EMPIRICAL APPROACH FOR THE DIAGNOSTIC ANALYSIS OF CHEMICALLY RELATED OIL YIELD LOSSES DURING THE RETORTING OF OIL SHALE

ABSTRACT

The analysis of chemically related oil yield losses during the retorting of oil shale is important for understanding the chemistry of a process, supplying data for modeling efforts and process control of a production facility. Previously developed gas chromatographic correlations for evaluating oil yield losses were duplicated using combined gas chromatograph/mass spectrometric data. Evaluation of these results through calculation of local oil yields indicated that they were higher than expected when compared to material balance oil yields.

A new correlation was developed to estimate the fraction of oil lost by cracking plus combustion. The approach to the new correlation was based on selection of steranes and pentacyclic triterpanes as the species in shale oil which would undergo cracking and combustion to yield selected aromatic compounds. Evaluation of the results from this correlation for determination of local oil yields was found to produce acceptable results.

The two approaches for estimating the fraction of oil lost by cracking plus combustion are compared. The differences appear to be that the earlier approach is dependent upon severe cracking and combustion conditions. The new approach for determining the fraction of oil lost by cracking plus combustion appears to be applicable to a wider range of process conditions and therefore is more useful in research.     

EMPIRICAL APPROACH FOR THE DIAGNOSTIC ANALYSIS OF CHEMICALLY RELATED OIL YIELD LOSSES DURING THE RETORTING OF OIL SHALE

The analysis of chemically related oil yield losses during the retorting of oil shale is important for understanding the chemistry of a process, supplying data for modeling efforts and process control of a production facility. Previously developed gas chromatographic correlations for evaluating oil yield losses were duplicated using combined gas chromatograph/mass spectrometric data. Evaluation of these results through calculation of local oil yields indicated that they were higher than expected when compared to material balance oil yields.

A new correlation was developed to estimate the fraction of oil lost by cracking plus combustion. The approach to the new correlation was based on selection of steranes and pentacyclic triterpanes as the species in shale oil which would undergo cracking and combustion to yield selected aromatic compounds. Evaluation of the results from this correlation for determination of local oil yields was found to produce acceptable results.

The two approaches for estimating the fraction of oil lost by cracking plus combustion are compared. The differences appear to be that the earlier approach is dependent upon severe cracking and combustion conditions. The new approach for determining the fraction of oil lost by cracking plus combustion appears to be applicable to a wider range of process conditions and therefore is more useful in research.     

AIR OXIDATION OF EASTERN OIL SHALES OF KENTUCKY. II. THE EFFECTS OF AMBIENT AUTOXIDATION

ABSTRACT

Ambient air oxidation leads to lower Fischer assay oil yields and often lower process yields from retorting of eastern oil shales. Slight changes in the kerogen and mineral matter of the oil shale and in its pyrolysis products, both liquid and gaseous, were evident following autoxidation. Experimental observations suggest that the hydrogen deficiency of eastern kerogen, as compared to western kerogen, makes its synfuel potential (by Fischer assay) a more sensitive function of the degree of oxidation.

A better yield of oil from oxidized eastern oil shale could be obtained by dissolving away sulfates and other water soluble oxidized materials prior to retorting. The air oxidation of pyrite was demonstrated by SEH, and addition of iron(II) sulfate was shown to reduce assay oil yields. Such observations suggest that combusted shale may not always be a suitable heat transfer agent for atmospheric pressure retorting applications.     

