• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.445-451
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• 2002

The refractory-lined pipe is used to protect the system from high-temperature of the internal flow. The property of the refractory has an effect upon the stress analysis for fluid catalytic cracking(FCC) unit piping design. The equivalent elastic modulus and density considering steel and refractory must be applied in the stress analysis of the system. In the research, the theoretical method to obtain the value of the equivalent property is introduced and then the parametric analysis is carried out to understand the characteristic of the material properties, and the stress analysis is performed with reactor, the part of FCC unit.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.547-550
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• 2000

The steel pipe for fluid catalytic cracking(FCC) unit. petroleum refinery, is lined with refractory to protect the system from high-temperature of the internal flow. The property of the refractory has an effect upon the stress analysis of FCC unit. Because 1-D pipe element or 3-D shell element are usually used in commercial codes of stress analysis to evaluate the structural soundness, the equivalent elastic modulus considering steel and refractory should be applied. In the research, the theoretical method to obtain the value of the equivalent property is introduced and then the stress analysis is carried out with the part of FCC unit.

• Journal of Environmental Science International
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• v.13 no.7
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• pp.703-710
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• 2004

Petroleum refineries have been considered as an important emission source for atmospheric volatile hazardous air pollutants(HAPs). The emission source includes petroleum refinery processes and process equipment. The control strategy for volatile HAPs requires emission estimations of these pollutants. However, systematic methods of volatile HAPs emission from petroleum refineries have not yet been established. Accordingly, present study surveyed the estimation method of volatile HAPs emitted from the petroleum refinery processes and process equipment. The emission estimation methods for the petroleum refinery processes are applied for 11 petroleum refining facilities: fluidized catalytic cracking, thermal cracking, moving bed catalytic cracking, compressed engine, blowdown system, vacuum distilled column condensator, natural gas or distilled boiler, natural gas or distilled heater, oil boiler, oil heater and flare. Four emission estimation methods applied for the petroleum refinery process equipment are as follows: average emission factor approach, screening ranges approach, EPA correlation approach and unit-specific correlation approach. The process equipment for which emission factors are available are valves, pump seals, connectors, flanges and open-ended lines.

• Applied Chemistry for Engineering
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• v.23 no.3
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• pp.320-325
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• 2012

The catalytic cracking of waste lubricant oil was carried out on silica-alumina (SA), hydrogen-type mordenite (HM), and dealuminated mordenite (DM) with the silica/alumina ratio of 10.5, 10, and 12.5, respectively. Activity in the catalytic cracking was found to be in the order of SA > DM > HM. Carbon number distribution of the oil obtained over SA was similar to that of gasoline while that of the oil obtained over DM was similar to that of diesel. Carbon number distribution of the oil obtained over HM was similar to that between gasoline and diesel. Acid amounts of three kinds of catalysts were found to be in the order of $SA\;{\approx}\;HM$ > DM. Unlike HM and DM with pores of an uniform diameter below 10 A, SA had a pore size distribution within the range of 10 to 50 A. These results indicate that the acid amount and pore size of the catalysts may be related to the carbon number distribution of the cracked oil. The decrement of surface area by the accumulation of carbon and impurities on the surface of the catalyst was found to be in the order of SA > DM > HM.

• Journal of Energy Engineering
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• v.2 no.2
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• pp.208-214
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• 1993

Pyrolysis of bituminous coal has been carried out in a two-stage fixed bed reactor to produce high heating value gas(7000 kcal/N㎥) for industrial or town gas usage. The effects of coke catalyst, pyrolysis temperature (468∼565$^{\circ}C$), and catalytic cracking temperature (700∼850$^{\circ}C$) on the product gas properties from pyrolysis of bituminous coal have been determined. From pyrolysis of Dong Jin coal with coke, the carbon deposition on catalyst is found to be less than 5% of product tar and approximately 15% of total energy iii the parent coal can be recovered as high heating value gas. Oil composition in the product tar from the two-stage pyrolysis is higher than that from low-temperature pyrolysis. The tar produced from pyrolysis below 516$^{\circ}C$ can be easily catalytically cracked but, the tar produced above 565$^{\circ}C$ cannot be cracked easily with catalyst. From the product gas analysis, the catalytic cracking temperature should be maintained below 800$^{\circ}C$ since cracking speed of ethylene increases remarkably with the cracking temperature above 800$^{\circ}C$.

