improve adsorption capacity.

207 208

The effect of the porogen and crosslinker on the textural properties of different St-DVB adsorption resins synthesized, was investigated from the data obtained by 10


Page 10 of 35

Page 11 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


209

N2 adsorption-desorption isotherms experiments. According to the International

210

Union of Pure and Applied Chemistry (IUPAC) classification 26, all isotherms of

211

St-DVB adsorption resin belonged to type IV (see Fig. S1 to Fig. S4 in the

212

Supporting Information). At the low relative pressure (P/P00.90), all isotherms

219

presented a continuous nitrogen uptake, which suggested the presence of

220

macroporosity in the resins 27. These results were in agreement with the pore

221

diameter distribution (see Fig. S5 in the Supporting Information). Textural

222

parameters obtained from the N2 adsorption–desorption isotherms data are

223

summarized in Table S1 toTable S4 (see in the Supporting Information).

224

The effect of monomer/ crosslinker ratio (w/w) on the texture was analyzed by

225

comparing the values of BET surface area (SBET), pore volume (V) and pore

226

diameter (D ) of the resins synthesized using a fixed porogen (Tol and LP) and

227

different mass ratios of St/DVB. It could be obviously observed from Table S1 (see

228

in the Supporting Information) that the BET surface area and pore volume sharply

229

increased firstly, then reached a top value (199.10 m2/g and 1.09 cm3/g), and after

230

that decreased with mass ratios of St/DVB increased. While pore diameter showned 11



231

an upward trend as the mass ratios of St/DVB increased. It can be explained that

232

crosslinking process favours the formation of shorter chains with more compact

233

network structure, which leading to higher BET surface area and smaller pore

234

diameter. However, when porogen were removed, the compact network structure

235

would be damaged under excess crosslinker, which cause lower BET surface area

236

and larger pore diameter 27.

237

The amounts of porogen have a great influence on the pore structure of St-DVB

238

adsorption resin 20. By varying the amount of porogen (fixing mTol:mLP=1:1) and

239

fixing other reaction conditions. As shown in Table S2 (see in the Supporting

240

Information), with increase of mSt+DVB/mporogen ratio, pore volume and pore diameter

241

showed an upward trend, while BET surface area increased firstly and then

242

decreased. When mSt+DVB:mporogen=1:1, the maximum value of 199.10 m2/g is

243

reached. It may be attributed to the fact that the porogen did not react in the

244

copolymerization process and would be removed from copolymer after the reaction.

245

The more porogens were added, the more holes would be formed. Therefore, high

246

contents of porogen caused higher BET surface area, larger pore volume and pore

247

diameter. However, excess porogen was added would form excess pore, which result

248

in the collapse of pore structure and lower BET surface area 28.

249

Generally, according to thermodynamical affinity with the copolymer, the

250

porogen classify into good solvent and poor solvent 29. In this study, Tol was good

251

solvent, LP, n-heptane and cyclohexane were poor solvent. By varying the Tol/ LP

252

mass ratio and fixing other synthesis conditions, the resins were prepared. It can be 12


Page 12 of 35

Page 13 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


253

seen from Table S3 (see in the Supporting Information) that BET surface area and

254

pore volume sharply increased and reached the summit (199.10 m2/g and 1.09 cm3/g)

255

while mTol:mLP=1:1, and then decreased slightly. However, pore diameter showed a

256

downward trend with increase of Tol/ LP mass ratio. It can be explained that Tol, as a

257

good thermodynamic affinities for the polymer, possessing much slower phase

258

separation during polymerization than LP, which brings about a small pore size with

259

a large BET surface area. However, the excess high contents of Tol will cause the

260

polymer to be not rigid enough and shrinkage, and then decrease BET surface area

261

30

262

. The effect of the types of poor solvent can be analyzed comparing the textural

263

properties of HQ-16, HQ-17 and HQ-18 resin. When using the low molar mass poor

264

solvent (n-heptane or cyclohexane) and fixing other reaction conditions, the BET

265

surface area sharply increased, pore diameter sharply decreased and pore volume

266

was almost unchanged (see Table S4 in the Supporting Information). It may be

267

attributed to the fact that the low molar mass poor solvents molecular possess

268

smaller molecular size, which leading to form smaller pore diameter and larger BET

269

surface area.