NON-ISOTHERMAL PYROLYSIS OF TWO KINDS OF CHINESE OIL SHALE

Abstract

Non-isothermal pyrolysis of two kinds of Fushun oil shale with particle sizes, <0·075 mm, 0·3 - 0·5 mm, 0·75 - 1·0 mm and 1·5 - 2·0 mm, has been investigated in stream (nitrogen) at the flow rate of 100 ml/min by thermo-gravimetric analyzer with a linear heating rate 6·8K/min. It has been found that the temperaturee intervals of oil-generation from rich grade shale ( 9·8 % Fisher Assay oil yield ) and poor grade shale ( 3·9% Fisher Assay oil yield ) with particle size less than 2·0 mm are 400 - 500 °C and 400 - 520° C respectively. The kinetic treatment of the thermo gravimetric data reveals that pyrolytic reactions of the two kinds of Fushun oil shale are both of the first order, but with different activation energy E and pre-exponential factor A in different temperaturee regions during pyrolysis. This is different from what was described in general terms as global first order reaction for oil shale pyrolysis by other anthers. The kinetic parameters for pyrolysis of the two kinds of Fushun oil shale with different particle sizes were calculated by means of least square curve fitting, and the influence of particle size on pyrolysis was also discussed.     

热解干馏法测定油砂的含油率

采用铝甑低温干馏方法对新疆克拉玛依油砂样品进行了含油率的测定，并考察了油砂粒径、升温速率、干馏终温、持温时间等因素对油砂含油率测定结果的影响。结果表明，热解干馏法测定油砂含油率的最佳操作条件是：粒径3～5 mm，升温速率15 ℃/min，干馏终温500 ℃，持温时间20 min。以二甲苯为溶剂进行水分的蒸馏分离，油水分离效果较好。测定结果与常用的Dean-Stark甲苯抽提法的测定结果十分接近。     

大庆柳树河油页岩特点及干馏工艺选择

大庆柳树河盆地油页岩资源丰富，分布比较稳定。研究了该盆地油页岩含油率、热值、水分、热稳定性、强度等特性，针对该地区油页岩 “三高一低”（高含油、高含水、高热值和低强度）的特点，采用自主研制的2 kg级别室内干馏装置对油页岩进行全面室内评价，同时自主研发了新型小颗粒固体热载体干馏工艺，提出对大庆柳树河油页岩可采用小颗粒固体热载体干馏工艺技术。     

A SINGLE PARTICLE MODEL FOR PYROLYSIS OF OIL SHALE

ABSTRACT

In many heterogeneous pyrolysis reactions the porous solid undergoes geometrical changes due to the consumption of solid reactant which decrease the compressive strength of the solid matrix. In this study a volume expansion model is proposed for pyrolysis of a single shale particle. This model not only takes into account the structural changes and the intraparticle gradients, but also the functional dependencies of various parameters on the variation of solid reactant conversion and internal temperature distribution.

Effects of various parameters which are expected to be encountered in an in-situ retorting process were investigated. Primary emphasis was placed on determining the manner in which transport processes affect the yield of pyrolysis product. The results indicate that Intraparticle heat transfer is a dominant factor in the pyrolysis of oil shale and that volume expansion favors the decomposition rate.     

AIR OXIDATION OF EASTERN OIL SHALES OF KENTUCKY. II. THE EFFECTS OF AMBIENT AUTOXIDATION

Ambient air oxidation leads to lower Fischer assay oil yields and often lower process yields from retorting of eastern oil shales. Slight changes in the kerogen and mineral matter of the oil shale and in its pyrolysis products, both liquid and gaseous, were evident following autoxidation. Experimental observations suggest that the hydrogen deficiency of eastern kerogen, as compared to western kerogen, makes its synfuel potential (by Fischer assay) a more sensitive function of the degree of oxidation.

A better yield of oil from oxidized eastern oil shale could be obtained by dissolving away sulfates and other water soluble oxidized materials prior to retorting. The air oxidation of pyrite was demonstrated by SEH, and addition of iron(II) sulfate was shown to reduce assay oil yields. Such observations suggest that combusted shale may not always be a suitable heat transfer agent for atmospheric pressure retorting applications.     

抚顺油页岩热分解过程的热重法研究

采用线性升温速率6.8k/min的热重装置,在惰性气(氮)流量100ml/min的条件下,考察了粒度<0.075mm,0.3～0.5mm,0.75～1.0mm及1.5～2.0mm的两种抚顺页岩的非等温热分解过程.根据试验得出的热重曲线,失重速率-温度曲线及转化率-温度曲线,获得了抚顺页岩的初始分解温度及失重速率峰值温度等动力学特征值,并确定,粒度小于2.0mm的抚顺富矿页岩(铝甑产油率9.8%)及贫矿页岩(铝甑产油率3.9%)的主要热解生油阶段分别为400～500℃及400～520℃.     

