Hydrocrackate naphtha catalytic

Catalytic conversion processes include naphtha catalytic reforming, catalytic cracking, hydrocracking, hydrodealkylation, isomerization, alkylation, and polymerization. In these processes, one or more catalyst is used. A common factor among these processes is that most of the reactions are initiated hy an acid-type catalyst that promotes carhonium ion formation. 

Hydrogenation Hydroformylation 100-300 edible oils hydrogasification hydrocracking desulfurization catalytic cracking naphtha hydroforming coal liquefaction fatty alcohols 1-6-hexanediol 1-4-butanediol hexamethylenedi amine C4 to Cl5 products... 

In catalytic reforming, a low octane naphtha cut (typically a straight run or hydrocracked naphtha) is converted into high-octane aromatics, including benzene, toluene, and mixed xylenes. Aromatics are separated from the reformate by using a solvent such as diethylene glycol or sulfolane and then stripped from the solvent. Distillation is then used to separate the benzene-toluene-xylene into its components. 

Catalytic reformer feeds are saturated (i.e., not olefinic) materials in the majority of cases that feed may be a straight-run naphtha but in others by-product low-octane naphtha (e.g., coker naphtha) can be processed after treatment to remove olefins and other contaminants. Hydrocracker naphtha that contains substantial quantities of naphthenes is also a suitable feed. 

If not removed, mercaptans in hydrocracker naphtha may cause problems for downstream catalytic reforming units. Often, they are removed with a post-treat bed - a small layer of hydrotreating catalyst imdemeath the last... 

Catalytic Reforming. Worldwide, approximately 30% of commercial benzene is produced by catalytic reforming, a process ia which aromatic molecules are produced from the dehydrogenation of cycloparaffins, dehydroisomerization of alkyl cyclopentanes, and the cycHzation and subsequent dehydrogenation of paraffins (36). The feed to the catalytic reformer may be a straight-mn, hydrocracked, or thermally cracked naphtha fraction ia the... 

Naphtha is also obtained from other refinery processing units such as catalytic cracking, hydrocracking, and coking units. The composition of naphtha, which varies appreciably, depends mainly on the cmde type and whether it is obtained from atmospheric distillation or other processing units. 

Kerosine, a distillate fraction heavier than naphtha, is normally a product from distilling crude oils under atmospheric pressures. It may also he obtained as a product from thermal and catalytic cracking or hydrocracking units. Kerosines from cracking units are usually less stable than those produced from atmospheric distillation and hydrocracking units due to presence of variable amounts of olefinic constituents. 

This reaction is endothermic and is favored by low pressure. In practice, however, the process is conducted at a pressure of 1-3 MPa (because of a concurrent hydrocracking reaction) and a temperature of 300-450°C using Pt-based catalysts [7]. The feedstock for the reforming process must be carefully purified from S- and N-compounds (below 1 ppm), which may use up a significant portion of hydrogen produced. The typical composition of the off-gas from the catalytic reforming of naphtha is as follows (vol%) H2—82, CH4—7, C2—5, C3—4, and C4—2 [7]. 

To produce the maximum yield of finished gasoline in a hydrocracker-reformer combination, the hydrocracker should be operated to give maximum liquid yields, followed by a modem low pressure catalytic reformer to give the desired octane improvement (6). More severe hydrocracker operation produces higher octane naphtha but leads to an increase in the production of butanes with reduced yields of finished... 

In the platforming process (Fig. 1), the feedstock is usually a straight-run, thermally cracked, catalytically cracked, or hydrocracked C6 to 200°C naphtha. The feed is first hydrotreated to remove sulfur, nitrogen, or oxygen compounds that would foul the catalyst, and also to remove olefins present in cracked naphthas. The hydrotreated feed is then mixed with recycled hydrogen and preheated to 495 to 525°C at pressures of 116 to 725 psi (0.8 to 5 MPa). Typical hydrogen charge ratios of 4000 to 8000 standard cubic feet per barrel (scf/bbl) of feed are necessary. 

Catalytic reforming Naphtha hydrotreating Distillate hydrotreating Gas oil desulfurization Resid desulfurization Resid hydrocracking... 

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