The influence of grain size on the products yield and shale oil composition from the Pyrolysis of Sultani oil shale

Nazzal, Jamal M.

doi:10.1016/j.enconman.2008.03.028

Cited by 42 publications

(23 citation statements)

References 14 publications

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“…Rock fragment size is one of the most important variables affecting the rate and efficiency of oil shale pyrolysis (Nazzal 2008). Oil yield predictions using the two models are quite close for small fragment sizes, but as size increases the two models gradually diverge.…”

Section: Effects Of Rock Fragment Size and Heating Ratementioning

confidence: 80%

An Efficient Modeling Approach to Simulate Heat Transfer Rate between Fracture and Matrix Regions for Oil Shale Retorting

Zhai

Parker

2009

Transp Porous Med

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The conversion of hydrocarbons in oil shale into liquid fuels has gained interest due to decreasing conventional oil reserves. Thermal conversion involves heating fractured rock and recovering gas and liquid phase products. The efficiency of this process is markedly dependent on heat transfer limitations between fracture porosity and rock matrix. Computer models are useful tools for process optimization. Explicit modeling of heat transfer processes within rock fragments would require great computational effort, making inverse modeling and forward process optimization very difficult if not impracticable. In this article, we evaluate the feasibility of using first-order heat transfer formulations to approximate these processes by comparing first-order model results with a rigorous explicit formulation and by comparison with laboratory retorting experiments published in the literature. Comparison of the two modeling approaches indicates that the first-order heat transfer approximation can be used without significant loss of accuracy if the block size and/or heating rate are not too large, as quantified by a proposed dimensionless heating rate. However, computational effort can be decreased by an order of magnitude compared with explicitly simulating diffusive heat transfer. List of symbols bHeating rate d m Rock fragment diameter E m Rate of heat generated (+) or absorbed (−) by reactions H fm Heat transfer rate from the matrix to fractures (+) or visa versa (−) r Radial distance from the center of the rock fragment r H Rate of temperature increase in fractures r m Radius of rock fragments r H Rate of rock surface temperature increase R H Dimensionless heating rate S m Specific heat of the rock matrix, T m is the rock matrix temperature t Time T f Fracture-rock interface temperature at the corresponding location T 0 Initial rock temperature T m Average rock matrix temperature β Linearized heat transfer coefficient λ m Thermal conductivity of the rock matrix ρ m Rock matrix density defined as the solid phase mass per total fracture-matrix volume

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Section: Effects Of Rock Fragment Size and Heating Ratementioning

confidence: 80%

An Efficient Modeling Approach to Simulate Heat Transfer Rate between Fracture and Matrix Regions for Oil Shale Retorting

Zhai

Parker

2009

Transp Porous Med

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“…The obtained gaseous products have relatively high energy values and therefore can be used as potential fuels [3] whose yields and characteristics depend on several factors, such as the properties and component composition of oil shale, retorting temperature, heating rate, catalysts, reactor type, etc. [4][5][6]. For producing gas products with high yield and quality, it is necessary to investigate the characteristics of their evolution under different retorting conditions.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Effects of Fe- And Ca-Based Additives on Gas Evolution During Pyrolysis of Dachengzi Oil Shale of China

Wang¹,

Song²,

Jiang³

2018

Oil Shale

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The pyrolysis of Dachengzi oil shale (OS), Huadian City, China, was carried out in a stainless-steel cylindrical retort at 520 °C both in the absence and presence of catalyst under argon atmosphere to evaluate the catalytic effects of Fe 2 O 3 and CaCO 3 additives on the products yield and characteristics of non-condensable gases. The results showed that the catalyst significantly affected the reactivity of OS kerogen pyrolysis. The shale oil yield increased after adding the catalyst, especially Fe 2 O 3 , but the shale char yield decreased in the presence of the catalyst. The noncondensable gases yield rose in the CaCO 3-catalysed pyrolysis and declined upon the Fe 2 O 3-catalysed process, indicating that CaCO 3 had a more pronounced catalytic effect on the secondary reactions of oil vapors. In addition, the gaseous products obtained both with and without the catalyst had a higher volume content of CO 2 , CH 4 and H 2 , and a lower volume content of CO and C 2-C 4 hydrocarbons. The peak concentrations of CO 2 and H 2 increased in the presence of the catalyst, especially Fe 2 O 3 , while that of CO enhanced with addition of CaCO 3 as a catalyst. H 2 was generated at higher temperature compared to CO 2 and CO. Furthermore, Fe 2 O 3 and CaCO 3 exhibited different effects on the evolution of C 1-C 4 hydrocarbons. COS and H 2 S evolved almost simultaneously, the amount of H 2 S released being higher than that of COS. The peak concentrations of the said gases decreased with adding the catalyst, especially Fe 2 O 3. The non-condensable gases produced both before and after catalysis mainly consisted of CO 2 and CH 4 , and some minor gases, in terms of mass distribution. The mass contents of ethane, butane, CO 2 and H 2 increased after the use of the catalyst, while those of butane, H 2 S and COS decreased. Moreover, adding Fe 2 O 3 and CaCO 3 resulted in the decline in the ethene/ethane and propene/propane ratios, respectively, suggesting that different catalysts possibly led to different changes in the physical structure of oil shale and then caused the secondary reactions of pyrolysis products to proceed to different extents.

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“…He established that the higher the activation energy, the higher the amount of heat required for the pyrolysis reaction. Nazzal [16] studied the pyrolysis of oil shale of different particle sizes. He claimed that oil shale with large particle size produced more hydrocarbon gas during the pyrolysis process compared with oil shale of smaller particle size.…”

Section: Introductionmentioning

confidence: 99%

Experimental Research of the Pyrolytic Properties and Mineral Components of Bogda Oil Shale, China

Zhang¹,

Liu²,

Kang³

et al. 2018

Oil Shale

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The purpose of this paper was to investigate the pyrolysis properties and mineral structures of Bogda oil shale, Xinjiang, China. To this end, techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and thermogravimetry-mass spectrometry (TG-MS) were used. The results showed that oil shale was rich in clay minerals, quartz, calcite, frondelite and pyrite. Aliphatic hydrocarbons were mainly dominant in the functional groups contained in the organic material of oil shale whose semi-coke possessed diverse structures of polycyclic aromatic hydrocarbons. The pyrolysis process of Bogda oil shale was conducted in three stages: from room temperature to 320 °C, 320 °C to 630 °C, and 630 °C to 800 °C. The pyrolysis was the most intensive in the temperature range of 320-630 °C. The mass loss of oil shale in this temperature range accounted for 70% of the total mass loss. The volatile materials were pyrolysed rapidly. The main gaseous pyrolysis products included H 2 O, CO 2 , H 2 , CH 4 , and some lower alkanes.

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The influence of grain size on the products yield and shale oil composition from the Pyrolysis of Sultani oil shale

Cited by 42 publications

References 14 publications

An Efficient Modeling Approach to Simulate Heat Transfer Rate between Fracture and Matrix Regions for Oil Shale Retorting

An Efficient Modeling Approach to Simulate Heat Transfer Rate between Fracture and Matrix Regions for Oil Shale Retorting

Catalytic Effects of Fe- And Ca-Based Additives on Gas Evolution During Pyrolysis of Dachengzi Oil Shale of China

Experimental Research of the Pyrolytic Properties and Mineral Components of Bogda Oil Shale, China

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