The study comprises an in-depth characterization of compositional groups of the liquid by-products obtained from the pyrolysis of swine manure at 500 degrees C, with the aim of providing an alternative and efficient approach for the valorisation of this waste stream, alongside with the production of biogas and char, the latter of which can be further converted into activated carbon. Two samples were considered: de-watered cake and solid product from anaerobic digestion of swine manure. Biocrude oils were fractionated into weak acidic, strong acidic, alkaline and neutral oil fractions. Subsequently, the neutral oil fraction was separated into paraffinic-naphthenic, slightly polar and polar fractions. All fractions were analyzed by GC-MS. The major identified compositional groups were: (i) for de-watered cake: steroids (40.7%), fatty acids, FAs (23.7%) and n-alkenes/n-alkanes (23.3%); (ii) for solid product from anaerobic digestion: FAs (31.0%), phenols/methoxy phenols (26.6%), n-alkenes/n-alkanes (10.8%) and steroids (10.6%). A variety of short-chain FAs (i.e., linear saturated, mono- and di-unsaturated, cis (i-), trans (ai-), isoprenoid, phenyl alkanoic, amongst others) and methyl esters (FAMEs) were identified as well. FA distribution, nC12-nC20, was similar for both manures studied with nC16 and nC18 as major compounds. FAMEs (nC14-nC28, with even carbon number dominance) in the slightly polar fraction of both samples were accompanied by considerable amounts of oleic (nC18:1) and linoleic (nC18:2) acids, and corresponding methyl esters. Hydrocarbons, i.e., n-alkenes/n-alkanes, were in the range of nC15-nC34, with nC18 maximizing. Anaerobically digested manure has resulted in (i) an increase in the portion of longer homologues of hydrocarbons and FAMEs and (ii) the appearance of new FAs series of long chain members nC22:1-nC26:1, omega-9. The comprehensive analysis of the biocrude oils obtained from the slow pyrolysis of swine manure indicates their potential for use as biodiesel additives or as feedstock to produce value-added materials.

Pyrolysis coupled “off-line” with thermal desorption gas chromatography–mass spectrometry (TD-GC/MS) instrument for flue gas analysis is used to specify qualitatively/quantitatively organic functionalities in “Maritsa-Iztok” lignite lithotypes thermal decomposed in the range 250–900 °C. The aim of the study is to specify organic volatiles and to assign identified components to the lignocellulose biomass building blocks of coal forming vegetation. In pyrolysates the total amounts of the analyzed organics, expressed in mg/g TOC, amount up to 58.14 for liptain, 21–37 for humoclarain and xylain, and the lowest values are determined for humovitrain, 12. The samples immaturity reflects in high diversity of phenols, methoxy phenols (only guaiacyl structures), furans, etc. maximizing at xylain lithotype, 68% of the total analyzed amount. Carbohydrate degradation products, i.e. furaldehydes, 2-cyclopenten-1-ones, etc. are identified as well. In lithotypes studied, coal biomarkers as n-alkene/n-alkanes, sesqui-, di-, polar diterpenoids and hopenes/hopanes, are present in different proportions.

The study comprises the determination of compositional groups of the liquid by-products from swine manure pyrolyzed at 500°C, in view of finding solution for an efficient utilization of this waste stream. Two samples were studied, de-watered cake (SMc) and solid product from anaerobic digestion (SMd) of swine manure. Biocrude-oils were fractionated into weak acidic, strong acidic, basic and neutral oil fractions. Subsequently, the neutral oil was separated into paraffinic-naphthenic, slightly polar and polar fractions. All fractions were analyzed by GC-MS. The major registered compositional groups were: i) for SMc: steroids (40.7%), FAs (23.7%) and n-alkanes/n-alkenes (23.3%); ii) for SMd: FAs (31.0%), phenols/methoxy phenols (26.6%), n-alkanes/n-alkenes (10.8%) and steroids (10.6%). A variety of short chain FAs (i.e. linear saturated, mono- and di-unsaturated, i-, ai-, isoprenoid, phenyl alkanoic, etc.) and some of them as methyl esters (FAMEs) were identified. Hydrocarbons, i.e. n-alkanes/n-alkenes, were in the range nC15-nC34, with nC18 as major representative.

