A sustainable system for maleic acid synthesis from biomass‐derived sugar

Abstract

BACKGROUND: The preparation of maleic acid from the oxidation of renewable furfural has attracted significant attention, but research regarding the direct transformation of biomass-derived sugar to maleic acid is rare. The research regarding the direct transformation of xylose to maleic acid would further promote its industrial applications. RESULTS: The direct synthesis of maleic acid from xylose was investigated based on a sustainable system of deep eutectic solvents (DESs). Four DESs were screened to evaluate their abilities for the dehydration of xylose. Hydrogen peroxide (H 2 O 2 )was then loaded to realize the oxidation of furfural without the separation of intermediates. A good maleic acid yield of 20.8%, along with 5.0% of fumaric acid, based on the xylose content were obtained under the initial xylose loading of 50 mM, a tin(IV) chloride (SnCl 4 )-xylose molar ratio of 4:1, in a monophase choline chloride (ChCl)-formic acid (Fa) (molar ratio of 1:6) system at 120 ∘ C for 2 h. Then, 4 mL of H 2 O 2 per mmol furfural was loaded for a further 10 min at 120 ∘ C.CONCLUSION: This ChCl-Fa-SnCl 4 -H 2 O 2 system possesses a higher oxidation selectivity to maleic acid with no furanone and succinic acid. Moreover, it was interesting that ChCl and SnCl 4 could be recovered through natural recrystallization.

Catalytic Transformation of the Furfural Platform into Bifunctionalized Monomers for Polymer Synthesis

“…141 Because betaine hydrochloride is a strong organic acid having a pH value of ∼1, the authors next applied it in maleic acid and fumaric acid synthesis directly from xylose, in which xylose dehydration to furfural was performed at 453 K, and the next furfural oxidation was conducted at 363 K, which provided 17 and 4% yields of maleic acid and fumaric acid, respectively, from xylose. Zhang also explored a deep eutectic solvent system composed of choline chloride−formic acid−SnCl 4 for maleic acid synthesis, 142 starting from xylose dehydration followed by H 2 O 2 oxidation without intermediate separation, and obtained a 34.4% yield of maleic acid with an 8.2% yield of fumaric acid. Remarkably, the mixture of choline chloride and SnCl 4 could be recrystallized after the oxidation process and retained high activity for furfural production.…”

Effects of Sugars and Degradation Products Derived from Lignocellulosic Biomass on Maleic Acid Production

“…In general, furfural is unstable and polymerizes to form humins, owing to the condensation of furan and sugars. Therefore, the yield and selectivity of furfural from xylose and xylooligomer were reduced, owing to humin formation [29]. Here, humin production increased with increasing acid concentrations at each CSF.…”

Recent Advances in the Catalytic Conversion of Biomass to Furfural in Deep Eutectic Solvents

“…However, the thermal stability of ChCl/oxalic acid is poor at temperatures above 379 K ( Zhang et al, 2014 ). A comparative investigation by Qiang et al found that adding SnCl 4 ·5H 2 O ( Table 4 , entries 7–10) to the ChCl/formic (Fa) system was the most successful ( Yu et al, 2019a ). Because the metal cation catalyzed the conversion of carbohydrates to furfural is related to its ionization potential, the furfural yields produced with different metal chlorides can vary.…”