Fischer Assay Research Articles

STUDY ON ULTRASONIC EXTRACTION OF KEROGEN FROM HUADIAN OIL SHALE BY SOLVENTS

Ultrasonic extraction of kerogen derived by acid treatment of Huadian oil shale is performed using an organic solvent. The most effective solvent is the 60:40 (wt%) mixture of chloroform and carbon disulfide, and the suitable mass ratio of the demineralized oil shale to solvent is 1:20. The oil yield by ultrasonic extraction can reach 15.6% based on the demineralized oil shale, compared with a Fischer Assay oil content of 18.9%. The optimum operating parameters as determined by the orthogonal test are: 60 kHz ultrasonic frequency, 200 W ultrasonic power, 30 min extraction time, and 313 K extraction temperature. Through the gas chromatographic- mass spectrometric analysis, the most plentiful compounds in the extracts are low molecular weight alicyclic hydrocarbons, accounting for about 68.3% of total species. The physicochemical properties of the extracts indicated that these can act as an important complementary resource for the production of diesel after appropriate processing.

Modeling of an Oil Shale Low Temperature Retorting Process by Using Aspen Plus

In this paper, the feasibility of employing Aspen Plus in the simulation of oil shale retorting would be discussed by modeling of a low temperature retorting process with fischer assay experimental condition. The samples of 4th layer of No.1 deposit and 11th layer of No.2 deposit of Huadian oil shale have been simulated, and draw a comparison between the simulation and determination results of oil content, moisture content, retorting gas yield, semi-coke yield and ultimate analysis. The tolerance between the simulation and determination results is within a reasonable range, which indicate that the process built and the physical method selected are correct and reasonable and would provide reference for building the process of oil shale comprehensive utilization system.

The Pyrolysis of Buton Oil Sands and Its Kinetics

In this article, the pyrolysis characteristics and kinetics of oil sands from Buton, Indonesia were investigated. The results show that Buton oil sand has high oil content, analyzed by Fischer assay analysis and Dean-Stark extraction, and a retorting temperature of which should be controlled at 480–500°C. Differential thermal analysis was used to investigate pyrolysis kinetics and weight loss occurring mainly from 280 to 480°C, which is similar to that of Fischer assay analysis. The apparent activation energy, E, of samples is about 190 kJ·mol−1, which is calculated by the maximum pyrolysis rate method. Researches show that Buton oil sand's application is a good prospect.

Evolution of an organic‐rich lake basin – stratigraphy, climate and tectonics: Piceance Creek basin, Eocene Green River Formation

AbstractThe Piceance Creek basin formed as a continental foreland basin ca 53 to 48 Ma in the early to middle Eocene. On a global basis, the basin contains one of the richest oil shale resources known, where the profundal oil shale deposits, kerogen‐rich mudstones (clay and carbonate), exist over most of the basin. Despite its economic importance, the evolution of the Piceance Creek basin is still somewhat unclear. Based on facies association analysis, depositional trends, and gamma ray and Fischer assay data, six evolutionary lake stages are recognized: (i) fresh lake; (ii) transitional lake; (iii) highly fluctuating lake; (iv) rising lake; (v) high lake; and (vi) closing lake. Lake stages are composed of depositional units and characterize large‐scale changes in sedimentological patterns, depositional trends and fluctuations in the oil shale richness related to changes in climate and tectonics. Lake stage evolution is also consistent with the global Eocene climate trend. Stage 1 formed prior to the Eocene climate optimum. At the beginning of the Eocene climate optimum, a saline‐restricted lake formed (Stage 2) and evolved into the highly fluctuating lake (Stage 3) indicating rapid climate changes during the peak of the Eocene climate optimum. This stage was followed by the rising and high lakes (Stages 4 and 5) after the climate optimum and during a change to a more humid climate. The closing of the lake (Stage 6) was caused by increased sand input from the north, indicating the influence of both tectonics and climate. Based on depositional trends and climate evolution, it is suggested that, during the arid climate, laterally heterogeneous highly cyclic depositional units dominate, whereas, during the humid climate, depositional units form laterally continuous sediments that can be traced over long distances.

