Solid Catalyst Washcoat Process for Low-Temperature Exhaust Treatment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for manufacturing catalyst-coated supports are complex and costly, involving multilayer deposition and high-temperature processes, which are inefficient and require significant energy consumption, especially when aiming to eliminate volatile organic compounds (VOCs), CO, and particulate matter from exhaust gases.
Innovation Solution
A simplified process involving the preparation of solutions A and B with specific solvents and surfactants, followed by dip-coating and calcination, to create a catalytic layer on a support, allowing for efficient pollutant elimination at lower temperatures and reducing the need for high-energy processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multilayer deposition of metal oxides is used to create catalytic substrate, then catalytic degradation efficiency is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent combines multiple metal oxide precursors (aluminum, silicon, titanium, zirconium, iron, zinc, niobium, vanadium, and/or cerium) into a single washcoat solution applied in one coating step, eliminating the need for sequential multilayer deposition. This merging approach maintains catalytic effectiveness while significantly simplifying the manufacturing process.
Solution Approach 2:
The washcoat solution serves multiple functions simultaneously: it provides the catalytic active phase, creates a porous support structure, and forms a cohesive coating layer. This multi-functionality eliminates the need for separate deposition steps for each layer, reducing manufacturing complexity while maintaining catalytic performance.
2Reliability
If impregnation of active phase is performed after deposition of catalytic layers, then catalytic activity is improved, but manufacturing cost increases
Solution Approach 1:
The active phase and support materials are combined into a single washcoat solution that is applied in one step. The metal precursors are dissolved together with the binder and surfactant, eliminating the need for separate impregnation steps and reducing manufacturing cost while maintaining catalytic activity.
Solution Approach 2:
The active phase precursors are pre-dissolved in the washcoat solution before coating application. This preliminary incorporation ensures uniform distribution of the active phase throughout the coating layer, achieving high catalytic activity without requiring subsequent impregnation steps.
3Productivity
If gel formation and drying process is used to prepare catalyst powder, then catalyst synthesis is achieved, but process complexity and time increase
Solution Approach 1:
The patent extracts and eliminates the time-consuming gel formation and drying steps from the traditional catalyst synthesis process. By using a washcoat solution with controlled solvent evaporation during coating, the catalyst layer is formed directly without requiring separate powder synthesis, gelation, and drying operations.
Solution Approach 2:
The process skips the intermediate gel formation and powder drying stages by directly applying the catalyst precursors in solution form and converting them to the final catalytic structure through controlled calcination, significantly reducing overall process time.
4Stability of the object's composition
If high temperature processes are used for catalyst coating, then coating stability is improved, but energy consumption increases
Solution Approach 1:
The patent changes the processing parameters by using a washcoat solution with specific solvent composition and controlled drying conditions, allowing the coating to be formed and stabilized at lower temperatures. The gradual solvent evaporation and controlled calcination replace high-temperature processing while maintaining coating stability.
Solution Approach 2:
The washcoat solution acts as an intermediary medium that enables low-temperature coating formation. The binder and surfactant in the solution facilitate coherent layer formation at lower temperatures, replacing the need for high-temperature processing while ensuring coating stability.
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
This process enables the production of a solid catalyst with a high surface area, effective at low temperatures (starting from 180°C), with a long lifetime and reduced material usage, suitable for treating industrial and domestic emissions.
Implementation Method 1
The process of manufacture of this catalytic filter comprises the hydrolysis of metallic precursors in an alcoholic solvent. The viscosity of the solution increases and a gel is obtained which is subsequently dried
Implementation Method 2
The coating of the filter substrate with the washcoat solution can be carried out, for example by dipping the substrate in the washcoat solution and subsequently drying
Implementation Method 3
Their elimination is crucial. They are present, in particular, in exhaust fumes generated by stoves or wood-burners or incinerators or cement plants or in vapors emitted when evaporating solvents in paint cabins. Current catalytic systems used for this aim
Data Source
AI summary
A process of manufacture of a solid catalyst made of a support coated with a thin catalytic layer and a process for eliminating gaseous and/or particulate pollutants in an exhaust gas. The process of manufacture includes preparing a solution A by dissolving alkoxide and/or chloride precursors of at least one metal selected from Al, Si, Ti, Zr, Fe, Zn, Nb, V and Ce in a solvent S1, preparing a solution B containing a surfactant, an organic acid, and/or hydrochloric acid (HCl) in a solvent S2, mixing solution A and solution B together, thereby obtaining a washcoat solution C, and dip-coating, drying, and calcinating the support into washcoat solution C. The processes provide for elimination of volatile organic compounds (VOCs), CO, and/or particulate pollutants in an exhaust gas.