270

3.2. Detoxification and decolorization of hydrolysate

271

The aim of the detoxification and decolorization processes is to separate organic

272

acids, furan derivatives , ASL and pigments from fermentation sugars in rice straw

273

hydrolysate. To compare different St-DVB adsorption resins, batch experiment of all

274

fermentation inhibitors and sugars on the resins was determined. The results 13



275 276

obtained from different resins are shown in Figs. 3-7. As shown in Figs. 3-7, with all resins, fermentation sugars and organic acid are

277

the least adsorbed species. Furan derivatives , ASL and pigments are strongly

278

adsorbed compounds. This phenomenon was probably attributed to the fact that all

279

resins, were made of a polystyrene-divinylbenzene, possessing strong

280

hydrophobicity and resulting tendency to associate with hydrophobic compouds.

281

Fermentation sugars and organic acid possessed hydroxyl groupwith more

282

hydrophilic than furan derivatives , ASL and pigments that have a benzene ring or

283

furan ring.

284

It is interesting to observe in Fig. 3 and Fig. 4 that the sugar loss and the

285

adsorption capacity of organic acid are in well accordance with the pore diameter.

286

Higher adsorption capacity of organic acid or sugar loss can be obtained from the

287

resin with bigger pore diameter. However, it is worth noting that the sugar loss and

288

the adsorption capacity of organic acid are small when mTol:mLP is 1:3 and 1:2(Fig

289

3(C) and Fig 4 (C)). This phenomenon is possibly because that the BET surface area

290

is much small when mTol:mLP is 1:3 and 1:2 (see Table S3 in the Supporting

291

Information).Therefore both BET surface area and pore diameter are critical for the

292

adsorption capacity of resins and the pore diameter is key factor on adsorbing

293

organic acids and sugars. It is further observed from Fig. 3 that the loss rate of

294

D-glucose, D-xylose, L-arabinose in all resins have the same trend and is very low

295

(less than 7%), which is the first prerequisite for a successful purification of the

296

hydrolysate. In addition, it can be concluded from Fig. 4 that the order of adsorption 14


Page 14 of 35

Page 15 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


297

capacity is formic acid < acetic acid < levulinic acid for all resins. It can be

298

explained that the hydrophobic interactions between ligands exist in the resin matrix

299

and alkyl chain of carboxylic acids was enhanced with the increase of molecular

300

weight of carboxylic acids 31.

301

It is also interesting that the decolorization rate (Fig. 5) and the adsorption

302

capacity of furan derivatives (Fig. 6) and ASL (Fig. 7) are in well accordance with

303

the BET surface area. Higher decolorization rate or adsorption capacity of furan

304

derivatives and ASL can be obtained from the resin with higher BET surface area.

305

However, it is worth noting that the decolorization rate and the adsorption capacity

306

of furan derivatives and ASL are small when using cyclohexane or n-heptane as poor

307

solvent(Fig 5-7 (D)). This phenomenon is probably attributed to the fact that the pore

308

diameter is much smaller when using cyclohexane or n-heptane as poor solvent(see

309

Table S4 in the Supporting Information).This results further evidenced both BET

310

surface area and pore diameter significantly affected the adsorption capacity of

311

resins. The BET surface plays a pivotal role in the adsorption of pigments, furan

312

derivatives and ASL. It can be further seen from Fig. 6 that furfural is stronger

313

adsorbed than HMF onto all adsorbents. This result is due to HMF possessed

314

hydroxy group with more hydrophilic than furfural. Compared with other

315

fermentation inhibitors, ASL are the most strongly adsorbent species for all resins.

