Polychlorinated Hydrocarbon Dehalogenation Using Lime
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Solution Overview
Problem
Current methods for dehalogenation of polychlorinated aromatic hydrocarbons are inefficient, costly, and generate hazardous by-products, with high energy requirements and the need for specialized equipment and skilled labor, while also being slow and non-selective.
Innovation Solution
A process using low-cost lime or limestone as a dechlorinating agent at elevated temperatures (800-950°C) in the presence of water vapor and air, which achieves 99.9999% destruction efficiency and produces valuable calcium chloride as a side product, with a continuous reactor design that prevents the formation of harmful chlorinated organic pollutants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hazardous waste incinerators with secondary combustion chambers operating at temperatures higher than 1200°C are used, then destruction efficiency of polychlorinated aromatic hydrocarbons is improved, but investment costs and operational complexity increase significantly
Solution Approach 1:
The patent changes the temperature parameter from >1200°C to 800-950°C, and changes the chemical environment by introducing lime or limestone as a dehalogenation agent. This parameter change achieves comparable destruction efficiency while reducing thermal stress on equipment and simplifying the overall system design.
Solution Approach 2:
The patent introduces lime or limestone as an intermediary substance that facilitates the dehalogenation reaction. This mediator enables effective destruction of polychlorinated aromatic hydrocarbons at lower temperatures, eliminating the need for complex secondary combustion chambers and high-temperature resistant materials.
2Reliability
If high temperatures (1200°C) are maintained for sufficient residence time (minimum 2 seconds), then destruction efficiency is improved, but energy consumption increases
Solution Approach 1:
The patent changes the temperature parameter from 1200°C to 800-950°C and optimizes residence time to 0.5-5 seconds. The presence of lime or limestone as a dehalogenation agent enables effective destruction at these lower temperature-time conditions, significantly reducing energy consumption while maintaining high destruction efficiency.
3Reliability
If fuels such as gasoline are used to reach high temperatures, then destruction efficiency is improved, but harmful by-products (dioxins, furans, hexachlorobenzene) are generated during start-up and shut-down
Solution Approach 1:
The patent introduces lime or limestone as an intermediary dehalogenation agent that enables effective destruction at lower temperatures (800-950°C). This eliminates the need for fossil fuel combustion, thereby preventing the formation of harmful by-products such as dioxins, furans, and hexachlorobenzene during operation, start-up, and shut-down.
Solution Approach 2:
The patent converts the harmful chlorinated hydrocarbons into beneficial calcium chloride product through dehalogenation reaction with lime/limestone. This transformation not only destroys the harmful substances but also produces a marketable by-product, turning a hazardous process into a beneficial one.
4Reliability
If specialized equipment and qualified staff are required for operation, then destruction efficiency is improved, but operational costs and complexity increase
Solution Approach 1:
The patent changes the operating temperature to 800-950°C, which is more manageable than 1200°C, and introduces lime or limestone as a stable dehalogenation agent. These parameter changes enable the use of conventional equipment and simplify operation, reducing the need for specialized staff while maintaining high destruction efficiency.
5Reliability
If conventional dehalogenation methods are used, then destruction of polychlorinated aromatic hydrocarbons is achieved, but valuable resources are wasted and hazardous by-products are generated
Solution Approach 1:
The patent converts the harmful chlorine atoms in polychlorinated aromatic hydrocarbons into valuable calcium chloride through dehalogenation reaction with lime/limestone. This transforms waste chlorine into a marketable product, eliminating resource waste and eliminating hazardous by-products simultaneously.
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 process effectively dehalogenates polychlorinated hydrocarbons, achieving high destruction efficiency with reduced operational costs and environmental impact, producing marketable calcium chloride and eliminating the need for hazardous by-products, while being safer and more energy-efficient.
Implementation Method 1
a process for the annihilation of harmful wastes containing polychlorinated hydrocarbons, especially polychlorinated aromatics by using low cost and widely available lime or limestone as dehalogenating agent
Implementation Method 2
The dehalogenation is carried out in the presence of water vapour and air in order to eliminate the formation of carbonaceous polymers and coke
Implementation Method 3
The dehalogenation is carried out in the presence of water vapour and air in order to eliminate the formation of carbonaceous polymers and coke
Implementation Method 4
achieves 99.9999% destruction efficiency and produces valuable calcium chloride as a side product
Data Source
Figure 1
AI summary
The present invention relates to a process consists of the hydrolytic decomposition of the polychlorinated hydrocarbons: of polychlorinated aliphatics and especially of polychlorinated aromatics and oxidizing the chlorine-free product at elevated temperature in the presence of a carrier gas in one unit characterized by a hot and a transitional temperature zone, whereby the calcium chloride and the exiting gas mixture are removed continuously and the excess heat of the highly exothermic process is utilized. The present invention also relates to an apparatus for the process which is carried out in an Apparatus of Figure 1.