Sulfuric Acid Production via Multi-Zone Combustion and Catalytic Oxidation

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Solution Overview

Problem

Current industrial processes for producing sulfuric acid from sulfur compounds like elemental sulfur and hydrogen sulfide are inefficient and emit harmful pollutants due to the need for large apparatus and high blower outputs, as well as the difficulty in maintaining optimal reaction conditions for catalytic oxidation.

Innovation Solution

A continuous process that divides the combustion of sulfur compounds into multiple zones within a combustion chamber, using a high oxygen content gas mixture, and employs a single-stage tubular contactor for catalytic oxidation, allowing direct conversion to sulfur trioxide without intermediate storage or purification, with heat dissipation between zones to control temperature and reduce apparatus size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If combustion of sulfur compound is carried out with high proportion of oxygen (pure oxygen) to avoid nitrogen oxide emissions and reduce apparatus dimensions, then harmful emissions are reduced and apparatus size is decreased, but the reaction temperature increases excessively and catalyst damage occurs

Engineering Contradiction:
Improvenitrogen oxide emissionsVSAvoidreaction temperature
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The combustion chamber is divided into multiple zones with different oxygen concentrations. The first zone uses air or oxygen-enriched air for moderate temperature combustion, while subsequent zones use progressively higher oxygen concentrations. This segmentation allows the process to achieve low emissions eventually while controlling the temperature in each zone to prevent catalyst damage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sulfur compound is partially combusted in the first zone with controlled oxygen concentration to generate heat and initiate the reaction. This preliminary combustion prepares the gas mixture for subsequent zones where higher oxygen concentrations are introduced, ensuring that when pure oxygen is used, the temperature is already managed from previous stages.

Inventive Principle:
Principle #10Preliminary action

2Volume of stationary object

If multi-stage combustion with progressive oxygen increase is used to control temperature and enable direct catalytic oxidation, then apparatus dimensions are reduced and emissions are minimized, but the process complexity increases

Engineering Contradiction:
Improveapparatus dimensionsVSAvoidprocess complexity
Core Design Contradiction:
Volume of stationary objectVSDevice complexity

Solution Approach 1:

The combustion chamber serves multiple functions: it acts as both a combustion reactor and a pre-heating zone for the catalytic converter. The gas mixture generated in the combustion chamber is directly fed to the catalytic oxidation stage without intermediate storage or purification, simplifying the overall process flow while achieving temperature control through the multi-zone oxygen feeding strategy.

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

3Quantity of substance

If direct catalytic oxidation of sulfur dioxide is attempted at low temperatures for equilibrium favorability, then sulfur trioxide yield increases, but the reaction rate becomes too slow for economical operation

Engineering Contradiction:
Improvesulfur trioxide yieldVSAvoidreaction rate
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The process uses progressive oxygen concentration changes in different combustion zones to optimize both equilibrium and kinetics. By controlling the oxygen partial pressure and temperature in each zone, the system achieves conditions where the reaction rate is sufficiently high for economical operation while maintaining favorable equilibrium for sulfur trioxide production in the catalytic oxidation stage.

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 enables cost-effective, nearly emission-free production of sulfuric acid in a compact plant by optimizing the coordination of reaction stages and reducing the need for large apparatus and high blower outputs, while maintaining efficient conversion and temperature control.

Implementation Method 1

reacting the elemental sulfur and/or the sulfur compound with a combustion gas containing oxygen in a combustion chamber to form sulfur dioxide

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

catalytically oxidizing the sulfur dioxide from step (a) to form sulfur trioxide

Methodology Applied
Scientific EffectCatalytic oxidation: Catalysis

Implementation Method 3

absorption and/or condensation of the sulfur trioxide from step (b) into sulfuric acid

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 4

reaction heat from the reaction between the zones is discharged with the combustion gas containing oxygen such that the temperature inside the combustion chamber does not exceed 2000°C

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2330075B1Method for making sulphuric acid
Publication Date: 2015.11.04 BAYER AG
  • EP2330075B1 patent drawingFigure 1
  • EP2330075B1 patent drawingFigure 2
  • EP2330075B1 patent drawingFigure 3

AI summary

The present invention relates to the field of sulfuric acid production. The invention relates to a device and a process for the continuous production of sulfuric acid.