Hydrocarbon yields

Several biomass species have been found to contain oils and/or hydrocarbons (Table 13). It is apparent that oil or hydrocarbon formation is not limited to any one family or type of biomass. Interestingly, some species in the Euphorbiaceae family, which includes Hevea bra liensis form hydrocarbons having molecular weights considerably less than that of natural mbber at yields as high as 10 wt% of the plant. This corresponds to hydrocarbon yields of about 3.97 mVhm2-yr(25bbl/hm2-yr). 

Photolysis of Cp2TiAr2 in benzene solution yields titanocene and a variety of aryl products derived both intra- and intermolecularly (293—297). Dimethyl titan ocene photolyzed in hydrocarbons yields methane, but the hydrogen is derived from the other methyl group and from the cyclopentadienyl rings, as demonstrated by deuteration. Photolysis in the presence of diphenylacetylene yields the dimeric titanocycle (28) and a titanomethylation product [65090-11-1]. 

Chlorinated organics are hydrocarbons that have one or many chlorine atoms. Oxidation of chlorinated hydrocarbons yields COj, water vapor and hydrogen chloride (HCl) gas. Some typical chlorinated organics are TCE and PCE. These organics have calorific values as low as 5,000 BTU/lb. 

Hexahydrobenzoyloxodedelphonine acetate (VI) was dehydrogenated by selenium at 330° and gave as chief product a hydrocarbon, b.p. 90°/0-02 mm., whose composition, ultra-violet absorption spectrum and chemical properties, so far as examined, indicate that it may be a bicyclopentenobenzene and therefore in a different category from the phenanthrene hydrocarbons yielded by the atisine group of bases. 

Almost all of the biomedical research done in the 25 years following the liquid-breathing work was conducted with commercially available fluorocarbons manufactured for various industnal uses by the electrochemical Simons process (fluonnation in a hydrofluoric acid solution) or the cobalt fluoride process (fluori-nation with this solid in a furnace at about 200 C) These processes tended to yield many by-products, partly because they were, to some extent, free radical reactions and partly because it was difficult to easily achieve complete fluonnation Aromatic hydrocarbons gave better products with the cobalt tnfluonde [73] method, whereas saturated hydrocarbons yielded better products with fluonnation using diluted or cooled gaseous fluorine (Lagow) Incompletely fluormated matenal was either... 

Combustion (Section 2.18) Burning of a substance in the presence of oxygen. All hydrocarbons yield carbon dioxide and water when they undergo combustion. 

An isopropyl carbocation cannot experience a beta fission (no C-C bond beta to the carbon with the positive charge).It may either abstract a hydride ion from another hydrocarbon, yielding propane, or revert back to propene by eliminating a proton. This could explain the relatively higher yield of propene from catalytic cracking units than from thermal cracking units. 

Typical Mossbauer spectra for the fresh, reduced, carblded and used Fe/ZSM-5 system are shown in a composite Fig. 5. Similar spectra were obtained for the Fe-Co/ZSM-5 system. The product distribution for the F-T reaction, using the Fe and Fe-Co systems, are shown in Table 1. The gasoline range hydrocarbon yield increased from 75 to 94%, when the Fe-Co clusters were used in place of Fe only. In a typical CEMS (Conversion Electron Mossbauer Spectroscopy) of the Fe-Co system, no spectrum for 57pg vas observed even after one week from this. It was concluded that in the Fe-Co clusters Co was predominantly in the "mantle" and Fe species were In their "core," in the parlance of metallurgy/geophysics. This model Is sometimes referred to as the cherry model. 

However, it was generally found that the total C2 hydrocarbon selectivity decreases drastically with increasing conversion of methane, so that Yc2 (the total C2 hydrocarbon yield) was always found, until very recently, to be less than 30% [1-9]. Achieving C2 hydrocarbon yield in excess of 50% is a necessary requirement for the development of an economically viable industrial process. 

A measure for the hydrocarbon growth is the chain growth probability . For optimum liquid hydrocarbon yields, it is typically in the order of 0.85 to 0.90. 

The liquid hydrocarbon yield from the BTL production via gasification and FT synthesis is about 42% based on the LHV, which is similar to the production of BTL via gasification, methanol synthesis and the MtSynfuel process (Dena, 2006). 

