The solid heat carrier (SHC) retorting method, so-called Galoter process, was developed for oil shale processing at the end of the 1940s. Since then the method has undergone several improvements. Nowadays there are different modifications of Galoter process in use - Petroter, Enefit-140 and TSK-500 technologies. The major differences between these technologies are in sizing (throughput), technical solutions and layouts. Recently a shale oil plant based on a new technology, Enefit-280, was commissioned. Enefit-280 is a technology successor of Enefit-140 where the heating of solid heat carrier is accomplished using the circulating fluidized bed (CFB) combustion technology as opposed to the conventional heat carrier combustion technology in Enefit-140. The CFB technology in Enefit-280 was integrated into the process to improve the performance of SHC heating process and reduce the emissions. Operational experience has demonstrated that the modified technology of SHC oil shale retorting has a potential to play a key role in shale oil production with reduced environmental impact.
The result of quantitative determination of selected non-hydrocarbon elements present in shale oils produced by pyrolysis of oil shales from El-Lajjun, Attarat Umm Ghudran, Al-Wehda dam and Al-Sultani deposits is presented. Fischer Assay analysis of oil shales indicated their water content to range from 2.4 to 2.9 wt%, liquid shale oil amount to vary between 5.44 and 15 wt%, spent shale to be in the range 78-90.93 wt% and gaseous loss from 1.03 to 4.0 wt%. Distillation of shale oils showed comparable volume percent distilled with temperature. Seventeen non-hydrocarbon elements were quantified using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The detected elements were: arsenic (As), barium (Ba), beryllium (Be), boron (B), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), selenium (Se), strontium (Sr), tin (Sn), vanadium (V) and zinc (Zn). The concentrations of these elements depended on oil shale deposit location. The elements concentration ranges determined were the following: As 2.11-2.59 ppm, B 0.57- 0.58 ppm, Cd 5.00-6.13 ppm, Cr 1.78-2.47 ppm, Ni 8.91-11.10 ppm, V 2.29- 0.887 ppm, antimony (Sb) 1.43-1.52 ppm, molybdenum (Mo) 0.42-0.78 ppm, Zn 10.5-12.93 ppm, Se 1.79-1.91 ppm and Sr 0.78-0.94 ppm.
A side stream of shale oil production contains alkylresorcinols as main constituents, which could prove to be useful intermediates to highly porous and versatile materials - metal-organic frameworks (MOFs). The latter structures have been used as adsorbents for various organic and inorganic compounds, including organic sulfur containing molecules. In the current work, a pathway from phenolic compounds in shale oil toward metalorganic framework linkers was indicated and its utility was proved by using related metal-organic frameworks as effective adsorbents for sulfur from model fuels exemplified in the form of benzothiophene (BT) and isooctane, respectively.
The combustion characteristics of Huadian oil shale and its semicoke are comparatively studied using a thermobalance (TB) and a drop-tube furnace (DTF). It is found that the ignition mechanism of oil shale and semicoke is hetero-homogeneous and heterogeneous, respectively. Drop-tube furnace experiments with both oil shale and semicoke show that the carbon (C) conversion proceeds almost simultaneously with the particle burnout, while the hydrogen (H) conversion is faster and that of nitrogen (N) and sulphur (S) slower than the particle burnout. The kinetic behavior of semicoke combustion is analyzed by drop-tube furnace experiments based on the first-order reaction model, and the kinetic model with known pre-exponential factor Aa (26.3 g.cm-2 s-1.atm-1) and apparent active energy Ea (65.8 kJ/mol) is obtained.
Palynofacies analysis of 38 rock samples of the Late Oxfordian- Early Kimmeridgian Naokelekan Formation from two exploratory wells and two outcrops in northern Iraq was performed. All samples taken from outcrops in Duhok and Sulaymaniyah provinces and well Bj-1 in northern Iraq were classified as palynofacies Type I (PF-1), which comprises mainly amorphous organic matter (AOM). The samples were deposited in a distal suboxic-anoxic basin and their organic matter (OM) is considered as Type II kerogen. Samples from well Jk-1 were interpreted as palynofacies Type II (PF-2) having mixed AOM and phytoclasts. These samples were deposited in a distal dysoxic-anoxic shelf basin and their organic matter is classified as Type II kerogen.
