Petroleum refining – process identification In refinery history, the Thermofor (often spelled “Thermofer” in older notes) catalytic cracking unit refers to which general process type?

Introduction / Context:
Refineries have used several catalytic cracking configurations over time. The Thermofor Catalytic Cracking (TCC) process is a classic historical design that predates modern fluid catalytic cracking (FCC). Identifying its reactor/catalyst handling style helps students contrast legacy moving-bed systems with today’s fluidised-bed FCC units.

Given Data / Assumptions:

• The name in some texts appears as “Thermofor” or “Thermofer.”
• The question asks for the overall process type (how catalyst and oil contact is arranged).
• We consider the standard, widely taught configuration from refinery history.

Concept / Approach:
In moving-bed cracking, solid catalyst particles move continuously or intermittently through reactors and regenerators by gravity or mechanical means. The TCC design circulated formed catalyst pellets between reaction and regeneration—distinct from fluidised beds where catalyst behaves like a fluidized powder stream.

Step-by-Step Solution:

Verification / Alternative check:
Standard refining overviews depict TCC alongside Houdry fixed-bed and modern FCC fluidised-bed, explicitly labeling TCC as moving-bed.

Why Other Options Are Wrong:

• Fixed bed: Characteristic of early Houdry units with cyclic operation, not TCC.
• Fluidised bed: Describes FCC, not TCC.
• Non-catalytic thermal unit: Cracking is catalytic in TCC.

Common Pitfalls:
Confusing TCC with FCC because both circulate catalyst; however, FCC uses fine powder in fluidisation, whereas TCC used moving pellets.

Final Answer:
Moving bed