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Ultrasonic coal-wash for de-sulfurization.
B Ambedkar1, R Nagarajan, S Jayanti
1Department of Chemical Engineering, IIT Madras, Chennai, India.
Ultrasonics Sonochemistry
|December 1, 2010
Summary
Ultrasonic de-sulfurization effectively removes sulfur from coal before combustion, offering an eco-friendly alternative to traditional methods. This advanced oxidation process converts sulfur into water-soluble sulfates, mitigating pollution risks.
Area of Science:
- Environmental Science
- Chemical Engineering
- Materials Science
Background:
- Coal combustion releases sulfur dioxide (SOx), a major air pollutant harmful to ecosystems and human health.
- Current flue gas desulfurization methods produce by-products like FGD gypsum, posing disposal challenges.
- Effective pre-combustion coal beneficiation is crucial for reducing sulfur emissions.
Purpose of the Study:
- To investigate the efficacy of power ultrasound for pre-combustion coal desulfurization.
- To compare ultrasonic desulfurization with conventional chemical methods.
- To explore the mechanisms and advantages of ultrasonic sulfur removal.
Main Methods:
- Application of power ultrasound to coal in aqueous and solvent-based media (2N HNO3, 3% H2O2).
- Utilizing acoustic cavitation, acoustic streaming, and advanced oxidation processes (AOPs) generated by ultrasound.
- Experimental comparison with conventional soaking and stirring desulfurization techniques.
Main Results:
- Ultrasonic treatment demonstrated significant sulfur removal from coal.
- Advanced Oxidation Processes (AOPs) converted coal sulfur into water-soluble sulfates.
- Ultrasonic methods showed advantages over conventional chemical-based approaches.
Conclusions:
- Power ultrasound is a viable and effective technology for coal desulfurization prior to combustion.
- Ultrasonic desulfurization offers environmental benefits by reducing SOx emissions and avoiding problematic by-products.
- Further research into aqueous-based and solvent-based ultrasonic desulfurization mechanisms is warranted.
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