Processed naphthas, compositions

The compositions of progressively processed naphtha were also determined by mass spectrographic analysis and are summarized in Table VI. These show the expected shifts from paraffins in the straight-run naphtha as well as naphtha from hydrocracking LGO to aromatics, especially benzenes in the reformate. 

Quantitative analysis by NIR of petrochemicals dates back to the 1930s. Since then a range of NIR calibrations have been developed, for example, for octane number, methyl group analysis, and methanol content in petroleum. NIR has been used to monitor water, detergent solids, and glycerol in shampoo, and to analyze moisture and lubricant levels on polymer films. Process NIR spectrometers have been used to monitor naphtha composition and NIR instrumentation has been used to monitor ethylene polymerization. 

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. 

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]. 

Introduction of zeolites into catalytic cracking improved the quality of the product and the efficiency of the process. It was estimated that this modification in catalyst composition in the United States alone saved over 200 million barrels of crude oil in 1977. The use of bimetallic catalysts in reforming of naphthas, a basic process for the production of high-octane gasoline and petrochemicals, resulted in great improvement in the catalytic performance of the process, and in considerable extension of catalyst life. New catalytic approaches to the development of synthetic fuels are being unveiled. 

The model is user friendly and the input requirements are simple. An example of typical user input is shown in Table XIV, which contains all necessary information to run the model. In the example, charge stock information for a blend of two naphthas is produced by means of naphtha library codes the detailed composition developed by the module INPUT for the specified naphtha codes is shown in Table XV. Optional output of yields, temperature, and octane at six points through each reactor can also be generated. The process and reactor conditions are summarized in Table XVI, and complete yields along with the product properties are shown in Table XVII. 

For commercial simulations, KINPTR s selectivity kinetics determine the reformate composition and overall yield at a target reformate octane. Reformer yield-octane behavior from pilot and commercial units are shown in Fig. 29a. The large variation in the reformate yields at a given octane, as much as 25%, results from the wide range of process conditions and naphtha feed quality used in Mobil reformers. As demonstrated in Fig. 29b, KINPTR accurately normalizes these reformate yields over a wide range of octanes, including those required for gasoline lead phaseout. 

Conventional Fixed-Bed Hydroforming. Pilot plant results on Hastings, California, East Texas, West Texas, and mid-continent heavy naphthas for the fixed-bed process are summarized in Table V the feed stock inspections are presented as Table VI. Yield-octane curves based on these data are on Figure 2, where the wide variation from naphthas of different compositions is apparent. The following tabulation shows the relative yields at two octane levels ... 

During World War II, an improved process was developed for producing petroleum naphthas ensuring unlimited quantities of toluene. Purification techniques were improved for TNT. Composites mixtures of TNT-PETN, TNT-RDX, TNT-tetryl, TNT-ammonium picrate, TNT aluminium, etc., were prepared. 

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