Lime Feed Integration in Flash Dry Absorber Scrubber
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Solution Overview
Problem
Current sulfur dioxide (SO2) reduction systems in power plants, such as flash dry absorber (FDA) scrubbers and limestone feed systems, are costly and inefficient, failing to meet stringent emission regulations while generating nitrogen oxide (NOx) emissions that require additional costly removal systems.
Innovation Solution
Incorporating a lime feed into the flash dry absorber scrubber upstream of the particulate collection mechanism in a circulating fluidized bed (CFB) power plant, where dry hydrated lime acts as a sorbent to enhance SO2 removal efficiency, reducing the need for limestone and associated costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If limestone is introduced into the boiler to reduce SO2 emissions, then SO2 removal efficiency is improved, but fuel consumption increases and NOx generation increases
Solution Approach 1:
The patent introduces hydrated lime as an intermediary substance in the FDA scrubber to remove SO2 from flue gases. The lime is injected into the reactor column where it reacts with SO2 in the flue gases, serving as a mediator that captures sulfur dioxide without requiring limestone addition to the boiler, thereby avoiding the negative effects of limestone on fuel consumption and NOx generation
Solution Approach 2:
The patent extracts the SO2 removal function from the boiler process and relocates it to the FDA scrubber. By removing the limestone feed system from the boiler and replacing it with a lime feed system in the FDA, the invention separates the combustion process from the desulfurization process, eliminating the impact of limestone on combustion efficiency and NOx formation
2Reliability
If limestone feed system is added to the power plant to reduce SO2 emissions, then SO2 removal efficiency is improved, but system cost increases
Solution Approach 1:
The patent merges the SO2 removal function with the existing FDA scrubber system that is already part of the particulate collection system. By integrating lime injection into the FDA reactor column and utilizing the existing flue gas flow and particulate recycling system, the invention avoids the need for a separate limestone feed system, thereby reducing overall system complexity and cost
Solution Approach 2:
The FDA scrubber system is designed to perform multiple functions: particulate collection and SO2 removal. The hydrated lime injection system utilizes the existing FDA infrastructure for both particulate control and desulfurization, making the system multi-functional and eliminating the need for dedicated limestone handling, storage, and feeding equipment
3Reliability
If limestone is introduced into the boiler to reduce SO2 emissions, then SO2 removal efficiency is improved, but NOx generation increases
Solution Approach 1:
The patent uses hydrated lime as an intermediary substance in the FDA scrubber to remove SO2 from flue gases. The lime is injected into the reactor column where it reacts with SO2 in the flue gases, serving as a mediator that captures sulfur dioxide without requiring limestone addition to the boiler, thereby avoiding the negative effects of limestone on fuel consumption and NOx generation
Solution Approach 2:
The patent extracts the SO2 removal function from the boiler process and relocates it to the FDA scrubber. By removing the limestone feed system from the boiler and replacing it with a lime feed system in the FDA, the invention separates the combustion process from the desulfurization process, eliminating the impact of limestone on combustion efficiency and NOx formation
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 reduces SO2 emissions while minimizing limestone usage, lowering overall sorbent costs, improving combustion efficiency, and decreasing NOx generation, resulting in significant cost savings and reduced environmental impact.
Implementation Method 1
dry hydrated lime acts as a sorbent to enhance SO2 removal efficiency
Implementation Method 2
The hydrated particulate including the residual CaO reacts with the flue gases in the reactor column and in the particulate collection mechanism to remove SO2 therefrom
Data Source
AI summary
A circulating fluidized bed power plant 100 includes; a circulating fluidized bed boiler 110 which generates flue gases, a flash dry absorber scrubber 140 configured to receive the flue gases from the circulating fluidized bed boiler 110, and a lime feed 150 configured to introduce lime into the flash dry absorber scrubber 140.