Feedstock analysis

PyGC-MS/TG-MS Residual monomer/solvent identification, feedstock analysis... 

The deactivation of cracking catalysts by coking with vacuum gas oils (VGO) is studied in relation to the chemical deactivation due to site coverage, and with the increase of diffusional limitations. These two phenomena are taken into account by a simple deactivation function versus catalyst coke content. The parameters of this function arc discussed in relation to feedstock analysis and change of effective diffiisivity with catalyst coke content. 

Polymers, oils, and other organic materials can often be analyzed by dissolution in an organic solvent. Lubricating oil and petroleum feedstock analysis was discussed in Section... 

The next t5 ical catalyst bed in a hydrogen plant is the desulfiirizer bed. The desulfiirizer removes the H2S from the feed gas. The desulfiirizer catalyst bed design is based on the loading of the sulfur compounds. Therefore, the exiting gas from the desulfiirizer bed should be checked to ensure that the sulfur levels are below 0.1 ppmv. If the original design life of the catalyst bed is known, then periodic feedstock analysis can be used to forecast when the bed may require change out. 

The copolymer composition equation relates the r s to either the ratio [Eq. (7.15)] or the mole fraction [Eq. (7.18)] of the monomers in the feedstock and repeat units in the copolymer. To use this equation to evaluate rj and V2, the composition of a copolymer resulting from a feedstock of known composition must be measured. The composition of the feedstock itself must be known also, but we assume this poses no problems. The copolymer specimen must be obtained by proper sampling procedures, and purified of extraneous materials. Remember that monomers, initiators, and possibly solvents are involved in these reactions also, even though we have been focusing attention on the copolymer alone. The proportions of the two kinds of repeat unit in the copolymer is then determined by either chemical or physical methods. Elemental analysis has been the chemical method most widely used, although analysis for functional groups is also employed. 

Methods have been developed for analysis or deterrnination of free amino acids in blood, food, and feedstocks (116). In proteins, the first step is hydrolysis, then separation if necessary, and finally, analysis of the amino acid mixture. 

As can be seen from this analysis, the natural gas feedstock and capital charges amount to over 93% of the total production cost before return on investment. Therefore, energy consumption and capital investment are the key factors in determining ammonia production profitabiUty. 

Table 8 summarizes the Chem Systems analysis of the cost of production of BTX from these feeds, resulting ia a recommendation of the best-suited technology for each feedstock. 

PETROLEUM, FUELS, FEEDSTOCKS AND COMBUSTION ANALYSIS METHODOLOGIES... 

The analysis of combustion products presents problems of complexity similar to that of feedstock and raw fuel analysis. A highly complex matrix of aliphatic material often exists (as unburnt fuel in the combustion exhaust), whilst the species of interest, for example, carcinogens or mutagens are often at very low concentrations. A classic example of multidimensional GC is its use in the analysis of flue-cured tobacco essential oil condensate. 

Hydrocarbons heavier than methane that are present in natural gases are valuable raw materials and important fuels. They can be recovered by lean oil extraction. The first step in this scheme is to cool the treated gas by exchange with liquid propane. The cooled gas is then washed with a cold hydrocarbon liquid, which dissolves most of the condensable hydrocarbons. The uncondensed gas is dry natural gas and is composed mainly of methane with small amounts of ethane and heavier hydrocarbons. The condensed hydrocarbons or natural gas liquids (NGL) are stripped from the rich solvent, which is recycled. Table 1-2 compares the analysis of natural gas before and after treatment. Dry natural gas may then be used either as a fuel or as a chemical feedstock. 

Selecting the naphtha type can be an important processing procedure. For example, a paraffinic-base naphtha is a better feedstock for steam cracking units because paraffins are cracked at relatively lower temperatures than cycloparaffins. Alternately, a naphtha rich in cycloparaffins would be a better feedstock to catalytic reforming units because cyclo-paraffins are easily dehydrogenated to aromatic compounds. Table 2-5 is a typical analysis of naphtha from two crude oil types. 

A method has been developed which determines the amount of residual alk-ene and secondary alcohol in AOS using an aqueous-organic extraction solvent system followed by GC analysis. Alkanes present (impurities in the feedstock) will also be determined with the unreacted alkene. 

Gasafi et performed LCA in combination with a dominance analysis in order to identify hot-spots in process chains in early phases of process design to efficiently improve the environmental performance. The authors illustrated their approach on the example of super-critical water gasification for the treatment of organic feedstock with high moisture content. 

In a silane-hydrogen discharge the feedstock gases SiHa and H2 take part in all the processes that occur. A large number of reactions have been proposed (see e.g. Kushner [190]). Nienhuis et al. [191] have performed a sensitivity analysis in their self-consistent fluid model, from which a minimum set of reactions have been extracted for a typical low-pressure RF discharge. Tables II and III list these reactions. They will be used in the plasma models described in subsequent sections. The review articles on silane chemistry by Perrin et al. [192] and on hydrogen by Phelps [193] and Tawara et al. [194] have been used. The electron collision data are compiled in Figure 13 [189]. 

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