Enhanced hydrolysis of bamboo biomass by chitosan based solid acid catalyst with surfactant addition in ionic liquid

doi:10.1016/j.carbpol.2017.05.082

Carbohydrate Polymers

Volume 174, 15 October 2017, Pages 154-159

https://doi.org/10.1016/j.carbpol.2017.05.082 Get rights and content

Highlights

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A sulfonated cross-linked chitosan solid acid catalyst (SCCAC) was used for hydrolysis.
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Tween 80, polyethylene glycol 4000 (PEG 4000), and sodium dodecyl sulfate (SDS) were tested as surfactants for improving the bamboo hydrolysis in this study.
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Compared to SCCAC in 1-Butyl-3-methylimidazolium chloride ([BMIM]Cl), the surfactants improved the total reducing sugar (TRS) yield.
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Tween 80 achieved a yield of 68.01% for TRS at 120 °C after 24 h.

Abstract

Surfactants were used for the hydrolysis of bamboo biomass to enhance lignocellulose hydrolysis. Tween 80, polyethylene glycol 4000 (PEG 4000), and sodium dodecyl sulfate (SDS) were tested as surfactants for improving the bamboo hydrolysis with a novel sulfonated cross-linked chitosan solid acid catalyst (SCCAC) in ionic liquid (IL). Compared to the use of only SCCAC in 1-Butyl-3-methylimidazolium chloride ([BMIM]Cl), the surfactants facilitated hydrolysis and improved the yield of total reducing sugar (TRS) under the same conditions. Tween 80 was the most effective surfactant, with a TRS yield of 68.01% achieved at 120 °C after 24 h. Surfactants broke the lignocellulose structure, promoted lignin removal, and increased positive interactions between cellulose and the catalyst, which were favorable for hydrolysis. This novel surfactant-assisted hydrolysis strategy with SCCAC and IL as the solvent demonstrated a promise for the large-scale transformation of biomass into biofuels and bioproducts.

Introduction

Lignocellulosic biomass demonstrates promise as the most economical, highly renewable natural resource in the world. The development of renewable energy obtained from lignocellulosic biomass as an alternative to fossil fuel is ultimately essential for the survival of the human race (Ragauskas et al., 2006). Considerable research and development programs have been initiated worldwide to convert lignocellulosic biomass into various valuable products in biorefineries, where the liberation of reducing sugars from lignocellulose is a crucial step (Jäger & Büchs, 2012). However, lignocellulosic biomass is resistant to hydrolysis because of its complex hetero-matrix structure (Himmel et al., 2007), and cellulose fibers in the lignocellulose matrix are naturally protected by lignin and hemicellulose to resist microbial and enzymatic attack (Goshadroua & Lefsrud, 2017).

Ionic liquids (ILs) exhibit attractive properties such as chemical and thermal stability, high ionic conductivity, non-volatility, recyclability, and good dissolving capacity (Welton, 1999; Zhao, Xia, & Ma, 2005). Previous studies have indicated that ILs can decrease the crystallinity of cellulose, where hemicelluloses and lignin are partially removed; this partial removal leads to the chemical transformation of cellulose chains (Shafiei, Zilouei, Zamani, Taherzadeh, & Karimi, 2013; Swatloski, Spear, Holbrey, & Rogers, 2002). The dissolution of lignocellulosic substrates in various ILs as an effective pretreatment method has attracted significant attention worldwide (Bian et al., 2014; Silva, Lopes, Roseiro, & Bogel-Lukasik, 2013; Zavrel, Bross, Funke, Büchs, & Spiess, 2009).

From the viewpoint of green chemistry and industrialization, solid acid catalysts have become one of the excellent choices for the hydrolysis of lignocellulose into glucose. As these catalysts demonstrate tremendous potential to overcome limitations such as reactor corrosion, waste treatment, poor recyclability, isolating difficulty (Shen, Wang, Han, Cai, & Li, 2014), and energy- and cost-intensive pretreatment for enzymatic hydrolysis (Hu, Lin, Wu, Zhou, & Liu, 2015). Hara et al. (2004) and Suganuma et al. (2008) have independently reported that a carbon-based solid acid consisting of polycyclic aromatic carbon and functional groups, e.g., sulfonic acid, can act as strong solid acid catalyst for various acid-catalyzed reactions. Nata, Irawan, Mardina, and Lee (2015) have obtained highly sulfonated carbonaceous spheres in the presence of hydroxyethyl sulfonic acid and acrylic acid, which can be used as a solid acid catalyst for the hydrolysis of cornstarch. Zhong et al. (2015) have prepared a nanoscale catalyst, which can effectively hydrolyze hemicellulose while retaining cellulose and lignin. Chitosan is useful in many different applications (Deng et al., 2011, Huang et al., 2015; Xiao & Zhou, 2008; Xin et al., 2013), one of which is to synthesize resin and catalyst. In our laboratory, preliminary studies have been conducted to synthesize a novel sulfonated cross-linked chitosan solid acid catalyst (SCCAC), and examine the effectiveness of it in ILs for the hydrolysis of lignocellulose, with a comparatively ideal yield obtained for TRS (Cheng et al., 2016). Nevertheless, the yield is predominantly attributed to the large amount of the added catalyst and the consumption of the IL. Consequently, the development of an auxiliary strategy is urgently required for the economical, efficient hydrolysis of lignocellulose using solid acid catalysts in ILs.