• Journal of Aerospace System Engineering
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• v.14 no.4
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• pp.32-39
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• 2020

A technological review and analysis were performed on thermal cracking of aviation hydrocarbon fuels that circulate as coolants in regenerative cooling systems of hypersonic flights. Liquid hydrocarbons decompose into low-carbon-number hydrocarbons when they absorb a considerable amount of energy at extremely high temperatures, and these thermal cracking behaviors are represented by heat sink capacity, conversion ratio, reaction products, and coking propensity. These parameters are closely interrelated, and thus, they must be considered for optimum performance in terms of the overall heat absorption in the regenerative cooling system and supersonic combustion in the scramjet engine.

• Mass Spectrometry Letters
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• v.2 no.2
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• pp.41-44
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• 2011

Molecular compositions of two types of heavy oil were studied using positive atmospheric pressure photoionization (APPI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Vacuum gas oil (VGO) was generated from vacuum distillation of atmospheric residual oil (AR), and slurry oil (SLO) was generated from catalytic cracking of AR. These heavy oils have similar boiling point ranges in the range of 210-$650^{\circ}C$, but they showed different mass ranges and double-bond equivalent (DBE) distributions. Using DBE and carbon number distributions, aromatic ring distributions, and the extent of alkyl side chains were estimated. In addition to the main aromatic hydrocarbon compounds, those containing sulfur, nitrogen, and oxygen heteroatoms were identified using simple sample preparation and ultra-high mass resolution FT-ICR MS analysis. VGO is primarily composed of mono- and di-aromatic hydrocarbons as well as sulfur-containing hydrocarbons, whereas SLO contained mainly polyaromatic hydrocarbons and sulfur-containing hydrocarbons. Both heavy oils contain polyaromatic nitrogen components. SLO inludes shorter aromatic alkyl side chains than VGO. This study demonstrates that APPI FT-ICR MS is useful for molecular composition characterization of petroleum heavy oils obtained from different refining processes.

• Computers and Concrete
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• v.25 no.1
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• pp.29-36
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• 2020

This work presents a numerical modeling procedure to simulate the refractory concrete lining in fluid catalytic cracking units of oil refineries. The model includes the simulation of the anchors that reinforce the contact between the refractory concrete and the steel casing. For this purpose, the constitutive relations of an interface finite element are set to values that represent the homogenized behavior of the anchored interface. The parameters of this constitutive relation can be obtained by experimental tests. The model includes also multi-surface plasticity, in order to represent the behavior of the refractory concrete lining. Since the complexity of real case applications leads to high computational costs, the models presented here were implemented in a high-performance parallelized finite element platform. A case study representing a riser similar to the ones used by the refinery industry demonstrates the potential of the model.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.2
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• pp.98-109
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• 2021

Fundamental parameters describing overall operational characteristics of active cooling systems of a hypersonic flight vehicle are mainly classified into endothermic hydrocarbon fuels, regenerative cooling channels, and materials and system structures. Of primary importance is the improvement of endothermic performance of hydrocarbon aviation fuels in a series of studies developing efficient regenerative cooling systems. In a previous study, therefore, an extensive technical analysis has been carried out on thermal decomposition characteristics of liquid hydrocarbon fuels. As a subsequent study, catalytic cracking and steam reforming technologies have been reviewed to find a way for the improvement of endothermic reaction performance of hydrocarbon aviation fuels.

• Smart Structures and Systems
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• v.29 no.4
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• pp.577-588
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• 2022

Oil refineries' Fluid Catalytic Cracking Units (FCCU) when in full operation may exhibit strong fluid dynamics caused by turbulent flow in the piping system that may induce vibrations in other mechanical and structural components of the Unity. This paper reports on the experimental-theoretical-computational program performed to get the vibration properties and the dynamic response amplitudes to find out alternative solutions to attenuate the excessive vibrations that were causing fatigue fractures in components of the bottle like reactor-regenerator of an FCC unit in operation in an existing oil refinery in Brazil. Solutions to the vibration problem were sought with the aid of a 3D finite element model calibrated with the results obtained from experimental measurements. A short description of the found solutions is given and their effectiveness are shown by means of numerical results. The solutions were guided by the concepts of structural stiffening and dynamic control performed by a nonlinear pendulum controller whose mechanical design was based on parameters determined by means of a parametric study carried out with 2D and 3D mathematical models of the coupled pendulum-structure system. The effectiveness of the proposed solutions is evaluated in terms of the fatigue life of critical welded connections.