Extraction of Bright Coals by Anhydrous Ethylene Diamine

Dryden, I. G. C.

doi:10.1038/162959a0

Cited by 15 publications

(8 citation statements)

References 1 publication

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“…N-methyl pyrollidone (NMP) is considered to be a good solvent for coal extraction (Renganathan and Zondlo 1993;Takanohashi et al 1996;Kirk and Othmer 2006;Dryden 1948). It is an H-bond acceptor and has good interacting ability with the aromatic structures.…”

Section: Introductionmentioning

confidence: 99%

Design of experiments to optimize the extraction parameters of a power grade Indian coal

Dhawan

Upadhyayula

Sharma

2018

Int J Coal Sci Technol

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Low grade high ash coals with difficult physical washability characteristics require chemical cleaning techniques such as solvent extraction to obtain super clean coal with lower ash contents. Kedla, an Indian low grade coal has ash content around 44%-50% and there is a need to maximize its solvent extraction yield so as to make this power grade coal industrially useful. This paper highlights the use of definitive screening design and response surface methodology to extract the maximum organic matter from Kedla coal using ethylenediammine (EDA) and N-methyl pyrollidone (NMP) as solvents under mild atmospheric pressure conditions. The coal was pre-treated with acetic acid before extractions were carried out. The parameters such as the acid pre-treatment time, acid concentration, particle size, the co-solvent concentration and the solvent concentration were optimized in this paper. With this design of experiments technique about 40% of the organic matter with minimal ash (less than 2%) content was rendered extractable unlike the already postulated designer solvent system-e, N system (i.e. NMP containing small amount of EDA) that uses coal to solvent ratio as 1:17 (wt/vol) and coal to co-solvent ratio as 1:1(wt/vol) thus only giving 19% extraction yield. Therefore, the present design of experiments technique helps in conserving the number of experiments for process intensification.

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Section: Introductionmentioning

confidence: 99%

Design of experiments to optimize the extraction parameters of a power grade Indian coal

Dhawan

Upadhyayula

Sharma

2018

Int J Coal Sci Technol

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“…5,6 Hence, exfoliating these aromatic islands from this cross linked macromolecules require a reactive solvent such as ethylenediamine (EDA), N-methyl-2-pyrrolidone (NMP). 3 Extracting the pure form of coal by refluxing the lignite in EDA has been in practice 7 since 1948. The lone pair of electrons available on the amino nitrogen collapses the hydrogen bonding interaction in coals and also it acts as a nucleophile towards the covalent bridging ester group, which favors the dissolution of the brown coal.…”

Section: Introductionmentioning

confidence: 99%

“…These solvent extracted coal are referred as "super clean coal" which has the high percentage of carbon content and the optical studies of these solution extracts reported in 1949, suggested that the extracts are comprised of colloidal particles of the order of hundreds of angstrom in diameter together with a background of somewhat smaller material. 7 But there is no report addressing the molecular structure and morphology of this colloidal particles until now. To the best of our knowledge this study is the first report, where these colloidal particles are isolated and identified as luminescent Carbon Nano Particles (CNPs).…”

Section: Introductionmentioning

confidence: 99%

Fluorescent carbon nano dots from lignite: unveiling the impeccable evidence for quantum confinement

Thiyagarajan

Suresh

Palanivel

et al. 2016

Phys. Chem. Chem. Phys.

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Synthesizing nano carbon from its bulk precursors is of recent research interest. In this report, luminescent carbon nanoparticles (CNPs) with tunable particle size and surface functionality are fabricated from lignite using ethylenediamine as the reactive solvent and surface passivating agent via different experimental methods. From the steady-state and time-resolved photophysical studies of these differently sized CNPs, it is unveiled that the energy of the excitons generated after photoexcitation is quantum confined, and it influences the observed photophysical behaviour significantly only when the particle size is less than 10 nm. A larger size of the CNPs and less surface functionalization lead to aggregation, and quenching of the fluorescence. But by dispersing smaller size CNPs in sodium sulfate matrix exhibits fluorescence in the solid state with an absolute fluorescence quantum yield of ∼34%. The prospective application of this hybrid material in sensing and removal of moisture in the atmosphere is illustrated.

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“…Since swelling and extraction have common fundamental causes (i.e. coal−solvent interactions), the two are related, and normally good swelling solvents are also good solvents for extraction. ,,, In fact, ethylenediamine (EDA) has been identified to be a powerful swelling solvent for coals capable of extracting a considerable quantity of coal . Work on the use of EDA as a solvent for coal has been extensively reviewed. ,,,, EDA is also an industrial solvent and has been used by the chemical industries over the years.…”

Section: Introductionmentioning

confidence: 99%

“…coal−solvent interactions), the two are related, and normally good swelling solvents are also good solvents for extraction. ,,, In fact, ethylenediamine (EDA) has been identified to be a powerful swelling solvent for coals capable of extracting a considerable quantity of coal . Work on the use of EDA as a solvent for coal has been extensively reviewed. ,,,, EDA is also an industrial solvent and has been used by the chemical industries over the years. EDA is considered to be a specific solvent for coal owing to its ability to disrupt specific interactions in coal such as the H-bonds. ,,,,− Therefore, an approach of successive extraction of coals by using both NMP and EDA in a stepwise process was adopted.…”

Section: Introductionmentioning

confidence: 99%

Ethylenediamine-Assisted Solvent Extraction of Coal in N-Methyl-2-pyrrolidone: Synergistic Effect of Ethylenediamine on Extraction of Coal in N-Methyl-2-pyrrolidone

Pande

Sharma

2001

Energy Fuels

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Coals ranging from lignite to high rank bituminous coal were extracted with N-methyl-2pyrrolidone (NMP), ethylenediamine (EDA), and NMP containing a small amount of EDA (e,N) under reflux conditions at atmospheric pressure. The extraction yield was maximum in the third case suggesting a synergistic effect of the system. The system was found to enhance the extraction yield in NMP. Stepwise successive extraction in NMP was also possible using this system. A possible explanation for the results obtained is given.

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Extraction of Bright Coals by Anhydrous Ethylene Diamine

Cited by 15 publications

References 1 publication

Design of experiments to optimize the extraction parameters of a power grade Indian coal

Design of experiments to optimize the extraction parameters of a power grade Indian coal

Fluorescent carbon nano dots from lignite: unveiling the impeccable evidence for quantum confinement

Ethylenediamine-Assisted Solvent Extraction of Coal in N-Methyl-2-pyrrolidone: Synergistic Effect of Ethylenediamine on Extraction of Coal in N-Methyl-2-pyrrolidone

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