We sampled and studied a borehole located in the southern part of Maritsa Iztok lignite field (Bulgaria) which comprises Late Miocene-Pliocene sediments of Maritsa Formation. The current report of Troyanovo-3 Mine sequence is the first to our knowledge. It represents a lignite-mudstone succession with variations in organic matter (OM) maturity. Thirty eight coal and mudstone core samples showed predictable ash and sulfur content. The XRD study showed illite/muscovite, illite/smectite, kaolinite, chlorite and quartz as main constituents that argue for a detrital origin. Additionally, we identified pyrite and gypsum and some peaks of marcasite and elemental sulfur. A set of eight mudstone samples rich in OM was selected for further geochemical analyses. The OM was classified as type III and II/III kerogen based on Rock-Eval pyrolysis data. The low amounts of extractable organic matter (0.01-2.25%) we found are consistent with the samples' low maturity and kerogen type. The yields of two samples were too low for further fractionation. Asphaltene amount (26.1-79.7%) pre-dominates in the extracts. Diterpenoids (neutral fraction) and their polar analogues (slightly polar fraction) are highly abundant. In slightly polar fractions we registered ketotriterpenoids (mainly lupenones) in addition to the linear n-alkan-2-ones. OM elevated maturity of the deepest sample (59.60 m depth) was evidenced mainly by hopane distributions, i. e. Ts/(Tm + Ts), homohopane H31 alpha beta index, hopane ratios (H29 alpha beta/H30 alpha beta) and H27 beta/H27 alpha. The organic geochemistry results do not fit the ordinary regional maturity trend. OM maturity variation, superimposed over natural low coalification degree, could be ascribed to an interaction with ascending hot reductive fluids. The sulfide mineralization found in the fractures also gives indications about the fluid circulation. Another thermal alter-ation affecting the middle part samples (24.0-28.3 m) was suggested due to elevated Tmax values and HI and OI relation for a charcoal piece and carbonaceous mudstone. Smoldering processes affecting these samples were presumed. Low-temperature alteration processes were identified by n-alkanes, n-alkan-2-ones, and n-alcohols expulsion and downwards migration (from 18.0 m to 30.0 m) accompanied by a clear terpenoids depletion. The 17,21-seco- hopane-17,21-dione found for the first time for Maritsa Iztok Basin (MIB) samples further suggested processes of water seepage and wash-out. Microbial degradation activities usually accompanying water-washing possibly led to a specific n-alkan-2-one distribution. All the features we report point to either an even-numbered n-alkanoic acid decarboxylation or to a selective microbial degradation of odd-numbered n-alkanes to n-alkan-2-ones. In all, the history of the coal-mudstone sequence is complex, overprinted by variable alteration processes, first ever reported for MIB samples.

The activated carbons were produced from waste biomass using a mixture of used motor oil and diverse plastic residues, such as high-density polyethylene and thermoplastic phenol formaldehyde resins. They were used as a host matrix of iron and/or chromium oxide nanoparticles. The obtained materials were characterized in details by a complex of physicochemical techniques, such as low-temperature nitrogen physisorption, Boehm method, Powder X-ray Diffraction, Temperature-Programmed Reduction with Hydrogen, FTIR and Mössbauer spectroscopies. Methanol decomposition to CO, hydrogen and methane was used as a catalytic test. A strong regulation effect of the activated carbon pore topology on the dispersion, phase composition and catalytic behaviour of the loaded metal oxide species was established. Higher and relatively good efficiency of the iron-chromium-activated carbon composites with predominant mesoporous texture has been established.

