Shift Reactor Heat Recovery for Gasification Power Efficiency
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Solution Overview
Problem
In power generation systems with carbon dioxide recovery devices, the heat energy generated by shift reactions is not effectively utilized, leading to suboptimal power generation efficiency.
Innovation Solution
A carbon dioxide separation and recovery device is integrated into the gasification power generation system, which includes a shift reactor, a carbon dioxide absorption tower, and an absorption liquid recycling device, along with an evaporator to recover shift reaction heat and reduce the need for auxiliary steam, thereby improving power generation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If steam is supplied from the exhaust heat recovery boiler to the shift reactor, then the shift reaction can proceed, but the power generation efficiency is reduced due to loss of steam that could drive the steam turbine
Solution Approach 1:
The shift reactor is designed to utilize the heat generated by the exothermic shift reaction itself to vaporize water and produce steam. This self-service mechanism eliminates the need to supply steam from the exhaust heat recovery boiler, thereby preventing loss of steam that could drive the steam turbine and improving overall power generation efficiency
Solution Approach 2:
The invention changes the thermal parameters within the shift reactor by utilizing the exothermic heat of the shift reaction to raise the temperature of the reactants and generate steam in-situ. This parameter change allows the system to be self-sufficient for steam supply while maintaining reaction stability
2Device complexity
If shift reaction heat is not recovered, then the system operation is simple, but the power generation efficiency is not improved
Solution Approach 1:
The invention merges the heat recovery function with the existing shift reactor by incorporating a water vaporization section directly into the reactor. This integration allows the shift reaction heat to be recovered and utilized for steam generation without adding separate, complex heat recovery equipment, thereby improving power generation efficiency while maintaining relatively simple system configuration
Solution Approach 2:
The shift reactor is designed to perform multiple functions: conducting the shift reaction, recovering heat from the exothermic reaction, vaporizing water, and generating steam for the steam turbine. This multi-functionality allows the same equipment to improve power generation efficiency without significantly increasing system complexity
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 effective recovery of shift reaction heat enhances power generation efficiency by reducing the amount of steam required from the exhaust heat recovery boiler, increasing the output of the steam turbine and improving overall plant efficiency.
Implementation Method 1
the shift reaction to obtain carbon dioxide and hydrogen from carbon monoxide and steam, the main components of gas produced in coal gasification, represented by the following equation (1) is generally used in carbon dioxide recovery systems at chemical plants, etc. CO + H2O → CO2 + H2
Implementation Method 2
This shift reaction is an exothermic reaction
Implementation Method 3
an evaporator to generate steam heated by heat exchange with the fuel gas heated by shift reaction heat generated in the shift reactor
Implementation Method 4
the carbon dioxide is absorbed by an absorption liquid at a carbon dioxide absorption tower
Data Source
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AI summary
A gasification power generation system provided with a carbon dioxide separation and recovery device (200) comprising: a carbon dioxide separation and recovery device (200) having: a shift reactor (5) to convert carbon monoxide contained in fuel gas into carbon dioxide; a carbon dioxide absorption tower (37) to produce fuel gas; and an absorption liquid recycling device (38) to recycle an absorption liquid; and a gasification power generation system having: a gas turbine device driven by burning the fuel gas; an exhaust heat recovery boiler (20) having a drum (30,31) to generate steam; and a steam turbine (23) driven by the steam generated by the drum (30,31); wherein an evaporator (6) to generate steam is disposed downstream of the shift reactor (5), a steam line to supply a steam mixer (4) disposed in a fuel gas line upstream of the shift reactor (5) with the heated steam generated by the evaporator (6) is provided, and the heated steam supplied through the steam line is allowed to flow from the steam mixer (4) into the shift reactor (5) as shift steam together with the fuel gas.