Acid-Functionalized Nanoparticles for Pretreatment of Wheat Straw

Abstract

Perfluoroalkylsufonic (PFS) and alkylsufonic (AS) acid-functionalized magnetic nanoparticles were synthesized and characterized, then evaluated for their ability to hydrolyze hemicelluloses. The magnetic core was made of cobalt spinel ferrite and was coated with silica to protect it from oxidation. The silanol groups allowed surface chemical modification of the nanoparticles with the PFS and AS acid functionalities. Thermogravimetric analysis gave a total organic load of 12.6% and 32.5% (w/w) for AS and PFS nanoparticles, respectively. The surface sulfur content was calculated from XPS analysis as 1.37% and 1.93% for PFS and AS nanoparticles, respectively. Wheat straw samples were treated with the acid-functionalized nanoparticles at two different conditions: 80℃ for 24 h and 160℃ for 2 h. These experiments aimed to hydrolyze wheat straw hemicelluloses to soluble oligosaccharides. PFS nanoparticles solubilized significantly higher amounts of hemicelluloses (24.0% ± 1.1%) than their alkyl-sulfonic counterparts (9.1% ± 1.7%) at 80℃, whereas the hydrothermolysis control solubilized 7.7% ± 0.8% of the original hemicelluloses in the sample. At 160℃, PFS and AS nanoparticles gave significantly higher amounts of oligosaccharides (46.3% ± 0.4% and 45 ± 1.2%, respectively) than the control (35.0% ± 1.8%). The hemicelluloses conversion at 160?C reached 66.3% ± 0.9% using PFS nanoparticles and 61.0% ± 1.2% using AS nanoparticles compared with the control experiment, which solubilized 50.9% ± 1.7% of hemicelluloses in the biomass

Pre-treatment of biomasses using magnetised sulfonic acid catalysts

“…Their results show that after 24-h reaction at lower temperature (80°C), 3.5±0.1% and 1.0±0.2%, of monosaccharides from xylan were obtained from the two catalysts. However, at higher temperature (160°C for 2 h) xylose yields were observed to be 0.3% and 1.2% from PFS and AS catalysts respectively (Wang et al, 2012). In addition, Tan and Lee (2015) reported 0.77 g glucose (glucose yield of 0.77%) in the pre-treatment liquid, when 100 g of macroalgae cellulosic residue was treated using Dowex (TM) Dr-G8 solid acid catalyst.…”

“…It appeared that for Triticale hay regular and magnetic A catalysts facilitated solubilisation of carbohydrate ( Figure 1A and B) corresponding to total sugar yields of 48.87±1.42 mg g -1 and 53.37±0.58 mg g -1 respectively. Wang et al (2012) reported the use of perfluoroalkylsulfonic (PFS) and alkylsulfonic (AS) acid-functionalised magnetic nanoparticles for pre-treatment of wheat straw and attempted to solubilise hemicellulose. Their results show that after 24-h reaction at lower temperature (80°C), 3.5±0.1% and 1.0±0.2%, of monosaccharides from xylan were obtained from the two catalysts.…”

Propyl-Sulfonic Acid Functionalized Nanoparticles as Catalyst for Pretreatment of Corn Stover

“…Acid functionalized silica materials have been used as catalyst of the α-1,4glycosidic bonds in sucrose and starch [15] and β-1,4glycosidic bonds in cellobiose [16]. Acid functionalized nanoparticles were previously used for the hydrolysis of cellobiose [17] and for the solubilization of hemicelluloses [18]. In this work, silica coated cobalt iron oxide nanoparticles functionalized with propyl-sulfonic acid groups were synthesized and used as catalyst for the pretreatment of corn stover.…”

Synthesis of Propyl-Sulfonic Acid-Functionalized Nanoparticles as Catalysts for Cellobiose Hydrolysis

“…Numerous studies have been reported on functionalization of nanoparticles for various applications [28] [30]- [32]. In previous work, for instance, magnetic nanoparticles have been successfully coated with silica [33] [34]. These nanoparticles can be separated out of aqueous solutions using a magnetic field, and their silica surface can be further modified.…”