Liquid products characterization

Products from coking processes vary considerably with feed type and process conditions. These products are hydrocarbon gases, cracked naphtha, middle distillates, and coke. The gas and liquid products are characterized by a high percentage of unsaturation. Hydrotreatment is usually required to saturate olefinic compounds and to desulfurize products from coking units. 

A wide variety of liquid products are produced from petroleum, that varying from high-volatile naphtha to low-volatile lubricating oil (Guthrie, 1967 Speight, 1999). The liquid products are often characterized by a variety of techniques including measurement of physical properties and fractionation into group types (Chapter 7). 

Detailed analysis of residual products, such as residual fuel oil, is more complex than the analysis of lower-molecular-weight liquid products. As with other products, there are a variety of physical property measurements that are required to determine that residnal fnel oil meets specifications. But the range of molecular types present in petrolenm prodncts increases significantly with an increase in the molecular weight (i.e., an increase in the number of carbon atoms per molecule). Therefore, characterization measurements or studies cannot, and do not, focus on the identification of specific molecular structures. The focus tends to be on molecular classes (paraffins, naphthenes, aromatics, polycyclic compounds, and polar compounds). 

A frequent complication in the use of an insoluble polymeric support lies in the on-bead characterization of intermediates. Although techniques such as MAS NMR, gel-phase NMR, and single bead IR have had a tremendous effect on the rapid characterization of solid-phase intermediates [27-30], the inherent heterogeneity of solid-phase systems precludes the use of many traditional analytical methods. Liquid-phase synthesis does not suffer from this drawback and permits product characterization on soluble polymer supports by routine analytical methods including UV/visible, IR, and NMR spectroscopies as well as high resolution mass spectrometry. Even traditional synthetic methods such as TLC may be used to monitor reactions without requiring preliminary cleavage from the polymer support [10, 18, 19]. Moreover, aliquots taken for characterization may be returned to the reaction flask upon recovery from these nondestructive... 

A. Zandona, 0. J. Busch, L. E. Hettinger, W. P., Jr. "Reduced Crude Conversion Symposium on Production, Characterization and Processing of Heavy Oils, Tar Sand Bitumens, Shale Oils and Coal-Derived Liquids", University of Utah, 1981. 

How does the team characterize the process for which the pilot plant is to be manufactured The first question that needs to be answered is What is the ultimate goal for the facility Is it to support development for solid dosage forms, liquid products, or biologically derived products Or does it have to serve multiple functions The answer to this question will allow us to focus and generate more accurate plans. Until later on in the design phase, this process characterization should be kept broad and not very detailed. Included in the evaluation should be the ancillary service equipment and support services, such as electrical and air handling requirements. 

Liquid chromatography (also called adsorption chromatography) has helped to characterize the group composition of crude oils and hydrocarbon products since the beginning of this century. The type and relative amount of certain hydrocarbon classes in the matrix can have a profound effect on the quality and performance of the hydrocarbon product. The fluorescent indicator adsorption (FIA) method (ASTM D-1319) has been used to measure the paraffinic, olefinic, and aromatic content of gasoline, jet fuel, and liquid products in general (Suatoni and Garber, 1975 Miller et al., 1983 Norris and Rawdon, 1984). 

In 1999, Muzafarov and coworkers published a preliminary report describing the synthesis of a hyperbranched poly(siloxane) from triethoxysilanol via a rapid, ammonia-catalyzed condensation process (Scheme 28)192. The authors acknowledged the potential difficulties of this process (e.g. head-head condensation leading to crosslinked products) but presented 29Si NMR data to support their conclusion that hyperbranched polymer was formed. The fact that no gel formation was observed also suggested that the polymerization proceeded as expected. The polymer, a transparent, yellow liquid, was characterized with NMR and IR spectroscopy, and GPC. 

The remaining four distillate fractions were characterized in detail as was each liquid product obtained. The results for the starting materials are listed in Table I. 

The tests were conducted for a 3-day period. Gas products were taken and analyzed by mass spectrometry (MS). Daily liquid samples were taken and their nitrogen contents were determined. The liquid product taken at the end of the test period was characterized by elemental analysis, distillation, and benzene extraction. A representative sample of the spent catalyst was obtained by rifling, then washing with benzene. Its carbon content was determined. 

For the processes of different reactor types, kiln and retort pyrolysis processes are characterized by a relatively low capital investment. However, they suffer from unfavorable economics, due to the high processing costs compared with the value of the oil product obtained. Also, the characteristics of this process are relatively long residence times of waste in the reactor, poor temperature control due to large temperature gradients across their internal dimensions, fouling walls of the reactor by carbon residue and low liquid product quahty due to the production of a diverse number of pyrolysis products. 

M. F. Laresgoiti et al, Characterization of the liquid products obtained in tyre pyrolysis. Journal of Analytical and Applied Pyrolysis, 71, 917-934 (2004). 

While all pyrolysis oil production reactor systems produce similar materials, each reactor produces a unique compound slate. The first decision, especially for a potential chemical or fuel producer, rather than a reactor developer, is to determine what products to make and which reactor system to use. The operating parameters of any reactor system designed to produce pyrolysis oil, especially temperature, can be altered to change the pyrolysis oil product composition and yield. Different feedstocks will produce different pyrolysis oil compositions and by-products, e.g. amorphous silica from rice hulls or rice straw, fatty acids from pine. Finally, feedstock pretreatment and/or catalysis, or reactor-bed catalysis can be used to improve specific product yields (7). Reactor system developers need to examine what they can produce and make this information available to chemical manufacturers and suppliers/owners of biomass feedstocks. This assumes that analysis of die entire liquid product from thermal conversion can be made, including quantitative analysis for any compounds that are being considered for recoveiy. Physical characterization - pH, viscosity, solids content, etc.is also needed. However, what can be produced is of no value, if it cannot be recovered or used economically. This involves examining the trade-offs between yield and current commercial value, recovery costs, and potential commercial value,... 

G.c. - m.s. analyses of light liquid products was carried out using 40 m x 0,3 mm silica phased capillary column coated with SE 30 and connected with VQ-70HS mass spectrometer. Heavy liquid products (b.p, > 180 C) were analysed by n.m.r. spectroscopy ( Bruker MSL-400). For characterization of the heavy liquid products, their were separated on a particular families of compounds by a colume chromatography technique. Educed fractions were analysed by g.c. - m.s. technique. 

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