316

This is can be explained that the ASL , low molar mass phenolic compounds, can be

317

adsorbed onto St-DVB adsorption resin through hydrophobic interactions, as well as

318

π-π stacking formed between the benzene ring of ASL and cross-linked benzene ring 15



319

of resin.

320

3.3. Selectivity study

321

The adsorption selectivity is a important factor in the purification process. In

322

order to evaluate the adsorption selectivity of ASL, furfural and HMF with St-DVB

323

adsorption resin, distribution coefficient and selectivity coefficient are defined in eqs.

324

(3) and (4) was proposed and the result shown in Table 1. Based on Table 1, the

325

St-DVB adsorption resin presents a high distribution coefficient and selectivity

326

coefficient with respect to ASL, furfural and HMF, which indicates that the resin can

327

effectively and selectively remove these fermentation inhibitors from rice straw

328

hydrolysate. Moreover, it should be noticed that the order of distribution coefficient

329

and selectivity coefficient is HMF < furfural < ASL for all resins. This result further

330

indicated that the resin tendency to associate with hydrophobic compouds in the rice

331

straw hydrolysate.

332

3.4. Reusability study

333

As a significantly important parameter for evaluating the performance of

334

adsorbents in term of practical application, the regeneration and reuse of the three

335

resins were assessed by five cycles of reuse. It was obviously observed from Fig.8

336

that the resins exhibited excellent reusability with stable efficiency, which suggests

337

considerable potential of the resin for purification lignocellulosic hydrolysate.

338

4.Conclusion

339 340

In summary, a series of St-DVB adsorption resin were synthesized by O/W suspension polymerization technique. The results showed that crosslinker and 16


Page 16 of 35

Page 17 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


341

porogen had significant influence on the structure and textural properties of St-DVB

342

adsorption resin. The resin can be used to effectively remove ASL, furfural, HMF

343

and pigments from lignocellulosic hydrolysate with low sugar loss. Both BET

344

surface areas and pore diameter are critical for the adsorption capacity of resins. The

345

pore diameter is key factor on the adsorption of organic acids and sugars, while the

346

BET surface area is key parameter on the adsorption of pigments, furan derivatives

347

and ASL.

348

349

S Supporting Information ○

350

The Supporting Information is available free of charge on the ACS Publications

351

website at DOI: XXXXXXXXXX.

352

ASSOCIATED CONTENT

Textural parameters, N2 adsorption-desorption isotherm and pore diameter

353

distribution of St-DVB adsorption resins.

354

Corresponding Authors

355

* E-mail: [email protected] (X. Lin). Tel. /fax: +86- 20-39322172.

356

** E-mail: [email protected] (X. Chen). Tel. /fax: +86-20-37213916.

357

Notes

358

The authors declare no competing financial interest.

359

Acknowledgments

360

This work was supported by the financial support of the Science and

361

Technology Planning Project of Guangdong Province, China (2017A010103043,

362

2016A010104009, 2016A010105016), the Project of National Natural Science 17



363

Foundation of China (51508547, 21606229), the Open Foundation of Xuyi Center of

364

Attapulgite Applied Technology Research Development & Industrialization, Chinese

365

Academy of Sciences (201604), Pearl River S&T Nova Program of Guangzhou

366

(201710010096, 201610010014), and the project of Huai-An Science and

367

Technology (HAS201623).

368

References

369

1.

370

removal of phenolic lignin derivatives enables sugars recovery from wood

371

prehydrolysis liquor with remarkable yield. Bioresour. Technol. 2014, 174, 198-203.

372

2.

373

Brady, J. W.; Foust, T. D., Biomass recalcitrance: engineering plants and enzymes

374

for biofuels production. science 2007, 315 (5813), 804-807.

375

3.

376

xylooligosaccharides from rice straw by feed xylanase with ultrafiltration. Arch. Biol.

377

Sci. 2011, 63 (1), 161-166.

378

4.

