Effective removal of sulfur components from Brazilian power-coals by ultrasonication (40kHz) in presence of H2O2.

Applications involving high-power ultrasound are expanding rapidly as ultrasonic intensification opportunities are identified in new fields. This is facilitated through new technological developments and an evolution of current systems to tackle challenging problems. It is therefore important to continually update both the scientific and commercial communities on current system performance and limitations. To achieve this objective, this paper addresses two key aspects of high-power ultrasonic systems. In the first part, the review of high-power applications focuses on industrial applications and documents the developing technology from its early cleaning applications through to the advanced sonochemistry, cutting, and water treatment applications used today. The second part provides a comprehensive overview of measurement techniques used in conjunction with high-power ultrasonic systems. This is an important and evolving field which enables design and process engineers to optimize the behavior and/or operation of key metrics of system performance, such as field distribution or cavitation intensity.

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Review of high-power ultrasound-industrial applications and measurement methods

Ultrasonic assisted cleaning of high sulphur Indian coals in water and mixed alkali

Comparison of ultrasound-assisted and traditional caustic leaching of spent cathode carbon (SCC) from aluminum electrolysis

Numerical investigation of heat transfer and erosion characteristics for H-type finned oval tube with longitudinal vortex generators and dimples

Ultrasonic coal-wash for de-sulfurization.

The present work investigates utilization of ultrasound in reagent-based coal de-ashing and de-sulfurization. The coal under study was received from Girald mine, Rajasthan, India. Three different ultrasonic frequencies (25 kHz, Dual (58/192 kHz) and 430 kHz) and three reagents (HCl, HNO 3 and H 2 O 2 ) were used. The study employed a Taguchi fractional-factorial L 27 DOE. Experimental data were used to derive an empirical model for the prediction of total sulfur removal. The model incorporates cavitational intensity, reagent concentration, sonication time, coal particle size and coal concentration as key parameters. Effects of above factors on reagent-based ultrasonic coal-desulfurization are presented here. An optimum set of process parameters are identified and validated. Larger-scale trial with high-ash and high-sulfur coals is strongly recommended.

Feasibility of using ultrasound-assisted process for sulfur and ash removal from coal

While ultrasonic coal-wash is not entirely new in many countries, it has not yet been practiced in India, though it would appear that the relatively high-ash content of Indian coals would render th...

B. Ambedkar

Papers

Ultrasonic coal-wash for de-sulfurization.

Feasibility of using ultrasound-assisted process for sulfur and ash removal from coal

Investigation of High-Frequency, High-Intensity Ultrasonics for Size Reduction and Washing of Coal in Aqueous Medium

Development of predictive model for fly-ash erosion phenomena in coal-burning boilers