Unmixed Fuel Processor for Coal Gasification
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Solution Overview
Problem
Unmixed combustion technologies face challenges with ash agglomeration, which reduces the reliability and efficiency of coal-based gas turbines due to erosive fly ash, and emit pollutants like NOx and CO2, making coal a less viable fuel option.
Innovation Solution
The implementation of an unmixed fuel processor system with three circulating fluidized bed reactors, utilizing a CO2 sorbent and oxygen transfer material to separate gasification from solids, allowing for reduced agglomeration and lower pollutant emissions by maintaining a cool solids accumulation area and using high-temperature, high-pressure CO2 capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional combustion systems are used to burn coal, then energy production is achieved, but air pollution including NOx, CO2, and particulate emissions occurs
Solution Approach 1:
The combustion process is segmented into two separate reactors: an oxidation reactor where fuel is burned without air mixing, and a separate air inlet system. This segmentation prevents the formation of NOx by keeping fuel and air separate, while still achieving complete combustion and energy production.
Solution Approach 2:
A catalyst is introduced as an intermediary substance that facilitates combustion without requiring direct mixing of fuel and air. The catalyst enables the oxidation of fuel components (carbon to CO2, hydrogen to H2O) while preventing the formation of harmful emissions like NOx, thus mediating between energy production and pollution prevention.
2Power
If turbine inlet temperature is increased to improve efficiency, then thermodynamic efficiency increases, but turbine blade erosion from fly ash increases
Solution Approach 1:
The harmful fly ash is extracted and removed from the combustion gases before they enter the turbine. The oxidation reactor design allows fly ash to be separated from the cleaned combustion products, preventing blade erosion while maintaining high turbine inlet temperatures for efficient power generation.
Solution Approach 2:
The combustion process parameters are changed by using a catalyst-enabled unmixed combustion mode that produces cleaner combustion products. This allows the turbine to operate at higher inlet temperatures with reduced fly ash content, improving thermodynamic efficiency without compromising blade durability.
3Object-generated harmful factors
If unmixed combustion technology is used to reduce emissions, then NOx and CO2 emissions are lowered, but ash agglomeration reduces system reliability
Solution Approach 1:
A catalyst serves as an intermediary that enables unmixed combustion to proceed efficiently without causing ash agglomeration. The catalyst facilitates the oxidation reactions at lower temperatures and with different mechanisms that prevent alkali metal oxides from melting and forming agglomerates, thus maintaining system reliability while achieving emission reductions.
Solution Approach 2:
The combustion parameters are changed through catalytic action, allowing the process to operate in a regime where emissions are reduced but ash behavior is modified to prevent agglomeration. The catalyst enables complete combustion without the high temperatures and mixing conditions that cause harmful ash agglomeration, resolving the reliability issue.
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 enhances the efficiency and reduces emissions by eliminating agglomeration issues, lowering NOx production, and enabling higher turbine inlet temperatures, making coal a more economically viable gas turbine fuel while capturing CO2 for sequestration.
Implementation Method 1
a CO2 acceptor reactor, and is configured to receive syngas from the gasifier
Implementation Method 2
an oxidation reactor comprising an oxidation portion and a gasifier... The oxidation portion comprises an air inlet, effluent outlet, and an oxygen transfer material
Implementation Method 3
U.S. Pat. Nos. 5,339,754, 5,509,362, and 5,827,496, disclose a method of burning fuels using a catalyst that is readily reduced when in an oxidized state and readily oxidized when in a reduced state
Implementation Method 4
three circulating fluidized bed reactors
Data Source
AI summary
Disclosed herein are unmixed fuel processors and methods for using the same. In one embodiment, an unmixed fuel processor comprises: an oxidation reactor comprising an oxidation portion and a gasifier, a CO2 acceptor reactor, and a regeneration reactor. The oxidation portion comprises an air inlet, effluent outlet, and an oxygen transfer material. The gasifier comprises a solid hydrocarbon fuel inlet, a solids outlet, and a syngas outlet. The CO2 acceptor reactor comprises a water inlet, a hydrogen outlet, and a CO2 sorbent, and is configured to receive syngas from the gasifier. The regeneration reactor comprises a water inlet and a CO2 stream outlet. The regeneration reactor is configured to receive spent CO2 adsorption material from the gasification reactor and to return regenerated CO2 adsorption material to the gasification reactor, and configured to receive oxidized oxygen transfer material from the oxidation reactor and to return reduced oxygen transfer material to the oxidation reactor.