Oil shale pyrolysis kinetics and variable activation energy principle

A modified first order kinetic equation with variable activation energy is employed to model the total weight loss of Ellajjun oil shale samples. Fixed bed retort with 400 g of oil shale sample size is used in this study in 350–550 °C temperature range. Variable heating rate, h, in the range 2.6–5 °C min −1 are tested. Activation energy was allowed to vary as a function of oil shale conversion. The value of the activation energy increased from 98 to 120 kJ mol −1 while the corresponding frequency factor changed from 9.51 × 10 5 to 1.16 × 10 6. Fischer Assay analysis of the studied samples indicated 12.2 wt.% oil content. The oil shale decomposition ranged from 3.2% to 28.0%. The obtained kinetic data are modeled using variable heating rate, pyrolysis temperature and variable activation energy principle in a nitrogen sweeping medium. Good fit to the obtained experimental data is achieved.

Effect of demineralization of El-lajjun Jordanian oil shale on oil yield

The effect of demineralization on oil yield and mineral composition of Jordanian oil shale was investigated. A standard digestion procedure using a range of inorganic and organic acids including HCl, HNO 3, HF, and CH 3COOH was used to enhance the oil recovery of oil shale samples collected from the El-lajjun area. The total yield of the digested samples, as determined by Fischer Assay, has shown a maximum value (two folds the untreated sample) obtained when using CH 3COOH. The kaolin in the treated oil shale with a high concentration of CH 3COOH is believed to have transformed to illite as found in the XRD analysis. The treatment of oil shale using HCl has shown an increased ratio of oil to gas as a result of the digestion of calcite in the oil shale. At higher concentrations of HNO 3, the acid is believed to react with the kerogen in the oil shale resulting in high levels of low molecular weight compounds. Therefore, the amount of non-condensable gases produced by Fischer assay after treatment with a high concentration of HNO 3 is relatively high. HF is believed to drive off water from the oil shale by dissolving the clay minerals leading to increased oil to gas ratio.

RETORTING OF PULVERIZED OIL SHALE IN FLUIDIZED-BED PILOT PLANT

This paper describes the research on fluidized-bed retorting of pulverized oil shale on pilot-plant scale (daily processing capacity of 50 tonnes oil shale). Chinese Yi Lan pulverized oil shale 0–3 mm was used as feed. Oil shale is fed and pyrolyzed in a fluidized-bed pyrolyzer, where it is heated to about 500 °C by recycled hot shale ash coming from a fluidized-bed combustor. Nitrogen, coal gas or superheated steam is used as fluidizing agent in the pyrolyzer. The shale char formed from oil shale in the pyrolyzer mixed with shale ash is recirculated to the fluidized-bed combustor, where it is burnt by incoming air (as fluidizing agent) to form shale ash at about 700 °C and is recycled to the pyrolyzer as hot solid heat carrier. The mixture of shale oil vapors and pyrolysis gas, formed from oil shale, mixed with steam or other fluidizing agent coming from the pyrolyzer, comes through two cyclones for removal of entrained dust and is washed by warm water to condense heavy shale oil, then goes to cooler for recovery of light shale oil. The total shale oil yield accounts for 80% of Fischer assay. The properties of shale oil and pyrolysis gas are analyzed.

Mineralogy and organic petrology of oil shales in the Sangkarewang Formation, Ombilin Basin, West Sumatra, Indonesia

