Production of Furan Compounds from Sugarcane Bagasse Using a Catalytic System Containing ZnCl2/HCl or AlCl3/HCl in a Biphasic System

Abstract

In this work, two catalytic systems combining Lewis and Brønsted acids (ZnCl 2 /HCl and AlCl 3 /HCl) were applied in a tetrahydrofuran (THF)/NaCl aq biphasic system to produce furan compounds from plant polysaccharides. The following cellulosic matrices were applied for this purpose: α-cellulose, microcrystalline cellulose and both native and steam-exploded sugarcane bagasse. The AlCl 3 /HCl catalytic system afforded the best yields for α-cellulose conversion to furan compounds (hydrolysis followed by dehydration). The highest yields of 5-(hydroxymethyl)-furfural (HMF) and furfural were 44.0 and 92.2% for AlCl 3 /HCl and 36.5 and 81.4% for ZnCl 2 /HCl, respectively. Cellulosic materials with lower crystallinity indexes afforded the best performance in hydrolysis followed by dehydration, giving relatively high yields of HMF and furfural. The HMF yields were similar for both native and steam-exploded sugarcane bagasse and the presence of lignin had a negative effect on HMF production. The highest furfural yield from native sugarcane bagasse was 60.6% with AlCl 3 /HCl catalytic system. Keywords: acid-catalyzed dehydration, furans, cellulose, sugarcane bagasse, crystallinity IntroductionThe integral use of renewable feedstocks for fuels and chemicals is the key for the development of sustainable biorefineries. The International Energy Agency (IEA) defines biorefinery as the sustainable processing of biomass into a spectrum of products to be marketed as food, chemicals and supplies. In another definition, the American National Renewable Energy Laboratory (NREL) describes biorefinery as a facility that integrates equipment and processes for biomass conversion into fuels, energy and chemicals for industry. 1,2Sugarcane bagasse is an important agro-industrial byproduct for biorefining because large amounts are readily available at low cost in sugarcane-processing industrial facilities such as autonomous distilleries and sugar mills. Sugarcane bagasse is majorly composed of glucans (mostly cellulose), hemicelluloses (mostly xylans) and lignin and these macromolecular components are involved in a strong chemical association that reduces its accessibility to chemical conversion. 4 Different forms of pretreatment can break this strong association and increase the chemical accessibility of cane bagasse polysaccharides. One of the most interesting pretreatment technique is steam explosion, which combines chemical and physical processes to deconstruct the plant cell wall associative structure. 5,6 For this, the biomass is treated with saturated steam at temperatures between 170-230 °C for 2 to 30 min in the absence or presence of an exogenous catalyst. 7 The main feature of steam explosion is the total or partial acid hydrolysis of hemicelluloses to produce mono and oligosaccharides, which are intermediate chemicals for a variety of value-added products. In addition, changes in the lignin structure occur primarily due to the acid hydrolysis of aril-ether linkages, while both xylan and glucan degree of polymerization is decreas...

Direct Ethyl Levulinate Production from Raw Lignocellulosic Biomass Mediated by a Novel Taurine-Based Imidazolium Ionic Liquid

“…The experimental matrix and the EL yields (%) are presented in Table . The factors evaluated were temperature ( T : 160–190 °C), time ( t : 20–60 min), and IL quantity (1–10 equiv), and their levels were selected according to previous works. ,− As can be seen in Table , the highest EL yield (81%) from MCC was achieved when all factors were at the upper level: 190 °C, 60 min, and 10 equiv of [TauIm]­[HSO 4 ] (entry 8).…”

Development of Novel Imidazole–Poly(ethylene glycol) Solvent for the Conversion of Lignocellulosic Agro-Residues to Valuable Chemicals

“…The maximum yield of furfural and HMF obtained were 720 and 200 g kg –1 , respectively, at 190 °C, 1% H 2 SO 4 , and 10 min . Gomes et al reported the production of furfurals from dehydration of steam exploded sugar cane bagasse using AlCl 3 /HCl. The highest yield of HMF and furfural were 440 and 922 g kg –1 , respectively, at 180 °C .…”

“…Gomes et al reported the production of furfurals from dehydration of steam exploded sugar cane bagasse using AlCl 3 /HCl. The highest yield of HMF and furfural were 440 and 922 g kg –1 , respectively, at 180 °C . In this study, the maximum yields of HMF and furfural obtained from pretreatment of sugar cane bagasse using IPEG200 at 120 °C were 460 and 140 g kg –1 , respectively, which is comparable with the literature.…”

The Roles of H2O/Tetrahydrofuran System in Lignocellulose Valorization

“…In H 2 O/THF biphasic system, Fang et al (2019) obtained 76 and 81% yields of HMF and furfural from corn stover, respectively, using H 2 SO 4 /Na 2 SO 4 as catalyst. In combination of Lewis acid with Brønsted acids in NaCl-H 2 O/THF biphasic system, the yields of HMF and furfural was 44.0 and 92.2% catalyzed by AlCl 3 /HCl and 36.5 and 81.4% by the catalysis of ZnCl 2 /HCl, respectively (Gomes et al, 2018). As high as 71% yield of furfural and 30% yield of HMF could be simultaneously produced from wheat straw in NaCl-H 2 O/THF biphasic system catalyzed by SnCl 2 -PTA/β (Phosphotungstic acid) catalyst (Xu et al, 2019).…”