A sequence of three lignite seams and interlayering carbonaceous mudstone is characterized by geochemical proxies. The study is extended by the palaeoenvironmental details given by the fossil fauna (gastropods, ostracods, and fishes). The predominant minerals (quartz and kaolinite) and main oxide relations of the carbonaceous mudstone point to sand and clay washed from weathered and/or altered felsic rocks from the catchment area. The mudstone features to deposition from suspension in standing or slow to persistently moving fresh waters at the bottom of the core log, and slightly aerated, warm, fresh to low saline, acidic to alkaline waters on the top. Three communities of organisms are depicted. The first is the pre‐swamp environment characterized by standing or slow moving fresh waters and detrital organic matter deposition. The second is the environment of swamp of detrital forest trunks. Depending on the climate and water table, the main forest communities are of trees of families Cupressaceae, Taxodiaceae, and Podocarpaceae accompanied by trees of family Betulaceae, and herbaceous plants. Different Sphagnum species are also abundant. The dry/cold environment is reflected in the herbaceous organic matter deposition. Polar terpenoids ratio differentiates slight climatic oscillations for the samples with a strong Gymnospermae dominance. The second coal seam development reflects the optimum tectonic conditions for peat growth in a cold and dry climate leading up to 25 m lignite deposition. The third is the moss swamp environment with very fluctuating elements. At the top of the log, a Sphagnum ‐dominated peat has developed.

The paper reports the results of the organic petrological, palynological and geochemical characterization of lignite samples from the Kipra lignite seam (Late Miocene, Maritsa-West Basin, Bulgaria). The bulk of the organic matter (OM) is represented by highly gelified detrohuminite with locally abundant leaf-derived ulminite. Liptinite group is characterized by predominance of microsporinite and liptodetrinite, locally with cutinite and fluorinite. Terpene resinite and suberinite are rare. Low TPI and high GI indices indicate peat formation from vegetation with low preservation potential, deposited under water-logged environment of marsh- or fen-type. The palynological results reveal a vegetational community representing different habitats (i.e. mesophytic, marginal and aquatic). The relatively poor preservation of the palynomorphs, however, suggests vegetation that was more diverse during peat formation. Although gymnosperm palynomorphs predominate, the gymnosperm organic matter contribution was probably minor as indicated by the low contents of sesqui- and diterpenoid biomarkers. Because of the absence of triterpenoid biomarkers of neither oleanane, nor lupane or ursane-type, it is considered that angiosperms that do not synthesize their precursors predominated, or the depositional environment had unfavorable characteristics, which prevented the transformation of the triterpenoid precursors. The extractable organic matter yield from the Kipra lignite is low, and dominated by saturated compounds, while polar compounds and asphaltenes occur in low amounts. Aromatic compounds are completely absent. The saturated hydrocarbons are mainly composed of n-alkanes, accompanied by minor amounts of branched- (including isoprenoids) and cycloalkanes, sesqui- and diterpenoids, steroids and hopanoids. Straight chain alkanes are prevailed by long-chain homologues, but show rather mature distribution with CPI similar to 1. Biological (e.g. bacterial) activities and/or environmental control are considered as the main factor/s controlling the observed uncommon n-alkane distributions. A rather uncommon pentacyclic terpenoid, i.e. onocerane I, was tentatively identified in one sample, based on its characteristic fragmentation pattern. Based on its presence, a very specific plant community is considered, and/or specific palaeoenvironmental conditions occurred at least temporarily during the peat formation. However, the responsible plants could not be identified. The low amounts of hopanoid biomarkers, together with the low amounts of n-alkanones, are consistent with limited aerobic biodegradation of the plant remains. The mature 22S/(22S + 22R) C-30 hopane ratio (similar to 0.55), as well as the random huminite reflectance values (similar to 0.3-0.4%), which are more than twice higher than previously reported, argue for a local increase of coalification degree, presumably due to increased thermal influx around major faults.