The relationship between the carbon dioxide content of carbonates in the bomb calorimeter combustion residues and that in the corresponding oil shale samples originated from different deposits was investigated. As a result, a criterion for applying a correction for undecomposed carbonates to gross calorific value was established. A suitable standard method for determination of gross calorific value of oil shale samples was also suggested.
The huge oil shale resources in China have gradually attracted widespread attention due to the shortage of oil and gas resources in the country and the rapid recovery of world oil prices. A nationwide prospecting survey of oil shale in China was conducted for the first time during a period from 2003 to 2006, reporting on around 719.9 billion tons of oil shale. After that, many large oil shale deposits have been discovered in the country, and the exploration of oil shale is flourishing. Although the total shale oil production from oil shale of China has been fluctuating due to the low world oil prices in recent years, it, in general, has rapidly increased since 2006 and reached the highest annual production of 8.3 × 105 tons in 2015. At present, there are six oil shale production bases in operation in China, and two sets of pilot experiments carried out on oil shale in-situ conversion technology have preliminarily proved to be successful. A green industrial chain including refinery, power generation and building materials production from oil shale in oil shale enterprises has been formed due to the high added value and environmentally friendly impact of oil shale from this chain. Moreover, new insights were gained into the genesis of terrestrial oil shale in China and the characterization of deep lake, shallow lake and limnetic deposited oil shale. These theoretical breakthroughs further enriched the genesis theory of oil shale in continental basins. Although considerable progress has been made in China in the oil shale field both industrially and academically, more work needs to be done to establish a representative oil shale metallogenic model and to accurately evaluate oil shale for its development potential.
In this work, the thermal behavior of Nong'an oil shale of China was investigated and its pyrolysate analyzed in order to provide optimal pyrolysis parameters for the oil shale in-situ pyrolysis pilot project. Through thermogravimetric analysis (TGA) it was noted that the main mass loss of oil shale was in the temperature range of 310-600 °C and the maximum mass loss temperature was 465 °C. The retorting experiments showed that temperature had an important influence on shale oil yield and the maximum oil yield was obtained at 550 °C. The oil yield was reduced at higher temperatures, resulting in an increase in gas yield. According to the analysis of shale oil composition the high pyrolysis temperature could promote the formation of short-chain hydrocarbons. Meanwhile, more alkenes and aromatics and less heteroatomic compounds were found at high temperature. The longchain hydrocarbons and heteroatomic compounds were proved to be secondary products decomposed at higher temperature. In addition, the results of nitrogen adsorption/desorption and scanning electron microscopy (SEM) indicated that the shale surface became more porous due to the decomposition of kerogen and more micro- and mesopores were found after the treatment at high temperature.
The Silurian organic rich shale is the main source of hydrocarbons in the Ghadames Basin in North Africa. The basin has been widely characterized as a source rock for Ordovician oil and gas; yet understanding this shale as a shale resource play remains problematic and challenging. In this study, geochemical and mineralogical analyses of drill cuttings derived from five wellbores were carried out to evaluate the unconventional potential of Silurian organic rich shale. The results of geochemical analysis show that the present day total organic carbon (TOC) of this shale is generally medium to good, varying between 1 and 5 wt%. The hydrogen index (HI = 55-201 mg HC/g TOC) and Tmax (435-454 °C) values indicate type II kerogen in a mature state and its ability to generate wet gas. The results of mineralogical analysis show that clay minerals dominate in all samples of Silurian shale (39-58%) followed by quartz (16-37%). Geochemical parameters such as Mo, V, As, Zr and TiO2 indicate that these shales were deposited in anoxic conditions and were sourced from intermediate igneous rocks. In order to evaluate the potential of Silurian shale as oil and gas source, in this work, the chemostratigraphy technique was applied to identify the provenance of silica in shales, to characterize the shale brittleness and model a correlation between the mineralogy and organic matter content. In conclusion, the Silurian organic rich shale in the Ghadames Basin exhibits good characteristics for shale resource hydrocarbons production.
