Catalytic Upgrading of Biomass-Derived Furfuryl Alcohol to Butyl Levulinate Biofuel over Common Metal Salts

Abstract

Abstract:Levulinate ester has been identified as a promising renewable fuel additive and platform chemical. Here, the use of a wide range of common metal salts as acid catalysts for catalytic upgrading of biomass-derived furfuryl alcohol to butyl levulinate was explored by conventional heating. Both alkali and alkaline earth metal chlorides did not lead effectively to the conversion of furfuryl alcohol, while several transition metal chlorides (CrCl 3 , FeCl 3 , and CuCl 2 ) and AlCl 3 exhibited catalytic activity for the synthesis of butyl levulinate. For their sulfates (Cr(III), Fe(III), Cu(II), and Al(III)), the catalytic activity was low. The reaction performance was correlated with the Brønsted acidity of the reaction system derived from the hydrolysis/alcoholysis of cations, but was more dependent on the Lewis acidity from the metal salts. Among these investigated metal salts, CuCl 2 was found to be uniquely effective, leading to the conversion of furfuryl alcohol to butyl levulinate with an optimized yield of 95%. Moreover, CuCl 2 could be recovered efficiently from the resulting reaction mixture and remained with almost unchanged catalytic activity in multiple recycling runs.

Production of levulinic acid and alkyl levulinates: a process insight

“…However, some articles on the production of LEs from pentose route intermediates, as furfuryl alcohol, have been published in recent years. 135,173,175,188,[229][230][231][232] The reason may be because LA and LEs cannot be solely produced by solvolysis from these C5 compounds. After hydrolysis of xylose to stable molecular furfural, it needs an additional hydrogenation step to furfural alcohol, which was previously regarded as a precursor for the target production of levulinate ester by alcoholysis reaction in alcohols.…”

Conversion of Furfuryl Alcohol into Ethyl Levulinate over Glucose-Derived Carbon-Based Solid Acid in Ethanol

“…Moreover, EL is of particular interest due to its extensive applications in the flavoring, solvent, and plasticizer sectors [6]. Additionally, it has found applications in the area of organic chemistry for the synthesis of the viable biofuel γ-valerolactone [7,8].…”

Continuous Flow Alcoholysis of Furfuryl Alcohol to Alkyl Levulinates Using Zeolites

“…Various metal chloride salts, including AlCl 3 (entry 6), CuCl 2 (entry 14), and, also, FeCl 3 , showed very promising results, although their recovery by filtration may result costly or less efficient (metal leaching). 22 Sulfated zircona dioxide (entry 2) and titanium dioxide are also catalyst candidates. 14 All the experiments reported in the literature on FA conversion to alkyl levulinates were performed in batch reactors.…”

“…The formation of this oligomeric/polymeric side product can be suppressed by operating at moderate temperatures and reducing the reaction time. Most of the research studies on FA alcoholysis operated at temperatures between 110 and 140 °C, ,− ,− with some exceptions . Although strongly depending on the catalyst load and the alcohol chain length, most of the studies required at least 2 h to attain full conversion and typically 2–6 h to obtain high alkyl levulinates yields using 0.2–0.4 M feedstocks, with some exceptions. , Table compares the activity of the most promising solid acid catalysts reported for the conversion of FA to methyl-, ethyl-, and butyl levulinate after 2 h reaction.…”

“…Catalysts decorated with sulfonic acid groups were also reported in several occasions; SBA-15-SO 3 H (entry 15) was found to be the best performing catalyst, at least for the alcoholysis in 1-butanol (butyl levulinate). Various metal chloride salts, including AlCl 3 (entry 6), CuCl 2 (entry 14), and, also, FeCl 3 , showed very promising results, although their recovery by filtration may result costly or less efficient (metal leaching) . Sulfated zircona dioxide (entry 2) and titanium dioxide are also catalyst candidates …”