Steam Cracking Recycle Loop With Deep Hydrogenation for Light Olefins

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Solution Overview

Problem

Existing hydrocarbon refining processes struggle to maximize light olefin production while minimizing the production of heavy fuels and steam cracking by-products, leading to suboptimal economic outcomes.

Innovation Solution

A system and process that recycles heavier products from the steam cracking unit through deep hydrogenation, converting aromatics to naphthenes and paraffins, and further processing these products to increase feedstock for the steam cracking unit, thereby enhancing light olefin yield and reducing by-product generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If steam cracking is used to produce light olefins, then light olefin yield increases, but production of heavy fuels and by-products increases

Engineering Contradiction:

Improvelight olefin yieldVSAvoidheavy fuel production

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

The patent applies parameter changes by modifying the chemical composition of steam cracking feedstock through deep hydrogenation. By converting aromatics to naphthenes and paraffins in the feedstock preparation stage, the process changes the molecular structure parameters to favor light olefin production while minimizing heavy by-product formation during steam cracking.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the harmful effect of aromatic compounds (which produce heavy by-products during steam cracking) into a benefit through deep hydrogenation. The aromatics are transformed into naphthenes and paraffins that are more suitable for steam cracking, turning a problematic feedstock component into an advantageous one that enhances light olefin yield while reducing heavy fuel production.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Productivity

If deep hydrogenation is applied to saturate aromatics, then light olefin yield increases, but process complexity increases

Engineering Contradiction:

Improvelight olefin yieldVSAvoidprocess complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by performing deep hydrogenation of aromatics in the feedstock before steam cracking. This pre-treatment step converts difficult-to-crack aromatic molecules into more reactive naphthenes and paraffins, preparing the feedstock in advance for optimal steam cracking performance and maximizing light olefin yield.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses deep hydrogenation as an intermediary process between feedstock preparation and steam cracking. This intermediate step acts as a mediator that transforms the feedstock composition to ideal parameters for steam cracking, bridging the gap between raw feedstock and optimal cracking conditions.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Quantity of substance

If heavier products are recycled through deep hydrogenation, then feedstock for steam cracking increases, but energy consumption increases

Engineering Contradiction:

Improvefeedstock quantityVSAvoidenergy consumption

Core Design Contradiction:

Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The patent applies continuity of useful action by implementing a recycling loop where heavier products from steam cracking are continuously fed back through deep hydrogenation and then re-enter the steam cracking unit. This continuous circulation maximizes the utilization of feedstock materials, converting heavier molecules into lighter olefins through repeated hydrogenation and cracking cycles, thereby increasing overall feedstock efficiency.

Inventive Principle:

Principle #20Continuity of useful 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 approach increases light olefin production, maximizes ethylene output, and minimizes the production of heavy fuels, resulting in improved economic viability and profitability for crude oil refineries.

Implementation Method 1

hydrogenating, by a hydrogenation unit, at least a portion of the middle distillate stream to produce a hydrogenated middle distillate stream

Methodology Applied

Scientific EffectHydrogenation: Hydrogenation

Implementation Method 2

breaking carbon-carbon bonds of at least a portion of the hydrogenated middle distillate stream in the presence of steam to produce a pyrolysis gasoline, a pyrolysis oil, and a mixed gas product comprising light olefins

Methodology Applied

Scientific EffectPyrolysis: Pyrolysis

Data Source

PatentUS20250346820A1Enhancing light oilefins yield in crude oil refining with steam cracking recycling and deep hydrogenation

Publication Date: 2025.11.13 SAUDI ARABIAN OIL CO

AI summary

Crude oil obtained from a subterranean formation is fractionated to separate an atmospheric residue stream from the crude oil. At least a portion of the atmospheric residue stream is fractionated to separate a vacuum residue stream from the atmospheric residue stream. A feedstock including the vacuum residue stream, a second portion of the atmospheric residue stream, or both are upgraded to produce a middle distillate stream. At least a portion of the middle distillate stream is hydrogenated to produce a hydrogenated stream. Carbon-carbon bonds of the hydrogenated stream are broken in the presence of steam to produce a mixed gas product including light olefins and a liquid product. The liquid product is recycled to deep hydrogenation.