Sulfite Production Using Counter-Current Waste-Gas Absorption
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Solution Overview
Problem
Existing methods for producing sulfite products such as sodium metabisulfite are inefficient, environmentally harmful, and costly, failing to utilize industrial sulfur-containing waste gases effectively and resulting in high energy consumption and low product purity.
Innovation Solution
A device and method utilizing a column reactor system with counter-current gas-liquid contact and a bubbling reactor for sulfite production, incorporating a centrifuge and dryer, which recycles gases and liquids to produce high-purity sulfite products from sulfur-containing waste gases with reduced energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pure oxygen and elemental sulfur are used as raw materials, then product purity is improved, but raw material cost increases significantly
Solution Approach 1:
The patent converts harmful sulfur-containing waste gases (flue gas, regenerated gas from desulfurization processes) into valuable sulfite products. By using these waste gases as raw materials instead of pure oxygen and elemental sulfur, the process achieves both environmental benefit (waste utilization) and economic benefit (lower raw material cost) while maintaining product quality through controlled reaction conditions
Solution Approach 2:
The patent changes the physical and chemical parameters of the reaction system by using aqueous alkali solutions and controlled gas absorption processes. This allows the conversion of low-purity waste gases into high-purity sulfite products through parameter optimization including temperature control, pressure regulation, and stoichiometric ratio management in the absorption towers
2Manufacturing precision
If evaporation and crystallization steps are added, then product purity is improved, but energy consumption increases significantly
Solution Approach 1:
The patent extracts and removes impurities from the reaction solution through filtration and solid-liquid separation processes before crystallization. By taking out impurities early in the process rather than relying on multiple recrystallization steps, the method reduces the total energy consumption while achieving the required product purity through targeted removal of contaminants
Solution Approach 2:
The patent implements continuous gas absorption and reaction processes in the absorption towers, maintaining continuous useful action throughout the production cycle. This continuous operation eliminates the need for repeated batch evaporation and recrystallization cycles, thereby reducing cumulative energy consumption while maintaining steady product quality
3Ease of repair
If gypsum decomposition is used to obtain SO2, then resource reuse is achieved, but waste water and exhaust gas discharge increases
Solution Approach 1:
The patent directly utilizes sulfur-containing waste gases from industrial processes (flue gas, regenerated gas from activated coke desulfurization, organic amine desulfurization, and citric acid desulfurization) as raw materials. By converting these harmful waste gases into valuable sulfite products, the process achieves resource reuse while eliminating the need for gypsum decomposition and its associated waste water and exhaust gas problems
Solution Approach 2:
The patent demonstrates universality by showing that the same absorption and reaction system can effectively process multiple different types of sulfur-containing waste gases from various industrial sources. This multi-functional approach allows resource reuse across different industries while avoiding the specific environmental problems associated with gypsum decomposition
4Loss of substance
If three-stage bubbling reaction kettle is used, then sulfur utilization is improved, but gas pressure loss and energy consumption increase
Solution Approach 1:
The patent segments the gas absorption and reaction process into multiple absorption towers with counter-current flow arrangements. This segmentation allows for more efficient mass transfer and sulfur utilization across multiple stages while reducing the gas pressure loss associated with a single three-stage bubbling reaction kettle, as each tower operates with optimized gas and liquid flow patterns
5Productivity
If hot air drying is used, then drying efficiency is improved, but product oxidation rate increases
Solution Approach 1:
The patent changes the drying parameters by using low-temperature vacuum drying or protected atmosphere drying instead of high-temperature hot air drying. This parameter change maintains drying efficiency through vacuum conditions or protective gases while preventing product oxidation by eliminating oxygen exposure during the drying process
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 process achieves low energy consumption, high product purity, and increased production capacity while utilizing waste gases, reducing environmental impact and production costs.
Implementation Method 1
A device and method utilizing a column reactor system with counter-current gas-liquid contact and a bubbling reactor for sulfite production
Implementation Method 2
incorporating a centrifuge and dryer
Implementation Method 3
incorporating a centrifuge and dryer
Data Source
AI summary
A device for preparing a sulfite includes: a mother liquid tank and alkaline bin connected to a concentrated alkaline tank, connected to a tower reactor first reactor, one first reactor bottom output end is connected to a first gas-and-liquid mixer and another to a bubbling reaction kettle upper end, a bubbling reaction kettle gas output end is connected to the first mixer being connected to a first reactor upper portion; first reactor upper portion gas and second reactor bottom output ends are connected to a second mixer being connected to the second reactor top; and the bubbling reaction kettle is connected to a centrifugal machine or the alkaline tank, the machine being connected to a wet material bin and the liquid tank. A method includes preparing main and auxiliary absorption liquids, generating a middle slurry, reabsorbing residual gas SO2, generating a target product, separating the target product, drying and packaging.