379

biomass from rice industry as a source of renewable energy. Renew. Sust. Energ. Rev.

380

2012, 16 (5), 3084-3094.

381

5.

382

investigation of pyrolysis of rice straw using bench-scale auger, batch and fluidized

383

bed reactors. Energy 2015, 93, 2384-2394.

384

6.

Wang, Z.; Jiang, J.; Wang, X.; Fu, Y.; Li, Z.; Zhang, F.; Qin, M., Selective

Himmel, M. E.; Ding, S.-Y.; Johnson, D. K.; Adney, W. S.; Nimlos, M. R.;

Wang, F.; Guohua, H.; Xiao, J.; Liu, Y., Improvement in the productivity of

Lim, J. S.; Manan, Z. A.; Alwi, S. R. W.; Hashim, H., A review on utilisation of

Nam, H.; Capareda, S. C.; Ashwath, N.; Kongkasawan, J., Experimental

Cara, C.; Ruiz, E.; Oliva, J. M.; Sáez, F.; Castro, E., Conversion of olive tree 18


Page 18 of 35

Page 19 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


385

biomass into fermentable sugars by dilute acid pretreatment and enzymatic

386

saccharification. Bioresour. Technol. 2008, 99 (6), 1869-1876.

387

7.

388

inhibitory by-products and strategies for minimizing their effects. Bioresour. Technol.

389

2016, 199, 103-112.

390

8.

391

inhibitors and detoxification. Biotechnol. biofuels 2013, 6 (1), 16.

392

9.

393

lignocellulosic hydrolyzates for use in fermentative processes: a review. Bioresour.

394

Technol. 2004, 93 (1), 1-10.

395

10. Moreno, A. D.; Ibarra, D.; Alvira, P.; Tomás-Pejó, E.; Ballesteros, M., A review

396

of biological delignification and detoxification methods for lignocellulosic

397

bioethanol production. Crit. Rev. biotechnol. 2015, 35 (3), 342-354.

398

11. Santos, J. l. C.; Marton, J. M.; Felipe, M. G., Continuous system of combined

399

columns of ion exchange resins and activated charcoal as a new approach for the

400

removal of toxics from sugar cane bagasse hemicellulosic hydrolysate. Ind. Eng.

401

Chem. Res. 2014, 53 (42), 16494-16501.

402

12. Thang, V. H.; Novalin, S., Green Biorefinery: Separation of lactic acid from

403

grass silage juice by chromatography using neutral polymeric resin. Bioresour.

404

Technol. 2008, 99 (10), 4368-4379.

405

13. Song, M.; Jiao, P.; Qin, T.; Jiang, K.; Zhou, J.; Zhuang, W.; Chen, Y.; Liu, D.;

406

Zhu, C.; Chen, X., Recovery of lactic acid from the pretreated fermentation broth

Jönsson, L. J.; Martín, C., Pretreatment of lignocellulose: formation of

Jönsson, L. J.; Alriksson, B.; Nilvebrant, N.-O., Bioconversion of lignocellulose:

Mussatto, S. I.; Roberto, I. C., Alternatives for detoxification of diluted-acid

19



407

based on a novel hyper-cross-linked meso-micropore resin: modeling. Bioresour.

408

Technol. 2017, 241, 593-602.

409

14. Reyhanitash, E.; Kersten, S. R.; Schuur, B., Recovery of volatile fatty acids

410

from fermented wastewater by adsorption. ACS Sustainable Chem. Eng. 2017, 5 (10),

411

9176-9184.

412

15. Detoni, C.; Gierlich, C. H.; Rose, M.; Palkovits, R., Selective liquid phase

413

adsorption of 5-hydroxymethylfurfural on nanoporous hyper-cross-linked polymers.

414

ACS Sustainable Chem. Eng. 2014, 2 (10), 2407-2415.

