Advances in the chemical leaching (inorgano-leaching), bio-leaching and desulphurisation of coals

Dhawan, Heena; Sharma, D. K.

doi:10.1007/s40789-019-0253-6

Cited by 33 publications

(22 citation statements)

References 86 publications

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“…It can also be observed that the percent removal of Sulfur was on higher side for the particle size of 10 Mesh as compared to 6 Mesh with both of the solvents. Similar trends were observed in previous work conducted by [14], [17].…”

Section: Methodssupporting

confidence: 91%

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Desulfurization of Mach Coal of Balochistan by Leaching Method

Mushtaq¹,

Ullah²,

Khan³

et al. 2021

Journal of Applied and Emerging Sciences

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Coal desulfurization prior to usage is frequently subjected to preprocessing to achieve clean fuel and reduce environmental impacts. In this study, desulfurization of Mach coal of Balochistan was investigated with different leaching solvents. The solvents used are NaOH and HNO3. Effects of particle size and solvent weight% on sulfur removal were studied, whereas the leaching temperature and the agitation time were kept constant. Desulfurization experiments were carried out for 12 samples of different composition based on different particle size and solvent weight%. Significant reduction in Sulfur was attained when the coal particle size of 10 Mesh was used. The results indicated that Sulfur reduction was highest of 44.88% when HNO3 was used as compare to NaOH which gave maximum Sulfur reduction of 24.72%. Sulfur recovery was found to increase with increasing solvent concentration. Decreased desulfurization was observed with larger coal particle size of 6 Mesh. Leaching process using variable solvent concentration was found effective and could be inexpensive for desulfurization of coal.

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Section: Methodssupporting

confidence: 91%

“…Three different concentrations (wt. %) of each solvent were prepared using standard dilution method [17]. Solutions were prepared by dissolving 5 gm, 15 gm, and 30 gm of NaOH and HNO3 in 100 milliliter of distilled water and mixed thoroughly.…”

Section: Preparation Of Different Concentration Of Hno3/naoh Solutionsmentioning

confidence: 99%

Desulfurization of Mach Coal of Balochistan by Leaching Method

Mushtaq¹,

Ullah²,

Khan³

et al. 2021

Journal of Applied and Emerging Sciences

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“…The energy consumption assessment was based on experiences and on data from sludge drying plants [8], HTC, and slow pyrolysis [4,5,9]. The energy consumption comparison between drying and HTC plants was calculated considering a sludge input of 5000kg, at 20% dry matter.…”

Section: Mass Balance and Energy Consumptionmentioning

confidence: 99%

Integration of two-stage thermochemical treatment and chemical leaching for extraction of advanced biochar and high value critical raw materials from sewage sludge

Salimbeni¹,

Rizzo²,

Chiaramonti

2021

E3S Web Conf.

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The proposed study aims at assessing the reliability of a new sludge conversion technology, based on integrating thermochemical treatment, with a chemical leaching stage for producing high quality biochar and valuable liquid with high concentration of phosphorus and other critical elements. The concept is based on the fact that sludge ash usually contains about 25% of CaO, 20% of P2O5, and about 25-30% of SiO2. With the removal of these elements, ash content is drastically reduced. The study is thus composed of two phases: (1) assessment of sludge thermochemical conversion routes, and (2) chemical leaching produced biochar. In the first phase, three thermochemical routes are investigated: HTC of fresh sludge at 80% moisture, slow pyrolysis of dry sludge, slow pyrolysis of HTC solid (hydrochar). In the second phase, the solid obtained by slow pyrolysis (biochar) is upgraded through leaching treatment to extract inorganic valuable elements: P, Mg, K. The first phase of the study demonstrated that processing dry sludge in slow pyrolysis at 450°C allows to obtain a low volatile carbonaceous product with characteristics similar to a thermal coal. Second phase demonstrated that, after acid leaching process using HNO3, ash content in biochar decreased from 41.63% to 16.67%. This method also demonstrated to be a valid solution to extract more than 90% of P, K, and Mg contained in the solid, making these elements available for being recycled in agriculture and other industrial uses. At the same time, the increase of the biochar C content and calorific value makes it a valid substitute of fossil coals.

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“…Sometimes, mild acid washing also reduced the extra sodium compounds along with acid-soluble minerals in coal. 11 Previous reports on coal treatment also indicated that the types of leaching reagents affected the properties of coal or carbon materials. For instance, Starck et al 12 reported that the coal treatment with HCl and HF acid solution could remove ash and signicantly modify the surface chemistry of lignite, which was able to develop the adsorbent properties of lignite.…”

Section: Introductionmentioning

confidence: 99%