HCl Extraction from Chlorine-Combustion Flue Gas
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Solution Overview
Problem
Existing methods for purifying flue gas from chlorine-comprising materials fail to produce a high-quality acidic liquid and often result in neutralized solutions with high salt concentrations, which are difficult to exploit, and may use toxic products or produce non-reusable waste streams, not meeting current environmental standards.
Innovation Solution
A method involving a two-field electrofilter to remove solid particles, followed by absorption of hydrochloric acid in an aqueous solution with packing material, and subsequent adsorption using activated carbon to achieve a high concentration of hydrochloric acid, reducing waste and enabling the acidic liquid to be used as a catalyst or raw material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If strong base (lime) is used to neutralize acids in the gas stream, then acid removal efficiency is improved, but the resulting neutralized solution has high salt concentrations that are difficult to exploit and create waste
Solution Approach 1:
Instead of neutralizing the acidic flue gas with base to produce salt waste, the invention inverts the approach by directly absorbing HCl into water to produce hydrochloric acid solution. This reverses the traditional neutralization paradigm, converting what would be waste (acidic gas) into a valuable product (concentrated HCl solution) without forming unwanted salts.
Solution Approach 2:
The invention converts the harmful acidic flue gas directly into a beneficial concentrated hydrochloric acid solution through selective absorption. The HCl that would normally require neutralization and create waste is instead captured and concentrated into a usable chemical product, transforming a pollutant into a resource.
2Object-affected harmful factors
If traditional absorption methods are used, then acid capture is achieved, but the resulting solution has low acid concentration and cannot be used as catalyst or raw material
Solution Approach 1:
The invention changes the concentration parameter by using a controlled absorption process that produces a concentrated HCl solution (at least 30% HCl) rather than a dilute solution. This is achieved by optimizing the absorption conditions and using the electrofilter to pre-concentrate the acid before final absorption, enabling the product to meet industrial specifications for catalyst or raw material use.
Solution Approach 2:
The invention replaces traditional mechanical filtration and neutralization systems with an electrostatic field-based separation system. The two-field electrofilter uses electrostatic forces to selectively separate and concentrate HCl from the flue gas, achieving high acid concentration without the need for subsequent neutralization or dilution steps.
3Object-affected harmful factors
If existing purification methods are applied, then flue gas cleaning is achieved, but toxic products are used or non-reusable waste streams are produced, not meeting current environmental standards
Solution Approach 1:
The invention converts the harmful acidic flue gas directly into a beneficial concentrated hydrochloric acid solution through selective absorption. The HCl that would normally require neutralization and create waste is instead captured and concentrated into a usable chemical product, transforming a pollutant into a resource.
Solution Approach 2:
Instead of discarding the acidic components of flue gas through neutralization, the invention recovers the HCl by selective absorption and concentration. The electrofilter and absorption system work together to capture and concentrate HCl into a reusable product, eliminating the need to discard it as waste and preventing toxic waste stream generation.
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 method effectively removes pollutants, achieving a high-purity acidic liquid with a concentration of hydrochloric acid suitable for various applications, reducing waste, and meeting stringent environmental standards without using toxic products.
Implementation Method 1
a first cleaning step in which solid particles are removed from the flue gas via a two-field electrofilter
Implementation Method 2
absorbing hydrochloric acid from the flue gas in at least one absorption column with packing material
Implementation Method 3
adsorbing pollutants in the solution on one or more activated carbon filters
Data Source
Figure 1
AI summary
The invention relates to a method for obtaining an acidic liquid from flue gas originating from the combustion of chlorine-comprising material, in which at least the following steps are applied: the removal of solid particles from the flue gas via a two-field electrofilter; absorbing hydrochloric acid from the flue gas in at least one absorption column with packing material whereby a solution is obtained; and adsorbing pollutants in the solution on one or more activated carbon filters, whereby an acidic liquid is obtained, wherein the solution has a concentration of HCl of at least 3 wt%. The invention also relates to a device for purifying flue gas, and also relates to purified flue gas per se.