Exhaust Gas Catalyst Diluent Dispersion for SO3 Reduction
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Solution Overview
Problem
Existing exhaust gas treatment catalysts face performance degradation due to abrasion and poisoning, particularly when exposed to ash and poison components like arsenic, leading to increased sulfur trioxide formation and corrosion issues.
Innovation Solution
An exhaust gas treatment catalyst comprising a catalytic component, such as titania-tungsten oxide or silica with ruthenium, dispersed in a diluent component like silica, which enhances abrasion resistance and poisoning resistance by inhibiting sulfur trioxide formation and reducing nitrogen oxides, while being resistant to ash abrasion and poison diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a titania-vanadium-tungsten catalyst is used as a denitration catalyst, then excellent denitration performance is achieved, but low SO2 oxidation performance occurs leading to SO3 formation and corrosion
Solution Approach 1:
The patent extracts the SO3 reduction function from the traditional denitration catalyst by adding a separate SO3 reduction catalyst component. This component specifically reduces SO3 to SO2 using ammonia, separating the denitration and SO3 reduction functions to prevent SO3 formation and subsequent corrosion while maintaining denitration performance.
Solution Approach 2:
The patent creates a composite catalyst system combining a denitration catalyst (titania-vanadium-tungsten) with an SO3 reduction catalyst component. This composite structure allows simultaneous execution of denitration and SO3 reduction reactions, resolving the contradiction between maintaining denitration performance and preventing SO3 formation.
2Reliability
If the entire catalyst is composed of powder having SO3 reduction performance, then SO3 reduction is achieved, but abrasion resistance deteriorates due to ash exposure
Solution Approach 1:
The patent applies local quality by distributing the SO3 reduction catalyst component specifically on the surface of the denitration catalyst rather than making the entire catalyst powder. This surface-localized approach provides SO3 reduction functionality where it is most needed while the core denitration catalyst maintains its structural integrity and abrasion resistance.
Solution Approach 2:
The patent segments the catalyst into distinct functional components: a denitration catalyst core and a surface-coated SO3 reduction catalyst layer. This segmentation allows each component to optimize its specific function while the core provides mechanical strength and the surface layer provides chemical functionality.
3Reliability
If catalyst components are exposed to poison components like arsenic, then catalytic activity decreases, but using protective measures increases device complexity
Solution Approach 1:
The patent applies beforehand cushioning by positioning the SO3 reduction catalyst component as a protective layer on the surface of the denitration catalyst. This layer acts as a first line of defense against poison components like arsenic, absorbing or blocking their harmful effects before they can reach and deactivate the more sensitive denitration catalyst components underneath.
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 catalyst effectively reduces sulfur trioxide and nitrogen oxides throughout the treatment process, inhibiting sulfur trioxide formation, improving abrasion and poisoning resistance, and facilitating miniaturization and cost reduction of treatment apparatus.
Implementation Method 1
a catalytic component which removes the above-described pollutants
Implementation Method 2
SO3+2NH3+O2→SO2+N2+3H2O
Implementation Method 3
4NO+4NH3+O2→4N2+6H2O
Implementation Method 4
NOX reduction and removal reaction
Implementation Method 5
the above-described catalytic component is dispersed in the above-described diluent component
Data Source
AI summary
An exhaust gas treatment catalyst for removal of one or more pollutants in an exhaust gas, the catalyst comprising: a SO3-reducing catalyst powder which removes the above-described pollutants; and a diluent powder which is not the SO3-reducing catalyst powder nor a catalyst for reactions between exhaust gas components and a reagent, wherein the SO3-reducing catalyst powder is dispersed in the diluent powder.