Water-promoted selective heterogeneous catalytic trimerization of xylose-derived 2-methylfuran to diesel precursors

Carbon Chain Length Increase Reactions of Platform Molecules Derived from C5 and C6 Sugars

“…By adding water to the reaction media, the selectivity over Amberlyst-15 changed from tetramers to trimers, but, at the same time, the conversion decreased. In addition, other catalysts were studied, and the results were similar: adding water to the reaction mixture increases the yield of trimers and decreases the conversion . The trimer selectivity can also be enhanced by conducting the reaction in an ethanol–water solvent …”

“…As early as the 1960s, it was shown that 2-methylfuran forms 5,5-bis­(5-methyl-2-furyl)­pentan-2-one (trimer) through a condensation reaction in the presence of sulfuric acid . The reaction proceeds via the hydrolytic ring opening of one 2-methylfuran molecule to an aldehyde (4-oxopentanal), followed by hydroxyalkylation/alkylation of the formed aldehyde with two molecules of 2-methylfuran. ,, This trimerization can be done in aqueous sulfuric acid (50–12–38 (wt %) 2-MF–H 2 SO 4 –H 2 O) at 75% yield and a high-purity (96%) trimer can be achieved after distillation …”

“…30 The reaction proceeds via the hydrolytic ring opening of one 2-methylfuran molecule to an aldehyde (4oxopentanal), followed by hydroxyalkylation/alkylation of the formed aldehyde with two molecules of 2-methylfuran. 26,28,29 This trimerization can be done in aqueous sulfuric acid (50− 12−38 (wt %) 2-MF−H 2 SO 4 −H 2 O) at 75% yield and a highpurity (96%) trimer can be achieved after distillation. 26 When 2-MF trimerization was performed in the presence of solid acid catalysts, the formation of a tetramer product was also detected.…”

Production of jet fuel-range hydrocarbon biofuel by hydroxyalkylation–alkylation of furfural with 2-methylfuran and hydrodeoxygenation of C15 fuel precursor over a Ni/γ-Al2O3 catalyst: a reaction mechanism

“…Therefore, the HAA reaction of 2-MF was investigated with numerous carbonyl compounds, for instance, furfural, 5-HMF, butanal, acetone, angelica lactone, ethyl levulinate, mesityl oxide, acetoin, and hydroxyl acetone [13][14][15][16][17][18][19][20][21][22] . Further, 2-MF was oligomerized to trimer followed by HDO to produce diesel-range fuels 23 .…”

“…[13][14][15][16][17][18][19][20][21][22] Furthermore, 2-MF was oligomerized to a trimer followed by HDO to produce diesel-range biofuel. 23 HAA reaction proceeds in the presence of both homogeneous and heterogeneous acid catalysts. 18,24 Homogeneous acid catalysts are, however, unsuitable for industrial processes owing to their corrosiveness and complexity in separation and recycling.…”