Surfactants exhibit hydrophobic and hydrophilic properties and enhance the removal of hydrophobic substances by decreasing the surface tension between the two liquid phases (Qing, Yang, & Wyman, 2010). Furthermore, surfactants can serve as emulsifiers and dissolve the extractives present in the wood structure. These properties make surfactants prospective additives for the pretreatment of lignocellulose (Kim, Kim, & Kim, 2007; Kurakake, Ooshima, Kato, & Harano, 1994). Recent studies have investigated the synergistic effect of surfactants and IL for the hydrolysis of lignocellulose. Chang et al. (2016) have indicated that surfactant-assisted IL ([BMIM]Cl) pretreatment enhances the removal of lignin during pretreatment and cellulose conversion during subsequent enzymatic hydrolysis as compared with pretreatment without surfactants. Nasirpour, Mousavi, and Shojaosadati (2014) have assessed the effect of Tween 80 and polyethylene glycol 4000 (PEG 4000) on the pretreatment of sugarcane bagasse using [BMIM]Cl, and the removal of lignin is enhanced by 12.5% as compared to the IL-only pretreated sample. Pandey and Negi (2015) have assessed the impact of surfactant assisted acid and alkali pretreatment on pine foliage, it was proved to be efficient for removal of lignin. However, to our best of knowledge, the combination of surfactant-assisted solid acid catalysis and ILs as a novel strategy for hydrolysis has not been reported.

In this study, surfactants (e.g., Tween 80, PEG 4000, and SDS) were added to improve the hydrolysis of bamboo with SCCAC in IL (i.e., [BMIM]Cl). Reaction conditions were optimized to choose the best surfactants suited for the hydrolysis of bamboo. Furthermore, Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses were conducted to discuss the mechanism of the addition of surfactants with SCCAC and IL on hydrolysis.

Section snippets

Materials

Bamboo was readily obtained from a bamboo grove in Chongqing (China), sifted using an 80 mesh sieve. The main chemical composition of bamboo was determined by a two-step acid hydrolysis method developed by the National Renewable Energy Laboratory (NRTL) (Sluiter et al., 2008), with dry matter containing 20.3% of xylan, 22.3% of lignin, and 40.1% of glucan (Wang et al., 2014).

[BMIM]Cl used as a solvent in the system was purchased from Ke Neng Material Technology Co. Ltd (Linzhou, China). Table S1

Effect of the solid acid catalyst without surfactants on bamboo hydrolysis

Table 1 summarizes the yield of TRS obtained from the hydrolysis of bamboo biomass in [BMIM]Cl catalyzed by SCCAC without the surfactant. Results indicated that the novel solid acid catalyst is effective for the hydrolysis of bamboo biomass. The TRS yield obtained by the hydrolysis of bamboo powder by SCCAC was relatively greater than that observed for the control without SCCAC. When the mass ratios of SCCAC and bamboo were set to 1:1, 1:2, 1:5, and 1:20, the TRS yield increased to 50.73%,

Conclusions

This study has shown the enhancement of the addition of surfactants in bamboo hydrolysis with a novel sulfonated cross-linked chitosan solid acid catalyst in IL. Tween 80 was the most effective surfactant, and a maximum TRS yield of 68.01% was achieved at 120 °C after 24 h at 20 rpm. The addition of 0.08 g Tween 80, 0.04 g PEG 4000, and 0.03 g SDS increased the TRS yield by 34.06%, 15.28%, and 17.11%, respectively, compared with SCCAC alone. The addition of surfactants could break the lignocellulose

