Simultaneous Hot Gas Desulfurization and CO-Shift Conversion
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Solution Overview
Problem
Current hot gas cleanup systems for IGCC plants face challenges in efficiently removing sulfur compounds and other contaminants at high temperatures, leading to inefficiencies and material degradation, and require cooling steps that reduce process efficiency and increase costs.
Innovation Solution
A physical mixture or separated bed configuration using a nickel aluminate sulfur absorbent and a sulfur-tolerant iron oxide water gas shift catalyst to achieve simultaneous desulfurization and CO-shift conversion at temperatures between 250° to 550° C, allowing for complete removal of sulfur compounds and maximized hydrogen production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wet scrubbing techniques are used to clean up hot coal derived gases, then sulfur compounds and contaminants are removed, but the gas must be cooled and subsequently reheated, reducing process efficiency
Solution Approach 1:
The invention changes the temperature parameter from conventional low-temperature wet scrubbing to high-temperature operation (400-700°C). The sulfur absorbent and water gas shift catalyst are specifically designed to function effectively at these elevated temperatures, eliminating the need for cooling and reheating steps while maintaining cleanup effectiveness.
Solution Approach 2:
The invention uses a composite catalyst system comprising both a sulfur absorbent and a water gas shift catalyst that work synergistically at high temperatures. This composite material approach enables simultaneous desulfurization and CO conversion to H2 without requiring separate processing stages at different temperatures.
2Reliability
If conventional cold gas cleanup is used, then sulfur compounds are removed, but thermal efficiency and overall process efficiency are reduced
Solution Approach 1:
The invention fundamentally changes the operating temperature parameter from cold/ambient conditions to high temperatures (400-700°C). The sulfur absorbent and water gas shift catalyst are engineered to maintain high activity and selectivity at these temperatures, achieving both effective sulfur removal and improved process efficiency by eliminating thermal cycling.
Solution Approach 2:
The high-temperature process allows continuous operation without interruption for cooling and reheating. The sulfur absorbent and water gas shift catalyst operate continuously at elevated temperatures, maintaining productive action throughout the cleanup process rather than requiring periodic thermal conditioning.
3Loss of energy
If high temperature cleanup is used, then thermal efficiency is maintained, but sulfur absorbent materials degrade and require frequent replacement
Solution Approach 1:
The invention employs a composite material system where the sulfur absorbent is specifically designed with high-temperature stability. The material composition and structure are engineered to resist degradation at 400-700°C, maintaining both sulfur absorption capacity and structural integrity over extended operation periods.
Solution Approach 2:
The invention optimizes the chemical and physical parameters of the sulfur absorbent material to withstand high-temperature conditions. The material's thermal stability, chemical resistance, and mechanical strength are specifically tailored for operation in the 400-700°C range, preventing the degradation issues that plague conventional absorbents.
4Productivity
If a physical mixture or separated bed configuration is used for sulfur absorbent and water gas shift catalyst, then simultaneous desulfurization and CO-shift conversion are achieved, but device complexity increases
Solution Approach 1:
The invention segments the catalyst system into two functional components: a sulfur absorbent and a water gas shift catalyst. These can be arranged in separate beds or as a physical mixture, allowing each component to perform its specific function optimally while working together in the same reactor system.
Solution Approach 2:
The invention merges the desulfurization and water gas shift functions into a single reactor system operating at high temperature. By combining these two processes that traditionally require separate units, the invention achieves synergistic effects and simplifies the overall process flow despite the dual-catalyst requirement.
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 approach enables at least 80% CO-shift equilibrium conversion and complete removal of sulfur compounds, maximizing hydrogen production and enabling efficient capture of clean, concentrated CO2, while maintaining high process efficiency and reducing operational costs.
Implementation Method 1
a nickel aluminate sulfur absorbent... to achieve simultaneous desulfurization
Implementation Method 2
The nickel containing compound reacts with more than 10% of sulfur compounds within the gaseous stream
Implementation Method 3
a sulfur-tolerant iron oxide water gas shift catalyst to achieve simultaneous desulfurization and CO-shift conversion
Implementation Method 4
CO-shift conversion... maximizing hydrogen production
Data Source
AI summary
The present invention involves both separated beds (or physical mixture) and a process for treating a fuel gas comprising sending the fuel gas to a separated bed (or physical mixture), in which the separated beds comprise a first bed of a sulfur sorbent and a second bed of a water gas shift catalyst (a physical mixture of a sulfur sorbent and a water gas shift catalyst). The process comprises first sending the fuel gas to the first bed to remove sulfur compounds from said fuel gas and then the fuel gas goes to the second bed to undergo a water gas shift reaction in which carbon monoxide is converted to carbon dioxide and water is converted to hydrogen. (or sending the fuel gas simultaneously to the physical mixture to remove simultaneously the sulfur compounds and to react CO with water to CO2 and hydrogen).