Organic matter (OM) was isolated from two marine oil shales, El-Lajjun and Julia Creek, using NaOH-HCl and humin and humic acid fractions separated. Two treatments were required to reduce humin ash yield to below 11 wt% db. The humin yield of the autoclave method was 80 wt% of OM (dry mineral-matter-free, dmmf), compared to only 20-60 wt% dmmf for the oven method, possibly due to the increased NaOH solution strength and some oxidation. Oven and autoclave methods both gave humin similar in chemical structure to shale OM, regardless of yield. This similarity has implications as to shale OM structure.
Low international oil price, advance in renewable energy technology, development of energy storage technology and strict environmental regulations have presented encumbrance and opportunity for the current oil shale project development. Oil shale industry is at critical stage and facing challenges from competitive conventional energy, clean renewable energy and more strict environmental regulations. Through an innovative design of the oil shale pyrolysis process model by utilizing a developed new advanced technology, the oil shale project could improve its resilience and sustainability with excellent social and economic performance. This paper investigated the shale oil production process in terms of technology selection, utilization of resource, energy efficiency, oil yield, and mining to improve the resilience of oil shale project economic performance facing lower oil price. Innovative design options for the oil shale production process model were discussed from the following aspects: 1) itemized cost analysis and comparison of shale oil production technologies; 2) development of a new oil shale pyrolysis process model with combination of the existing vertical retort process (VRP) and horizontal rotary-kiln retort process (HRRP) technologies to improve the oil shale process economic gain; 3) discussion of innovative design options to improve the economic performance of the process by utilizing the current new advanced energy storage technology. Investigation of the applicability of the energy storage system (ESS) to the oil shale project was carried out with a sensitivity analysis of its cost-revenue.
The sulfur compounds content of the gasoline fractions of shale oil and oil obtained from used tires was investigated by the method of gas chromatography (GC). There was a marked difference in quantitative chromatograms estimation between the normalization method and the internal standardization method. The application of the internal standardization method proved to be preferable. In addition, the results obtained on the content of sulfur compounds in the studied gasoline fractions allow us to conclude that the co-processing of used tires with oil shale will not affect the quality of the light fraction of oil produced and thus, it enables not to change the method of purification from sulfur compounds.
Coal co-firing experiments were conducted in a 250 MW oil shale fired circulating fluidized bed combustion (CFBC) boiler. The objective of the experiments was to test whether adding coal to oil shale would allow the use of the latter with lower heating value. Bituminous coal was mixed with oil shale and fed into the boiler via existing fuel feeding ports. Two test series were accomplished: 11-29% thermal input of coal mixed with 8.4 MJ/kg oil shale (standard fuel), and 12-32% thermal input of coal mixed with 7.5 MJ/kg oil shale. During the experiments, which lasted in total for 15 days, ash samples were collected and flue gas analysis was performed. The boilers were able to continue work with all the fuel mixtures, but a significant increase of nitrogen oxides (NOx) emissions and heat losses due to unburnt carbon in the bottom and fly ashes were observed. The heat losses can be reduced by upgrading the fuel preparation system, but NOx emissions limit can be reached only with installation of an additional DeNOx system. The ash chemical composition remained similar. Sulphur emissions stayed minimal, but a slight increase of carbon monoxide concentration was noticed. Coal cofiring is possible in oil shale CFBC boilers, but the coal must have low fuel nitrogen content and extra attention to the fuel preparation system has to be paid.
Jordan has huge organic-rich oil shale resources. The exploitation of this resource for generating electrical power by direct combustion is eminent. This process will produce huge ash tailings that contain high concentrations of potentially leachable toxic elements (e.g. Cr+6, V+5, As+3, Cd+2). This ash is friable and eventually will interact with rainwater, forming a leachate rich in toxic elements that might reach soil, plants and surface and groundwater resources. Therefore, as a preventive measure, the current study analyzed the mobility of toxic elements in the ash of burned oil shale (BOS), in particular Cr+6, and aimed to fix them through mixing with other natural locally available materials such as phosphogypsum (PG) and red soil (RS). In addition, a study of the changes in mineralogy, petrography and engineering properties with time during a period of up to 12 months was conducted. The ageing results revealed that the ash + RS mixtures showed a lower leachability of toxic elements in the pH range of 5-9 in comparison with other mixtures. Besides, the said mixtures exhibited an increase in the values of unconfined compressive strength (UCS) and decrease in those of permeability (PE) unlike other mixtures. Moreover, ettringite and portlandite phases increasingly appeared in these mixtures with time, which explains the increase of UCS. The USC of the ash alone mixture was the second lowest and that of the ash + PG mixture the lowest. Therefore, mixing the produced ash with RS (3:1 ratio) under water saturation conditions would afford the best long-term solidification of harmful toxic elements.
