Catalyst Composition for Claus Tail Gas Sulfur Reduction
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Solution Overview
Problem
Current processes for catalytically reducing sulfur compounds in Claus unit tail gas streams are inefficient, particularly in converting COS and CS2 to H2S, and require high temperatures and specific catalyst compositions that do not effectively handle a broad range of sulfur compounds.
Innovation Solution
A catalyst composition comprising alumina, a group VI metal component, and a group VIII metal component with a unique pore structure, characterized by a high percentage of large and small pore volumes, is used to contact the gas stream at low temperatures, facilitating the hydrolysis of COS and hydrogenation of SO2 and S to achieve high conversion of sulfur compounds to H2S.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional catalysts are used for catalytic reduction of sulfur compounds, then the process requires high temperatures, but this increases energy consumption and reduces conversion efficiency
Solution Approach 1:
The patent changes the physical and chemical parameters of the catalyst by incorporating specific metal oxides (Cr2O3, MoO3, CoO, NiO) in optimized ratios and utilizing a hierarchical pore structure with specific surface area (200-500 m²/g) and pore volume characteristics. These parameter changes enable the catalyst to function effectively at lower temperatures (150-350°C), reducing energy consumption while maintaining high conversion efficiency of sulfur compounds to H2S
Solution Approach 2:
The patent employs a composite catalyst material combining alumina support with multiple metal oxide components (chromium oxide, molybdenum oxide, cobalt oxide, nickel oxide) in specific proportions. This composite structure creates synergistic effects where each metal oxide contributes to different aspects of catalytic activity, enabling efficient sulfur compound conversion at reduced temperatures and improving overall process productivity while reducing energy requirements
2Productivity
If high conversion of sulfur compounds is achieved, then treatment effectiveness improves, but process complexity increases due to specific catalyst composition requirements
Solution Approach 1:
The patent establishes specific parameter ranges for catalyst composition (metal oxide ratios, surface area, pore volume) that optimize conversion effectiveness. By defining these parameters within specific ranges rather than requiring exact compositions, the patent achieves high conversion while providing flexibility in catalyst preparation and reducing excessive complexity
3Adaptability or versatility
If the catalyst handles a broad range of sulfur compounds, then treatment versatility improves, but selectivity and conversion efficiency may decrease
Solution Approach 1:
The patent designs a multi-functional catalyst where different metal oxide components target different sulfur compounds: Cr2O3 and MoO3 primarily catalyze COS and CS2 hydrolysis, while CoO and NiO enhance SO2 and elemental sulfur conversion. This universal catalyst structure simultaneously handles multiple sulfur compounds (COS, CS2, SO2, S) with high overall efficiency, achieving both versatility and maintained conversion productivity through the synergistic action of multiple active sites
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 composition enables high conversion of sulfur compounds to H2S at lower temperatures than conventional methods, allowing for energy savings and efficient treatment of Claus unit tail gas streams with reduced sulfur concentrations, even at high gaseous space velocities.
Implementation Method 1
A process of catalytically reducing sulfur compounds contained in a gas stream
Implementation Method 2
facilitating the hydrolysis of COS and hydrogenation of SO2 and S
Implementation Method 3
A process of catalytically reducing sulfur compounds contained in a gas stream
Implementation Method 4
facilitating the hydrolysis of COS and hydrogenation of SO2 and S
Data Source
Figure 1~2
Figure 3
AI summary
Disclosed is a composition useful in the hydrolysis of sulfur compounds that are contained in a gas stream. The composition comprises alumina, a group VI metal component and a group VIII metal component. The composition has a pore structure such that a large percentage of its total pore volume is contained within the pores having a pore diameter greater than 10,000 angstroms.