Catalytic Conversion of Cellulose into Levulinic Acid by a Sulfonated Chloromethyl Polystyrene Solid Acid Catalyst

Abstract

A novel solid acid catalyst, sulfonated chloromethyl polystyrene (CP) resin (CP-SO 3 H-1.69), was synthesized by partially substituting chlorine groups (ÀCl) of CP resin with sulfonic group(ÀSO 3 H). This new type solid acid contains not only acid sites, but also cellulose-binding sites (ÀCl). A high yield of levulinic acid up to 65.5 % was obtained by converting microcrystalline cellulose over CP-SO 3 H-1.69. The high catalytic activity of CP-SO 3 H-1.69 was attributed to high amount of sulfonic group and chlorine on the catalyst, which is essential to keep the catalyst with great affinity to substrate.As the major component of plant biomass and nongrain feedstock, cellulose is extensively considered as an ideal raw material for the future for the production of biofuels and chemicals. [1] Cellulose is composed of glucose monomer units connected through b-1,4-glycosidic bonds and has a recalcitrant structure as a result of the existence of large amounts of intraand intermolecular hydrogen bonds among the chains of cellulose. These strong bonds provide researchers with a great challenge on how to effectively convert cellulose into some useful compounds. [2] In recent years, many catalytic systems, including ionic liquids, [3][4][5] aqueous media, [6,7] biphasic media, [8][9][10] and sub-and supercritical fluids, [11,12] have been developed, and various cellulose degradation products such as glucose [13][14][15][16][17] 5-hydroxymethylfurfural (HMF), [18][19][20] levulinic acid (LA), [21][22][23] 5-chloromethylfurfural, [24,25] ethylene glycol, [26][27][28] propylene glycol, [29] and sugar alcohols [30][31][32] have been obtained. Without underestimating the value of other cellulose degradation products, LA production from cellulose has received significant attention owing to the fact that LA not only has high chemical reactivity, which makes it suitable for the production of various organic chemicals, but it also has the potential to serve as a chemical intermediate in the production of biofuels through existing petrochemical technologies. For example, in combination with phenol, LA is a starting material in the synthesis of diphenolic acid, which has great potential to replace bisphenol A. [33,34] Furthermore, some fuel additives such as levulinic esters, [35] methyltetrahydrofuran (MTHF), [36] and valeric esters [37,38] can be synthesized from LA. g-Valerolactone (GVL), a hydrogenation product of LA, can be converted into liquid alkenes ranging from C 8 to C 24 , which could serve as fuel blendstocks. [39] Mineral acids, including H 2 SO 4 , [37,38,[40][41][42][43][44][45][46][47] HCl, [48][49][50][51] and HBr, [52,53] are used as homogeneous catalysts to produce LA from biomass feedstocks. Among these catalytic systems, in the Biofine process developed by Biofine Renewables LLC exhibits excellent performance in the production of LA (0.5 kg LA per kg cellulose). [46,47] The Biofine process is clearly a relatively economic process for the production of LA. However, this process also has some disadvantages because...

Review: Sustainable production of hydroxymethylfurfural and levulinic acid: Challenges and opportunities

“…However, this method is unsuitable for catalysts which are unstable at high temperatures (>200 C) [78]. In such cases, the catalyst may be washed with a reagent such as H 2 O 2 [78,81], HCl [82,83], ethanol [83], methanol [84], NaOH [71], acetone [85], etc. Such treatment appears to be successful in recovering catalytic activity in a number of cases.…”

New Frontiers in the Catalytic Synthesis of Levulinic Acid: From Sugars to Raw and Waste Biomass as Starting Feedstock

“…The layered structure of graphene oxide allows an efficient diffusion of reagent and products and the catalyst results thermally stable and recyclable. Table 3) [80].…”

“…However, interesting examples of heterogeneous catalysts applied to insoluble polysaccharides and raw biomasses are reported in the literature. Recently, Zuo et al studied a sulfonated chloromethyl polystyrene solid acid catalyst for the catalytic conversion of cellulose into LA, obtaining 24 wt % LA yield performing the reaction at 170 • C for 10 h in water (Experiment 79, Table 5) [80]. The authors employed the same catalytic system at 170 • C in water also for the conversion of the disaccharides cellobiose and sucrose to LA, achieving the LA yields of 12.9 wt % and 16.5 wt % after 5 and 10 h, respectively (Experiments 77 and 78, Table 5).…”

“…Table 6 shows some interesting examples (Experiments 90-93, Table 6). Zuo et al investigated the conversion of microcrystalline cellulose into LA catalyzed by a sulfonated chloromethyl polystyrene resin, obtaining at 170 • C yields to LA up to 65.5 mol % (which corresponds to 47 wt %) at complete substrate conversion [80]. The authors attributed the high yield of LA to the fact that GVL can solubilize cellulose and, therefore, improves the interactions between cellulose and the solid acid catalyst (Experiment 91, Table 6).…”

One-pot synthesis of levulinic acid from cellulose in ionic liquids

“…These systems have some limitations such as volatility, toxicity, costly, difficulty for solvent recovery, the demand for high temperature, the degradation of cellulose, or instability in application. In addition, various catalytic systems have been attempted to convert cellulose into LA directly, including mineral acids such as HCl and H 2 SO 4 , metal chlorides, solid acid catalysts, and SO 2 in water, whereas limiting issues were focused on improving the selectivity to LA, developing efficient strategies for product separation and recovery/reuse of the catalyst (Wettstein et al, 2012;Zuo et al, 2014).…”