Zeolite Catalytic Beds for Stack Gas Pollutant Removal
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for cleaning stack gases from coal-fired power plants and cement kilns are ineffective in reducing carbon monoxide, carbon dioxide, nitrogen oxides, sulfur oxides, and trace metals like mercury without consuming expensive catalysts or generating waste products, particularly due to the use of large zeolite particle sizes for carbon dioxide absorption and regeneration.
Innovation Solution
A method involving a series of catalytic flow-through beds with specific zeolite compositions and particle sizes, including calcium and sodium zeolites, is used to reduce sulfur oxides, nitrogen oxides, and carbon oxides, with optional bauxite collection, achieving at least 70% reduction in pollutants and 50% removal of mercury, without the need for additional gases or catalysts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If large particle sizes of zeolite are used for carbon dioxide absorption, then adsorption capacity is improved, but regeneration difficulty and disposal problems worsen
Solution Approach 1:
The patent changes the particle size parameter of zeolite from large (1/16 to 1/8 inch) to fine particles (200 mesh or finer, approximately 74 micrometers or smaller). This parameter change enables both effective carbon dioxide adsorption and easy regeneration through fluidization and gas stripping, resolving the contradiction between absorption capacity and regeneration ease.
2Object-affected harmful factors
If ammonia or urea is added to reduce nitrogen oxides, then pollution abatement is improved, but additional chemical consumption and process complexity worsen
Solution Approach 1:
The patent employs a self-service mechanism where the zeolite catalyst naturally facilitates the reduction of nitrogen oxides to nitrogen gas and water vapor through catalytic action, without requiring external addition of ammonia or urea. This eliminates the need for additional chemical supply systems and process control mechanisms.
Solution Approach 2:
The patent converts the harmful nitrogen oxides directly into beneficial nitrogen gas and water vapor through catalytic reduction, transforming a pollution problem into a harmless or even useful outcome without requiring additional chemical reactants.
3Object-affected harmful factors
If scrubbers are used to wash pollutants from stack gas, then pollution removal is improved, but liquid consumption and waste slurry generation worsen
Solution Approach 1:
The patent replaces the mechanical scrubbing system that uses liquid slurry with a catalytic system using fine zeolite particles. The zeolite catalyst chemically transforms pollutants into harmless substances through catalytic reactions, eliminating the need for continuous liquid consumption and slurry waste generation while maintaining effective pollutant removal.
4Object-affected harmful factors
If exhaust burners are used to combust volatile materials, then pollution reduction is improved, but energy consumption and temperature control requirements worsen
Solution Approach 1:
The patent replaces the high-energy combustion process with a low-energy catalytic process. The fine zeolite catalyst enables pollutant transformation at much lower temperatures through surface catalysis, dramatically reducing energy consumption while achieving effective pollution reduction.
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 effectively reduces sulfur oxides, nitrogen oxides, and carbon oxides by at least 70% and mercury by 50%, with optional 95% reduction in bauxite compounds, using natural zeolite beds that do not require additional catalysts or waste generation, thus addressing the limitations of existing technologies.
Implementation Method 1
A method involving a series of catalytic flow-through beds with specific zeolite compositions and particle sizes, including calcium and sodium zeolites, is used to reduce sulfur oxides, nitrogen oxides, and carbon oxides
Implementation Method 2
passing stack gases selected from the group consisting of volatiles from combustion of coal or from combustion of natural gas or from a cement kiln sequential through the first catalytic bed, the second catalytic bed, and the third catalytic bed each collecting materials in the catalytic beds
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A method and apparatus for cleaning and recycling stack gas from coal-fired power plants, from natural or propane burning heating plants, or from cement kilns by using renewable catalysts of zeolite to separate pollutants into recyclable and reusable materials. The method reduces from the stack gas carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxide (NOx), sulfur oxide (SOx) as well as halogens such as chloride and fluorides and trace metals particularly, mercury, lead, and zinc. Bauxite compounds can also be separately collected if desired. The method and apparatus also result in production of fertilizer products by purging with gaseous or liquid nitrogen the zeolite beds through which the stack gas flows. The oxygen split in the beds may be recycled to the burners in the plant.