Show simple item record

AuthorKiran, Aftab
AuthorJaved, Javeria
AuthorHabibhah Siddiqua, Umme
AuthorMalik, Ayesha
AuthorHassan, Afifa
AuthorRizwan Khan, Mohammad
AuthorBusquets, Rosa
AuthorAhmad, Naushad
AuthorHaque, Anzarul
Available date2024-05-01T08:54:49Z
Publication Date2024-08-01
Publication NameFuel
Identifierhttp://dx.doi.org/10.1016/j.fuel.2024.131796
ISSN00162361
URIhttps://www.sciencedirect.com/science/article/pii/S001623612400944X
URIhttp://hdl.handle.net/10576/54527
AbstractThe exploration of low-grade coal resources and progress in the extraction method of humic substances are the core aims of this study. Ultrasonic and microwave assisted alkali extractions were compared with conventional shake flask alkali extraction to trace the efficiency of the extraction of humic substances from a wide range of coal samples. Among the seven coal samples collected from coal mines in Chakwal district, Pakistan, the observed humification index values ranged from 1.22 to 1.35 for humic acids, and from 5.0 to 6.9 for fulvic acids. This indicates high ratio of polycondensed aromatic moieties. The coal sample with the highest humic content was used to assess extraction methods targeted to humic substances. The extractions supported with microwave and ultrasound, when compared to shake flask extraction, increased the yield in 6.3 % and 3.2 % for humic acids, and just under 1 % for fulvic acids along with 4 times reduction in extraction time. The highest recoveries of humic acids (39.2 ± 0.9 %) and fulvic acids (9.1 ± 0.3 %) were obtained with a microwave assisted alkali extraction using KOH (0.1 M)-urea (0.5 M) (4:1, v/v) solution, and microwave irradiation time 180 s. In general, the optimised method improved the humic and fulvic acids extraction yield up to 10.8 % and 4.4 %, respectively. Furthermore, the Yates model was well suited for predicting the efficiency of the study extractions.
SponsorThe present research work was conducted by funding of Higher Education Commission, Islamabad under NRPU-4198 project. The authors would also like to thank the Researchers Supporting Project Number (RSP2024R138), King Saud University, Riyadh, Saudi Arabia.
Languageen
PublisherElsevier
SubjectHumic acid
Fulvic acid
Extraction methods
Yates model
TitleProcess optimization and method validation for efficient valorization of low- grade coal into humic substances
TypeArticle
Volume Number369
ESSN1873-7153
dc.accessType Full Text


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record