Petrochemicals naphthenes

A petrochemical is any chemical (as distinct from fuels and petroleum products) manufactured from petroleum (and natural gas) and used for a variety of commercial purposes (Table 3.8). The definition, however, has been broadened to include the entire range of aliphatic, aromatic, and naphthenic organic chemicals, as well as carbon black and inorganic materials such as sulfur and anunonia. Petroleum and natural gas are made up of hydrocarbon molecules, which comprise one or more carbon atoms to which hydrogen atoms are attached. Currently,... 

Figure 5.33 shows an example dataset of mixed hydrocarbons used as a petrochemical feedstock. These are straight run naphthas, which consist of a wide range of alkane, isoalkane, aromatic and naphthenic... 

In 2000 two major petrochemical companies installed process NMR systems on the feed streams to steam crackers in their production complexes where they provided feed forward stream characterization to the Spyro reactor models used to optimize the production processes. The analysis was comprised of PLS prediction of n-paraffins, /xo-paraffins, naphthenes, and aromatics calibrated to GC analysis (PINA) with speciation of C4-C10 for each of the hydrocarbon groups. Figure 10.22 shows typical NMR spectral variability for naphtha streams. Table 10.2 shows the PLS calibration performance obtained with cross validation for... 

Figure 3.8 shows an example dataset of mixed hydrocarbons used as a petrochemical feedstock. These are straight-run naphthas which consist of a wide range of alkane, alkene, aromatic and naphthenic hydrocarbons, mainly in the range of C4-C9. The conventional analytical method for naphtha analysis is temperature-programmed gas chromatography (GC), which can provide a full analysis including C-number breakdown, but which is rather slow for process optimisation purposes. 

Another UOP zeolitic process that produces petrochemical feedstocks is the MaxEne process (27). The MaxEne process, another member of the Sorbex family of processes, separates C5 to Cn full-range naphtha into an extract stream containing more than 90 wt-% normal paraffins and a raffinate stream containing over 99 wt-% non-normals, namely isoparaffins plus naphthenic and aromatic hydrocarbons. The high normal-paraffin content of the extract makes it a preferred feedstock for a naphtha steam cracker, and the absence of normal paraffins in the raffinate makes it a preferred feedstock for catalytic reforming. 

The development of modem chemistry in the past thirty years dearly demonstrates that oil and natural gas are the ideal raw materials for the synthesis of most mass-consumption chemicals. In addition to the fact that they have been and still are very widely available, they are formed espedally in the case of oil, of a wide variety of compounds providing access to a multitude of possible hydrocarbon structures. The biological and physicochemical processes that contributed to their formation have furnished, apart from a certain quantity of aromatic hydrocarbons, a large proportion of saturated hydrocarbons (paraffins and naphthenes). In fact, these compounds generally display low reactivity, so that it is not easy to obtain the desired finished products. This is why the production of these derivatives entails a sequence of chemical operations which, in practice, require the combination of the facilities in which they take place within giant petrochemical complexes. 

Often naphtha is split at about lOO C into a heavy and a light fraction. The light fractions tend to have a higher paraffin content and more attractive to petrochemical operators and the heavy fraetion containing higher levels of naphthenes and aromatics are of interest to refiners for reforming into high octane blend stock. 

Paraffins - Obsolescent term for saturated hydrocarbons, commonly but not necessarily acyclic. Still widely used in the petrochemical industry, where the term designates acyclic saturated hydrocarbons, and stands in contradistinction to naphthenes. [5]... 

When converting paraffins and naphthenes by catalytic reforming into aromatics, hydrogen is released in relatively pure form. Reforming is therefore an important source of hydrogen for the refinery and the associated petrochemical plants. 

Feedstock Composition. Feedstock to a reformer typically contains paraffins, naphthenes, and aromatics ranging in the number of carbon atoms from six to twelve. Feedstocks to a reformer are typically called naphthas. These naphthas are reformed to produce high octane motor fuels or aromatics for petrochemical applications. A description of the sources of naphtha is given, followed by a more detailed description of naphtha s chemical composition, analytical characterization, and reactions. Most naphthas are treated in a process called... 

Reforming units specifically used for the production of aromatics are called BTX reformers. The acronym BTX is based upon the desire to produce benzene, toluene, and xylenes as petrochemical feedstocks. Naphthas for theses units consist substantially of naphthenes and paraffins of six to eight carbons. The desired reaction is aromatization through dehydrogenation of the naphthenes and cy-clization and dehydrogenation of the paraffins to the analogous aromatic. Characterization of Products. 

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