Carbon yields

Any solid mercury compound when fused with sodium carbonate yields a grey deposit of mercury. (Caution mercury vapour is formed.)... 

High Carbon Yield. Furfuryl alcohol and furfural are reactive solvents (monomers) and are effective in producing high carbon yield (heat induced carbonization in a reducing atmosphere). They function as binders for refractory materials or carbon bodies. Furfuryl alcohol usually requires acidic catalysis and furfural basic catalysis. Mixtures of furfuryl alcohol and furfural are generally catalyzed with acid although some systems may be catalyzed with base. 

Furfuryl alcohol alone, or in combination with other cross-linkable binders such as phenoHc reins, chemical by-products and pitch, catalyzed with acid, gives carbon yields of 35—56%. Furfural together with cyclohexanone, pitch, or phenoHc resins gives, under acid catalysis, yields of 35—55% carbon under basic catalysis yields of 5—50% are achieved. FurfuryHdeneacetone resins (13 and 14), catalyzed by acid or base, give carbon yields of 48—56 and... 

Human activity, particularly in the developing world, continues to make it more difficult to sustain the world s biomass growth areas. It has been estimated that tropical forests are disappearing at a rate of tens of thousands of hm per year. Satellite imaging and field surveys show that Brazil alone has a deforestation rate of approximately 8 x 10 hm /yr (5). At a mean net carbon yield for tropical rain forests of 9.90 t/hm yr (4) (4.42 short ton /acreyr), this rate of deforestation corresponds to a loss of 79.2 x 10 t/yr of net biomass carbon productivity. 

High carbon yielding resins are sometimes employed as raw material precursors for specialty carbons. Various chemical additives are also used in low concentrations to improve the processabiHty or to control puffing during graphitization. 

The composition varies with the heat treatment and the end point according to x-ray diffraction studies it is a form of carbon that reconverts to weU-ordered graphite on heating to 1800°C. Before the use of x-rays, chemists used the Brodie reaction to differentiate between graphitic carbons and turbostratic carbons. Turbostratic carbons yield a brown solution of humic acids, whereas further oxidation of graphite oxide produces mellitic acid (benzenehexacarboxyhc acid) [517-60-2] ... 

Traditionally, active carbons are made in particulate form, either as powders (particle size < 100 pm, with an average diameter of -20 pm) or granules (particle size in the range 100 pm to several mm). The main precursor materials for particulate active carbons, PAC, are wood, coal, lignite, nutshells especially from coconuts, and peat. In 1985, 360 kt of such precursors (including 36 % wood and 28 % coal) were used to make active carbons [10], of which nearly 80 % were used in liquid-phase applications, with the rest being used in gas-phase applications. Important factors in the selection of a precursor material for an active carbon include availability and cost, carbon yield and inorganic (mainly mineral) matter content, and ease of activation. 

Coal-tar pitch is particularly valuable to anode and electrode manufacturers The mam function is to plasticize coke gnst so that formed bodies can be extmded or molded without distortion during the later stages of processing Additionally, the pitch should give a high-carbon yield and not adversely affect the overall properties of the finished article. Although coal-tar pitch remains the bmder of choice, petroleum-based binders can perform satisfactorily for the aluminum industry [18]. 

Coal-tar pitches generally soften around 110°C, are about 70 wl% soluble in toluene and 12 wt% insoluble m quinoline. Excessive amounts of primary qumohne insolubles (QI) would contribute to increased carbon yield, but such a pitch may not wet coke well and could hinder the penetration of pitch into the coke voids. 

Veratramine, C27H3g02N, occurs naturally in V. viride and V. grandi-florum and is also formed by the hydrolysis of veratrosine. It has m.p. 209-210-5°, fa] — 68° (MeOH), and yields a dihydro-derivative, m.p. 198-200°, and a triacetyl-derivative, m.p. 204-6°, which on controlled hydrolysis leaves a. V-acetyl derivative, m.p. 177-180°. Aceording to Saito, veratramine on treatment with methyl iodide in methyl alcohol in presence of sodium carbonate, yields A-methylveratramine methiodide, m.p. 268° (dec.), from whieh the methoehloride, m.p. 277°, ean be prepared. 

Phenacylpyridinium bromide (155) with aqueous sodium carbonate yields the chloroform soluble zwitterion (156) which, with dimethyl acetylenedicarboxylate in the presence of palladium on charcoal, cyclized to the indolizine (157) in ca. 20% yield. In a similar way the pyrazine (158) gave a mixture of (159) and (160) through loss of the benzoyl group. The last compound was also ob-... 

