Converting Calcium-Based FGD Systems to Ammonia-Based Operations
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Solution Overview
Problem
Existing calcium-based flue gas desulfurization systems produce gypsum as a byproduct with limited commercial value, while ammonia-based systems produce ammonium sulfate, which has higher resale value, but the cost of replacing calcium-based systems is prohibitive.
Innovation Solution
Conversion methods and equipment to transform existing calcium-based FGD systems into ammonia-based systems, including a reagent system for preparing ammonia-based reagents, an absorber system with an ammonia-based slurry, a reaction tank for producing ammonium sulfate, and a dewatering system for isolating the byproduct, while modifying the absorber and reaction tank capacity to accommodate the different chemical processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If calcium-based FGD systems are used, then the system operation is reliable and well-established, but the byproduct (gypsum) has limited commercial value
Solution Approach 1:
The patent changes the chemical composition parameter of the scrubbing solution from calcium-based to ammonia-based, transforming the byproduct from low-value gypsum to high-value ammonium sulfate fertilizer, while maintaining system operational reliability through proven FGD technology
Solution Approach 2:
The patent replicates the successful operational framework of calcium-based FGD systems but substitutes the chemical reagent, allowing the system to copy the reliability and operational experience of existing systems while achieving improved economic returns through ammonia-based chemistry
2Quantity of substance
If ammonia-based FGD systems are used, then the byproduct (ammonium sulfate) has higher commercial value, but the replacement cost is prohibitive
Solution Approach 1:
The patent divides the conversion process into manageable segments: reagent system modification, absorber system adjustment, and reaction tank modifications, allowing incremental implementation and reducing overall conversion cost while achieving high-value byproduct production
Solution Approach 2:
The patent performs preliminary assessment and planning of the conversion process, identifying required modifications to reagent systems, absorbers, and reaction tanks before implementation, thereby reducing unexpected costs and facilitating smoother transition to ammonia-based systems
3Quantity of substance
If existing calcium-based FGD systems are converted to ammonia-based systems, then economic benefits increase through valuable byproduct production, but system complexity increases
Solution Approach 1:
The patent designs the conversion system to maintain multi-functionality, where the same absorber and reaction tank infrastructure serves both calcium-based and ammonia-based operations, reducing the need for entirely new equipment and simplifying the conversion process
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
Enables the conversion of calcium-based FGD systems to ammonia-based systems, generating the more valuable ammonium sulfate byproduct, addressing the economic and environmental benefits of increased fertilizer production and reducing waste.
Implementation Method 1
an absorber system that includes an absorber tower that uses an ammonia-based slurry to remove sulfur dioxide from a flue gas
Implementation Method 2
sulfur dioxide within the flue gas reacts with ammonia (NH3) to form an ammonium sulfate solution or ammonium sulfate crystals
Implementation Method 3
a reaction tank in which a reaction occurs between the ammonia-based reagent and the sulfur dioxide absorbed by the ammonia-based slurry to produce an ammonium sulfate byproduct
Implementation Method 4
a dewatering system for drying the ammonium sulfate byproduct to isolate the ammonium sulfate byproduct from the ammonia-based slurry
Data Source
AI summary
Conversion methods and equipment for converting a calcium-based flue gas desulfurization (FGD) system to an ammonia-based FGD systems, including modifying a reagent system and absorber system of the calcium-based FGD system to be capable of, respectively, delivering an ammonia-based reagent to the absorber system rather than the calcium-based reagent, and modifying the absorber system to increase capacity of a reaction tank thereof.