High-Yield Production of Levulinic Acid from Pretreated Cow Dung in Dilute Acid Aqueous Solution

Abstract

Agricultural waste cow dung was used as feedstock for the production of a high value–added chemical levulinic acid (LA) in dilute acid aqueous solutions. A high LA yield of 338.9 g/kg was obtained from the pretreated cow dung, which was much higher than that obtained from the crude cow dung (135 g/kg), mainly attributed to the breakage of the lignin fraction in the lignocellulose structure of the cow dung by potassium hydroxide (KOH) pretreatment, and thus enhanced the accessibility of cow dung to the acid sites in the catalytic reaction. Meanwhile, another value-added chemical formic acid could be obtained with a yield of ca. 160 g/kg in the process, implying a total production of ca. 500 g/kg yield for LA and formic acid from the pretreated cow dung with the proposed process. The developed process was shown to be tolerant to high initial substrate loading with a satisfied LA yield. This work provides a promising strategy for the value-increment utilization of liglocellulosic agricultural residues.

RETRACTED: Kinetic Study and Optimization of Levulinic Acid Production from Chicory with PTSA as Catalyst

“…Su et. al examined the in uence of HCl concentration on the production of LA and represented the results for 0.1, 0.2, 0.4, and 0.6 M HCl [30]. Their ndings are consistent with our study, and they concluded that maximum conversion succeeded with yields of LA as 309.7 and 338.9 g/kg at 0.4 and 0.6 M of HCl, respectively.…”

“…As a result, the reaction may proceed more completely, leading to higher LA yields. Literature ndings support this trend [30,31]. In terms of weightbased yields of LA, they decreased sharply from 48.5 to 33.3% as the b/s ratio doubled.…”

“…In the study of Su et al, cow dung is converted to LA with HCl at various operating conditions and substrate loading ratios. They performed the conversion with 0.1, 0.3, 0.5, and 1.0 g cow dung in 0.4 M HCl aqueous solution and found that the maximum yield of LA was achieved at low feed concentrations while slightly lower LA yields were observed with 0.5 and 1.0 g of substrate loading [30].…”