Carbon Dioxide Carrier Gas for Coal Gasification
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Solution Overview
Problem
The existing integrated coal gasification combined cycle plants face high power consumption and increased costs due to the need for an air separation unit to generate inert gas for carrying pulverized coal and char, which also results in low reliability in continuous operation.
Innovation Solution
The implementation of a carbon-dioxide recovery unit that recovers carbon dioxide from exhaust gas to carry coal and char to the gasification furnace, eliminating the need for an additional inert gas generation apparatus and reducing facility costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an air separation unit is installed to generate inert gas for carrying pulverized coal and char, then the plant can operate, but power consumption increases and facility costs increase
Solution Approach 1:
The patent recovers carbon dioxide from the exhaust gas of the gas turbine and reuses it as the carrier gas for pulverized coal and char. This discards the previously wasted exhaust gas and recovers useful carbon dioxide from it, eliminating the need for the air separation unit and reducing power consumption while maintaining continuous operation reliability
Solution Approach 2:
The system uses its own exhaust gas to provide the carrier gas function previously requiring external air separation. The exhaust gas from the gas turbine serves dual purposes: power generation and providing inert atmosphere for coal handling, making the system self-sufficient and eliminating additional facility requirements
2Ease of manufacture
If an air separation unit is installed to generate inert gas, then pulverized coal can be carried to the gasification furnace, but facility costs increase
Solution Approach 1:
The exhaust gas from the gas turbine is used for multiple purposes: it serves as the carrier gas for pulverized coal and char, and also as drying gas for raw coal. This multi-functional use eliminates the need for separate air separation facilities and reduces overall plant complexity and facility costs
Solution Approach 2:
Instead of discarding exhaust gas as waste, the system recovers and reuses it as the carrier gas medium. This eliminates the need for additional air separation facilities, reducing both facility costs and device complexity while maintaining operational effectiveness
3Use of energy by moving object
If carbon dioxide is recovered from exhaust gas to carry coal and char, then power consumption decreases and facility costs decrease, but the system requires a carbon-dioxide recovery unit
Solution Approach 1:
The patent extracts carbon dioxide from the exhaust gas stream using a recovery unit and separates it for specific use as carrier gas. This extraction approach allows the system to obtain pure carbon dioxide from the mixed exhaust gas while eliminating the need for more complex air separation units, reducing overall power consumption and facility costs
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 solution reduces power consumption, decreases facility costs, and enhances the reliability of the plant by utilizing recovered carbon dioxide as a carrier gas, thereby preventing efficiency decreases and lowering atmospheric carbon dioxide emissions.
Implementation Method 1
a carbon-dioxide recovery unit to which part of the exhaust gas let out from the gas turbine is introduced and which recovers carbon dioxide therein
Implementation Method 2
coal and char hoppers are pressurized using the carbon dioxide, and the coal and char are carried to the gasification furnace using the carbon dioxide as carrier gas
Implementation Method 3
coal and char hoppers are pressurized using the carbon dioxide
Data Source
AI summary
Synthesis gas (syngas) gasified in a gasification furnace to which coal is introduced burns in a combustor. An exhaust-heat recovery boiler generates steam by using exhaust gas let out from a gas turbine equipped with the combustor. The steam generated in the exhaust-heat recovery boiler is introduced to a steam turbine. A generator is driven by the steam turbine and the gas turbine to generate electrical power. Part of the exhaust gas let out from the gas turbine is introduced to a carbon-dioxide recovery unit, where carbon dioxide is recovered therefrom. Coal is carried to the gasification furnace by the carbon dioxide.