Yield, liquid

Evaporation from a spray of charged droplets produced from a stream of liquid yields ions that can be analyzed in a mass spectrometer. Thermally labile and normally nonvolatile substances such as sugars, peptides, and proteins can be examined successfully. 

A possible refinement to the proeess ean be made, partieularly to the 4.49 Btu lost on flashing the 200 psia saturated liquid to atmos-pherie pressure. If this were flashed first to 80 psia and then flashed to atmospherie pressure, over half of the flash gas would be released at 80 psia. The expansion of this gas in a turboexpander would reeover almost half of the total flash loss, and the liquid yield would inerease 4.74% plus eontribute 1% of the plant power. 

For more aromatics yield, the end point of the feed may be raised to include higher molecular weight hydrocarbons in favor of hydrocracking and dehydrocyclization. However, excessive hydrocracking is not desirable because it lowers liquid yields. 

Cracking n-hutane is also similar to ethane and propane, hut the yield of ethylene is even lower. It has been noted that cracking either propane or butanes at nearly similar severity produced approximately equal liquid yields. Mixtures of propane and butane LPG are becoming important steam cracker feedstocks for C2-C4 olefin production. It has been forecasted that world LPG markets will grow from 114.7 million metric tons/day in 1988 to 136.9 MMtpd in the year 2000, and the largest portion of growth will be in the chemicals field. 

A successful project is defined as one that meets its stated objectives (safety, improved reliability, increased liquid yield, reduced maintenance costs, etc.) on or under-budget and is completed on or ahead of schedule. Some of the helpful criteria that ensure a successful project are as follows ... 

From laboratory experiments, the internal energy of liquid water at room temperature is —8.1 kcal/mol. From our simulations, the two-body liquid yields an internal energy of —6.8 kcal/mol. The three-body liquid improves to —7.7 kcal/mol and the four-body liquid brings it to —8.95 kcal/mol. The quantum cor ... 

T, C dry gas % coke % liquid yield, % olefin in gasoline, % octane number... 

The effect of the following coal property parameters was studied in relation to liquid yields and conversions during coal hydrogenation using both experimental procedures. 

No data on liquid yields are available for the autoclave experiments because it is not possible to separate the product oil, which results from coal liquefaction, from the anthracene oil and its decomposition products. In the case of the hotrod experiments this complication does not exist. 

Figure 12. Effect of sulfur content on liquid yields and overall conversion (hot rod reactor) sand coal = 2 1 T = 450°C P = 25 MPa.

A comparison of potential yields from a combined SCT dissolution plus upgrading scheme with yields from other liquefaction schemes shows that the SCT scheme has potential to give significantly lower gas and higher liquid yields. This results in a more efficient utilization of hydrogen in the liquefaction process. 

Fundamental studies of coal liquefaction have shown that the structure of solvent molecules can determine the nature of liquid yields that result at any particular set of reaction conditions. One approach to understanding coal liquefaction chemistry is to use well-defined solvents or to study reactions of solvents with pure compounds which may represent bond-types that are likely present in coal [1,2]. It is postulated that one of the major routes in coal liquefaction is initiation by thermal activation to form free radicals which abstract hydrogen from any readily available source. The solvent may, therefore, function as a direct source of hydrogen (donor), indirect source of hydrogen (hydrogen-transfer agent), or may directly react with the coal (adduction). The actual role of solvent thus becomes a significant parameter. 

The bulk of the naphtha was hydrotreated and catalytically reformed over a chlorided Pt/Al203-based catalyst to produce an aromatic motor gasoline. However, the hydrotreated Fischer-Tropsch naphtha is a poor feed for standard catalytic reforming on account of its high linear hydrocarbon content (>75%).37 In order to limit liquid yield loss, typical operation resulted in a reformate with quite low octane value (Table 18.10). Higher octane reformate could be produced, but at the expense of significant liquid yield loss. 

MSCC [Millisecond catalytic cracking] A fluid catalytic cracking process which uses an ultra-short contact time reaction system. It is claimed that less capital investment and higher liquid yields can be achieved using this process, compared with conventional FCC units. Developed by Bar-Co and now offered by UOP it has been operating since 1994. 

For simplicity reasons, a liquid yield factor of one is assumed for bitumen upgrading operations. 

The literature on biomass fast pyrolysis is quite extensive and excellent research and technology reviews are available [51-55]. For an optimal fast pyrolysis process in terms of organic liquid yield the temperature is around 500 °C the biomass particle size should be small (<5 mm). 

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