Pyrolysis gasoline composition

Dicyclopentadiene (DCPD) is usually recovered as a high value product from the byproduct pyrolysis gasoline stream that is generated in steam cracking furnaces (see Ethylene and Propylene by Steam Cracking ). U.S. 6,258,989 (to Phillips Petroleum) gives a typical pyrolysis gasoline composition and describes a suitable... 

Vised directly. To obtain very pure propylene (99.5 per cent weight), however, it is necessary to remove the propane in a supplementary column. Table 2.10 offers a glance at the specifications that the ethylene and propylene thus separated are required to meet The heavier hydrocarbons obtained at the bottom of the depropanizer are treaty in a debutanizer, which produces a l,3>butadiene-rich cut at the top. In accordance with the severity, Table 2.11 provides a typical example of the composition of this effluent for a naphtha feedstock. The pyrolysis gasoline drawn off at the bottom may, depending on the severity, contain 50 to S5 per cent weight of aromatic hydrocarbons, of which more than half is benzene. Its composition and treatment are discussed separately in Section 2.1.5. 

This composition represents an average C8 aromatic mixture obtained by extraction from a catalytic reformate. Inclusion of aromatic extracts from pyrolysis gasolines and/or prefractionation to remove ethylbenzene can cause a wide variation in fresh feed composition. 

NAPHTHA STEAM CRACKINQ, VARIATION IN COMPOSITION OF PYROLYSIS GASOLINES WI1II SEVERITY... 

Indications are given in Tables 4.13 and 4.14 for the main industrial processes. They vary widely according to the type of feed considered (toluene, aromatics blends, pyrolysis gasolines etc.) and the composition and conditions of supply of the hydrogen gas employed. 

The two most important sources of aromatics from steam cracking are pyrolysis gasoline and pyrolysis tar. The composition of typical pyrolysis gasoline from cracking is shown in Table 3.25. 

Table 4.3 shows the composition of a typical pyrolysis gasoline fraction after hydrogenation. 

Table 8.1 shows the composition of C9-aromatics fractions from pyrolysis gasoline and catalytic reforming. 

Figure 5.22 RON value and composition of the gasoline fraction produced in the catalytic conversion of a PE pyrolysis oil over REY zeolite, as functions of the temperature.46...

Typical compositions of Cs gasoline Am aromatic cuts PRODUCED BY NAPHTHA PYROLYSIS... 

The third source of BTX aromatics is benzole, which is formed during coking of hard coal. Because of the high temperature of carbonization, the benzene content of benzole (Table 4.4) is noticeably higher than that of pyrolysis and reformer gasolines. The composition of benzole, similarly to coal tar, is less variable than that of corresponding petroleum-based fractions. 

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