Ammonia from wood

This section discusses the production of methanol and ammonia from wood. Methanol is a clean-burning material that may find widespread future use as an automotive fuel (directly or for conversion to gasoline by the Mobil process) as a fuel for industrial or utility boilers, gas turbines, or fuel cells as a chemical intermediate or as a biological feedstock for protein. 

The production of methanol and ammonia from wood involves similar concepts gasification followed by product synthesis. 

Table VIII presents the estimated revenue requirements. The methanol case uses regulated utility financing, and the ammonia case, non-regulated industrial financing, based on considerations of the likely markets to be served by these products. The estimated costs of producing methanol or ammonia from wood are higher than the costs of producing methanol or ammonia from coal. This is ejqplained in part by production rates (the rates from wood-derived methanol plants are about one-tenth of those from "typical" coal-derived methanol plants ammonia production rates are similar from the two resources since the ammonia market is typically demand-constrained) and partially by feedstock differences (e.g., green wood is half moisture).

MISSION III. SELECTED SUMMARY DATA AMMONIA FROM WOOD VIA GASIFICATION WITH AN OXYGEN-BLOWN REACTOR... 

Statfjord atmospheric resid (1). Atmospheric resid (2). SRC II (3). Prahoe shale oil (4). Directly liquefied oil from wood chips using the PERC process (5). Molar ratio adjusted assuming that ammonia, water and hydrogen sulfide are formed by the heteroatoms. 

Methylamine occurs in herring brine 2 in crude methyl alcohol from wood distillation,3 and in the products obtained by the dry distillation of beet molasses residues.4 It has been prepared synthetically by the action of alkali on methyl cyanate or iso-cyanurate 5 by the action of ammonia on methyl iodide,6 methyl chloride,7 methyl nitrate,8 or dimethyl sulfate 9 by the action of methyl alcohol on ammonium chloride,10 on the addition compound between zinc chloride and ammonia,11 or on phos-pham 12 by the action of bromine and alkali on acetamide 13 by the action of sodamide on methyl iodide 14 by the reduction of chloropicrin,15 of hydrocyanic or of ferrocyanic acid,16 of hexamethylenetetramine,17 of nitromethane,18 or of methyl nitrite 19 by the action of formaldehyde on ammonium chloride.20... 

SHELLAC. A secretion or excretion of the lac insect, Coccus lacca, found in the forests of Assam and Siam. Freed from wood it is called seed lac." It is soluble in alkaline solutions such as ammonia, sodium borate, sodium carbonate and sodium hydroxide, and also in various organic chemicals. When dissolved in acetone or alcohol, shellac yields the familiar shellac varnish of superior gloss and hardness. Orange shellac is bleached with sodium hypochlorite solution to form white shellac. See also Paints and Coatings. 

Effect of Water. Wood is usually treated with ammonia in the presence of some amount of water. The effect of water depends not only on the amount of water but also somewhat on the history of the wood sample and the method of treatment. Thus, when oven-dried veneer strips were treated with cold liquid ammonia-water mixtures at ambient pressure, the flexibility of the treated wood was substantially decreased when the moisture content of the ammonia was much above 10% (26). Other protonic solvents act similarly (26). In apparent contrast, the rate of sorption of ammonia from the gas phase by wood is markedly enhanced by moisture in the wood (19). Bone dry wood absorbs ammonia quite slowly at ambient temperatures but if the wood has ten to twenty percent moisture content, sorption and plasticization occur much more rapidly. Presumably the moisture opens the pore structure of the wood and also dissolves ammonia much more readily than bone-dry wood. On continued treatment, the water is presumably displaced from the wood by the ammonia... 

After the complete removal of the ammonia from the wood, the extent of the collapse can be measured. This collapse is entirely caused by the decrease in void volume, and is made up to a larger extent by the partial closure of the cell luminae and to a smaller extent by the reduction of the pore volume of the cell walls. At the molecular level, wood substance does not seem to remain loosened after the NH3-treatment except for an increase in amorphous areas. 

I enjoyed my research in Utah, from 1986 to 1990, at Brigham Young University, Provo, collaborating with Professor Reed Izatt and Professor Noel L. Owen, where calorimetric and electrometric studies were applied for used and fresh engine oils and FTIR spectrometric studies of solvated electrons in liquid ammonia with wood surface and wood components were analyzed. 

Most solvated electron-treated wastes require posttreatment. The first posttreatment involves removing and recovering ammonia from the matrix. This is accomplished by passing hot water or steam through the jacket of the treatment cell and by condensing the ammonia for reuse. Materials such as shredded paper, wood, plastic, rubber, and PPE can be volume-reduced after the SET treatment by using commercially available compacting equipment. 

In most cases the color of the ammonia-treated wood is darker and approaches a walnut color. Some color streaking is a drawback with certain wood species. In addition, the ammonia vapor reacts with some of the wood components to produce a liquid that drains from the wood upon release of the ammonia pressure. This process is not in commercial use at the present time. 

These are briefly reviewed, followed by summary economics for the production from wood of electricity, steam, and cogenerated products intermediate-Btu gas (IBG) and substitute natural gas (SNG) methanol ammonia fuel oil and pyrolytic oil and char. Several processing steps in these conversion schemes are conceptual or are at early stages of development by DOE, EPRI, GRI, and others (an exception would be wood steam/electric power plants, which are commercially used by the electric utility and wood products industries). Consequently, the economics presented here may generally tend to be optimistic. Additional details of the analyses can be found in Kohan and Barkhordar(1) Jones, Kohan and Semrau(2J and Kohan and Dickenson( 3). ... 

This process produces low or medium Btu gases from wood and wood wastes, agricultural residues and MSW. Processing these synthetic gases with water can produce ammonia, methanol, or hydrogen. Commercial gasification systems exist, but their widespread use has been limited by hauling distances for the feedstock. 

Before methyl sulfoxide became available, several attempts were made to use liquid ammonia for the isolation of hemicelluloses from wood. The use of this solvent was introduced by Yan and Purves, and the method was subsequently applied in isolating xylans from sugar maple and trembling... 

Table 6. Kerr and Goring, found that the removal of hemicellulose from wood increased the average pore size in the cell wall during all states of delignification and overall delignification rate of the fiber wall with respect to that of the middle lamella. In addition, for ammonia treated ground bagasse increased deformation may also relate to the enlargement of the capillarieslO and the loosening of the cell walls.

The building blocks of wood lignin are derived from carbohydrates metabolized via a so-called shikimic acid pathway and converted to phenylpropane amino acids (Figure 6.6). These amino acids supply precursors for the s Tithesis of lignin, plant proteins and flavonoids. The first step is the -elimination of ammonia from L-phenylalanine to form fra 5-cinnamic acid. Successive hydroxylation and methylation reactions convert cinnamic acid to />-coumaryl alcohol, caffeyl alcohol, coniferyl alcohol, 5-hydroxyconiferyl alcohol and sinapyl alcohol. Softwood mainly uses coniferyl alcohol with a small amount of p-cou-maryl alcohol. 

Supercritical fluid solvents have been tested for reactive extractions of liquid and gaseous fuels from heavy oils, coal, oil shale, and biomass. In some cases the solvent participates in the reactions, as in the hydrolysis of coal and heavy oils with water. Related applications include conversion of cellulose to glucose in water, dehgnincation of wood with ammonia, and liquefaction of lignin in water. 

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