Sulfuric Acid Recycling by IR-UV Peroxide Decomposition
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Solution Overview
Problem
The semiconductor industry generates large volumes of waste sulfuric acid contaminated with hydrogen peroxide, which is difficult to recycle due to its strong oxidizing properties, and current treatment methods produce hazardous substances or are inefficient and costly.
Innovation Solution
A device and method using IR and UV radiation to decompose hydrogen peroxide in sulfuric acid, heating the liquid to 90-130°C, and exhausting oxygen, without adding auxiliary agents, to produce high-purity recycled sulfuric acid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If hydrochloric acid is added as a catalyst to degrade hydrogen peroxide, then hydrogen peroxide concentration is reduced to ≤50 mg/L, but hazardous chlorine gas is generated and chloride ions remain in the purified sulfuric acid
Solution Approach 1:
The patent replaces the chemical catalytic degradation method (mechanical/chemical system using hydrochloric acid) with a physical decomposition method using UV irradiation and heating. This substitution eliminates the need for chemical catalysts, thereby preventing the generation of hazardous chlorine gas and chloride ion contamination while effectively reducing hydrogen peroxide concentration through photodecomposition and thermal decomposition.
Solution Approach 2:
The patent converts the harmful effect of hydrogen peroxide's strong oxidizing properties into a beneficial process by using UV irradiation and heating to decompose it into water and oxygen. The decomposition reaction H2O2 → H2O + O2 transforms the harmful oxidizing agent into harmless substances, eliminating the need for additional chemical treatments that would generate more hazards.
2Quantity of substance
If commercial enzyme is added to remove hydrogen peroxide, then hydrogen peroxide is degraded, but the process is expensive, has drug residues, changes acid quality, and the enzyme cannot be easily removed
Solution Approach 1:
The patent replaces the biological enzyme-based treatment system with a physical treatment system using UV irradiation and heating. This substitution eliminates all complexities associated with enzyme handling, including high costs, drug residues, quality changes, and removal difficulties. The physical method directly decomposes hydrogen peroxide without requiring any additional substances or complex separation processes.
Solution Approach 2:
The patent enables the waste sulfuric acid to treat itself through UV irradiation and heating, which directly decompose hydrogen peroxide into water and oxygen. This self-service approach eliminates the need for external enzymes or catalysts, simplifying the process and removing all associated complexities while maintaining effective hydrogen peroxide removal.
3Productivity
If waste sulfuric acid with >50 wt% sulfuric acid and 1-5 wt% hydrogen peroxide is directly reused, then recycling is simplified, but the strong oxidizing properties make it unsuitable for reuse
Solution Approach 1:
The patent replaces complex chemical treatment methods with a simple physical treatment system using UV irradiation and heating. This substitution achieves reliable hydrogen peroxide removal (decomposing it into water and oxygen) while maintaining high recycling efficiency. The method produces high-purity sulfuric acid suitable for reuse in semiconductor manufacturing without requiring multiple treatment steps or complex purification processes.
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
Efficiently decomposes hydrogen peroxide to water and oxygen, producing sulfuric acid suitable for reuse in industries like printed circuit boards, while avoiding hazardous gas generation and reducing operational risks.
Implementation Method 1
The IR lamp is for making contact with the liquid. IR radiation emitted from the IR lamp heats the liquid to 90° C. to 130° C.
Implementation Method 2
The UV lamp is used for making contact with the liquid. UV radiation emitted from the UV lamp decompose the hydrogen peroxide in the liquid to water and oxygen.
Implementation Method 3
IR radiation emitted from the IR lamp and UV radiation emitted from the UV lamp decompose the hydrogen peroxide in the liquid to water and oxygen. The IR radiation heats the liquid to 90° C. to 130° C.
Data Source
AI summary
A device for recycling sulfuric acid is provided. A container has an inner space. An inlet is located on the first side of the container for introducing a liquid containing sulfuric acid and hydrogen peroxide through a pump. An outlet is located on the second side of the container for exhausting the treated liquid from the container, and the first side and the second side are opposite sides. IR lamp and UV lamp are located in the inner space of the container for making contact with the liquid. IR radiation emitted from the IR lamp and UV radiation emitted from the UV lamp decompose the hydrogen peroxide in the liquid to water and oxygen. The IR radiation heats the liquid to 90° C. to 130° C., and the oxygen is exhausted through the air hole.