Separation And Analysis Of Soluble Organic Matter From Shengli Lignite And Xinjiang Changyan Coal

Main chemical problem for none-fuel use of low-rank coals is to know the composition oforganic matter in the coals. Isolating and identifying the low molecular weight compound fromthe soluble fraction in coal is an effective approach for better understanding coal structure andmaking full use of coals in the future. In order to investigate the compositions of solubleorganic molecules in low-rank coals, Shengli lignite (XL), and Xinjiang Changyan Coal (XCC)were selected in this subject. Firstly, we researched the thermal dissolution (TD) of SL in abenzene/methanol then separation and analysis of its soluble matter. On this basis, SL and XCCwere undergoing ultrasonic extraction (UE) and TD in a mixed solvent toluene/ethanol friendlyto the environment. The soluble mixture was analyzed with GC/MS, and then separated bygelatin column chromatography (GCC) and medium pressure liquid chromatography (MPLC).All the subfractions after separation were analyzed with GC/MS analysis to identify theircomposition and structure. The high purity and molecular mass of a compound withanti-inflammatory activity separated from TDSL with benzene/methanol were furtherconfirmed by HPLC/MS analysis.The yields of UESL, TDSL, UEXCC and TDXCC matter with toluene/ethanol are1.7%,40.5%,3.1%and52.4%, respectively. Seeing from the yields of the soluble matter from twodifferent low-rank coals, the yields of UEXCC and TDXCC are all obviously higher than thoseof SL’s. However, the yields of TD mixture are far greater than UE matter for the same coalunder different soluble conditions. The main reason is that soluble small molecules wereobtained after the bonds break of the macromolecule in toluene/ethanol at330oC.The results of GC/MS analysis indicate that all kinds of compounds were detected in thesoluble matter from SL and XCC under different dissolution conditions except that only9compounds detected in TDSL with benzene/methanol.41and109compounds were detectedfrom the UESL and TDSL in toluene/ethanol, respectively. The same number,63compoundswere both detected from the UEXCC and TDXCC with toluene/ethanol. The obvious characterof the above complex mixture especially the TD matter is that the relactive content oforganoxygen compounds (OOCs) is noticably high.71OOCs were decteted and the relativecontent are64.24%from TDSL with toluene/ethanol.37OOCs were decteted and the relativecontent are53.10%from TDXCC with toluene/ethanol. This gave us important theoreticalevidence to investigate the possibility for separating and enriching some OOCs from low-rankcoals. What’s more, some unusual phosphorus, fluorine and silicon-containing compoundswere detected in the soluble matter. With further isolation and purification of each soluble matter,7compounds with highpurity were separated successfully and identified as octathiocane and6-hydroxy-7-isopropyl-1,1,4a-trimethyl-2,3,4,4a,10,10a-hexahydrophenanthren-9(1H)-one(HIPTMHHP) with anti-inflammatory activity from TDSL in benzene/methanol,bis(6-methylheptyl)phthalate from UESL and TDSL in toluene/ethanol, tributyl phosphate and(naphthalen-1-yl)(naphthalen-2-yl) methane from UESL and TDSL with toluene/ethanol,respectively,1-methyl-7-isopropylphenanthrene and9,10-dihydro-9,10,11-trimethyl-9,10-methanoanthracen-11-ol from XCCTD.Further more, all kinds of group fractions were enriched and they mainly include: a seriesof normal normal alkanes in the range of C14-C32from every soluble matter of SL and XCC,various types of aromatics mainly including parent body of benzene-, naphthalene-andphenanthrene-ring and some heteratom atoms like nitrogen and phosphorus from TDSL withbenzene/methanol and XCCUE and TDXCC with toluene/ethanol,15methyl alkanones in rherange of C15-C27, methyl alkanoates of C17-C28,2alkanoic acids and4fatty acid amides fromTDSL with benzene/ethanol,18phenylcarbonates of C6-C23from UESL and TDSL withtoluene/ethanol,3tolyl benzoates isomers of each other and3OOCs from UESL withtoluene/ethanol,7OOCs mainly including physcion from UEXCC,3organonitrogencompounds (ONCs) with complex structure from UEXCC,21straight-chain ethyl alkanoatesfrom TDSL with toluene/ethanol,25ethyl alkanoates including20straight-chain ethylalkanoates,3side-chain ethyl alkanoates and2side-chain ethyl esters olefine acid fromTDXCC with toluene/ethanol.By dissolving the low-rank coals with suitable solvents at mild conditions, we can obtainsome high-valued organic chemicals and effectively remove the heteratom-containing organiccompounds to reduce their pollutions to the environment when coals are combusted directly.This could provide effective theoretical basis for clean and non-fuel use of low-rank coals.Further, probing deeply into the structure of small moleculars from direction separation andbonds break of the macromolecule could also give reliable evidences for research on thestructure of macromolecule in low-rank coals.