FCC Unit Heat Balance via Aromatic Complex Integration

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Solution Overview

Problem

FCC units processing heavy, severely hydrotreated feedstocks with high hydrogen content face thermal balancing issues due to coke deficits, requiring external heat sources, and struggle to efficiently recover valuable BTX molecules from effluents.

Innovation Solution

Integrating the FCC unit with an aromatic complex (CA) through material and heat flow exchanges, including recycling coking cuts and preheating FCC feedstocks with heat from catalytic reforming furnaces, to achieve heat balance and enhance BTX yield.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If FCC units process highly hydrotreated heavy feedstocks with high hydrogen content, then the feedstock quality is improved, but coke production decreases causing heat balance deficit

Engineering Contradiction:

Improvefeedstock qualityVSAvoidheat balance

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent combines the FCC unit with an aromatic complex to form an integrated system. The aromatic complex processes the LCN cut from FCC and returns heavy aromatics that serve as coke precursor feedstock for FCC, creating a synergistic loop that simultaneously improves feedstock quality and maintains heat balance through internal material exchange.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

Instead of discarding the LCN cut effluent from FCC, the patent recycles it to the aromatic complex for processing. The heavy aromatics recovered from this process are then fed back to FCC as valuable coke precursor material, transforming a waste stream into a useful resource that addresses the heat balance deficit.

Inventive Principle:

Principle #34Discarding and recovering

2Loss of energy

If external heat sources are used to compensate coke deficit, then heat balance is maintained, but process complexity and cost increase

Engineering Contradiction:

Improveheat balanceVSAvoidprocess complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The integrated FCC-aromatic complex system serves itself by internally generating the coke precursor feedstock needed for heat balance. The aromatic complex processes FCC effluents and returns heavy aromatics that become the feedstock for FCC, creating a self-sufficient loop that eliminates the need for external heat sources or additional complex equipment.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The aromatic complex performs multiple functions: it processes the LCN cut effluent from FCC, produces valuable aromatics products, and generates heavy aromatics that serve as coke precursor feedstock for FCC. This multi-functionality allows the system to maintain heat balance without requiring separate external heat sources or additional process units.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Productivity

If BTX molecules are recovered from FCC effluents, then product value is increased, but separation difficulty and cost increase

Engineering Contradiction:

ImproveBTX yieldVSAvoidseparation ease

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The aromatic complex performs preliminary processing of the LCN cut effluent from FCC, concentrating and transforming the BTX-containing molecules into a more easily separable form. By pre-processing the effluent through catalytic reforming and aromatic complex operations, the subsequent separation and recovery of BTX becomes significantly easier and more economically viable.

Inventive Principle:

Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This integration increases BTX production, improves heat balance in the FCC unit, and optimizes the recovery of high-value compounds like light olefins and BTX, while minimizing coke consumption and maximizing the use of heavy aromatics from the aromatic complex.

Implementation Method 1

recovery of the heat from the furnaces of the catalytic reforming units... recovering part of the heat available in the convection zones of the furnaces for preheating the catalytic reforming feedstock

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

heat from the furnaces of the catalytic reforming units... heat available in the convection zones of the furnaces

Methodology Applied

Scientific EffectConvection: Convection

Implementation Method 3

catalytic cracking (FCC) unit processing a heavy feedstock... cracking of highly hydrogenated cuts in the FCC processes

Methodology Applied

Scientific EffectCatalytic cracking: Catalysis

Implementation Method 4

unit for the catalytic reforming (CR) of gasolines... aromatic complex (CA) fed by the catalytic reforming (CR) effluents

Methodology Applied

Scientific EffectCatalytic reforming: Catalysis

Data Source

PatentUS9650579B2Process for production of light olefins and BTX using an FCC unit processing a heavy feedstock of the highly hydrotreated VGO type, coupled with a catalytic reforming unit and an aromatic complex processing a naphtha-type feedstock

Publication Date: 2017.05.16 IFP ENERGIES NOUVELLES

AI summary

The present invention relates to the FCC units processing heavy feedstocks enriched with hydrogen, such as for example a highly hydrotreated VGO, or the unconverted part at the end of hydrocracking this same type of VGO feedstock, feedstocks which have the characteristic of cracking to light olefins such as ethylene and propylene. The integration of an FCC with an aromatic complex allows the recovery by the aromatic complex of the BTX formed in the FCC, and the recovery by the FCC from the flow at the bottom of the column, of heavy aromatics from the aromatic complex.