415

16. Huang, Q.; Lin, X.; Xiong, L.; Huang, C.; Zhang, H.; Luo, M.; Tian, L.; Chen,

416

X., Equilibrium, kinetic and thermodynamic studies of acid soluble lignin adsorption

417

from rice straw hydrolysate by a self-synthesized macro/mesoporous resin. RSC Adv.

418

2017, 7 (39), 23896-23906.

419

17. Kundu, C.; Lee, J.-W., Bioethanol production from detoxified hydrolysate and

420

the characterization of oxalic acid pretreated Eucalyptus (Eucalyptus globulus)

421

biomass. Ind. Crop. Prod. 2016, 83, 322-328.

422

18. Kundu, C.; Trinh, L. T. P.; Lee, H.-J.; Lee, J.-W., Bioethanol production from

423

oxalic acid-pretreated biomass and hemicellulose-rich hydrolysates via a combined

424

detoxification process. Fuel 2015, 161, 129-136.

425

19. Weil, J. R.; Dien, B.; Bothast, R.; Hendrickson, R.; Mosier, N. S.; Ladisch, M.

426

R., Removal of fermentation inhibitors formed during pretreatment of biomass by

427

polymeric adsorbents. Ind. Eng. Chem. Res. 2002, 41 (24), 6132-6138.

428

20. Liu, Q.; Wang, L.; Xiao, A., Research progress in macroporous 20


Page 20 of 35

Page 21 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


429

styrene-divinylbenzene co-polymer microspheres. Des. Monomers Polym. 2007, 10

430

(5), 405-423.

431

21. Garcia-Diego, C.; Cuellar, J., Synthesis of macroporous poly

432

(styrene-co-divinylbenzene) microparticles using n-heptane as the porogen:

433

quantitative effects of the DVB concentration and the monomeric fraction on their

434

structural characteristics. Ind. Eng. Chem. Res. 2005, 44 (22), 8237-8247.

435

22. Lin, X.; Xiong, L.; Qi, G.; Shi, S.; Huang, C.; Chen, X.; Chen, X., Using

436

butanol fermentation wastewater for biobutanol production after removal of

437

inhibitory compounds by micro/mesoporous hyper-cross-linked polymeric adsorbent.

438

ACS Sustainable Chem. Eng. 2015, 3 (4), 702-709.

439

23. Sluiter, A.; Hames, B.; Ruiz, R.; Scarlata, C.; Sluiter, J.; Templeton, D.; Crocker,

440

D., Determination of structural carbohydrates and lignin in biomass. Laboratory

441

analytical procedure 2008, 1617, 1-16.

442

24. Shi, S.; Zhang, H.; Huang, C.; Lin, X.; Chen, X., Purification of lignocellulose

443

hydrolysate by org-attapulgite/(divinyl benzene-styrene-methyl acrylate) composite

444

Adsorbent. BioResources 2016, 11 (4), 8664-8675.

445

25. Yangui, A.; Njimou, J. R.; Cicci, A.; Bravi, M.; Abderrabba, M.; Chianese, A.,

446

Competitive adsorption, selectivity and separation of valuable hydroxytyrosol and

447

toxic phenol from olive mill wastewater. J. Environ. Chem. Eng. 2017, 5 (4),

448

3581-3589.

449

26. Thommes, M.; Kaneko, K.; Neimark, A. V.; Olivier, J. P.; Rodriguez-Reinoso, F.;

450

Rouquerol, J.; Sing, K. S., Physisorption of gases, with special reference to the 21



451

evaluation of surface area and pore size distribution (IUPAC Technical Report). Pure

452

App. Chem. 2015, 87 (9-10), 1051-1069.

453

27. Yang, X.; Wu, L.; Ma, L.; Li, X.; Wang, T.; Liao, S., Pd nano-particles (NPs)

454

confined in titanate nanotubes (TNTs) for hydrogenation of cinnamaldehyde. Catal.

455

Commun. 2015, 59, 184-188.

