Furfural, from bagasse

Furanose and pyranose, origin and definition of terms, III, 18 Furanose and pyranose rings, method of distinction in some cases, III, 103 Furfural, commercial production from pentosans, V, 288 from bagasse, IV, 296 from wood saccharification, IV, 178 —, 5-hydroxymethyl-, IV, 5, 307, 314, 336... 

Singh, A., Das, K., and Sharma, D. K., Integrated process for production of xylose, furfural, and glucose from bagasse by 2-step acid-hydrolysis. Industrial Eng Chem Product Res Dev 1984, 23 (2), 257-262. 

Ramos-Rodriguez E (1972) Process for jointly producing furfural and levulinic acid from bagasse and other lignocellulosic materials. US 3701789 A... 

Adipic acid can also be made from THF, obtained from furfural. It is carbonylated in the presence of nickel carbonyl-nickel iodide catalyst. Furfural is a chemurgic product obtained by the steam-acid digestion of corn cobs, oat hulls, bagasse, or rice hulls. 

The Purdue concepts have been applied to several different agricultural products, such as corn stalks, alfalfa, orchard grass, tall fescue, and sugarcane bagasse. No experiments have been reported on either hardwoods or softwoods. The processes have been explored in two major modes. In the first, the entire agricultural residue is treated with solvent in the second, a dilute acid pretreatment to remove hemicellulose precedes solvent treatment. The first process is especially desirable for making furfural or fermentation products from hemicellulose as a separate activity. Then, the hemicellulose-free raw material can be converted to substantially pure glucose. 

Pentoses contained in hemicellulose are used to produce furfural, a useful industrial chemical, used as a solvent for resins and waxes and in petrochemical refining. It is also used as a feedstock for a range of aromatic substances (it has an almond odour) including preservatives, disinfectants and herbicides. Furfural can be converted to furfuryl alcohol and used to make resins for composite applications with fibreglass and other fibres. These are of interest in the aircraft component and automotive brake sectors. Furfural is commercially derived from acid hydrolysis of waste agricultural by-products, such as sugarcane bagasse, com cobs and cereal brans. Around 450 000 tonnes is produced by this method per year. 

The production of furfural requires raw materials rich in pentosan. The pentosan content of some materials is given in Table 1. From these figures, it is readily understood why most furfural plants use corncobs. Bagasse, employed widely in hot climates, has not only less pentosan but also a very low bulk density, so that plants using this inferior raw material must accept the significant disadvantage of operating with less mass per unit of reactor volume. 

According to Hagglund, for woods the ratio of methyl pentosan to pentosan ranges from 0.04251 to 0.73256. It is believed that for bagasse, com cobs, and other raw materials of furfural manufacture this ratio is smaller than the low value of this range for wood, so that levels in the order of 1 percent are considered as reasonable. 

Of these components, only ethanol is not formed in the furfural reactors. In the typical case of bagasse as the raw material, ethanol results from a partial unwanted fermentation of the cane on the fields and in the sugar mill. In other words, the ethanol is already part of the bagasse before the latter enters the furfural reactors. 

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]. 

However, a correctly specifically manufactured and configured stoker is an excellent combustor of cellulose waste such as (1) wood—shredded trees to sawdust (2) garbage—refuse-derived fuel (3) bagasse—sugarcane residne (4) industrial residue—paper, plastics, and wood (5) furfural residue (6) peanut shells and (7) shredded tires. Most of these fuels can be bnrned without auxiliary fuel with proper attention to fnel moisture, design heat release, combustion air system design, and preheated air temperature. Cogeneration and the emphasis on renewable fuels have driven increased use of these fuels. Size distribution of the fuel is important from the standpoint of efficiency, availability, and low emissions. 

Furfural or 2-furancarboxyaldehyde (F) was first obtained in the early nineteenth century and became an industrial commodity about a century later, to reach an industrial production today of some 280 000 tons pa- year [9]. It can be readily and economically prepared from a vast array of agricultural and forestry wastes containing pentoses (see Chapter 13) in sufficient amounts to justify a commercial exploitation. Examples of these renewable resources are com cobs, oat and rice hulls, sugarcane bagasse, cotton seeds, olive husks and stones, as well... 

FA is a bio-based material, produced by hydrogenation of furfural on an industrial scale. Furfural has been prepared in commercial quantities for many decades from pentose-rich agricultural residues, including rice hulls, bagasse, oat huUs, and corn cobs. Furfural can also be derived from wood and wood products, which represent a second natural storehouse for furfural [62],... 

Furfural is the starting material for the industrial production of almost all furan compounds and is industrially produced from a pentosan-rich biomass like corn cobs, oat hulls, almond husks, cottonseed hull bran, birch wood, bagasse and sunflower husks in large quantities (>200,000 mt/a). Several process improvements have been developed at pilot scale in recent years which lead to higher yields (up to 80%) due to reduced side reactions and improved product recovery [12,13]. 

---