Petroleum products process schemes

Natural gas and crude oils are the main sources for hydrocarbon intermediates or secondary raw materials for the production of petrochemicals. From natural gas, ethane and LPG are recovered for use as intermediates in the production of olefins and diolefms. Important chemicals such as methanol and ammonia are also based on methane via synthesis gas. On the other hand, refinery gases from different crude oil processing schemes are important sources for olefins and LPG. Crude oil distillates and residues are precursors for olefins and aromatics via cracking and reforming processes. This chapter reviews the properties of the different hydrocarbon intermediates—paraffins, olefins, diolefms, and aromatics. Petroleum fractions and residues as mixtures of different hydrocarbon classes and hydrocarbon derivatives are discussed separately at the end of the chapter. 

Table 7.6 shows the solution of the refineries network using the SAA scheme with N = 2000 and N = 20000 where the proposed model required 790CPUs to converge to the optimal solution. In addition to the master production plan devised for each refinery, the solution proposed the amounts of each intermediate stream to be exchanged between the different processes in the refineries. The formulation considered the uncertainty in the imported crude oil prices, petroleum product prices and demand. The three refineries collaborate to satisfy a given local market demand where the model provides the production and blending level targets for the individual sites. The annual production cost across the facilities was found to be 6 650 868. 

Thus, investigations of the character of petroleum need to be focused on the influence of its character on refining operations and the nature of the products that will be produced. Furthermore, one means by which the character of petroleum has been studied is through its fractional composition. However, the fractional composition of petroleum varies markedly with the method of isolation or separation, thereby leading to potential complications (especially in the case of the heavier feedstocks) in the choice of suitable processing schemes for these feedstocks. 

Studies estimate that there are various synthetic fuel production technologies and process schemes available that can be competitive with petroleum-derived fuels under certain market conditions and prices (25). However, the high capital requirements and long planning and construction lead times create substantial risks. Additionally, the limited introduction of some of these technologies poses significant technical risks which may be unacceptable to project developers and investors. 

Modem petrochemical complexes manufacture various high-quality oils and fuels as well as new types of chemical products. The quality of these products depends on the quality of the initial raw material, i.e. crude petroleum. In the past, the technological processing scheme of older oil refineries could be used to process crude petroleum with mineral salts contents of 100—500 mg/L. Petroleum with a lower salt content is required in modern refineries. Thus, frequently before... 

Chapters 5 and 6 of Part III of the book introduce the reader to the science of crude oil refining. An illustration of the complete process scheme that starts from crude oil all the way to final products is given. In particular, the process route of crude oil from the well to the gas station and indeed the car tank is provided. These chapters also present the techniques and technologies involved in most of the important processes used in modern petroleum refineries for processing light and heavy distillate fractions. Chapter 7 in Part III looks at ecological problems that... 

Perhaps the best-known fluidized-bed process is the one developed by Gishler and Peterson (17, 24, 25) in Canada. The process scheme resembles that of catalytic cracking as used in the petroleum industry. Tar sand is fed to the pyrolysis or coker bed, where the oil vapor produced is carried by the fluidizing gas to the product collection system. Coked sand is withdrawn from the coker and blown by preheated air into the burner where the coke... 

These process schemes include three primary processing steps (i) s mthesis gas production, (ii) production of S5mthetic hydrocarbons, and (iii) upgrading of the S5mthetic hydrocarbons to commercial products. Additionally, all of them include oxygen plants and all the utilities normally included in petroleum refineries and chemical plants. 

The Secunda process scheme was conceived to maximize gasoline production - therefore, it includes hydroprocessing and catalytic reformers similar to those used in petroleum refineries. Due to the scale of operation, it includes facilities for the recovered of ethylene, alcohols, ketones, phenols, ammonia and other chemical products. Its twin plant at the same location, Sasol 3, has a very similar configuration. At present all the original Synthol reactors have been replaced by the more efficient Sasol Advanced Synthol (SAS) reactors, with capacities of up to 20 000 bpd per train. 

Having traversed some of the key events in the history of olefin metathesis, it is now appropriate to discuss some of the resultant fruits of that early labor in the form of practical applications in organic synthesis. Since the general reaction was bom in the industrial sector, we felt it appropriate to commence with some examples of commercial processes. Among several of the profitable industrial procedures that benefit from olefin metathesis, one of the oldest is the Phillips triolefin process (Scheme 7a) which utilizes a molybdenum-based catalyst system to convert propene (17) into a mixture of 2-butene (18) and ethene (19). These products are then used as monomers for polymer synthesis as well as for general use in petroleum-related applications. The reverse reaction can also be employed to prepare propene for alternative uses. 

Although olefins are intermediates in this reaction, the final product contains a very low olefin concentration. The overall reaction is endothermic due to the predominance of dehydrogenation and cracking. Methane and ethane are by-products from the cracking reaction. Table 6-1 shows the product yields obtained from the Cyclar process developed jointly by British Petroleum and UOP. ° A simplified flow scheme for the Cyclar process is shown in Figure 6-6. 

The production ofp-xylene begins with petroleum naphtha, as does the production of the other mixed xylene components, benzene and toluene. Naphtha is chemically transformed to the desired petrochemical components and the individual components are recovered at required purity in what is known in the industry as an aromatics complex [12]. A generic aromatics complex flow scheme is shown in Figure 7.2. It is useful to briefly review the general flow scheme of this complex for subsequent discussion of the liquid adsorptive processes. The process blocks... 

The complex nature of the HDS and HDN problems requires a broad, transdisciplinary approach in order to try to answer the most varied questions related to these important classes of reactions. The key issues include the practical aspects related to process and product engineering, a precise knowledge of the nature and the composition of petroleum and of refinery fractions, and the thermodynamics and detailed kinetics of the different processes involved. Also, a number of more fundamental solid-state and surface chemistry considerations regarding the preparation, the characterization, and the resulting properties of HDS and HDN catalysts, as well as the complicated reaction mechanisms involved for the various important families of substrates, need to be understood in depth. Even though some very impressive achievements have been disclosed over the last 30-40 years, it seems that some of the major new discoveries desired today may have been held back by the lack of a better understanding of some key issues. Of particular importance are the nature and the structure of HDS-HDN active sites on metal sulfide catalysts, and the intimate details of the elementary reactions implicated in the commonly accepted catalytic schemes. 

Refining operations (of which at least 80% are catalytic processes) are designed to transform and purify various petroleum cuts, derived from primary distillation, into the various fuels and refined products. As a reminder, a list of the main refining units is shown as a simplified refining scheme in Figs. 2 and 3. 

Major advancement in minimizing processing risks will be accomplished by using arrays of micro-reactors, in series or in parallel, in conjunction with robotics and sophisticated control schemes. The use of mini-factories will also enhance product flexibility and production agility. Most chemical plants, except those for petroleum cracking and well-established bulk materials, will be miniaturized to the extent possible. This will be another paradigm of manufacturing. 

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