From FCC gasoline

BTX recovery from FCC gasoline Carboxylic acid Dimethyl terephthlate Isomerization... 

Sulfur Removal by Selective Adsorption. The ConocoPhillips S Zorb process uses selective adsorption to remove sulfur from FCC gasoline." The feed is combined with a small amount of hydrogen, heated, and injected into an expanded fluid-bed reactor, where a proprietary sorbent removes sulfur from the feed. A disengaging zone in the reactor removes suspended sorbent from the vapor, which exits the reactor as a low-sulfur stock suitable for gasoline blending. 

Table 10.10 is an evaluation of the improvement resulting from the addition of alkylate and ethers to an FCC gasoline. 

Figures 1-1 through 1-3 contain sketches of typical unit configurations offered by some licensers. Although the mechanical configuration of individual FCC units may differ, their common objective is to upgrade low-value feedstock to more valuable products. Worldwide, about 45% of all gasoline comes from FCC and ancillary units, such as the alkylation unit.

In 1990, U.S. gasoline contained about 10 vol% olefins, the majority of which emanate from FCC gasoUne. FCC gasoline has 25 vol% to 35 vol% olefins. Of these olefins, Cg-C olefins account for about 85% of the total pool. For non-RFG gasoline, as with sulfur, the regulation allows the maximum olefin content to be 125% of the 1990 baseline values. 

Figure 11 SCD chromatogram of catalytic cracked (FCC) gasoline, demonstrating the selectivity for sulfur compounds. (A) SCD response (B) FID response. (Reprinted from American Laboratory 23(3) 117, 1991. Copyright 1991 by International Scientific Communications, Inc.)...

MBR [Mobil benzene reduction] A catalytic process for reducing the benzene content of gasoline. It combines features of three earlier processes benzene alkylation with tight olefins, olefin equilibration with aromatization, and selective paraffin cracking. The olefins are obtained from FCC offgas. The catalyst is a modified ZSM-5 zeolite. Developed by Mobil Research Development Corporation in 1993. 

Oxypro (1) A process for making di-isopropyl ether (DOPE) from a propane/propylene stream from FCC. The catalyst system is superior to other acid catalysts such as zeolites because of its greater activity at low temperatures. The Oxypro catalyst functions at below 175°C, whereas zeolites require temperatures closer to 260°C. DOPE is used as a gasoline additive. Developed by UOP in 1994 first licensed in Chile in 1996 for completion in 1997. 

When in 1984 the Environmental Protection Agency (EPA) proposed the lead phaseout from gasoline, the emphasis on FCC research shifted toward the generation of octane-selective catalysts. Environmental concerns have also proposed limits on sulfur emissions from FCC units, thus initiating research on on catalysts capable of sorbing S-impurities in the regenerator and releasing them as H S in the reactor side from where they can be easily adsorbed. 

To the extent that motor octane is dependent on aromatic and isoparaffin content, motor octane increases in an FCC unit will be difficult to achieve. Thermodynamics does not allow the production of highly branched isoparaffins in an FCC unit, and blending studies show that motor octane is relatively insensitive to the aromatic content of an FCC gasoline in the range of 35-507e aromatics. However, a more aromatic gasoline may have better blending characteristics in that less aromatics from other sources will be required to achieve the same motor octane number increase. 

Toluene / 50% Xylene mixture) on research octane (clear) of an FCC gasoline from a USY type of octane catalyst. 

The specifically formulated CGP-1 catalyst plays a vital role in the MIP-CGP process. Unique catalyst design, such as metal promoted MFl zeolite, phosphorus modified Y zeolite, and a novel matrix with excellent capability to accommodate coke [12] were involved to ensure the primary cracking and secondary reactions to proceed within a defined path. The commercial trial results of the MIP-CGP process in SINOPEC Jiujiang Company showed that, in combination with CGP-1 catalyst, the propylene yield was 8.96 wt%, which increased by more than 2.6% as compared with FCC process. The light ends yield and slurry yield are basically equal. The olefin content of the gasoline produced by MIP-CGP process was 15.0 v%, which was 26.1% lower than that of FCC gasoline. The sulfur content of gasoline was decreased from 400 to 270 pg/g. 

The study of the desulfurization of model oils, predesulfurized diesel oil, and FCC-gasoline focused on extraction by halogen-free ILs (alkylsul-fates of alkylmethylimidazoliums) was reported in Ref. 45. The highest DBT partition coefficient was observed for [C4CiIm][C8S04j. After four extraction steps, sulfur concentration in the oil decreased from 500 to 10 ppm. 

The feed used was an FCC gasoline sample obtained from a European refinery and was subsequently distilled to give an approximate boiling range of 35-190°C. 

FCC gasoline is an important gasoline blending stock world-wide- In Table 4.7, the FCC naphtha has a blending octane of 86 and comprises 38% of the gasoline pool. It contributes 98% of the pool sulfur, 98% of the pool olefins, and 35% of the pool aromatics. The heavy naphtha product from the hydrocracker, along with heavy... 

The PetroFCC process changes an FCC unit from a gasoline-producing device to a source of petrochemical feedstocks. It can provide both aromatic naphtha to an aromatics complex and light olefins to a polyolefins complex. Feedstock utilization can be further improved by recycling the raffinate by-product from BTX solvent extraction back to the PetroFCC reactor for conversion to light olefins. 

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