Hydrogen yields

The performance of the MEC reactor for hydrogen generation can be evaluated using different methods. The hydrogen yield based on COD removal, Jh2 (mg-H2/mg-COD) is calculated as 

For known substrates, it is easier to base the calculation on the mass of substrate used. Assuming a change in the mass concentration of substrate, C5, with a molecular weight of Ms, the yield Th2 (g-H2/g-substrate) is 

Glucose fermentation by bacteria can produce a maximum of 4 mol-H2/mol-glu. (a) Compare this to the the maximum molar and mass yields for hydrogen production in a MEC process, (b) Convert this to volumetric yields at 30 C. 

we can produce 12 moles of hydrogen as a result of a removal of 24 e per mole of glucose. The mass yield is calculated as 

These results are summarized in Table 8.1, along with the volumes at 0 C, for complete glucose oxidation versus that possible from fermentation. 

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The sex attractant by which the female housefly attracts the male has the molecular formula C23H46 Catalytic hydrogenation yields an alkane of molecular formula C23H4g Ozonolysis yields... 

A useful alternative to catalytic partial hydrogenation for converting alkynes to alkenes IS reduction by a Group I metal (lithium sodium or potassium) m liquid ammonia The unique feature of metal-ammonia reduction is that it converts alkynes to trans alkenes whereas catalytic hydrogenation yields cis alkenes Thus from the same alkyne one can prepare either a cis or a trans alkene by choosing the appropriate reaction conditions... 

Alkynes are completely hydrogenated yielding alkanes in the presence of the customary metal hydrogenation catalysts... 

Introduction of a 16P-methyl group into the corticosteroid molecule was effected by a reaction (83) whereby a 16-dehydropregnenolone (62) was treated with dia2omethane to form the pyra2oline (75) which was decomposed with perchloric acid in acetone to give the 16-methylpregn-16-en-20-one derivative (76). Catalytic hydrogenation yielded the 16P-methyl intermediate (77), which was converted into... 

The 0X0 and aldol reactions may be combined if the cobalt catalyst is modified by the addition of organic—soluble compounds of 2inc or other metals. Thus, propylene, hydrogen, and carbon monoxide give a mixture of aldehydes and 2-ethylhexenaldehyde [123-05-7] which, on hydrogenation, yield the corresponding alcohols. 

After the steam reforming step, the product gas stream contains a considerable quantity of carbon monoxide which may undergo reaction with additional steam, thereby increasing the hydrogen yield ... 

A useful apphcation of phosphines for replacing a carbonyl function with a carbon—carbon double bond is the Wittig reaction (91). A tertiary phosphine, usually triphenylphosphine, treated with the appropriate alkyl halide which must include at least one a-hydrogen, yields the quaternary salt [1779A9-3] which is then dehydrohalogenated to form the Wittig reagent, methylenetriphenylphosphorane [19943-09-5] an yhde. 

In disproportionation, rosin is heated over a catalyst to transfer hydrogen, yielding dehydro (5) and dihydro (8) resin acids. The dehydro acids are stabilized by the aromatic ring the dihydro acids contain only an isolated double bond in place of the less stable conjugated double bonds. 

The first commercial oil-fumace process was put into operation in 1943 by the Phillips Petroleum Co. in Borger, Texas. The oil-fumace blacks rapidly displaced all other types used for the reinforcement of mbber and today account for practically all carbon black production. In the oil-fumace process heavy aromatic residual oils are atomized into a primary combustion flame where the excess oxygen in the primary zone bums a portion of the residual oil to maintain flame temperatures, and the remaining oil is thermally decomposed into carbon and hydrogen. Yields in this process are in the range of 35 to 50% based on the total carbon input. A broad range of product quaHties can be produced. 

As severity is increased, C5+ gasoline yields decrease, with a corresponding increase in C, to C4 products. Hydrogen yields increase with severity until the level at which no further aromatics are produced as severity is increased even further, hydrogen yields then decrease. 

Seheuing and Winterhalder treated 2 6-distr3rrylpyridine tetra-bromide with potassium hydroxide in alcohol, so producing 2 6-di-)3-phenylacetylenylpyridine (XI) which by the action of 50 per cent, sulphuric acid was converted into 2 6-diphenacylpyridine (XII), and this, on hydrogenation in presence of platinic oxide, barium sulphate and methyl alcohol, was reduced to 2 6-di-(6-hydroxy-(6-phenylethylpyridine, and the hydrochloride of this, on similar catalytic hydrogenation, yielded worlobelanidine (XIII). This can be methylated to lobelanidine, from which in turn dMobeline and lobelanine can be obtained. 

Hydroxylaudanosims. King, I Ecuyer and Pyman have shown that papaverinol methochloride prisms, m.p. 211-2° corr.), on catalytic hydrogenation yields tw o hydroxylaudanosines,... 

Since dihydrothebainone is also formed by hydrogenation of thebainone (Schopf and Hirsch i), and as Schopf and Pfeifer have shown that 1 5-dibromodihydrothebainone, on treatment with alkali, is converted into. 1-bromodihydrocodeinone by formation-of the C -C oxygen bridge, and this, on catalytic hydrogenation, yields dihydrocodeinone (LIII, p. 246), the constitution of which has been demonstrated by Schopf (p. 244), there can be little doubt that dihydrothebainone is represented by (LI). Schopf and Winterhalder have also isolated as an oxime (m.p. 228°, [a] °° — 115-8°) an e.pidihydrothebainone, which is regarded as the epimeride of dihydrothebainone. 

Papaverine was condensed with formaldehyde to methylenepapaverine (XXII), which on successive catalytic and electrolytic hydrogenation yielded two dZ-methyltetrahydropapaverines (XXIII), which on successive demethylation, condensation with formaldehyde and re-methylation yielded a mixture of bases, from which the two optically inactive corydalines (XXIV), jwesocorydaline, m.p. 163-4° (nac.), and dZ-corydaline, m.p. 132-3°, identical with the products obtained by the hydrogenation of dehydrocorydaline were isolated. For the conversion of corycavine to corydaline, see p. 304. 

It contains one double bond and on catalytic hydrogenation yields N(6)-niethyldihydroclia odihydroneostrychnidine-A, m.p. 177 , isomeric with (5). 

Teloidine, the basic hydrolytic product of meteloidine, has been synthesised recently under physiological conditions by Schdpf and Arnold, on the lines of the tropinone synthesis, mesotartaric aldehyde (CHOH. CHO)j, being condensed at 25° with aeetonediearboxylic acid bnd methylamine hydrochloride to teloidinone (5-keto-l 2-dihydroxy-tropane) whieh on eatalytic hydrogenation yielded teloidine (1 2 5-trihydroxytropane). 

The bicyclic nature of the labile adduct (79) from 3-methyl-pyridine was established by Acheson and Taylor who found that hydrogenation, yielding (80), followed by oxidation gave pyridine-3,4,5-tricarboxylic acid. This conclusion is consistent with Diels and Alder s observations that acid hydrolysis of the labile pyridine adduct gave pyridine and some crotonaldehyde, whereas alkaline hy-... 

Hydrogenation of 2- (4-oxo-4//-pyrido[l, 2-n]pyrimidin-2-yl)oxymethyl -4-isopropyl-6-alkoxysaccharins 134 over 10% Pd/C catalyst at 50 psi Parr hydrogenator yielded 6,7,8,9-tetrahydro derivatives 135... 

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