Abstract Polycyclic aromatic hydrocarbons (PAHs) in six samples from Bulgarian Lignite Dumps Maritsa Iztok are tracked and amounts are determined. For isolation of soluble organic matter (SOM) ca: 40 g of powdered dump samples were Soxhlet extracted by chloroform. After asphaltenes precipitation, maltenes were separated via column chromatography. The first two fractions were further analyzed. Gas chromatography-mass spectrometry (GC-MS) was applied to appreciate organic matter sources and to identify and quantify PAHs in the samples. The set of PAHs determined pointed out that 3 and 4 ring unsubstituted PAHs as dominant in the dump extracts. Total organic carbon (TOC) values of the samples varied in the range 1.18-5.63 wt.%. Phenanthrene + Methylphenanthrene amounts were in the range 0.44-2.98 mg/kg TOC, while for Fluoranthene + Pyrene were in the range 0.06-0.52 mg/kg TOC. Total amounts of PAHs varied in the range 7-41 microg/kg sample. Values were compared with the legislation norms for PAHs in soils. All magnitudes were under the regulation norms for harmful substances in soil published by the Bulgarian National Legislation (2008). In conclusion, the study is in an equivocal proof for the negligible amounts of PAHs in dump materials from Maritsa Iztok lignite mining. However, their amounts in dumps should be measured and monitored bearing in mind the huge territories covered by these waste materials of mining industry.

This paper describes state-of the art for isolation and determination of polycyclic aromatic hydrocarbons (PAHs) in fly ash from lignite combustion in Maritza East Thermal Power Plant, Bulgaria. Total sum of-17 microg/kg solid by-product PAHs was determined. The profile of PAHs distribution according to the number of aromatic rings in the molecule (R) was determined. Organic extracts were mainly composed by PAHs, their alkylated homologues and heteroatom containing counterparts with dominance of three/four cyclic aromatic compounds. Respectively, relative carcinogenic potency values for PAHs compared to Benzofajpyrene with TEFEPA =1 was not high - 0,07385. Seventeen PAHs, some of them in the list of USEPA for priority pollutants with expressed carcinogenic/mutagenic potential, were identified and quantified by mass spectroscopy (GC/MS/MS) and d-PAHs as internal standards. Determined values for contents of PAHs under regulation were lower than their backgrounds in Bulgarian soils. Nevertheless PAHs in combustion fly ash should be monitored because of high solid by-products annual production and problems of reuse

Activated carbons (ACs) from swine manure (SM), i.e. preliminary de-watered SM cake (Mc) and solid digestate (Md) were prepared by pyrolysis and water vapour activation. Demineralisation on obtained chars after carbonization was applied as well. Additionally, the adsorption capacity of demineralised ACs towards chromium in aqueous solutions was investigated and compared to non-demineralised ACs. Demineralisation caused a decrease in mineral matter content with more than 50% and affected characteristics and adsorption behaviour of these ACs. As a result, ACs with better developed porous texture were produced. Prepared ACs with reduced ash content demonstrated higher adsorption capacity toward Cr compared to non-demineralised ACs. The adsorption kinetics were investigated by applying two kinetic models, i.e. Lagergren pseudo-first order and pseudo-second order. The pseudo-second order kinetic model provided a better fit. Better fits are obtained for the Langmuir isotherm model and therefore a monolayer coverage chemisorption of the Cr(VI) on the ACs surface is suggested.

