Levoglucosan production

Gravitis, J., Vedernikov, N., Zandersons, J. and Kokorevics, A. 2001. Furfural and Levoglucosan Production from Deciduous Wood and Agricultural Wastes. ACS Symposium Series, 784, 110-122. 

Unpublished data from studies of levoglucosan production, by I. A. Wolff, D. W. Olds and O. E. Hilbert at the Northern Regional Research Laboratory. 

Table II. Effect of Acid, Alkaline, and Neutral Additives on Levoglucosan Production...

Furfural and Levoglucosan Production from Deciduous Wood and Agricultural Wastes... 

Radlein D. Study of levoglucosan production—a review. In Bridgwater AV, editor. Fast pyrolysis of biomass a handbook volume 2. UK CPL Press 2002. p. 205-41. 

Figure 11.9 Pyrogram of a paint sample collected from sixteenth century wall paintings in the Messer Filippo cell of the tower in Spilamberto, Italy. Pyrolysis was performed with a micro furnace pyrolyser, at 600°C, in the presence of HMDS. 1, Carbohydrate pyrolysis products 2, lauric acid 3, suberic acid 4, levoglucosane 5, azelaic acid 6, miristic acid 7, hexadecanenitrile 8, palmitic acid 9, octadecanenitrile 10, oleic acid 11, stearic acid. TMS derivative [74]...

Several researchers have shown that alkali present in the feedstock influences the yields and compositions of the pyrolysis products [56, 59]. An interesting result was reported by Brown and coworkers [60] who found that addition of (NH4)2S04 as catalyst to the pyrolysis of dematerialized (alkali free) corn stover resulted in a pyrolysis oil that contained 23 wt.% levoglucosan (normally 1-3 wt.% levoglucosan is present in pyrolysis oil). Levoglucosan is a component from which various fuel blends and chemicals can be produced. 

The wood pyrolysis is attractive because forest and industrial wood residues can be readily converted into liqtrid products. These liqtrids, as erode bio-oil or slurry of charcoal of water or oil, have advantages in transport, storage, combustion, retrofitting and flexibility in production and marketing (Demirbas, 2007). In the first step of pyrolysis of carbohydrates dehydration occtrrs and at low temperatures dehydration predominates. Dehydration is also known as a char-forming reaction. Between 550 and 675 K volatile products, tar, and char are formed. The volatile products are CO, CO, H O, acetals, furfural, aldehydes and ketones. Levoglucosan is the principle component in tar. 

Fig. 7. The major decomposition products from burning of cellulose. Levoglucosan is the dominant compound, and mannosan and galactosan are formed as well as levoglucosan from burning of hemicelluloses.

The first successful polymerizations were obtained in solution, with cationic initiators, under conditions typical of ring-opening polymerization. Bredereck and Hutten polymerized the perbenzyl ether and peracetate of levoglucosan, using, as initiators, various carbonium ions formed in situ from organic halides and silver perchlorates. The products were apparently not stereoregular, but were definitely poly-... 

No triester of levoglucosan was found92 that polymerized at temperatures much below 0°. At —78°, the triacetate complexed with phosphorus pentafluoride, and, at high concentration, precipitated from solution.91 The tris(monofluoroacetate) failed to polymerize under a variety of conditions.91 The trinitrate polymerized at 0°, but the product was not fully characterized.92 Polymerization of the triacetate proceeded to reasonable conversions with a number of catalysts at 0°, but the viscosity and the stereoregularity of these polymers were low.92 In a simple, copolymerization experiment, it was demonstrated that the low polymerizability of levoglucosan triacetate was due not only to a failure to initiate but also to sluggish propagation.92... 

Korshak and coworkers20 polymerized levoglucosan in p-dioxane at 80-90°, using, as the catalyst, benzenesulfonic acid or such Lewis acids as boron trifluoride, ferric chloride, or aluminum chloride. Highly branched, amorphous products having Ma 38,000-68,000 (by light-scattering) were obtained. 

Condensed-Phase Mechanisms. The mode of action of phosphorus-based flame retardants in cellulnsic sy stems is probably best understood. Cellulose decomposes by a noncalalyzed route lo tarry depolymerization products, notably levoglucosan, which then decomposes to volatile combustible fragments such as alcohols, aldehydes, ketones, and hydrocarbons. However, when catalyzed by acids, the decomposition of cellulose proceeds primarily as an endothermic dehydration of the carbohydrate to water vapor and char. Phosphoric acid is particularly efficaceous in this catalytic role because of its low volatility (see Phosphoric Acids and Phosphales). Also, when strongly heated, phosphoric acid yields polyphosphoric acid which is even more effective in catalyzing the cellulose dehydration reaction. The flame-retardanl action is believed to proceed by way of initial phosphory lation of the cellulose. 

Interest in the xanthates of carbohydrates has arisen almost entirely through the importance of the viscose process in the technical production of rayon and related products.126 The selective character of the reaction of carbon disulfide and alkali with polyhydroxy compounds has been studied. Lieser and Nagel126 found that a monoxanthate is formed with polyhydric alcohols and methyl a-D-glucopyranoside when they react with carbon disulfide and aqueous barium hydroxide. The xanthation that has been demonstrated in the cases of glycerol 1,3-dimethyl ether and levoglucosan (LXIX) shows that secondary hydroxyl groups can... 

A key compound for levoglucosan chemistry is 1,6-anhydro-2,4-di-<3-tosyl-/ -D-gl ucopyranose (36)176 which, after treatment with sodium ethoxide, affords a valuable starting compound, l,6 3,4-dianhydro-2-O-tosyl-jS-D-galactopyranose, as a single product (see Section IV. 1). Another example illustrating synthetic versatility of the ditosylate 36 is its oxidation to 3-keto derivative 37124.210.211 followed by reductive detosylation to afford the useful chiral synthon, l,6-anhydro-2,4-dideoxy-/i-D-g/ycero-hcxopyranos-3-ulose (38).210,212 Keto derivative 37 is readily isomerized by the action of pyridine into compounds of the D-arabino, D-xylo, and D-lyxo configurations.210... 

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