Extraction of organic compounds from brown coal

Abstract

The paper presents the study on the extraction of organic compounds (low-molecular weight - diterpenes, high-molecular weight - fullerenes and humic acids) from Handlová brown coal and pyrolytic soot. It was confirmed that the coal extract with a diterpene content - 16 β (H) kaurene was obtained by the supercritical fluid extraction (using CO2 and modificator - tetrahydrofurane/acetone, 8:2 w/w) at T = 90 oC and p = 30 MPa. The occurrence of fullerenes in the toluene extract of solid carbon product has confirmed by the MALDI - TOF - MS and UV-VIS spectroscopy. In the extraction process of GACL (Grinding Aqueous Caustic Leaching) at the concentration of 0.1 % NaOH, the content of humic acids (HK) in the physically untreated and pretreated sample increased by 6.09 and 4.57 times, respectively. In the case of higher leaching agent concentration (2 % NaOH), the content of HK in the physically untreated and pretreated sample increased by 8,67 and 8,21 times, respectively.

Keywords

• Handlová brown coal
• extraction of organic compounds
• mechanical activation