In this energy chain, coal is gasified to generate synthesis gas. The H2 CO ratio required for an optimum efficiency is adjusted via the CO shift reaction of a part of the carbon monoxide (CO) contained in the synthesis gas. The remaining synthesis gas is converted to liquid hydrocarbons via Fischer-Tropsch synthesis or via methanol synthesis with a downstream MtSynfuels (trademark by Lurgi) process (see beginning of Section 7.3.4). The liquid hydrocarbon yield amounts to about 0.40 MJ per MJ of hard coal, which is of the same order of magnitude as in the case of BTL ( 0.40 MJ/MJ) to calculate the thermal process efficiency, the electricity export must also be taken into account (see Table 7.12). 

The goal of the calculation was to maximize recycle ratio of each recycle stream until the coke yield of the base feed at 70% conversion was reached. The calculated hydrocarbon yields, on the fresh feed basis are shown in Table 1.7. In the cases of the 650°F-750°F and 650°F-800°F streams, the maximum available recycle levels, based on SIMDIST (Table 1.2), were reached before the coke limit was hit therefore, the maximum available recycle ratio was used. 

Methanol was converted to hydrocarbons on HZSM5 and HUSY in the low temperature range 250 - 280 °C and the yield of hydrocarbons measured as a function of duration of experiment (Fig. 2). The reaction is seen to be highly autocatalytic. E. g. with the HZSM5 and 260 °C only after 30 minutes a small hydrocarbon yield of about 2 % is observed. Within the next 30 minutes the yield increases approximately exponentially and after 50 minutes duration of experiment a 100 % conversion of methanol to hydrocarbons and coke is obtained. Autocatalysis is very sensitive against temperature. At an only 10 °C lower reaction temperature the increase of hydrocarbon yield from about 5 to 50 % occurs, from 50 to 100 minutes after start of reaction. At 280 °C increase of hydrocarbon yield from zero to 100 Z occurs already in the period from 5 to 20 minutes and at 300 °C no autocatalysis is observable the degree of conversion... 

Fig. 2 Autocatalysis and retardation during methanol conversion on HZSM5 (left) and HUSY (right) at different temperatures. Yield of hydrocarbons (yield of coke neglected) as a function of duration of the experiment (inlet Pruonu =2.5 bar, WHSV = 1 h ) Catalysts HSZM5 Si/Al = 26, obtained from DEGlTSSiii HUSY basic cracking catalyst Si/Al = 4.5, obtained from Engelhard.

The complexes of heterocyclic compounds with acceptors of the type mentioned, like similar complexes of benzenoid hydrocarbons, yield a linear plot of energies of the first charge-transfer bands against HOMO energies of the donors.50 Table V presents experimental and theoretical data for complexes of pyridine-like heterocycles with... 

Solid Catalysts. Nafion-H is an active catalyst for acylation with aroyl halides and anhydrides.60,61 The reaction is carried out at the boiling point of the aromatic hydrocarbons. Yields with benzoyl chloride using 10-30% Nafion-H for benzene, toluene, and p-xylene are 14%, 85% and 82%, respectively. Attempted acylation with acetyl chloride, however, led to HC1 evolution and ketene formation. Nation resin-silica nanocomposite materials containing a dispersed form of the resin within silica exhibits significantly enhanced activity in Friedel-Crafts acylations.62,63... 

Naphtenic hydrocarbons yield products similar to paraffins upon oxidation. Aromatic hydrocarbons are che most readily oxidized constituents of lubricating oils. The end products are very complex condensation and polymerization products and tend to be Insoluble in oil. These products constitute the sludges, resins and varnishes which allegedly cause piston ring sticking in the engine. 

Hydrocarbons yield more energy upon combustion than do most other organic compounds, and it is, therefore, not surprising that one important type of food reserve, the fats, is essentially hydrocarbon in nature. In terms of energy content the component fatty acids are the most important. Most aerobic cells can oxidize fatty acids completely to C02 and water, a process that takes place within many bacteria, in the matrix space of animal mitochondria, in the peroxisomes of most eukaryotic cells, and to a lesser extent in the endoplasmic reticulum. 

Totally deuterated aromatic hydrocarbons yield measured phosphorescence lifetimes greater than their protonated analogs.182 This behavior is ascribed to the closer spacing of vibrational levels in deuterated compounds with a consequent decrease in probability for nonradiative T -> S0 transitions. Quantum mechanical tunnelling may also contribute to the rate of the radiationless process with the normal compounds. 

As expected, gaseous hydrocarbon yields and mineral carbonate decomposition increase with increases in temperature (Figure 9). The results are very encouraging—in all tests, over 90% of the organic carbon was recovered as gaseous and liquid products. At 1200°F, over 80% of the organic carbon was converted to liquids at 1400°F, over 60% was converted to gas. 

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