Page 88 - Synthetic Fuels Handbook

FUELS FROM PETROLEUM AND HEAVY OIL 75

Reactor products Steam Coke gas to
to fractionator generation sulfur removal

Fines
removal
Scrubber
Cooling

Coke fines
Recycle

Heater
Bitumen
Gasifier

Purge
Steam Reactor coke

Air
Steam
FIGURE 3.8 Flexicoking process.

TABLE 3.3 Summary of Catalytic Cracking Processes
Conditions
Solid acidic catalyst (silica-alumina, zeolite, etc.)
Temperature: 480–540°C (896–1004°F) (solid/vapor contact)
Pressure: 10–20 psi
Provisions needed for continuous catalyst replacement with heavier feedstocks (residua)
Catalyst may be regenerated or replaced
Feedstocks
Gas oils and residua
Residua pretreated to remove salts (metals)
Residua pretreated to remove high molecular weight (asphaltic constituents)
Products
Lower molecular weight than feedstock
Some gases (feedstock and process parameters dependent)
Isoparaffins in product
Coke deposited on catalyst
Variations
Fixed bed
Moving bed
Fluidized bed