Coals are suspected for many human health problems and are an object of the new discipline -"medical geology". Potential human health risk of organic compounds with coal/lignite provenance includes endocrine disruption, nephrotoxicity, cancer, etc. Recent investigations proved that different organic components, i.e. hydrocarbons, phenols etc. move through/release out of the dump area as a result of alteration processes of the organic matter (OM) caused by the wash-out and/or drainage processes. The timeliness of the present study is based on the scarcity of information on organic geochemistry of dump materials from open pit coal mines and weathered lignites in particular. The limited number of studies on dumps clarifies that even for the " short" time span (some tens of years) in geological point of view, processes of transformation of the extractable OM are detectable. The secondary phases, a result of the OM transformations, move through and out of the dump area and could be potential contaminants for the surface/underground waters and soils in the area. Another environmental problem comes from the air-born VOCs and products of the modern chemical industry. By GC-MS in the slightly polar fractions of the chloroform extracts of dump samples a broad set of components was determined, i.e. phthalates (dominant), i-propyl palmitate, ipropyl myristate, n-hexyl benzoates, etc. These organic contaminants could be regarded more likely as anthropogenic (originating from plasticizers, industrial pollutants, etc.). Presently, it seems that the identified compounds do not represent an acute toxic risk from an environmental viewpoint. However, some compounds could raise concerns and further attention is needed to be focused on them.

Lignites from Thrace- and Sofia- coal basins, i.e. “Maritsa-East” and “Stanjanci” mines, were subjected to aqueous sequential extraction at 25°C during 10weeks. Each 7days leachates were separated and pH and conductivity were measured. According to the extraction curves μS vs. time two portions were prepared, enriched in salts, extracts from the first two weeks (“front” of the elution) and in organic matter, extracts from the rest of time (“tail” of the elution curve). Combined freeze-dried extracts were characterized by yields, technical and elemental analyses. They were studied by X-ray photoelectron spectroscopy (XPS) and Infrared spectroscopy (IR). According to XPS spectra the main species on the leachate surfaces were carbon atoms in aromatic and aliphatic structures, 48–53at. % from the total C1s signal. The intensive N1s signal at 400eV was assigned to pyrroles and amines (1–3at. %). The most abundant sulphur form was inorganic sulphates while intensities for the other ones were <1%. Respectively, the sulphatic sulphur content (13.6%) determined for Maritsa leachate was almost seven times higher than the same sulphur for Stanjanci leachate. FTIR spectra gave evidences for oxygen-containing functional groups, i.e. COOH groups in benzene carboxylic acids and their derivatives, in short-chain aliphatic fatty acids and for polyols. The appearance of mineral matter, mainly gypsum and kaolinite, made equivocal the IR spectra interpretation.Acetone soluble portions of “tail” leachates have represented relatively small parts of the organic matter (340mg/kg Maritsa East and 80mg/kg Stanjianci lignite) but have assigned reliable evidences for the polar constituents of leachates. Linear fatty acids, nC12–nC32, nC16max, n-alcohols, benzoic acids, i.e. hydroxy-, methoxy-, phthalic acids, were highly abundant. Sterols, stanols, ketosterols were present in both extracts. Phthalates were recognizable as well.AP-TPR-TD-GC/MS technique has proved the presence of phenols, PAHs and heteroatom containing components in leachates flue gases. From an environmental viewpoint it seems that the identified compounds do not represent an acute toxic risk. However, N-containing compounds could raise concerns and further attention is needed to be focused on them.

Humic substances naturally occur in Miocene/Pliocene-aged lignite at very high concentrations. Here biomarkers in the bitumen-free extract of humic acids from Thracian lignite, Bulgaria, are studied. Applying methods of organic geochemistry a broad range of compounds are isolated and characterised. Species are classified according to abundance, possible source input and diagenetic transformation. A feature of humic acids derived from Thracian coal is the extremely high content of 16α(H)Phyllocladane, ~60% of aliphatic fraction, or 1.6 wt.% of initial lignite. The high diterpenoids content, especially with abietane skeleton, proved the conifer contribution to the peat-forming helophytes, i.e. Cupressaceae s. str., Podocarpaceae, Araucariaceae, Taxodiaceae, Phyllocladus, Piceae. Tightly-trapped, linear long-chain fatty acids (FAs) are the main constituents of the acidic fraction of humic acids. Their distribution patterns indicate a dominant higher plant origin. The presence of αOH-FAs and hopanoid acids assumes bacterial activity in the plant material reworked. A hint for the input of plant biopolymers, i.e. cutin, suberin, is the relative high content of “even” carbon numbered ωΟΗFAs and α,ω-alkanedioic FAs. “Even” numbered short-chain ωΟΗFAs could originate from cutin-derived constituents of the needles of numerous species of gymnospermous families.

