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2 Production of Fuels (or Fuel Additives) and Chemicals
from Furanics
The catalytic transformation of biomass-derived building block platform compounds is essential for the production of fuels and value-added chemicals. Among
the identified biomass derivatives, furanics such as furfural (FUR) and
5- hydroxymethyl furfural (HMF) are known as platform compounds that can be
subsequently converted into a wide range of biofuels and biochemicals. FUR and
HMF are obtained from sugars by dehydration. The catalytic transformation of
furan ring and −CHO or hydroxymethyl group through hydrogenation, condensation, oxidation, dehydration, decarbonylation, polymerization, amination, nitration,
or opening ring reactions can yield a variety of high-value-added products, important building blocks for both the production of liquid hydrocarbon fuels, fuel additives, and valuable chemicals.
2.1 Hydrogenation of Furanics
2.1.1 Furfural
The catalytic hydrogenation of FUR has been extensively studied to produce an
attractive and wide range of compounds with potential uses as chemicals, biofuels,
or fuel additives. Various types of products such as furfuryl alcohol (FA), 2-methyl
furan (MF), tetrahydrofurfuryl alcohol (THFOL), tetrahydrofuran, 2-methyl tetrahydrofuran (2-MTHF), lactones, levulinates, cyclopentanone, or diols can be
obtained by the hydrogenation of FUR, directly or by further transformation. The
reaction route for converting FUR via hydrogenation can be divided into (1) hydrogenation without opening the furan ring and (2) hydrogenation with the opening of
the furan ring. The activity as well as selectivity pattern is directly related to the
catalytic conditions and the nature of the active phase.
There have been several attempts to use a supported catalyst based on noble metals such as Pt, Pd, Ru, and Ir (Table 3) [44–48]. However, the high cost, high H 2
pressure, and poor selectivity due to over hydrogenation with some noble metal
catalysts exclude them from their large-scale application. Thus, one of the biggest
challenges is the development of inexpensive catalysts for the selective reduction of
C=O bond in FUR under ambient H 2 pressure. Over the past few years, catalysts
based on non-noble metals were developed with advanced modification to make
their properties and activity comparable to noble metals. In particular, catalysts
based on non-noble metals (Ni [49], Co [50, 51], Cu [52]), metal oxides [53–56],
and mixed metal oxides [53] have been investigated for the hydrogenation of FUR
(Table 3). Among the various alternatives, Cu, Ni, and Co catalysts show a great
promise for replacing noble metal catalysts, taking the advantage of low cost and
high H 2 activation activity. However, they suffer from poor selectivity for
M. Baithy et al.
2 Production of Fuels (or Fuel Additives) and Chemicals
from Furanics
The catalytic transformation of biomass-derived building block platform compounds is essential for the production of fuels and value-added chemicals. Among
the identified biomass derivatives, furanics such as furfural (FUR) and
5- hydroxymethyl furfural (HMF) are known as platform compounds that can be
subsequently converted into a wide range of biofuels and biochemicals. FUR and
HMF are obtained from sugars by dehydration. The catalytic transformation of
furan ring and −CHO or hydroxymethyl group through hydrogenation, condensation, oxidation, dehydration, decarbonylation, polymerization, amination, nitration,
or opening ring reactions can yield a variety of high-value-added products, important building blocks for both the production of liquid hydrocarbon fuels, fuel additives, and valuable chemicals.
2.1 Hydrogenation of Furanics
2.1.1 Furfural
The catalytic hydrogenation of FUR has been extensively studied to produce an
attractive and wide range of compounds with potential uses as chemicals, biofuels,
or fuel additives. Various types of products such as furfuryl alcohol (FA), 2-methyl
furan (MF), tetrahydrofurfuryl alcohol (THFOL), tetrahydrofuran, 2-methyl tetrahydrofuran (2-MTHF), lactones, levulinates, cyclopentanone, or diols can be
obtained by the hydrogenation of FUR, directly or by further transformation. The
reaction route for converting FUR via hydrogenation can be divided into (1) hydrogenation without opening the furan ring and (2) hydrogenation with the opening of
the furan ring. The activity as well as selectivity pattern is directly related to the
catalytic conditions and the nature of the active phase.
There have been several attempts to use a supported catalyst based on noble metals such as Pt, Pd, Ru, and Ir (Table 3) [44–48]. However, the high cost, high H 2
pressure, and poor selectivity due to over hydrogenation with some noble metal
catalysts exclude them from their large-scale application. Thus, one of the biggest
challenges is the development of inexpensive catalysts for the selective reduction of
C=O bond in FUR under ambient H 2 pressure. Over the past few years, catalysts
based on non-noble metals were developed with advanced modification to make
their properties and activity comparable to noble metals. In particular, catalysts
based on non-noble metals (Ni [49], Co [50, 51], Cu [52]), metal oxides [53–56],
and mixed metal oxides [53] have been investigated for the hydrogenation of FUR
(Table 3). Among the various alternatives, Cu, Ni, and Co catalysts show a great
promise for replacing noble metal catalysts, taking the advantage of low cost and
high H 2 activation activity. However, they suffer from poor selectivity for
M. Baithy et al.