The Ombilin Basin is filled by late Eocene to early Oligocene marginal fan deposits (Brani Formation) and lacustrine shales (Sangkarewang Formation), unconformably overlain by a late Oligocene to early Miocene fluvial sequence (Sawahlunto and Sawahtambang Formations) and capped by an early to mid-Miocene marine sequence (Ombilin Formation). Significant oil shale deposits occur in the Sangkarewang Formation, intercalated with thin laminated greenish-grey calcareous sandstones. X-ray diffraction shows that the sediments consist mainly of quartz, feldspar, carbonates and a range of clay minerals, together in some cases with minor proportions of sulphides, evaporites and zeolites. Feldspar and non-kaolinite clay minerals decrease up the sequence, relative to kaolinite, suggesting a changing sediment source as the basin was filled. Calcite, thought to be mainly of authigenic origin, is also more abundant in the middle and upper parts of the sequence. The organic matter in the oil shales of the sequence is dominated by liptinite macerals, particularly alginite (mainly lamalginite) and sporinite. Cutinite also occurs in some samples, along with resinite and traces of bituminite. The dominance of lamalginite in the liptinite components suggests that the material can be described as a lamosite. Samples from the Sangkarewang Formation have vitrinite reflectance values ranging between 0.37% and 0.55%. These are markedly lower than the vitrinite reflectance for coal from the overlying Sawahlunto Formation (0.68%), possibly due to suppression associated with the abundant liptinite in the oil shales. Fischer assay data on outcrop samples indicate that the oil yield is related to the organic carbon content. Correlations with XRD data show that, with one exception, the oil yield and organic carbon can also be correlated directly to the abundance of carbonate (calcite) and inversely to the abundance of quartz plus feldspar. This suggests that the abundance of algal material in the lake sediments was preferentially associated with carbonate deposition. High yields of oil are noted in some samples, as a percentage of the organic carbon content. This may indicate that partial generation of hydrocarbons from the material has already taken place, in association with thermal maturation of the Sangkarewang succession.

STEAM PYROLYSIS OF BULGARIAN OIL SHALE KEROGEN

The effect of water vapor on the yield and composition of products formed at thermal treatment of Bulgarian oil shale kerogen at atmospheric pressure has been studied. It was found that water steam reacts with oil shale organic matter significantly affecting the yield and composition of liquid and gaseous products. As for the yield of liquid products, it is about 20% higher than the yield obtained at Fischer Assay. The yield of semicoke is about 10% less. Liquid products formed in the presence of water vapor are richer in aromatic and aliphatic hydrocarbons among which long-chain paraffins with up to 33 carbon atoms predominate.

Parallels between slow pyrolysis of Estonian oil shale and forest biomass residues

Different types of forest residual biomass, including pine wood, pine bark and spruce needles, and Estonian Kukersite oil shale, were parallelly subjected to the slow pyrolysis in similar conditions. A Fischer assay, modeling industrial semi-coking retorts, was used. Both the yield and the composition of liquid, gaseous and solid products of pyrolysis were determined. FTIR-spectroscopic and chromatographic methods were used to study products group and individual composition. Common and specific features in biomass and oil shale semi-coking have been described. In comparison with oil shale, the biomass yielded less oil and more gas. Specifically large amounts of reaction water and carbon dioxide were obtained in biomass pyrolysis resulting in formation of significantly deoxygenated liquid and solid products. Bio-oils can be distinguished by the solubility in conventional solvents. Kukersite shale oil and the benzene-soluble fractions of different bio-oils were characterized by similar group composition.

COMPARISON OF OIL SHALES FROM DIFFERENT DEPOSITS: OIL SHALE PYROLYSIS AND CO-PYROLYSIS WITH ASH

This paper studies the effect of alkaline oil shale ash on oil shale thermal decomposition products during oil shale and ash co-retorting. Experiments with and without ash were carried out in a standard laboratory-scale retort (Fischer Assay) to determine relative yields of retorting products and sulfur distribution in them. Oil shales compared in this study were kukersite and Dictyonema shales from Estonia, Jordanian El-Lajjun oil shale and Saveljev oil shale from Russia. Oil shales were primarily selected due their difference in sulfur composition. Ash for co-retorting experiments was prepared from kukersite oil shale. The ash contains about 57.5 wt.% alkaline compounds CaO and MgO.