The valorisation of waste tyres into adsorbents, i. e. technical and activated carbons, is considered in the current research. The technical carbons (TCs) are prepared through treatments with conc. HNO3, conc. HNO3 + conc. H3PO4 or conc. HNO3 + C2H4Cl2 and subsequent Soxhlet extraction with acetone, while activated carbon (AC) is obtained though physical activation of TCs in a stream of water vapour. Using low temperature N-2 adsorption and Surfer apparatus of Thermo Scientific, the adsorption isotherms of samples under consideration are measured and used for assessment of porous structure. It has been revealed that TCs are mesoporous material characterized by "poor" porous structure since calculated S-BET and V-0.95 are rather low, i. e. up to 63 m(2) g(-1) and 0.205 cm(3) g(-1), respectively. Thus further processing as physical activation is required in order to improve their porous texture characteristics and respectively their adsorption abilities. The obtained AC exhibits much better developed porous structure represented by micro-and the mesopores. The calculated S-BET and V-0.95 are 527 m(2) g(-1) and 0.489 cm(3) g(-1), respectively. This determines the promising features of prepared AC to be used as an adsorbent.

Activated carbons obtained from used motor oil mixtures with furfural or coal tar pitch were prepared and tested as a host matrix of zinc and/or iron oxide nanoparticles. The obtained composites were characterized by nitrogen physisorption, Boehm method, XRD, UV–Vis, FTIR, Moessbauer spectroscopy and temperature programmed reduction. The catalytic behaviour of the samples was tested in methanol decomposition to syngas. The activated carbon obtained from motor oil and furfural was more amorphous and characterizes with higher acidic surface functionality, specific surface area and pore volume due to the simultaneous presence of micro- and mesopores. The modification procedure promoted development of “secondary” porosity which facilitated the formation of accessible to the reactant molecules finely dispersed and highly active metal oxide particles. Zinc ferrite modifications of both activated carbons exhibited higher catalytic activity, stability and good selectivity to syngas in comparison with the individual metal oxide ones.

Bulgarian part from the Thrace Basin is recognized as its NW flank. Hydrocarbon generation for some formations in the Bulgarian part, analogue to Turkish ones with already proven generative abilities, is expected. In order to assess source rocks and to foresee exploration activities in the region, eleven samples from the prospective formations, i.e. seven well samples and four outcrops samples, are evaluated by geochemical proxies. Extractable organic matter (OM), the so-called "free" bitumens, and extracted after demineralization ("bound" bitumens), are characterized. A broad range of biomarkers is considered. In this study linear structures, i.e. n-alkanes, regular isoprenoids, n-alkan-2-ones, n-alcohols, fatty acids, etc. will be considered. Rock Eval data and component analysis determine immature Type III and mixed Type II/III kerogen. n-Alkanes are dominant in all bitumen extracts. Their distributions are complex, depth dependent and give a hint for more mature OM redeposition. The cross-plots of regular isoprenoids in Pr/nC(17) vs. Ph/nC(18) diagram implies immature mixed Type II/III kerogen. Pr/Ph ratios, argue for immature OM deposited in anoxic/sub-oxic environment. The cross-plots of TOC vs. P-aq argue for at least two pools of n-alkanes: (i) short chain homologous from algal/bacterial contribution; (ii) and, mid-chain, from submerged/floating macrophytes wax. Fatty acids, nC(12)-nC(34) with "even" numbered dominance and changes with depth, are identified only in the "bound" bitumens. A similarity in possible origin with n-alkanes is assumed. Dicarboxylic fatty acids, nC(18)-nC(30), maximizing at nC(26), nC(28), nC(30) are recognizable as well.

