Residuum upgrading

The FTC Process is a heavy oil and residuum upgrading process in which the feedstock is thermally cracked to produce distillate and coke, which is gasified to fuel gas (Miyauchi et al., 1981 Miyauchi and Ikeda, 1988). 

Anon. 1981a. Novel solvent recovery enhances residuum upgrading. Chem. Eng., November 30, 69. 

Ng, S.H. 1997. Nonconventional residuum upgrading by solvent deasphalting and fluid catalytic cracking. Energy Fuels 11 1127-1136. 

Residuum which is less refractory and thus amenable to upgrading in a conventional second-stage hydrocracker... 

Distillations. The upgraded coal liquids were distilled with a metal-mesh-spinning-band still under the conditions shown in Figure 1 to produce cuts at 200°, 325°, and 425° C. Asphaltenes were then precipitated from each >425° C residuum dissolved in benzene by addition of 50 volumes of normal pentane (15). Further distillations on the asphaltene-free materials, at 202° C and 4 micron pressure using a wiped-wall molecular still, produced 425° to 540° C distillate cuts and residua fractions. 

Upgraded on same temperature-time program as Illinois No. 6 Run Asphaltenes removed from >425° C residuum. 

This source of hydrogen is being effectively utilized with the aid of the cryogenic hydrogen upgrader to recover and purify hydrogen for return to such refinery applications as residuum hydrocracking and hydrodesulfurization. 

Table II shows the experimental results and conditions for the catal>d ir upgrading tests of the six pyrol -tic oils. It gives the weight percents of the various fractions of products collected. Coke 1 corresponds for example to the total weight of the material deposited on the wall of the empty pyrex tube whereas coke 2 is the one left in the tubular reactor (on the catalyst) at the end of a test. The tar collected in the hot trap is designated as the residuum, whereas the cumulative mass recovered in all three cold traps is indicated as "traps".

Upgrading to a cracking refinery reduces the amount of low value fuel oil that a refinery yields (Figure 3). For Arabian Light Crude, heavy product (fuel oil) is reduced from 47% of refinery products to 27% by the addition of the FCC and ancillary equipment. The refinery product slate is now roughly in balance with Western European demands. The refinery is still long on fuel oil by U.S. product demands so further upgrading of the 1000°F+ residuum may be necessary (e.g., in a resid FCC or a coker). 

There are some general criteria to decide which technology is more appropriate than other to upgrade a specific heavy oil, such as that shown in Figure 2.3. The used criteria are mainly the amount of metals and carbon residue in the atmospheric residuum (343°C+) recovered from the heavy oil (Houde and McGrath, 2006). 

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