Tar yields from low-temperature carbonization of coal facies from the Powder River Basin, Wyoming, USA

Tar yields from low-temperature carbonization correlate with the amount of crypto-eugelinite in samples selected to represent petrographically distinct coal facies of the Wyodak-Anderson coal zone. Tar yields from Fischer Assay range from <1 to 11 wt.% on a dry basis and correspond ( r = 0.72) to crypto-eugelinite contents of the coal that range from 15 to 60 vol.%. Core and highwall samples were obtained from active surface mines in the Gillette field, Powder River Basin, Wyoming. Because the rank of the samples is essentially the same, differences in low-temperature carbonization yields are interpreted from compositional differences, particularly the crypto-eugelinite content. In the Wyodak-Anderson coal zone, crypto-eugelinite probably was derived from degraded humic matter which absorbed decomposition products from algae, fungi, bacteria, and liptinitic plant parts (materials possibly high in hydrogen). Previous modeling of the distribution of crypto-eugelinite in the discontinuous Wyodak-Anderson coal zone indicated that tar yields should be greater from coal composing the upper part and interior areas than from coal composing the lower parts and margins of the individual coal bodies. It is possible that hydrocarbon yields from natural coalification processes would be similar to yields obtained from laboratory pyrolysis. If so, the amount of crypto-eugelinite may also be an important characteristic when evaluating coal as source rock for migrated hydrocarbons.

ECONOMIC EVALUATION, RECOVERY TECHNIQUES AND ENVIRONMENTAL IMPLICATIONS OF THE OIL SHALE DEPOSIT IN THE ABAKALIKI ANTICLINORIUM, SOUTHEASTERN NIGERIA

An extensive geological mapping and geochemical studies of the oil shale deposit in the Abakaliki Anticlinorium, southeastern Nigeria were carried out to determine its areal extent, reserve estimate, recovery techniques and possible environmental impacts. The total area of the exploitable zones that is characterized by shale alternating with marl has been calculated to be 72.7 km{sup 2} by placing a 1,000 m by 1,000 m grid outlay on the mapped sections. Using an exploitable thickness of 34 in and an areal extent of 72.7 km{sup 2}, the oil shale reserve estimate is 5.76{center_dot}10{sup 9} tonnes. Moreover, using an average Fischer Assay yield value of 56.35 litre/tonne, the recoverable hydrocarbon reserve estimate is 1.7{center_dot}10{sup 9} barrels. Retorting recovery method is suggested for exploitation of local oil shale because of shallow upper soil and. a relatively cheap cost of establishments. Low concentration of sulphur (between 0.33 and 0.74%) and trace elements such as Ba, Cd, Cr, Ni, Pb and Zn supports the economic viability of oil shale as refinery feedstock. (authors)

04/01219 Screening method for oil shale samples for Fischer assay: Sato, S. and Matsumura, A. Journal of the Japan Petroleum Institute, 2003, 46, (3), 210–213

A method for utilization of waste rubber and plastics by means of their combined pyrolysis with a solid fuel is described. Oil shale, different kinds of waste rubber, polyethylene and polypropylene were pyrolyzed. The oil yield was 43–50 wt% from rubbers, and 93–95 wt% from thermoplastics. Gas yield was 3–6 wt%.

Utilisation of shale oil by the extraction and retorting of oil shale

Extraction of the bitumen fraction of oil shale was carried out using two different solvents, chloroform and toluene. Oil shale of 4.0 mm particle size from the El-Lajjun area in Jordan was used in this study. The solvents were recovered by distillation. The spent shale was retorted using a special retort and shale oil (Kerogen) was recovered. The quantity of the hydrocarbon was compared with that produced by using a Fischer Assay retort. When chloroform was used as solvent, it was found that the average amount of bitumen extracted was 0.034 g/g of oil shale and the amount of kerogen obtained was 0.099 g/g of oil shale with a total amount of oil 0.133 g/g and with 86.4% of the solvent recovered. When toluene was used as solvent it was found that the amount of bitumen extracted was 0.026 g/g oil shale and the amount of kerogen obtained was 0.116 g/g oil shale with a total amount of oil 0.142 g/g and with 94.7% of the solvent recovered. The quantities of oil recovered using both solvents were higher than that recovered using the Fischer Assay retort where only 0.106 g/g oil shale were obtained.

