Refinery units

Petroleum asphalts, compared to native asphalts, are organic with only trace amounts of inorganic materials. They derive their characteristics from the nature of their cmde origins with some variation possible by choice of manufacturing process. Although there are a number of refineries or refinery units whose prime function is to produce asphalt, petroleum asphalt is primarily a product of integrated refineries (Fig. 1). Cmdes may be selected for these refineries for a variety of other product requirements and the asphalt (or residuum) produced may vary somewhat in characteristics from one refinery-cmde system to another and even by cut-point (Table 2) and asphalt content (Fig. 2) (5,6). The approximate asphalt yields (%) from various cmde oils are as follows ... 

For refinery units such as hydrocrackers in which the hydrogen partial pressure is much higher, e.g., above l,350psi and the operating temperatures are above 800°F, the 2 A Cr-1 Mo steel is eommonly used. The higher alloy... 

Butikofer (1986) Accidents in petrochemical and refinery units equipment and design failures 41% personnel and maintenance failures 41% inadequate procedures 11% inadequate inspection 5% other 2%... 

Figure 1-16B. Detailed layout and piping model for a refinery unit. Courtesy of Socony Mobil Oil Co. Inc.

In Fig. 4 we present the final induced decision tree, as well as the partition of the (xi,X4) plane defined by its leaves, together with a projection of all the available (x, y) pairs on the same plane. These two decision variables are clearly influencing the current performance of the refinery unit, and the decision tree leaves perform a reasonable partition of the plane. To achieve better performance, we must look for operating zones that will result in obtaining mostly y = 3 values. Terminal nodes 2... 

Nowadays more refineries are seeking lighter and higher quality products out of the heavy residues. Coking and other thermal processes convert heavy feedstocks, usually from distillation processes, to more desirable and valuable products that are suitable feeds for other refinery units. Such units include coking and visbreaking. 

In order to develop an ANN model for a refinery unit that is able to predict product yields and properties, one must first decide on the important inputs and outputs of the process. The choice of these inputs and outputs is the most important factor in successfully preparing an ANN model. These inputs and outputs must be chosen by carefully examining plant data. A good expertise in relation to the process is necessary. 

Reeently, several groups have investigated the eatalytie eonversion of bio-oils or model bio-oils over HZSM-5 eatalysts, and reeently a review was published deseribing how biomass eould be eonverted into fuels or ehemieals in a eonventional petrochemieal refinery in FCC or hydrotreating refinery units. 

Cycle Oil. Heavier, distillate range compounds formed during FCC processing can accumulate within the FCC fractionator. The primary fraction is called light cycle oil (LCO) and contains high percentages of monoaromatic and diaromatic compounds plus olefins and heavier branched paraffins. Unhydrotreated LCO is often quite unstable and has a very low cetane number. For this reason, it is blended into diesel fuel in controlled amounts. Heavy cycle oil and heavy naphtha are additional side cuts that can be produced. These streams can be pumped around to remove heat from the fractionator, used to supply heat to other refinery units, or used as low-quality blendstock component. 

Progress 23, 565-73 (1957) (Destruction of a large refinery unit by gaseous detonation)... 

Replace PSA with CO2 Recovery 15-20% 4-10% Decrease Same Increase Low/ High Purity Benefits in Refinery Units... 

Development of TOLPREP, the LP preprocessor system, was sponsored by Sun Petroleum s Toledo refinery as an improved method to perform a variety of economic studies. Since downstream refinery unit performance is affected by variations in... 

Sweeney, J. C., Smith, S. V., Brown, H. L., Hamel, B. B., and Grossman, E. D., "A Fundamental Approach to the Thermodynamic Configurational Analysis of Process Flowsheets as Applied to a Refinery Unit," Energy Institute Report No. 75-4, Drexel University, Philadelphia, PA, June (1975). 

As with most refinery units, the delayed coker has been updated to be as energy efficient as possible. Modern coker heaters now... 

ElfAtochem. At this stage anyway and for historical reasons the approach of TotalFinaElf can be considered unconventional when we compare it with that of the oil companies. With improving crude oil prices and better capacity utilization in their refinery units, the oil companies are concentrating their major reinvestments on what they consider to be their core business and limiting their production of chemicals to the base commodities derived from the olefins of the steam cracker or other feedstocks. 

The ratio can be expressed either as a percent or a decimal. For example, if a refinery unit undergoes one shutdown period for one month during a three-year duration, its operating factor is (36 - l)/36, or 0.972, or 97.2%. 

Distribution of Cases of Stress Corrosion Cracking Among Various Refinery Units... 

The nickel concentration on this particle is extremely low with traces of the nickel impurity at the external surface. This low nickel concentration means that the particle in Figure 2 was in the refinery unit only a short time, otherwise more nickel would be present for the average particle (by bulk chemical analysis) contains 900ppm Ni and 4700 ppm V. The particle in this image contains a disproportionate amount of vanadium relative to nickel. If the nickel on the external skin of the catalyst accumulates by nickel porphyrin cracking at the first surface contacted, then vanadium must arrive not only by cracking vanadyl porphyrins but also by some other means like transfer from older catalyst particles in the FCC unit. The high vanadium concentration relative to nickel on new catalyst particles provides evidence that vanadium has interparticle mobility as well as intraparticle mobility. 

Commodity chemicals share the same benefits of economies of scale. Typical process units are 1-2 orders of magnitude smaller than refinery units, although large methanol synthesis plants can produce up to several Mt/a (Section 4.7.1). Since a chemically pure material is being produced, often in a stoichiometric reaction, the catalyst system now becomes more specialized, the reactor may require special metallurgy, and product purification starts to be an issue. 

The 1984 AMOCO Oil hardcover book is an accumulation of nine individual, previously published booklets. The booklets are each chapters in the 1984 edition with titles including The Hazards of Water, The Hazards of Air, Safe Furnace Firing, Safe Ups and Downs for Refinery Units, The Hazards of Steam, and other fundamentals needed by operators, supervisors, and engineers. 

Arandes et al. [84] studied the catalytic degradation of several plastics (polypropylene, polystyrene, polystyrene-polybutadiene) dissolved in a light cycle oil (ECO) in a riser simulator of a ECC unit using both a fresh and an equilibrated ECC catalysts. Similarly, De la Puente [85, 112] studied the catalytic degradation of styrene-based polymers dissolved in benzene streams in the same riser simulator. Although the reported results are promising, oil refiners are reluctant regarding the inherent risks for the normal operation of the refinery units. 

A more interesting approach for co-processing is the conventional treatment of plastic with a heavy petroleum fraction blend in a refinery unit. The main advantage of this coprocessing method is that it utilizes existing processes within a refinery complex, resulting in reduced capital costs. Little research has focused on the co-processing of plastics with a feedstock of a refinery unit. Studies have been carried out with different plastics and refinery feeds. 

The principal limitation to co-processing is the need for important refining liquid streams which are necessary taking into account the limited amount of plastics that can be mixed, and the restricted use of chlorine and other hetereoatoms contained in the plastics that can negatively affect the refinery unit and catalyst. 

Reconciliation of 1989 Toxic Release Inventory Report and Pollution Prevention Inventory Yorktown Refinery (Units of TonsA ear)... 

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