Biomass furfural

As furan derivatives, both furfural and 5-hydroxymethylfurfural (HMF) are readily prepared from renewable biomass. Furfural can be easily obtained from a variety of biomass containing pentoses, mainly including com cobs, oats and rice hulls, sugar cane bagasses, cotton seeds, ohve husks and stones, and wood chips. Furfuryl was first produced in the early nineteenth century and right now the annual production is 300,000 tons [101]. On the other hand, HMF is another major promising furan derivative due to its rich chemistry and potential availability from hexose carbohydrates or from their precursors such as fructose, glucose, sucrose, cellulose, and inulin [14]. 

Furfural is derived from biomass by a process in which the hemiceUulose fraction is broken down into monomeric 5-carbon sugar units which then are dehydrated to form furfural. 

Among the various derivatives of biomass, furanic compounds obtained from furfural are important (200,0001 year-1). A new family of furanic diethers has been obtained by alkylation of 2,5-furandimethanol or furfuryl alcohol under microwave irradiation with PTC solvent-free conditions [83] (Scheme 8.59). 

In some cases, the hydrolysis reaction liberates the sugars from the biomass and converts them directly into derivatives such as furfural, hydroxymethyl furfural and/or levulinic acid. These derivatives can be further converted into various chemical intermediates. We will not discuss these further conversions as they are extensively reported in the literature, e.g., for furfural [15, 44], hydroxymethyl furfural [15, 44, 50] and levulinic acid [15, 44-47]. 

The potential of combining a lower need for deoxygenation and a higher product value is illustrated in Fig. 2.15. It shows that the selective incorporation of oxygen into a hydrocarbon, as done in the petrochemical industry, is very expensive. In contrast, the bio-based alternative enjoys two advantages. Firstly, the feedstock is cheaper than crude oil, even on an energy and carbon base, as discussed above. Secondly, its selective deoxygenation has been proven to cheaper than the petrochemical route in a few cases, e.g., for ethanol and furfural. The same can be expected for other biomass derivates in the future. 

In order to gain some information about the fundamentals of the hydrothermal carbonization process, the hydrothermal carbonization of different carbohydrates and carbohydrate products was examined [12, 13]. For instance, hydrothermal carbons synthesized from diverse biomass (glucose, xylose, maltose, sucrose, amylopectin, starch) and biomass derivatives (HMF and furfural) were treated under hydrothermal conditions at 180 °C and were analyzed with respect to their chemical and morphological structures by SEM,13 C solid-state NMR and elemental analysis. This was combined with GC-MS experiments on residual liquor solutions to analyze side products... 

Decarbonylation. Furfural is easily obtained from biomass waste such as oat and rice hulls that are rich in pentosans. Further valorisation of furfural can be done by decarbonylation to produce furan, which can be further converted into tetrahydrofuran by catalytic hydrogenation. 

Fig. 15. Furfural, phenols, and ethanol production from wood in a multiproduct process biomass chemical plant (52). Wood (qv) is ca 50% cellulose (qv),...

Furfural - [BUTADIENE] (Vol 4) - [cross-reference entry] (Vol 12) - [EXTRACTION - LIQUm-LIQUID] (Vol 10) -from biomass [FUELS FROMBIOMASS] (Vol 12) -as chemical feedstock [FURANDERIVATIVES] (Supplement) -use of cast copper alloys with [COPPER ALLOYS - CAST COPPER ALLOYS] (V ol 7)... 

Chheda, J.N., Roman-Leshkov, Y. and Dumesic, J.A. 2007. Production of 5-Hydroxymethylfurfural and Furfural by Dehydration of Biomass-Derived Mono- and Poly-Saccharides. Green Chem., 9, 342-350. 

When the structure of biomass components has to be quite drastically rearranged compared to the building blocks needed, synthesis gas or different sugars can serve as platform chemicals. The latter can be converted, for example, to sugar-derived building blocks (Figure 2.2.3) - that is, to glycerol, sorbitol, levulinic acid, and furfural. 

The liquid portion of biomass-derived process samples may also contain carbohydrate degradation products, such as 5-(hydroxymethyl)-2-furaldehyde (HMF), levulinic acid, and furfural, as well as other components of interest, such as organic acids and sugar alcohols. Portfolio methods are available for the quantitative measurement of these degradation products and byproducts of polymer hydrolysis. 

The removal of water from initially formed biomass sugars is an important process for the production of primary biorefinery building blocks. Of particular interest are 5-hydrox-ymethylfurfural and levulinic acid (from the dehydration of glucose or other C6 sugars) and furfural (from xylose dehydration). Recent research has led to new catalytic processes for the production of each of these materials. 

Montane, D., Salvado, J., Torras, C., and Farriol, X., High-temperature dilute-acid hydrolysis of olive stones for furfural production. Biomass Bioenergy 2002, 22 (4), 295-304. 

FIGURE 13.1 Isolation of pentose, lignin, and hexose intermediates from woody biomass for conversion to furfural, phenols, and ethanol. 

Presuming the market for furfural and its derivatives ultimately grows to the point where commodity uses require the availability of large amounts of furfural, woody and waste biomass feedstocks can serve as a much more abundant and distributed source of supply than com cobs, oat hulls, and rice... 

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