A SINGLE PARTICLE MODEL FOR PYROLYSIS OF OIL SHALE

In many heterogeneous pyrolysis reactions the porous solid undergoes geometrical changes due to the consumption of solid reactant which decrease the compressive strength of the solid matrix. In this study a volume expansion model is proposed for pyrolysis of a single shale particle. This model not only takes into account the structural changes and the intraparticle gradients, but also the functional dependencies of various parameters on the variation of solid reactant conversion and internal temperature distribution.

Effects of various parameters which are expected to be encountered in an in-situ retorting process were investigated. Primary emphasis was placed on determining the manner in which transport processes affect the yield of pyrolysis product. The results indicate that Intraparticle heat transfer is a dominant factor in the pyrolysis of oil shale and that volume expansion favors the decomposition rate.     

ANALYSIS OF OIL SHALE RETORT PRODUCTION STREAM GASES FOR SULFUR SPECIES

ABSTRACT

Analysis of the sulfur species in the production gas stream of oil shale retorts is important for environmental and process development needs. Combined gas chromatography/mass spectrometry and gas chromatography with flame photometric detection have been applied to the qualitative and quantitative analysis of sulfur species in the production gas stream from six oil shale retorting experiments. Hydrogen sulfide was determined to be the most abundant species and represented approximately 95 percent (wt.) of the sulfur present. Minor sulfur species identified and quantitated include carbonyl sulfide, carbon disulfide, methylmercaptan, ethylmercaptan, propylmercaptan, and thiophene. Sulfur dioxide was not identified during any of the retorting experiments studied.

The distribution of these sulfur species from the six retorting experiments is important because it provides a baseline for the design of process control technologies. The importance of the liquid product collection train for control of sulfur emissions was also demonstrated.     

CHEMICAL COMPOSITION OF OIL SHALE II. DEPENDENCE ON THE EXTRACTION PROCESS

ABSTRACT

Eastern and Western U.S. and Australian oil shales were retorted in a fixed-bed, bench-scale retorter, using nitrogen and carbon dioxide as sweep gases. The resulting shale oils were chemically characterized by GC/MS techniques. Shale oils extracted by nitrogen and carbon dioxide retorting processes were found to have different chemical compositions, even when applied to the same oil shale samples. The extraction process dependent nature of shale oils is fully assessed in this paper and the information may be used for comparison among various extraction processes as well as for choosing appropriate upgrading processes for the crude shale oils.     

BOILING RANGE DISTRIBUTIONS OF VARIOUS SHALE OILS AND INFLUENCE OF CARBON DIOXIDE RETORTING

Abstract

The boiling range distributions of seven different shale oils from the United States and Australia which were retorted in the same retort under identical conditions were obtained and compared. These data are important in forming an engineering data base for shale oils.

Also, the effects of carbon dioxide retorting versus nitrogen retorting on oil quality were investigated. Through the study of the initial and final boiling points and the boiling range distribution it was found that carbon dioxide retorting increased the yield of low to mid-distillate fractions in the shale oil, thus enhancing the oil quality.     

CHEMICAL COMPOSITION OF SHALE OIL I. DEPENDENCE ON OIL SHALE ORIGIN

ABSTRACT

Shale oils obtained by nitrogen retorting of North Carolina, Cleveland, Ohio, Colorado, Rundle, Stuart, and Condor oil shales have been chemically characterized by g.c.-m.s. techniques. After species identification, chemical compositions of the shale oils have been related to the geological origins of the parent shales. Based on the characteristics observed in the chromatograms, eight semi-quantitative parameters have been used to describe the chromatograms. Six of these parameters describe the relative abundance and distribution of straight chain alkanes and alkenes in the chromatograms. The other two parameters represent the abundance, relative to the total amount of volatiles in the oil, of alkylbenzenes and alkylphenols.     