This contribution reviews the geopolymeric potential of Ca-rich oil shale processing residues and aims at the characterization of the effects of different alkaline activator solutions on the polymerization of oil shale processing residues experimentally tested in recent-case studies. The analysis shows that the alkali activation of Estonian oil shale solid wastes is controlled by the presence and dissolution of reactive Ca-bearing phases. However, the geopolymeric potential of oil shale ashes is limited by the amount of available reactive Si and Al in the source material. Excess Ca in activated samples is precipitated as Ca-hydroxide showing Si deficiency in the system. To induce a substantial polymer formation, additional sources of readily available Si and Al must be introduced in the mix design. In addition, for industrial applications, further optimization of the mix design and curing conditions, including thermal curing, is needed to reduce dry shrinkage and microstructural cracking.
...]International Oil Shale Conference (BAU-SIOSC) October 9-11, 2018 Oil shale is the twin of petroleum and it is abundantly available, but not in ripened state. The expected upcoming conference would be held in 2021 in Amman, Jordan. Since the exploitation of oil shale has nexus to petroleum, research, application and technology developments are directly proportional to crude oil prices. ...]acknowledgment and gratitude belong to Her Excellency, Minister of Energy and Mineral Resources, Eng.
The organic matter of oil shale samples from four major Bulgarian deposits was investigated using thermal and oxidative treatments. Neutral oils from oil shales were obtained by low-temperature pyrolysis. Gas chromatography-mass spectrometry (GC-MS) was used to study the oxidation products and their chemical composition. A stepwise alkaline permanganate degradation of oil shale concentrate at ambient temperature was carried out, affording a high total yield (90 %) of oxidation products and a minimum yield of gas products. Two different types of high molecular substances were detected in oil shales. The results allowed conclusions to be made about the utilization of prospective Bulgarian oil shale deposits as energy sources.
The thermal decomposition of Estonian Kukersite oil shale under supercritical conditions was carried out using a continuous flow tubular reactor. The effects of the retorting times of 0, 30, 60 and 120 minutes on the yield of thermobitumen (TB), solid residue, oil, gas, coke and undecomposed kerogen at temperatures of 390 °C and 420 °C were investigated. The maximum yield of organics was 93.8% by using the benzene solvent at 420 °C. The influence of physicochemical factors on the efficiency of liquefaction under supercritical conditions was studied. The reaction conditions and solvent for maximum extraction were established.
Estonia's basic power supply is covered mainly by oil shale-fired thermal power plants. The pulverized combustion (PC) and circulating fluidized bed combustion (CFBC) technologies are used. The power plant exploitation has revealed the emission of gaseous pollutants, as well as ash handling problems. The hydro ash removal is used at large power plants in Estonia. An overview of the formation and properties of oil shale ash is given. The polluting impact of ash in contact with water is analyzed. Taking into account precipitation and evaporation conditions the amount of water bound by ash as well as ash field water balance is given. The leaching behaviour of oil shale ash is analyzed. The analysis of the ash field structure shows that the degree of water penetration of the ash field body meets the requirements for hazardous waste landfills. The water permeability through dense layers ranges from 0.15 × 10-9 to 16.1 × 10-9 m/s.
Oil shale is one of the most promising replacements for traditional energy resources. Its total reserves are enormous, and, moreover, they are widespread. This makes shale oil insensitive to problems of individual suppliers. A lot of countries, which lack traditional energy sources for their development, are conducting investigations in the field of an increase of the effectiveness of oil shale as a substitute for oil and gas. These studies are mostly concerned with processing of oil shale. At this, economic and ecological effects could also be reached upon extraction. This paper deals with experimental studies on cutting oil shale by high-pressure water jets. The outcome was establishing a generalized equation for calculating the efficiency of oil shale cutting by high-pressure water jets and equations for estimating rational values of hydraulic parameters such as water pressure and diameter of the nozzle orifice as well as rational value of the traverse speed.