Liquid Sulfur Degassing via Multi-Point Gas Injection

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Solution Overview

Problem

The Claus process for sulfur recovery results in liquid sulfur containing hydrogen sulfide and polysulfides, which degrades slowly, posing health, safety, and environmental risks due to toxic and flammable gas release, and existing degasification processes face challenges with long residency times, large space requirements, and corrosion issues.

Innovation Solution

A process involving intimate mixing of gases with liquid sulfur, either during transport or in a separator/storage vessel, using gases like air, nitrogen, or Claus tail gas, to rapidly decompose hydrogen polysulfides and remove hydrogen sulfide, reducing residency time and equipment size needs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional degasification processes (bubbling air through liquid sulfur or co-current/counter-current contacting) are used, then hydrogen sulfide can be removed from liquid sulfur, but long residency times are required to achieve desired H2S levels

Engineering Contradiction:
Improvedegassing rateVSAvoidresidency time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The patent segments the liquid sulfur stream into multiple phases by injecting gas at multiple locations (suction side, discharge side, and intermediate points) to create distributed contact zones, thereby increasing the effective degassing rate without extending residency time

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from single-point gas injection to multi-dimensional gas distribution throughout the sulfur stream, utilizing both temporal (continuous injection) and spatial (multiple injection points) dimensions to accelerate H2S removal

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If conventional degasification processes are used, then hydrogen sulfide can be removed from liquid sulfur, but large plot space requirements result for sulfur pit and associated degassing equipment

Engineering Contradiction:
Improvedegassing efficiencyVSAvoidplot space
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The patent merges the degassing function with the existing sulfur transfer pump system, eliminating the need for separate large-scale degassing vessels and reducing overall plot space requirements while maintaining high degassing efficiency

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sulfur transfer pump is given multiple functions: it not only transports liquid sulfur but also serves as a gas injection and mixing device, thereby reducing the need for dedicated degassing equipment and minimizing space occupation

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

3Productivity

If conventional degasification processes are used, then hydrogen sulfide can be removed from liquid sulfur, but corrosion of degassing vessels and internals occurs requiring maintenance

Engineering Contradiction:
Improvedegassing performanceVSAvoidequipment durability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent utilizes the existing sulfur transfer pump system to perform degassing, allowing the process to occur during normal sulfur handling operations without requiring separate corrosion-prone degassing vessels that need maintenance

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the operational parameters by injecting gas at controlled locations and pressures within the pump system, enabling effective degassing while avoiding the corrosion issues associated with traditional open-vessel degassing methods

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 approach significantly reduces hydrogen sulfide and polysulfide levels in liquid sulfur, minimizing safety risks and environmental impact, while reducing equipment size and maintenance needs, and operating costs through faster degassing and lower corrosion risks.

Implementation Method 1

Mixing gas with the liquid sulfur mixture comprises introducing the gas into a suction of a sulfur transfer pump used for transporting the liquid sulfur mixture

Methodology Applied
Scientific EffectGas-liquid mixing:

Implementation Method 2

The sulfur-gas mixture is then transported to a separator, storage vessel or storage tank for separating the sulfur-gas mixture

Methodology Applied
Scientific EffectGas-liquid separation:

Implementation Method 3

The hydrogen polysulfides degrade slowly, producing toxic, odorous and highly flammable hydrogen sulfide gas

Methodology Applied
Scientific EffectDecomposition: Decomposition (biological)

Data Source

PatentEP3268309B1High efficiency process for degassing of hydrogen sulfide from liquid sulfur
Publication Date: 2020.02.05 WORLEYPARSONS EURO LTD
  • EP3268309B1 patent drawingFigure 1
  • EP3268309B1 patent drawingFigure 2
  • EP3268309B1 patent drawingFigure 3

AI summary

Processes and systems for degassing liquid sulfur may include mixing a gas, such as air, with a liquid sulfur mixture comprising sulfur, hydrogen sulfide, and hydrogen polysulfides to form a sulfur-gas mixture. The sulfur-gas mixture may then be transported to a separator, storage vessel or storage tank for separating the sulfur-gas mixture.