Staged Combustion for Odor Gas Incineration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for burning fuel containing nitrogen and sulfur in chemical pulp mills result in high nitrogen oxide emissions, requiring large incinerators to maintain temperature stability and control NOx formation.
Innovation Solution
A method involving preheated primary combustion gas at 450°C or higher, with controlled oxygen levels, followed by staged combustion using tertiary and quaternary air to reduce NOx formation, and complete oxidation of sulfur compounds, allowing for smaller incinerator designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If excess air is used for combustion to oxidize sulfur compounds, then sulfur oxidation is improved, but nitrogen oxide emissions increase
Solution Approach 1:
The combustion process is divided into multiple stages with different air supply rates. The first stage uses limited air (0.3-0.7 of stoichiometric amount) to burn fuel with nitrogen while minimizing NOx formation. The second stage supplies remaining air to complete combustion and oxidize sulfur compounds. This temporal segmentation of air supply resolves the contradiction between sulfur oxidation and NOx emission control.
Solution Approach 2:
The fuel is preheated to 450°C or higher before combustion begins. This preliminary heating ensures that when limited air is supplied in the first stage, the combustion reactions can still proceed effectively at lower oxygen concentrations, maintaining sulfur oxidation efficiency while controlling NOx formation. The preheating action prepares the system for staged combustion conditions.
2Object-generated harmful factors
If large incinerators are used to maintain temperature stability and control NOx formation, then nitrogen oxide emissions are reduced, but device size and cost increase
Solution Approach 1:
The invention changes the parameters of combustion air supply from constant to staged variable supply. By controlling the air-fuel ratio dynamically through two stages with different air amounts, the system achieves effective NOx control without requiring large incinerator volumes. The parameter change in air supply timing and quantity enables compact design while meeting emission standards.
Solution Approach 2:
The combustion process transitions from static single-stage combustion to dynamic two-stage combustion with varying air supply rates. The first stage operates with air supply rate of 0.3-0.7 times stoichiometric requirement, then transitions to the second stage with remaining air supply. This dynamic control enables effective NOx management in compact incinerators rather than requiring oversized static systems.
3Object-generated harmful factors
If staged combustion with limited air is used to reduce NOx formation, then nitrogen oxide emissions are minimized, but complete combustion and sulfur oxidation may be insufficient
Solution Approach 1:
The combustion process is segmented into two distinct stages: first stage with limited air (0.3-0.7 of stoichiometric amount) to minimize NOx formation, and second stage with remaining air supply to ensure complete combustion and sulfur oxidation. This segmentation allows each stage to optimize for its specific function while achieving overall combustion completeness.
Solution Approach 2:
The two-stage combustion process continues without interruption, with the second stage seamlessly following the first. The air supply transitions from limited to sufficient amounts, ensuring that sulfur compounds are oxidized and combustion is completed after the initial low-NOx phase. This continuous process maintains both NOx control and combustion completeness.
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 effectively minimizes NOx emissions and sulfur oxidation in a more compact system, reducing the size and cost of incinerators while maintaining efficient combustion.
Implementation Method 1
preheated primary combustion gas at 450°C or higher
Implementation Method 2
The Sulphur is oxidized
Implementation Method 3
burning fuel that comprises nitrogen and Sulphur such that only a small amount of nitrogen oxides are formed
Data Source
AI summary
A method for burning primary fuel (F1), wherein the primary fuel (F1) comprises at least a first compound containing nitrogen and a second compound comprising sulfur. The method comprises producing primary combustion gas (G1) having a temperature of at least 450° C. and comprising oxygen; feeding the primary fuel (F1) and the primary combustion gas (G1) to a primary process zone (Z1) of a furnace (200); feeding tertiary combustion gas (G3) to a secondary process zone (Z2) of the furnace (200); letting the primary fuel (F1), the primary combustion gas (G1), and/or their reaction products to move from the primary process zone (Z1) via the secondary process zone (Z2) to a tertiary process zone (Z3) of the furnace (200); and feeding quaternary combustion gas (G4) comprising oxygen to the tertiary process zone (Z3) of the furnace (200). An embodiment comprises collecting the primary fuel (F1) from a pulp process. A corresponding system.