Heavy atmosphere gas oils

Figure 12.5. Diagram of the H-Coal process. DAO, de-ashed oil DEA, diethanolamine HAGO, heavy atmospheric gas oil HVGO, heavy vacuum gas oil.

Residues (petroleum), heavy coker and light vacuum Residues (petroleum), catalytic reformer fractionator Residues (petroleum), hydrodesulphurized atmospheric tower Residues (petroleum), topping plant, low sulphur Residues (petroleum), heavy coker gas oil and vacuum gas oil Residues (petroleum), thermal cracked... 

Gas oils Utilized as straight-run distillate after desulfurization. Lighter atmospheric and vacuum gas oils are often hydrocracked or catalytically cracked to produce gasoline, jet, and diesel fuel fractions heavy vacuum gas oils can be used to produce lubestocks or as fluid catalytic cracking (FCC) feedstock... 

Spent catalyst samples were collected from benchscate runs with Arabian heavy vacuum gas oil (VGO) or Kuwait atmospheric resid, For the VGO samples, the conditions of these runs were P = 50 atm., LHSV = 2.0 h 1, T = 375°C, run length approx. 500 hours. The testing of the resid samples was performed at P = 123 atm., LHSV = 0,25 h 1, T -407°C and a run length of 7500 hm. The catalysts were presulfided for 24 hours at 350°C and 100 aim. using the VGO, After presulfiding and introduction of test conditions, the feedstock was introduced. 

In present-day refineries, the fluid catalytic cracking (FCC) unit has become the major gasoline-producing unit. The FCC s major purpose is to upgrade heavy fractions, that is, gas oil from the atmospheric and vacuum distillation columns and delayed coker, into light products. Atmospheric gas oil has a boiling range of between 650-725°F.9... 

The atmospheric residuum is then fed to the vacuum distillation unit at the pressure of 10 mmHg where light vacuum gas oil, heavy vacuum gas oil, and vacuum residue are the products (Fig. 13.4). 

Figure 8. Combined fingerprints of light-(LAGO) and heavy-(HAGO) atmospheric gas oils...

The nature of crude oils depends on their source. Initial separation into components is carried out by atmospheric and vacuum distillation. Heavy ends are particular boiling point cuts, which can include atmospheric gas oil (250-350°C), atmospheric residues (350°C+) vacuum gas oil (350-5S0°C) and vacuum residues (5S0°C+). The descriptions are based on boiling points and, within a particular distillation cut, various chemical species can be identified. These include saturated and unsaturated hydrocarbons, aromatic and polyaromatic hydrocarbons and inorganic atoms such as V, Ni, and S, which are associated with large organic molecules [5]. As a result of this complexity, the composition of the boiling cuts is often described in terms of their content of oils, resins and asphaltenes [6,7,8], the relative amounts of which vary depending on the cut and the source of the crude [6] Of these species, asphaltenes are particularly important in the present context since they are known to be associated with heavy coke formation [7,8]. 

A recent GRACE survey of the European refining industry showed that over 40 percent of European refiners add various amounts of resid to their FCC unit feeds. The term "Resid" covers a broad range of feeds boiling above 350°C such as Long Resid or Atmospheric Tower Bottoms, Short Resid or Vacuum Tower Bottoms, Heavy Vacuum Gas Oil, Aromatic Extracts and Deasphalted Oil. 

Consideration of the nature of the petrochemical refinery itself gives some clues as to another source of its profit problem. In the simple, basic unit depicted in Figure 2 thermal cracking dominates the operation. Over 90% of the crude input is consumed without regard to relative values. Thus, it is an indiscriminate cracker of butanes, light naphtha, heavy naphtha, kerosene, distillate, atmospheric gas oil, and vacuum gas oil. Since acceptably similar product slates can be obtained from many of these fractions, it is obvious that the economics suffer when the high valued naphtha and kerosene fractions are thermally cracked. 

In order to apply the proposed sequential method for kinetic parameter estimation in the FCC process three feeds were used for MAT experiments GO-1, a typical FCC feedstock, GO-2, Heavy Vacuum Gas Oil and, GO-3, the typical FCC feedstock plus 5 vol% atmospheric residuum. Characterization of theses feeds were presented in a previous work [5]. 

Atmospheric gas oil (AGO). Heavy boiling range jet fuel components will be downgraded to fluid cracker feed due to poor stripping of the AGO product. 

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