Fluidised bed pyrolysis of Moroccan oil shales using the hamburg pyrolysis process

In the present work, the pyrolysis of the Moroccan Timahdit oil shale was studied, using a fluidised bed process. Four experiments were carried out at different temperatures between 520 and 630 °C. By mass balance could be shown that in relation to the kerogen content up to 60 wt.% of oil and 25 wt.% of gas are obtained. These are 40% higher yields compared with the Fischer assay. It was shown that the carbon in the residue, which is much lower (only 12 wt.%) than in the Fischer assay (26 wt.%), explains this difference.

The use of thermogravimetry in establishing the Fischer tar of a series of South African coal types

A method has been developed, by which the tar producing propensity of coal (Fischer assay) can be assessed from a single trace of a thermogravimetric simulation of the proximate analysis of coal. It was found that, for a suite of 22 South African coal types under well defined experimental thermogravimetric conditions, the mass loss observed in the temperature interval of 460–510 °C is related to the Fischer assay by the formula: Y=1.17 X−2.0 where Y represents the expected Fischer tar and X represents the observed mass loss in the 460 and 510 °C temperature interval as calculated on a dry, ash free basis. The co-efficient of correlation, r 2, was found to be >0.91.

Screening Method for Oil Shale Samples for Fischer Assay

The oil shale deposit survey requires testing of a number of oil shale samples. However, the Fischer assay can process only 4-5 samples a day, so the number of samples should be limited. Hence a quick method to screen the samples for the Fischer assay test is required. The automatic micro carbon residue (MCR) test is proposed as a quick and simple screening method which requires only 100 mg of sample. The MCR test, as specified in JIS K 2270 (modified ISO 10370), can predict the weight loss of oil shale samples in the Fischer assay. Although the MCR test provides only data on the weight loss of oil shale, 12 samples can be processed in 2-3 h, the structure and control are simple, the cost is relatively low, and the equipment is easy to use. There is a definite correlation between the upper limit of oil yield from oil shale and the weight loss of oil shale, so the MCR test can facilitate the rapid screening of a large number of oil shale samples.

Pyrolysis of the Moroccan (Youssoufia) rock phosphate

Phosphate rocks from the Youssoufia site are pyrolysed in a modified Fischer assay retort to determine the influence of the heating rate and the final pyrolysis temperature. The heating rates investigated were respectively β=1.7, 5, 10, 15 and 21 °C min −1 while the final temperatures were in the range 200–600 °C. The maximum oil yield was optimum at a heating rate of 10 °C min −1 and temperature of 450 °C. The analytical studies of oil fractions are presented. The kinetics of the thermal decomposition of the phosphate has been studied by non-isothermal thermogravimetry (TGA). The weight loss data have been analyzed by the Coats–Redfern model. The kinetic parameters for the decomposition of the samples were determined and discussed.

99/00237 Viscosity estimation and discharge control of coal liquefaction residues

Fischer assay shale oil from the Condor oil shale deposit at Proserpine, Queensland, was chemically separated into 20 fractions and analysed by gas chromatography-mass spectrometry. Over 600 compounds were identified, including homologous series of linear alkanes, 2-methylalkanes, alkylcyclopentanes, alkylcyclohexanes, 1-, 2-, 3- and 4-alkanes, alkylcyclohexenes, alkylcyclopentenes, linear dienes, alkylbenzenes, alkylindans, alkylnaphthalenes, nitriles, 2- and 3-alkanones. Substituted cyclopentanes, cyclohexanes, benzenes, naphthalenes, polycyclic aromatic hydrocarbons, phenols, pyridines, dihyroindoles, quinolines and tetrahydroquinolines were also identified. The Condor oil is highly aliphatic in character (H/C=1.7), with alkanes (≈28%) alkenes (≈18%) alkadienes (≈2%) nitriles (≈11%) and alkanones (≈4%) being the most abundant components. The carbon chain length distributions of the alkanes, nitriles and methyl ketones (bi-, tri- and bimodal respectively) are indicative of both algal and higher plant sources with algal predominating.