The information on composition of lignite water-soluble fractions, the so-called leachates, formed during coal mining, storage and exploration is scarce. The aim of the present study is to characterize by wet chemical and spectral methods leachates from some Bulgarian lignites and to estimate their role as potential organic pollutants in groundwaters. In this study, lignites from Thrace- and Sofia-coal basins, i.e. Maritza-East and Stanjanci mines, were subjected to water sequential extraction by distilled water at 25 degrees C for 10 weeks. The freeze-dried extracts (leachates) were characterized by yields (1.4% for Stanjanci lignites and 1.7% for Maritza-East lignites), technical and elemental analysis. Soluble in dichlormethane portions of leachates, 330 mg/kg Maritsa East (ME) lignites and 75 mg/kg Stanjanci (Stan) lignites, were analyzed by GC-MS. Two groups of components were identified: ketophenols, 12 mg/kg ME lignite and 1.2 mg/kg Stan lignite, were 5,6-dehydroferruginol, hinokione, 7-ketototarol and sugiol were the main extracted polar diterpenoids. Oxygenated polar diterpenes of abietane-type are widely distributed in the plant realm. They are not harmful for the environment. Keto-and unsaturated steranes were the other group of compounds in leachates. They are not harmful to human health as well. The study will continue with application of instrumental technique capable to analyze at molecular level essential portion of leachates organic matter. Data from the various approaches will be compared and their joint interpretation will allow making reasonable conclusions for potentially harmful/harmless components in coal leachates.

The generative potentials of four core samples of pure to silty shales of the Stefanets Member (Etropole Fm.) from the Central South Moesian platform margin, Bulgaria have been evaluated by geochemical proxies. Extractable organic matter, i.e. "free" and "bound" bitumens, was characterized by approaches of organic geochemistry. Biomarkers were tracked, quantified and correlated. n-Alkanes distributions argue for at least three pools of supply: (i) from algal or bacterial contribution; (ii) from submerged/floating macrophytes wax; and (iii) from vascular plant leaf wax. CPI, TAR and P-aq ratios pointed out mixed n-alkanes origin, namely, from higher plant/macrophyte wax and algal or bacterial contributions. Pr/nC(17) vs. Ph/nC(18) cross-plots determined Type II and mixed Type II/III kerogens with different maturity. Biomarker parameters calculated on the base of hopanes distributions determine organic matter as early mature. A considerable portion of C-29, C-30 hop-17(21)-ene and hop-22(29)-ene in "bound" bitumen proved the presence of "bound" hopanes to the kerogen. The total amounts of hydrocarbons determined for all samples studied were comparable, 1300-1764 mu g/g TOC. Nevertheless, sample St-16 seems to be the most perspective inasmuch as it possesses the highest content of "free" short-chain hydrocarbons of aquatic provenance. This point is additionally reinforced by its Rock Eval characteristics as the value for S-1, measured for this sample, is the highest compared to the other samples. The tendency is confirmed by GC-MS data.

Atmosphere Pressure–Temperature Programmed Reduction (AP-TPR) coupled “off-line” with thermal desorption gas chromatography-mass spectrometry (TD-GC/MS) is used to evaluate qualitatively and quantitatively organic functionalities in Stanianci lignite from Sofia coal basin, Bulgaria. The total content of the identified compounds in pyrolysate is 22 mg g-1 Corg. Alkyl benzenes (C6 C10) referring to 44 rel. % dominate there. The low sample maturity reflects high abundance of phenols C6 C8 (8.4 rel. %) and methoxy phenols (6.3 rel. %). The presence of 0.4 rel. % of sesquiterpenoids of predominantly cadalene skeleton, suggests gymnospermous flora contribution to the Stanianci coal-forming palaeomire. The arrangement of the four classes of organic compounds identified in pyrolysate, i.e. aliphatics, aromatics, O-containing compounds and S+N-containing compounds in a cluster diagram provides to outline some peculiarities of the fractional