Wet Scrubber CO2 Acidification for SO2 Removal
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Solution Overview
Problem
Existing wet scrubbers are not efficient enough in removing sulphur dioxide from process gases in oxy-fuel combustion processes, particularly due to limitations in sulphur dioxide removal efficiency and potential decomposition of sulphur species.
Innovation Solution
A method involving a wet scrubber that mixes the absorption liquid with a carbon dioxide containing gas and an oxygen containing gas, along with an absorbent material, to enhance sulphur dioxide removal efficiency, where the carbon dioxide gas is sourced from the oxy-fuel boiler process gas, reducing operational costs and minimizing decomposition risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional wet scrubbers are used to remove sulphur dioxide from process gas, then the scrubbing operation can be performed, but the sulphur dioxide removal efficiency is insufficient
Solution Approach 1:
The patent changes the chemical parameters of the absorption liquid by adding carbon dioxide to adjust the pH level. This parameter change enhances the absorption capacity for sulphur dioxide, directly resolving the issue of insufficient removal efficiency while maintaining reliable operation.
Solution Approach 2:
Carbon dioxide acts as an intermediary substance that mediates between the absorption liquid and sulphur dioxide removal. By introducing carbon dioxide, the system creates optimal pH conditions that facilitate more effective sulphur dioxide absorption, thereby improving both efficiency and reliability.
2Productivity
If absorbent material is added to the absorption liquid, then the sulphur dioxide removal capacity increases, but the risk of decomposition of sulphur species increases
Solution Approach 1:
The patent performs preliminary action by adjusting the pH of the absorption liquid to an optimal range before adding absorbent material. This preliminary pH adjustment creates stable conditions that prevent decomposition of sulphur species while maximizing the removal capacity, thus resolving the contradiction between productivity and harmful effects.
Solution Approach 2:
By carefully controlling and changing the pH parameter of the absorption liquid through carbon dioxide addition, the system creates optimal conditions for absorbent dissolution without promoting sulphur species decomposition. This parameter control allows increased removal capacity while maintaining stability.
3Ease of manufacture
If external carbon dioxide source is used to mix with absorption liquid, then the pH optimization for absorbent dissolution is achieved, but the operational cost increases
Solution Approach 1:
The patent applies self-service by using the process gas itself, which contains carbon dioxide, to adjust the pH of the absorption liquid. Instead of requiring external carbon dioxide input, the system utilizes its own waste stream, thereby achieving pH optimization without increasing operational costs.
Solution Approach 2:
The patent converts the potentially harmful waste gas (process gas with carbon dioxide) into a beneficial resource for pH adjustment. By utilizing the carbon dioxide already present in the process gas, the system turns a cost burden into a cost-saving opportunity, achieving optimization without additional expenses.
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
The method significantly increases sulphur dioxide removal capacity and efficiency by optimizing the pH conditions for absorbent dissolution and sulphur species oxidation, reducing the risk of decomposition and operational costs.
Implementation Method 1
an absorption vessel operative for bringing the process gas into contact with an absorption liquid to absorb sulphur dioxide from the process gas
Implementation Method 2
mixing the absorption liquid with a carbon dioxide containing gas comprising at least 20 % by volume carbon dioxide
Implementation Method 3
mixing the absorption liquid with an oxygen containing gas containing at least 3 % by volume oxygen, O2
Data Source
Figure 1
Figure 2
AI summary
A wet scrubber (8) for cleaning a process gas containing sulphur dioxide comprises an absorption vessel (40) operative for bringing the process gas into contact with an absorption liquid to absorb sulphur dioxide from the process gas. The wet scrubber (8) further comprises an acidification system (90) operative for mixing absorption liquid that has absorbed sulphur dioxide from the process gas with a carbon dioxide containing gas, an absorbent dissolution tank (54) operative for adding an absorbent material to at least a portion of the absorption liquid, and a return pipe (104) operative for returning to the absorption vessel (40) at least a portion of the absorption liquid that has been mixed with the carbon dioxide containing gas.