Catalyst-free synthesis of biodiesel precursors from biomass-based furfuryl alcohols in the presence of H₂O and air

Abstract

Dimerization of biomass-based furfuryl alcohols to biodiesel precursors was realized by using only H2O and air without adding any other catalysts.

Effective Synthesis of a Biodiesel Precursor from Furan Derivatives at Room Temperature with NaHSO4 as a Recyclable Catalyst

“…As shown, it could be found that NaHSO 4 and H 2 SO 4 offered higher hydrogen ion concentration in the presence of acetonitrile (MeCN) as the solvent. Besides, Qin et al 24 reported that the oxygen or air atmosphere could significantly affect the outcome of the reaction from 5-MFA to the 5-methylfurancarboxylic acid (MFCA). However, there was no change in the reaction result of this work after we purged the air of the reactor by N 2 (Table 1, entry 12).…”

“…Another profitable way of utilizing biomass is converting it to energy products such as alcohol and biodiesel. , Many studies on biofuel have been published in the past 2 decades. − Furan derivatives can be converted to biofuels via a further hydrodeoxygenation process because of the relatively higher carbon content, − which provides light fractions of C5–C6 bio-gasoline . However, the synthesis methods of urgently demanded jet fuel with long carbon chain alkanes (C7–C15) require the carbon chain elongation of furan derivatives. , According to the literature, there were mainly four methods for elongating the carbon chains of furan derivatives, which include the aldol condensation, hydroxyalkylation/alkylation, polymerization, and C–C coupling.…”

“…For example, the two-phase system was often used to improve reaction and product separation efficiency. Organic solvents were usually used together with water as the reaction system, such as cyclohexane and heptane. , Complexly synthesized catalysts and ionic liquid catalysts were often used. High reaction temperature or long reaction time was also indispensable in most condense reactions.…”

“…27 However, the synthesis methods of urgently demanded jet fuel with long carbon chain alkanes (C7−C15) require the carbon chain elongation of furan derivatives. 28,29 According to the literature, 24 there were mainly four methods for elongating the carbon chains of furan derivatives, which include the aldol condensation, hydroxyalkylation/alkylation, polymerization, and C−C coupling.…”

“…Luo et al 33 combined two molecular 2,5-dimethylfuran by C−C coupling reaction with a polymer yield of 60% (Scheme 1c). Qin et al 24 reported an efficient method to obtain BMFM from 5-MFA with 81% yield at the condition of 100 °C and 2 h (Scheme 1d). However, the harsh reaction conditions, complex solvent system, or precious catalysts reported in the previous methods limited the large scale production of the BMFM.…”