456

28. Kimmins, S. D.; Cameron, N. R., Functional porous polymers by emulsion

457

templating: recent advances. Adv. Funct. Mater. 2011, 21 (2), 211-225.

458

29. Kangwansupamonkon, W.; Damronglerd, S.; Kiatkamjornwong, S., Effects of

459

the crosslinking agent and diluents on bead properties of styrene–divinylbenzene

460

copolymers. J. Appl. Polym. Sci. 2002, 85 (3), 654-669.

461

30. Hu, Y.; Zhou, Z.; Sheng, W., Preparation and pore structure of porous

462

styrene-divinylbenzene copolymer. Polym. Mater. Sci. Eng. 2010, 11, 022.

463

31. Nielsen, D. R.; Prather, K. J., In situ product recovery of n-butanol using

464

polymeric resins. Biotechnol. Bioeng. 2009, 102 (3), 811-821.

22


Page 22 of 35

Page 23 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


465

Tables

466

Table 1. Selective adsorption of fermentation inhibitors from rice straw hydrolysate

467

by St-DVB adsorption resin.

23



Page 24 of 35

468

Table1. Selective adsorption of fermentation inhibitors from rice straw hydrolysate

469

by St-DVB adsorption resin. Distribution coefficient(mL/g) compound

HQ-16

HQ-17

HQ-18

total sugar

2.18

0.89

0.51

ASL

22.80

24.63

furfural

22.64

HMF

7.26

Selectivity coefficient HQ-16

HQ-17

HQ-18

20.01

10.46

27.67

39.24

21.93

16.72

10.39

24.64

32.78

6.21

4.92

3.33

6.98

9.65

24


Page 25 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


470

Figure captions

471

Fig. 1 FT-IR spectra of the HQ-17

472

Fig. 2 SEM images of HQ-17.

473

Fig. 3 The relationship between the different reaction factors and the sugar loss (A)

474

different monomer/crosslinker ratios : mSt+DVB:mporogen=1:1, mTol/mLP=1:1,

475

moil:mwater=1:3; (B) different amounts of porogen: mSt:mDVB=1:1, mTol/mLP=1:1,

476

moil:mwater=1:3; (C) different good/poor solvent ratios :mSt+DVB:mporogen=1:1,

477

mSt:mDVB=1:1, moil:mwater=1:3; (D) different types of poor solvent :

478

mSt+DVB:mporogen=1:1, mSt:mDVB=1:1, mTol : mpoor solvent=1:1, moil:mwater=1:3.

479

Fig. 4 The relationship between the different reaction factors and the adsorption

480

capacity of ASL (A) different monomer/crosslinker ratios : mSt+DVB:mporogen=1:1,

481

mTol/mLP=1:1, moil:mwater=1:3; (B) different amounts of porogen: mSt:mDVB=1:1,

482

mTol/mLP=1:1, moil:mwater=1:3; (C) different good/poor solvent

483

ratios :mSt+DVB:mporogen=1:1, mSt:mDVB=1:1, moil:mwater=1:3; (D) different types of

484

poor solvent :mSt+DVB:mporogen=1:1, mSt:mDVB=1:1, mTol:mpoor solvent=1:1,

485

moil:mwater=1:3.

486

Fig. 5 The relationship between the different reaction factors and the decolorization

487

rate (A) different monomer/crosslinker ratios : mSt+DVB:mporogen=1:1, mTol/mLP=1:1,

488


489


490

mSt:mDVB=1:1, moil:mwater=1:3; (D) different types of poor

491

solvent :mSt+DVB:mporogen=1:1, mSt:mDVB=1:1, mTol:mpoor solvent=1:1, moil:mwater=1:3. 25



492


493

capacity of furan derivatives (A) different monomer/crosslinker ratios :

494

mSt+DVB:mporogen=1:1, mTol/mLP=1:1, moil:mwater=1:3; (B) different amounts of

495

porogen: mSt:mDVB=1:1, mTol/mLP=1:1, moil:mwater=1:3; (C) different good/poor

496

solvent ratios :mSt+DVB:mporogen=1:1, mSt:mDVB=1:1, moil:mwater=1:3; (D) different

497

types of poor solvent :mSt+DVB:mporogen=1:1, mSt:mDVB=1:1, mTol:mpoor solvent=1:1,

498

moil:mwater=1:3.

