C4 Absorber Stripping Aldehydes from Butadiene Stream

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Solution Overview

Problem

The increasing demand for butadiene, due to its use in commercial polybutadiene rubbers, faces challenges as traditional naphtha cracking yields decrease, necessitating new sources and processes for efficient production, particularly in removing oxygenates from butadiene reactor effluent streams to enhance energy management and process efficiency.

Innovation Solution

A process involving a quench tower, oxygenate stripper, compression unit, oxygenate scrubber, C4 absorber, degasser, and C4 stripper is employed to remove oxygenates from butadiene reactor effluent streams using inert gases like nitrogen, which replaces steam and reduces energy requirements, allowing for better separation and recycling of solvents and C4 hydrocarbons.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If steam is used in the oxygenate stripper to remove oxygenates from the reactor effluent, then the oxygenate removal efficiency is improved, but the energy consumption increases significantly

Engineering Contradiction:
Improveoxygenate removal efficiencyVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces steam with an inert gas (nitrogen or recycled C4 stream) as the stripping medium in the oxygenate stripper. This inert gas flows through the reactor effluent stream to strip out oxygenates without the high energy requirements of steam heating, thereby maintaining oxygenate removal efficiency while significantly reducing energy consumption.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

2Productivity

If multiple separation units are added to improve process efficiency and oxygenate removal, then the production efficiency is improved, but the device complexity increases

Engineering Contradiction:
Improveproduction efficiencyVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into integrated process units. The oxygenate stripper is designed to simultaneously perform oxygenate removal and prepare the stream for subsequent C4 separation. The quench tower integrates cooling and initial separation functions. This merging of functions improves production efficiency while avoiding the need for numerous separate units that would increase complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The inert gas used in the oxygenate stripper serves multiple purposes: it strips oxygenates from the effluent, and when recycled from the C4 separation section, it also provides a means to handle the C4 stream. The quench tower both cools the reactor effluent and performs initial condensation and separation. This multi-functionality improves productivity without proportionally increasing device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If the quench tower and oxygenate stripper are used to separate C4 hydrocarbons and oxygenates, then the purity of C4 stream is improved, but the loss of substance increases due to multiple separation steps

Engineering Contradiction:
Improvepurity of C4 streamVSAvoidloss of C4 hydrocarbons
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent recycles the inert gas stream from the C4 separation section back to the oxygenate stripper. This recovered inert gas continues to serve as a stripping medium, eliminating the need to discard it. The quench tower condensate is also recycled back to the system. This recovery and recycling minimizes loss of C4 hydrocarbons and other valuable substances while maintaining high purity through the separation steps.

Inventive Principle:
Principle #34Discarding and recovering

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 improves butadiene production efficiency by effectively removing oxygenates, reducing energy consumption, and enabling the recycling of solvents, thereby enhancing the overall management of process streams and increasing butadiene yields.

Implementation Method 1

cooling and quenching the butadiene reactor effluent stream to generate an overhead stream comprising C4 hydrocarbons

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 2

passing an inert gas to the oxygenate stripper, and generating a stripper overhead stream comprising oxygenates and the inert gas

Methodology Applied
Scientific EffectStripping: Sparging

Implementation Method 3

passing the compressed C4 stream to an oxygenate scrubber to generate a scrubbed C4 stream

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 4

passing the butadiene reactor effluent to a heat exchanger to generate steam, and a cooled butadiene reactor effluent

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3371145B1Use of c4 absorber for stripping aldehydes
Publication Date: 2023.07.19 UOP LLC
  • EP3371145B1 patent drawingFigure 1

AI summary

A process is presented for the production of butadienes. The process includes the separation of oxygenates from the product stream from an oxidative dehydrogenation reactor. The process includes quenching the product stream and solvent and oxygenates from the product stream. The oxygenates are stripped from the solvent with an inert gas to reduce the energy consumption of the process, and the solvent is recycled and reused in the process.