PETROLEUM CRACKER

They are classified apart in this text because their use differs from that of petroleum solvents they are used as raw materials for petrochemicals, particularly as feeds to steam crackers. Naphthas are thus industrial intermediates and not consumer products. Consequently, naphthas are not subject to governmental specifications, but only to commercial specifications that are re-negotiated for each contract. Nevertheless, naphthas are in a relatively homogeneous class and represent a large enough tonnage so that the best known properties to be highlighted here. 

Until 1960, coal was the source material for almost all benzene produced in Europe. Petroleum benzene was first produced in Europe by the United Kingdom in 1952, by Erance in 1958, by the Eederal Republic of Germany in 1961, and by Italy in 1962. Coal has continued to decline as a benzene source in Europe, and this is evident with the closure of coke ovens in Germany (73). Most of the benzene produced in Europe is now derived from petroleum or pyrolysis gasoline. In Europe, pyrolysis gasoline is a popular source of benzene because European steam crackers mn on heavier feedstocks than those in the United States (73). 

Table 6 compares the total production of butylenes in the United States, Western Europe, andjapan. Included in this table are relative amounts of productions from different processes. In the United States, about 92% of the butylene production comes from refinery sources, whereas only about 45% in Western Europe andjapan are from this source. This difference arises because the latter cracks mostiy petroleum distillates in the steam crackers that produce larger amounts of butylenes than the light feedstocks cracked in the United States. 

Additive inhibitors have been developed to reduce the contaminant coke produced through nickel-cataly2ed reactions. These inhibitors are injected into the feed stream going to the catalytic cracker. The additive forms a nickel complex that deposits the nickel on the catalyst in a less catalyticaHy active state. The first such additive was an antimony compound developed and first used in 1976 by Phillips Petroleum. The use of the antimony additive reportedly reduced coke yields by 15% in a commercial trial (17). 

Unlike coke produced from coal, petroleum cokes are derived from the residua of petroleum refining. Suitable feedstocks for good quality coke are thermal tars, catalytic cracker bottoms, and decant oils [17]. 

Separation of raw feedstock. The pyrolysis of petroleum feedstream is carried out at 650-900°C at normal pressure in the presence of steam. The so-called steam-cracking process involves carbon-carbon splitting of saturated, unsaturated and aromatic molecules. The following steam-cracker fractions are used as raw materials to produce hydrocarbon resins. 

Before proceeding, it is helpful to examine how a typical cat cracker fits into the refinery process. A petroleum refinery is composed of several processing units that convert raw crude oil into usable products such as gasoline, diesel, and jet fuel (Figure 1-4). 

The overhead stream from the debutanizer or stabilizer is a mix of C, s and C4 s, usually referred to as LPG (liquefied petroleum gas). It is rich in olefins, propylene, and butylene. These light olefins play an important role in the manufacture of reformulated gasoline (RFG). Depending on the refinery s configuration, the cat cracker s LPG is used in the following areas ... 

Assuming that demand for petroleum continues to increase at a rate of 1.2% per annum to 2010,37 and that all gasoline and diesel produced by U.S. refineries will have a sulfur content of less than 30 ppm, desulfurization of gasoline and diesel to these low levels will require extensive hydrotreating of both catalytic cracker feed and product of distillate. 

Of the many factors which influence product yields in a fluid catalytic cracker, the feed stock quality and the catalyst composition are of particular interest as they can be controlled only to a limited extent by the refiner. In the past decade there has been a trend towards using heavier feedstocks in the FCC-unit. This trend is expected to continue in the foreseeable future. It is therefore important to study how molecular types, characteristic not only of heavy petroleum oil but also of e.g. coal liquid, shale oil and biomass oil, respond to cracking over catalysts of different compositions. 

This paper discusses developments in solvent extraction with emphasis on applications to petroleum fractions in the kerosene and heavier boiling range. Many of these techniques have been extended to the refining of gasoline, Diesel fuels, catalytic cracker feed and cycle stocks, and butadiene. 

In the cracker, heavy oil cracking and the steam-iron reaction take place simultaneously under conditions similar to thermal cracking. Any unconverted feedstock is recycled to the cracker from the bottom of the scrubber. The scrubber effluent is separated into hydrogen gas, liquefied petroleum gas (LPG), and liquid products that can be upgraded by conventional technologies to priority products. 

Well over 50 large-scale EO model-based RTO applications have been deployed for petroleum refining processes. These model applications have been deployed in petroleum refineries Liporace et al., 2009 Camolesi et al., 2008 Mudt et al., 1995, both on separation units (crude atmospheric and vacuum distillation units) and on reactor units (including fluidized catalytic crackers (FCC), gasoline reformers, and hydrocrackers). 

Phillips, Qatar Petroleum, and Total is investing in a 1.3 mmt/year cracker in Ras Laffan, Qatar. However, because ethane production is linked to gas and oil production, the Middle East ethane supply will be able to meet only around 17 percent of global ethylene demand, which is expected to be 135 mmt/year by 2010 (Fig. 7.6). 

Together with China Petroleum Chemical Corp. (Sinopec) in a 50-50 partnership, BASF planned to build its first Verbund project in East Asia - an integrated petrochemical site (IPS) on 220 hectares of land. The core of the project was an ethylene cracker with a capacity of 600,000 tons per year. Nine new plants downstream would be supplied by the cracker, producing 1.7 million metric tons of chemical products for local consumption, including ethylene, aromatics, poly-ethylenes, ethylene oxide and ethylene glycols, acrylic acid, acrylates, oxo alcohols, formic acid, propionic acid, methylamine, and dimethylformamide. 

Phillips Petroleum Company discovered and developed the antimony metals passivation process in the early 1970 s, and successfully applied the process at its Borger, Texas heavy oil cracker (HOC) in 1976 (2). For catalytic cracking units with... 

The oil furnace process uses aromatic petroleum oils and residues as feedstock and in the oil furnace process (Fig. 1), a highly aromatic feedstock oil (usually a refinery catalytic cracker residue or coal tar-derived material) is converted to the desired grade of carbon black by partial combustion and pyrolysis at 1400 to 1650°C in a refractory (mainly alumina) -lined steel reactor. 

Fluidized beds are used for both catalytic and noncatalytic reactions. In the catalytic category, there are fluidized catalytic crackers of petroleum, acrylonitrile production from propylene and ammonia, and the chlorination of olefins to alkyl chlorides. Noncatalytic reactions include fluidized combustion of coal and calcination of lime. 

To facilitate the maintenance and updating of plant performance inputs, we have developed and implemented an LP preprocessor. This preprocessor automatically generates and stores in the LP database the usage of equipment and utilities, the product yields, and the product properties for six process units at Sun Petroleum Products Company s Toledo Refinery. Linked to the preprocessor are three already existing process simulators a fluid catalytic cracker or FCC simulator, a hydrocracker simulator, and a catalytic reformer simulator. 

Catalytic Cracker Bottoms (CCB) which is the heavy residue from the catalytic cracking of petroleum distillate is a common aromatic feedstock used for synthetic carbons and pitch production. CCB, like other heavy aromatic feedstock, is composed of alkyl-substituted polycondensed aromatics with a very wide molecular weight distribution. 

The large distillation tower at left is used to separate petroleum into fractions based on their boiling points. The cat cracker at right uses catalysts and high temperatures to crack large molecules into smaller ones. 

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