499


500


501


502


503

ratios:mSt+DVB:mporogen=1:1, mSt:mDVB=1:1, moil:mwater=1:3; (D) different types of

504


505

moil:mwater=1:3.

506

Fig. 8 Reusability of the three St-DVB resin (A) ASL (B) Decolorization rate.

26


Page 26 of 35

Page 27 of 35

3084 3058

Transmittance(%)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


1499 1600

3022

2844

1450

2927

4000

3500

3000

2500

2000

1500 -1

Wavenumbers(cm ) 507 508

. Fig. 1 FT-IR spectra of the HQ-17

27


1000

500


509

510 511

Fig. 2 SEM images of HQ-17.

28


Page 28 of 35

Page 29 of 35

512 6

90

34

30 4 28 3

26

2

24

1

22

0

20 1： 3

1： 2

1： 1

2： 1

(B)

70 4 60 3

50 40

2 30 1 20 0

3： 1

10 3:5

7:9

1： 1

9:7

5:3

mSt+DVB:mporogen

mSt:mDVB 5

5

4

180

140 120

3

100 2

80 60

1

24

160

D-glucose D-xylose L-arabinose

4

(D) Sugar loss(%)


Pore diameter (nm)

(C)

80

22 20

3 18 2

16 14

Pore diameter(nm)

Sugar loss(%)

5

5

32

Sugar loss(%)

(A)


Pore diameter (nm)

6


Pore diameter (nm)

7

Sugar loss(%)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


1

40

12

20 0

0 1:3

513

1:2

1:1

2:1

3:1

10 n-heptaneand

LP

cyclohexane

Different type of poor solvent

mTol:mLP

514

Fig. 3 The relationship between the different reaction factors and the sugar loss (A)

515

different monomer/crosslinker ratios : mSt+DVB:mporogen=1:1, mTol/mLP=1:1,

516


517


518

mSt:mDVB=1:1, moil:mwater=1:3; (D) different types of poor solvent :

519

mSt+DVB:mporogen=1:1, mSt:mDVB=1:1, mTol:mpoor solvent=1:1, moil:mwater=1:3.

29



90

32 30

4 28 3

26

2

24

(B)

Adsorption capacity (mg/g)

5

formic acid acetic acid levulinic acid

6

Pore diameter (nm)


(A)


80 70

5

60 4 50 3 40 30

2

22

Pore diameter (nm)

34

6

20

1

1 20 1:3

1:2

1:1

2:1

10

3:1

3:5

1： 1

7:9

9:7

5:3

mSt+DVB:mporogen

mSt:mDVB 5 180 160

4.5

(D)

140 120

3

100 2

80 60

1

40


4.0 3.5

24 22 20

3.0

18

2.5

16

2.0 14 1.5 12 1.0

20

10

0 1： 3

1： 2

1： 1

2： 1

3： 1

n-heptaneand

mTol:mLP

520

LP

cyclohexane


521


522


523


524


525


526


527

moil:mwater=1:3.

30


Pore diameter (nm)


4


(C)


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60

Page 30 of 35

Page 31 of 35

210

70

68 200 66

150

55 50

120

45 90

(B)

180

64 62

160

60

140

58

120

56 100 54 80

52

40

60

50 60

35 1： 3

1： 2

1： 1

2： 1

40

48

3： 1

BET surfsce area (m2/g)

60

Decolorization rate (%)

180

BET surface area(m2/g)

(A)


65

3:5

7:9

mSt:mDVB

1： 1

9:7

5:3

mSt+DVB:mporogen

70

400

67 200

65 160

55 120

50 45

80 40 35

(D)