SUPERCRITICAL EXTRACTION OF STUART OIL SHALE

ABSTRACT

This paper describes the recovery of oil from Stuart oil shale using a supercritical extraction technique employing carbon dioxide as solvent. This supercritical technique provides yields superior to comparable retorting techniques. The importance of extraction temperature, pressure, and time has been investigated. In addition, the chemical composition of the oil extracted from the shale is presented. Simulated distillation has been employed to assess the effect of extraction conditions on the quality of the shale oil extracted.     

IDENTIFICATION OF THE MINERAL PHASES RESPONSIBLE FOR CEMENTATION OF LURGI SPENT OIL SHALE

ABSTRACT

Very large volumes of solid waste are generated during oil shale retorting. The reclamation and use of these wastes are desirable from an environmental and economical point of view. Two of the primary considerations in the disposal of these wastes are their structural integrity and the leaching of toxics into groundwater.

The spent shale used in this study was generated from oil shale mined from the Green River Formation in the Piceance Basin of western Colorado. The oil shale was processed using the Lurgi-Ruhrgas method (Schmalfeld 1975). The spent shale was packed in the Harvard miniature apparatus (Soiltest 1964) forming columns using three different water contents. Subsequently, the columns were allowed to cure for periods ranging from one day to eight weeks.

Pour types of analyses were performed on the cured columns. X-ray diffraction (XRD), scanning electron microscopy with an energy dispersive X-ray analyzer     

CHARACTERIZATION OF ORGANIC MATTER RECOVERED FROM GREEN RIVER OIL SHALE AT TEMPERATURES OF 400°C AND BELOW

Organic matter extracted from Green River oil shale by supercritical extraction experiments was characterized by elemental analysis, number average molecular weight determination and field ionization mass spectrometry. The organic matter was also separated into fractions of organic acids, bases, and hydrocarbons. Characterization data demonstrate that the organic matter recovered in high yield from autoclave experiments is similar in composition to organic matter extracted in low yield at solvent reflux temperatures. The composition of organic matter extracted from Green River shale by supercritical techniques is compared with the composition of Green River shale oil produced by several pilot-scale retorting processes.     

小颗粒页岩流化干馏工艺及其影响因素

以桦甸小颗粒页岩尾矿为原料,在流化干馏装置上进行热解实验。结果表明,页岩尾矿最佳热解反应条件为:粒径5 mm左右,加热速率6～10℃/min,干馏终温500℃。在此条件下,油页岩热解收率可达90%。     

ANALYSIS OF OIL SHALE RETORT PRODUCTION STREAM GASES FOR SULFUR SPECIES

Analysis of the sulfur species in the production gas stream of oil shale retorts is important for environmental and process development needs. Combined gas chromatography/mass spectrometry and gas chromatography with flame photometric detection have been applied to the qualitative and quantitative analysis of sulfur species in the production gas stream from six oil shale retorting experiments. Hydrogen sulfide was determined to be the most abundant species and represented approximately 95 percent (wt.) of the sulfur present. Minor sulfur species identified and quantitated include carbonyl sulfide, carbon disulfide, methylmercaptan, ethylmercaptan, propylmercaptan, and thiophene. Sulfur dioxide was not identified during any of the retorting experiments studied.

The distribution of these sulfur species from the six retorting experiments is important because it provides a baseline for the design of process control technologies. The importance of the liquid product collection train for control of sulfur emissions was also demonstrated.     

CHEMICAL COMPOSITION OF OIL SHALE II. DEPENDENCE ON THE EXTRACTION PROCESS

Eastern and Western U.S. and Australian oil shales were retorted in a fixed-bed, bench-scale retorter, using nitrogen and carbon dioxide as sweep gases. The resulting shale oils were chemically characterized by GC/MS techniques. Shale oils extracted by nitrogen and carbon dioxide retorting processes were found to have different chemical compositions, even when applied to the same oil shale samples. The extraction process dependent nature of shale oils is fully assessed in this paper and the information may be used for comparison among various extraction processes as well as for choosing appropriate upgrading processes for the crude shale oils.