Levulinic Acid Production from Delignified Rice Husk Waste over Manganese Catalysts: Heterogeneous Versus Homogeneous

Abstract

Delignified rice husk waste (25.66% (wt) cellulose) was converted to levulinic acid using three types of manganese catalysts, i.e., the Mn3O4/hierarchical ZSM-5 zeolite and Mn3O4 heterogenous catalysts, as well as Mn(II) ion homogeneous counterpart. The hierarchical ZSM-5 zeolite was prepared using the double template method and modified with Mn3O4 through wet-impregnation method. The structure and physicochemical properties of the catalyst materials were determined using several solid-state characterization techniques. The reaction was conducted in a 200 mL-three neck-round bottom flask at 100 °C and 130 °C for a certain reaction time in the presence of 10% (v/v) phosphoric acid and 2% (v/v) H2O2 aqueous solution, and the product was analyzed using HPLC. In general, 5-hydroxymethyl furfural (5-HMF) as the intermediate product was produced after 2 h and decreased after 4 h reaction time. To conclude, the Mn3O4/hierarchical ZSM-5 heterogenous catalyst gave the highest yield (wt %) of levulinic acid (39.75% and 27.60%, respectively) as the main product, after 8 h reaction time.

The new challenge of partial oxidation of methane over Fe2O3/NaY and Fe3O4/NaY heterogeneous catalysts

“…This is due to the presence of iron oxide in the vicinity of the silanol group that has hindered the interaction between water molecules and the silanol group. It is also observed in infrared spectra of Mn 3 O 4 /ZSM-5 [28]. The existence of magnetic phase iron oxides is indicated by the appearance of the peaks observed at 1401 cm À1 and 626 cm À1 in Fe 3 O 4 /NaY-2.55 and Fe 3 O 4 /NaY-3.22 were assigned to Fe-O bending and Fe-O stretching vibration, respectively [29].…”

Synergistic Catalytic Effect of Sulphated Zirconia—HCl System for Levulinic Acid and Solid Residue Production Using Microwave Irradiation

“…The deactivation of solid acid catalysts by humin formation can be controlled by the residence time of the reactor which can be partially achieved using continuous reactors [48]. Porous solid acid ZSM-5 has recently been found to be an effective pyrolysis catalyst for synthetic humins at 550 • C [49], as well as a potential catalyst for levulinic acid [18]. Han et al suggested that solid acid catalysts can catalyse the degradation of lignin-like residues; however, a porous catalyst structure is required to prevent repolymerisation of intermediaries towards char [50].…”

“…Despite their simplicity and high LA yields, utilisation of mineral acids has been associated with reactor corrosion, limited catalyst recovery and waste by-product yields, such as humins [2]. Heterogeneous solid acid catalysts have been proposed by several studies [16][17][18] as replacements for H 2 SO 4 and HCl mineral acids. Solid acid catalysts can significantly reduce equipment corrosion, lower the environmental impact and offer a more cost-effective catalyst separation method.…”

Advanced Ordered Nanoporous Materials

“…For example, various approaches have been utilized to modify ZSM-5 to enhance its efficiency for the catalytic pyrolysis of biomass (Che et al, 2019). Hierarchical Mn 3 O 4 /ZSM-5 has been reported as heterogeneous catalysts in biomass utilization, such as the conversion of cellulose from rice husks to levulinic acid (Krisnandi et al 2019b) also HMF, formic acid, and levulinic acid (Pratama et al 2020). Co 3 O 4 /ZSM-5 with hierarchical pores are reported to be used in catalytic partial oxidation conversion of methane to methanol with high (Beznis et al 2011;Krisnandi et al 2015) and catalytic cracking to increase the octane number of gasoline and alkylated gasoline products (Klerk 2018).…”