350

65 64

300

63 62

250

61

BET surface area (m2/g)

60

Decolorization ratio(%)

66

BET surface area(m2/g)

(C)


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


40 60

30

200 0

25 1： 3

528

1： 2

1： 1

2： 1

59

3： 1

n-heptaneand

LP

cyclohexane


mTol:mLP

529

Fig. 5 The relationship between the different reaction factors and the decolorization

530

rate (A) different monomer/crosslinker ratios : mSt+DVB:mporogen=1:1, mTol/mLP=1:1,

531


532


533

mSt:mDVB=1:1, moil:mwater=1:3; (D) different types of poor

534

solvent :mSt+DVB:mporogen=1:1, mSt:mDVB=1:1, mTol:mpoor solvent=1:1, moil:mwater=1:3.

31



furfural

BET surface area

HMF

furfural

14 12

150

10 8

120

6 4

(B)

90


180

200 180

14

160 12 140 10 120 8 100 6

80

4

2 0

60 40

2 1： 3

1： 2

1： 1

2： 1

3： 1

3:5

7:9

mSt:mDVB

1： 1

9:7

5:3

mSt+DVB:mporogen

20

400

18 furfural

18

HMF

BET surface area

14

160

12 120

10 8

80 6 4


16

furfural

BET surface area

16

200

(D)

40


HMF

(C)

BET surface area

16

16



(A)

220

18

210

14

350

12 10

300

8 6

250

4 2

2 0

0 1： 3

1： 2

1： 1

2： 1

200

0

3： 1

n-heptaneand

mTol:mLP

LP

cyclohexane


535 536


537

capacity of furan derivatives (A) different monomer/crosslinker ratios :

538

mSt+DVB:mporogen=1:1, mTol/mLP=1:1, moil:mwater=1:3; (B) different amounts of

539

porogen: mSt:mDVB=1:1, mTol/mLP=1:1, moil:mwater=1:3; (C) different good/poor

540

solvent ratios :mSt+DVB:mporogen=1:1, mSt:mDVB=1:1, moil:mwater=1:3; (D) different

541

types of poor solvent :mSt+DVB:mporogen=1:1, mSt:mDVB=1:1, mTol:mpoor solvent=1:1,

542

moil:mwater=1:3.

32



HMF 18


20

Adsorption capacity(mg/g)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60

Page 32 of 35

(B) 180

100 150

90

120

80

70

90

60

220

120

210



BETsurface area

ASL

110

60

BET surface area

100

180

90

160

80

140

70

120

60 100 50 80

40

60

30 20

40

10

20 0

0 1： 3

1： 2

1： 1

2： 1

200

3： 1


ASL

110

(A)

3:5

1： 1

7:9

mSt:mDVB

9:7

5:3

mSt+DVB:mporogen 400 106

100 160 80 120 60 80 40

(D)

40

20

BET surface area

ASL

104 350

102 100 98

300 96 94 250

92 90 88

200 86 0

0 1： 3

1： 2

1： 1

2： 1

3： 1

n-heptaneand

mTol:mLP

543

LP

cyclohexane


544


545


546


547


548


549


550

moil:mwater=1:3.

33



200


BET surface area

ASL


120

(C) Adsorption capacity (mg/g)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60



Page 33 of 35


120

(A)

HQ-16

HQ-17

HQ-18

(B)

100

Decolorization ratio (%)


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60

Page 34 of 35

80

60

40

20

HQ-16

70

HQ-17

HQ-18

60 50 40 30 20 10

0

0 1

2

3

4

5

1

2

Cycles

3

4

5

Cycles

551 552

Fig. 8 Reusability of the three St-DVB resin (A) ASL (B) Decolorization rate.

34


Page 35 of 35 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 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 52 53 54 55 56 57 58 59 60


553

Abstract graphic

554

35


Controllable Synthesis of Styrene-divinylbenzene Adsorption Resins

Recommend Documents