Coking flexicoking

There are two major commercial thermal cracking processes, delayed coking and fluid coking. Flexicoking is a fluid coking process in which the coke is gasified with air and steam. The resulting gas mixture partially provides process heat. 

Butylene yield Gas oil Residue Delayed coking Flexicoking Steam cracking of naphtha... 

Fig. 18.21. Fluid coking (Flexicoking)—ExxonMobil Research and Engineering Co. Includes reactor (1), scrubber (2), heater (3), gasifier (4), and coke fines (5). (Source Hydrocarbon Processing 2004 Refining Process Handbook. CD-ROM. September 2004 copyright 2004 by Gulf Publishing Co., all rights reserved.)...

Delayed coke (Sponge) Shot coke Fluid coke Flexicoke... 

Fig. 14. Preferred Hquefaction-coking Hquid yields in the EDS process for various coals where Hrepresents Flexicoking Hquids and , Hquefaction Hquids (124). A, Ireland (West Virginia) B, Monterey (Illinois) C, Burning Star (Illinois) D, Wyodak (Wyoming) and E, Big Brown (Texas).

Fig. 27. A Flexicoking unit combining fluid coking and gasification using three-bed fluidized beds.

Thermal Cracking. Heavy petroleum fractions such as resid are thermally cracked in delayed cokers or flexicokers (44,56,57). The main products from the process are petroleum coke and off-gas which contain light olefins and butylenes. This stream also contains a considerable amount of butane. Process conditions for the flexicoker are more severe than for the delayed coker, about 550°C versus 450°C. Both are operated at low pressures, around 300—600 kPa (43—87 psi). Flexicokers produce much more linear butenes, particularly 2-butene, than delayed cokers and about half the amount of isobutylene (Table 7). This is attributed to high severity of operation for the flexicoker (43). 

Figure 3-4. Flow diagram of an Exxon flexicoking unit (1) reactor, (2) scrubber, (3) heater, (4) gasifier, (5) coke fines removal, (6) HgS removal.

FIGURE 6.9 Flexicoking is a commercial process for refining petroleum that has been applied to heavy oil and tar sand fractions. The process employs circulating fluidized beds and operates at moderate temperatures and pressures. The reactor produces liquid fuels and excess coke. The latter is allowed to react with a gas-air mixture in the gasifier fluidized bed to provide a low-value heating gas that can be desulfurized and used as a plant fuel. Courtesy, Exxon Research and Engineering Company. 

FLUID COKING A noncatalytic, thermal process for converting bitumen and coal liquids to lighter hydrocarbon fluids and gases. Developed by the Exxon Research Engineering Company and used commercially since 1954. See also FLEXICOKING. 

Flexible polyurethane foam, 19 559 Flexible printed circuits, 10 456 Flexible searches, 6 10-11 Flexible tube pumps, 21 74 Flexicoking (fluid coking), 18 651, 652 ... 

Flexicoking integrates coke gasification with fluid coking. Product coke is converted to low heat content fuel gas reducing net coke production. Sulphur dioxide emissions are comparatively low. 

Yields of liquid products from flexicoking are the same as from fluid coking, because the coking reactor is unaltered. As with fluid coking, the extent of desulfurization depends on the sulfur content of the feedstock as well as on the chemical nature of the sulfur in the feed stock. 

Flexicoking a modification of the fluid coking process insofar as the process also includes a gasifier adjoining the burner/regenerator to convert excess coke to a clean fuel gas. 

Burton, Carburol, Cross, Dubbs, Dubrovai, Fleming, FLEXICOKING, Flexicracking, FLUID COKING, Gyro, Hall, Hoechst HTP, HSC, Jenkins, Knox, MHDV, TERVAHL, TPC, Tube and Tank, TVP, Visbreaking. See also catalytic cracking. 

There are three major coking processes (1) delayed coking, (2) fluid coking, and (3) flexicoking. 

The flexicoking process is an adaptation of the fluid coking process that uses the same reactor as a fluid coker but has an integrated gasification unit available for coke gasification to produce, in addition to the typical fluid coking slate of products, a low-BTU gas. 

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