Dimethylquinoxaline reacts with pyridine and iodine to form quinoxaline-2,3-bis(methylenepyridinium iodide) (55). Condensation of (55) with p-nitrosodimethylaniline in the presence of potassium carbonate yields the bis-(p-dimethylaminonitrone) (56) and this on acid hydrolysis gives quinoxaline 2,3-dialdehyde (57) in high over-all yield. The dialdehyde is also obtained by selenium dioxide oxidation of 2,3-dimethylquinoxaline. ... 

The temperature Is then raised to 170° to 200°C when the excess water and o-toluidine is gradually distilled off, finally maintaining the temperature at 180° to 200°C for 2 hours. After cooling to about 100°C dilute hydrochloric acid (3 parts) is added and the mixture boiled and stirred. The solution is then neutralized with NaOH with stirring and the product which separates is recrystallized twice from alcohol after decolorizing with carbon. Yield 70% of theoretical, MP 114° to 115°C. 

Reaction of an aldehyde or ketone with a secondary amine, R2NH, rather than a primary amine yields an enamine. The process is identical to imine formation up to the iminium ion stage, but at this point there is no proton on nitrogen that can be lost to form a neutral imine product. Instead, a proton is lost from the neighboring carbon (the a carbon), yielding an enamine (Figure 19.10). 

Other methods exist for the precipitation of tantalum and niobium hydroxides for subsequent use as oxide precursors. Application of ammonium carbonate, (NH4)2C03, instead of ammonia solution, also seems to have potential for the precipitation of tantalum and niobium hydroxides. Ammonium carbonate is relatively stable in aqueous media at room temperature and does not initiate the precipitation of hydroxides. Increasing the temperature of the solution causes hydrolysis and decomposition of ammonium carbonate yielding hydroxyl ions and an increase in pH, as follows ... 

The C6 position of a V,./V-dialkyl-3//-azepin-2-amine, e.g. 1, displays remarkable reactivity towards electrophilic substitution, and with dimethyl(methylsulfanyl)sulfonium tetrafluorobor-ate undergoes methylsulfanylation and quaternization to yield 6-(methylsulfanyl)-3//-azepin-ium tetrafluoroborates, e.g. 2, identical to those obtained by quaternization of the free bases with trityl tetrafluoroborate.64 Basification of the salts with potassium carbonate yields the free bases, e.g. 3, which decompose during distillation or on exposure to air. 

We assume that the double bonds in 1,3-butadiene would be the same as in ethylene if they did not interact with one another. Introduction of the known geometry of 1,3-butadiene in the s-trans conformation and the monopole charge of 0.49 e on each carbon yields an interaction energy <5 — 0.48 ev between the two double bonds. Simpson found the empirical value <5 = 1.91 ev from his assumption that only a London interaction was present. Hence it appears that only a small part of the interaction between double bonds in 1,3-butadiene is a London type of second-order electrical effect and the larger part is a conjugation or resonance associated with the structure with a double bond in the central position. 

Ref 5) CA Registry No 1493-05-6 It has been prepd by the reaction of Agnitrite with difluoroiodomethane (Ref 2) by the decarboxylation of difluoronitroacetic acid with anhyd K fluoride (Ref 3), or anhyd K carbonate, yield 46% (Ref 5) or by heating 1,1-difluoro-4-me thyl-1 -ni tro-2-triflu orome thy l-4-penten-2- ol to 100° with a trace of K hydroxide, yield 82% (Ref 4),... 

A mixture of 1.44 g. (0.0099 mole) of indole-3-carboxaldehyde,2 7.0 g. (0.053 mole) of diammonium hydrogen phosphate, 30 g. (30 ml., 0.34 mole) of 1-nitropropane, and 10 ml. of glacial acetic acid is refluxed for 12.5 hours. During the reflux period the pale-yellow mixture becomes dark red. The volatile reactants and solvent are removed under reduced pressure, and an excess of water is then added to the dark residue. After a short time, crude indole-3-carbonitrile precipitates rapidly. It is separated by filtration and dried under reduced pressure weight 1.20-1.34 g. (85-95%). Crystallization from acetone-hexane, with decoloriza-tion by activated carbon, yields 0.68-0.89 g. (48-63%) of fairly pure indole-3-carbonitrile, m.p. 179.5-182.5° (Note 1). 

The use of heterocyclic 1,2,3-amino, cyano, methylthio compounds with DMAD or DEAD in dimethyl sulfoxide in the presence of potassium carbonate yields polycyclic products, for example those shown in Scheme 8 <96H(42)53>. 

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