Fluid Catalytic Cracking Operations

Topic I: Introduction to Fluid Catalytic Cracking • Describe the purpose and basic operation of a fluid catalytic cracking unit. • Define the following terms: conversion, yield, and catalyst. • Identify and describe the functions of the major pieces of equipment in a typical fluid catalytic cracking unit. • Explain how the principle of heat balance applies to cat cracker operation. Topic II: Catalysts and the Cracking Reaction • Explain the role of the catalyst in fluid catalytic cracking operations. • Define the terms “selectivity” and “activity” in relation to catalysts. • Describe the cracking reaction and explain how it can be controlled. • Define the terms “over-cracking” and “severity.” Topic III: Fluid Catalytic Cracking Reactors • Identify and describe the function of risers in a typical fluid catalytic cracking unit. • Describe the design and function of a typical fluid catalytic cracking unit reactor. • Explain the process of recovering spent catalyst from a reactor and describe the equipment that is typically used. Topic IV: Catalyst Regeneration • Identify the major parts of a typical fluid catalytic cracking unit regenerator and describe the function of each part. • Describe a typical process for handling the flue gas from cat cracking operations. • Define the following terms: dense phase, dilute phase, afterburning, and snowballing. • Explain what the color of a regenerated catalyst sample typically indicates. Topic V: Fractionation • Identify the major pieces of equipment in a typical fractionation system and describe the basic operation of the system. • List the products typically obtained from a fluid catalytic cracking unit’s fractionation system. Topic VI: Catalyst Circulation • Explain how catalyst circulation may be controlled. • Describe two conditions that may result from improper catalyst circulation. Topic VII: Process Variables • Define the term “catalyst-to-oil ratio.” • Describe how yield, conversion, severity, catalyst-to-oil ratio, and charge rate are related. • Describe how a change in product yield can affect other process variables.