Integrated Steam Cracking and Hydrocracking Process

Solution Overview

Problem

Current steam cracking processes for producing light olefins, such as ethylene and propylene, are inefficient, as they produce significant amounts of higher hydrocarbons that require hydrogenation and recycling, increasing complexity and reducing yield.

Innovation Solution

An integrated process involving a steam cracker furnace section, separation units, hydroprocessing reactors, and recycling of hydrocracking products to enhance the production of light olefins by converting C4-5 hydrocarbons into ethane and propane, which are then recycled to increase ethylene and propylene yields.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If steam cracking is used to produce light olefins, then olefin production is achieved, but higher hydrocarbons are produced which require hydrogenation and recycling, increasing process complexity

Engineering Contradiction:

Improvelight olefin productionVSAvoidprocess complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by performing hydrocracking of C4-5 hydrocarbons before they are recycled to the steam cracker. This pre-processing step converts higher hydrocarbons into C2-3 hydrocarbons (ethane and propane) that are optimal steam cracking feedstocks, eliminating the need for complex hydrogenation and recycling infrastructure while improving overall process efficiency and light olefin yield

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the chemical composition parameters of the recycle stream by using hydrocracking to convert C4-5 hydrocarbons into C2-3 hydrocarbons. This parameter change transforms the recycle stream from a complex mixture requiring hydrogenation into a simplified stream of optimal cracking feedstocks, thereby reducing process complexity while maintaining or improving productivity

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If C4-5 hydrocarbons are steam cracked, then higher hydrocarbon conversion is achieved, but the efficiency for producing C2-3 olefins is low

Engineering Contradiction:

Improvehydrocarbon conversionVSAvoidC2-3 olefin production efficiency

Core Design Contradiction:

Quantity of substanceVSProductivity

Solution Approach 1:

The patent applies preliminary action by performing hydrocracking of C4-5 hydrocarbons before they are recycled to the steam cracker. This pre-processing step converts higher hydrocarbons into C2-3 hydrocarbons (ethane and propane) that are optimal steam cracking feedstocks, eliminating the need for complex hydrogenation and recycling infrastructure while improving overall process efficiency and light olefin yield

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the chemical composition parameters of the recycle stream by using hydrocracking to convert C4-5 hydrocarbons into C2-3 hydrocarbons. This parameter change transforms the recycle stream from a complex mixture requiring hydrogenation into a simplified stream of optimal cracking feedstocks, thereby reducing process complexity while maintaining or improving productivity

Inventive Principle:

Principle #35Parameter changes

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 process increases the yield of ethylene and propylene by 6-20% compared to traditional methods, simplifies downstream separations, and improves the ethylene to propylene weight ratio, making it more efficient and cost-effective.

Implementation Method 1

introducing a steam cracker feed stream to a liquid steam cracker furnace section to produce a steam cracker product stream

Methodology Applied

Scientific EffectSteam cracking: Pyrolysis

Implementation Method 2

feeding at least a portion of the hydrocarbons gas stream and hydrogen to one or more hydroprocessing reactors to produce a hydrocracking product stream, wherein the hydrocracking product stream comprises ethane and propane

Methodology Applied

Scientific EffectHydrocracking: Catalysis

Implementation Method 3

separating at least a portion of the steam cracker product stream in a separation unit into a hydrogen stream, a methane stream, an olefin gas stream, a saturated gas stream, a hydrocarbons gas stream

Methodology Applied

Scientific EffectFractionation: Distillation

Data Source

PatentUS10899979B2Light olefin production via an integrated steam cracking and hydrocracking process

Publication Date: 2021.01.26 SABIC GLOBAL TECHNOLOGIES BV

AI summary

A process for producing olefins comprising introducing a steam cracker feed to a liquid steam cracker furnace section to produce a steam cracker product comprising olefins, and wherein an amount of olefins in the steam cracker product is greater than in the steam cracker feed; separating the steam cracker product in a separation unit into a hydrogen stream, a methane stream, an olefin gas stream (ethylene and propylene), a saturated gas stream (ethane and propane), a hydrocarbons gas stream (C4-5 hydrocarbons), an aromatics stream (C6-8 aromatic hydrocarbons), a raffinate stream (C6-8 non-aromatic hydrocarbons), and a heavies stream (C9+ hydrocarbons); feeding the hydrocarbons gas stream and hydrogen to one or more hydroprocessing reactors to produce a hydrocracking product comprising ethane and propane; and recycling the hydrocracking product and the saturated gas stream to the liquid steam cracker furnace section.