Dry Mercury Removal via Real-Time Bromine Dosing
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Solution Overview
Problem
Existing methods for separating mercury from flue gases in high-temperature plants, such as power and waste incineration plants, are inefficient and costly, particularly due to the reliance on wet scrubbing and excessive use of bromine-containing compounds, which are toxic and not effectively adjustable to changing exhaust gas compositions.
Innovation Solution
A dry purification method involving the separate metering and addition of bromine-containing compounds and carbon-containing adsorbents, like activated carbon, downstream of the furnace, where the reactants are dosed based on real-time mercury concentration, allowing for effective bromination and adsorption of mercury at temperatures below 500°C, reducing the need for excess reactants and minimizing toxicity risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wet scrubbing is used to remove mercury from flue gases, then mercury separation efficiency is improved, but operational costs and complexity increase
Solution Approach 1:
The invention changes the fundamental parameter of the purification method from wet scrubbing to dry adsorption. By using activated carbon as an adsorbent in a dry purification system, the method achieves effective mercury removal without the operational complexity and water consumption associated with wet scrubbing systems
Solution Approach 2:
The invention extracts the mercury removal function from the complex wet scrubbing system and implements it through a simpler dry adsorption process using activated carbon, thereby reducing operational complexity while maintaining separation efficiency
2Reliability
If excess bromine-containing compounds are added to oxidize mercury, then mercury oxidation is improved, but toxicity risks and operational costs increase
Solution Approach 1:
The invention implements a feedback control system where the dosing rate of bromine-containing compounds is continuously adjusted based on real-time mercury concentration measurements in the flue gas. This ensures optimal oxidation efficiency while minimizing excess reactant addition and associated toxicity risks
Solution Approach 2:
The dosing system is made dynamic and adaptive, automatically adjusting the bromine compound addition rate according to varying mercury loads in the flue gas, thereby maintaining high oxidation efficiency while reducing toxicity risks through precise control
3Productivity
If high temperatures are used in the purification process, then reaction efficiency is improved, but energy consumption increases
Solution Approach 1:
The invention changes the temperature parameter from high-temperature processing to low-temperature adsorption. By using activated carbon as an adsorbent, effective mercury removal is achieved at lower temperatures, significantly reducing energy consumption while maintaining reaction efficiency
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 method achieves efficient and economical mercury separation with reduced toxicity risks and operational costs, as it allows for precise dosing of reactants and utilizes adsorbents to firmly bind mercury bromide, enabling effective separation without relying on wet scrubbing or high temperatures.
Implementation Method 1
carbon-containing adsorbents, preferably in the form of activated carbon and/or activated cokes, to be dosed separately and added to the flue gas stream
Implementation Method 2
bromine and/or bromine-containing compounds...to be fed as a function of a preferably continuously measured mercury concentration in the flue gas flow
Data Source
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AI summary
The invention relates to a method for precipitating mercury from flue gases of high-temperature plants, in particular of power stations and waste incineration plants, wherein reactants, for example in the form of bromine or alkali sulphides, are added to the flue gas downstream of the furnace in the flow direction and subsequently the flue gas is at least subjected to dry cleaning for removing the mercury and any excess reactants, wherein the method is characterized in that the reactants and carbonaceous adsorbents are discharged in the form of activated carbon and/or activated coke separately metered to the flue gas and that the reactants are metered on the basis of a preferably continuously measured mercury concentration in the flue gas stream.