Acknowledgements

We would like to thank the financial support from the National Natural Science Foundation of China (Nos. 21106191, 21206175), the State Key Laboratory of Materials-Oriented Chemical Engineering (KL14-11), Open foundation of Hubei Key Laboratory of Edible Wild Plants Conservation and Utilization (EWPL201507), Natural Science Foundation Project of CQ CSTC (cstc2015jcyjA90008), and Technology Foundation for Selected Overseas Chinese Scholar, Ministry of Personnel of China. This work is also

References (40)

J. Bian et al.
Effect of [Emim]Ac pretreatment on the structure and enzymatic hydrolysis of sugarcane bagasse cellulose
Carbohydrate Polymers
(2014)
K.L. Chang et al.
Synergistic effects of surfactant-assisted ionic liquid pretreatment rice straw
Bioresource Technology
(2016)
J. Cheng et al.
The enhancement of the hydrolysis of bamboo biomass in ionic liquid with chitosan-based solid acid catalysts immobilized with metal ions
Bioresource Technology
(2016)
H.B. Deng et al.
Enhanced bacterial inhibition activity of layer-by-layer structured polysaccharide film-coated cellulose nanofibrous mats via addition of layered silicate
Carbohydrate Polymers
(2011)
T. Eriksson et al.
Mechanism of surfactant effect in enzymatic hydrolysis of lignocellulose
Enzyme and Microbial Technology
(2002)
L. Hu et al.
Chemocatalytic hydrolysis of cellulose into glucose over solid acid catalysts
Applied Catalysis B
(2015)
R. Huang et al.
Biomimetic LBL structured nanofibrous matrices assembled by chitosan/collagen for promoting wound healing
Biomaterials
(2015)
M.H. Kim et al.
Surface deactivation of cellulose and its prevention
Enzyme and Microbial Technology
(1982)
M. Kurakake et al.
Pretreatment of bagasse by nonionic surfactant for the enzymatic hydrolysis
Bioresource Technology
(1994)
K.M. Lee et al.
Ionic liquid-mediated solid acid saccharification of sago waste: Kinetic, ionic liquid recovery and solid acid catalyst reusability study
Industrial Crops and Products
(2015)

M. Malmsten et al.

Adsorption of poly(ethylene glycol) amphiphiles to form coatings which inhibit protein adsorption

Journal of Colloid and Interface Science

(1996)

M. Mohan et al.

Hydrolysis of bamboo biomass by subcritical water treatment

Bioresource Technology

(2015)

N. Nasirpour et al.

A novel surfactant-assisted ionic liquid pretreatment of sugarcane bagasse for enhanced enzymatic hydrolysis

Bioresource Technology

(2014)

I.F. Nata et al.

Carbon-based strong solid acid for cornstarch hydrolysis

Journal of Solid State Chemistry

(2015)

A.K. Pandey et al.

Impact of surfactant assisted acid and alkali pretreatment on lignocellulosic structure of pine foliage and optimization of its saccharification parameters using response surface methodology

Bioresource Technology

(2015)

Q. Qing et al.

Impact of surfactants on pretreatment of corn stover

Bioresource Technology

(2010)

M. Shafiei et al.

Enhancement of ethanol production from spruce wood chips by ionic liquid pretreatment

Applied Energy

(2013)

S.G. Shen et al.

Influence of reaction conditions on heterogeneous hydrolysis of cellulose over phenolic residue-derived solid acid

Fuel

(2014)

N. Wang et al.

Effects of metal ions on the hydrolysis of bamboo biomass in 1-butyl-3-methylimidazolium chloride with dilute acid as catalyst

Bioresource Technology

(2014)

Y. Xiao et al.

Synthesis and properties of a novel crosslinked chitosan resin modified by l-lysine

Reactive & Functional Polymers

(2008)

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Enhanced hydrolysis of bamboo biomass by chitosan based solid acid catalyst with surfactant addition in ionic liquid

Highlights

Abstract

Introduction

Section snippets

Materials

Effect of the solid acid catalyst without surfactants on bamboo hydrolysis

Conclusions

Acknowledgements

Carbohydrate Polymers

Bioresource Technology

Bioresource Technology

Carbohydrate Polymers

Enzyme and Microbial Technology

Applied Catalysis B

Biomaterials

Enzyme and Microbial Technology

Bioresource Technology

Industrial Crops and Products

Journal of Colloid and Interface Science

Bioresource Technology

Bioresource Technology

Journal of Solid State Chemistry

Bioresource Technology

Bioresource Technology

Applied Energy

Fuel

Bioresource Technology

Reactive & Functional Polymers