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Thermodynamic analysis of reaction pathways and equilibrium yields for catalytic pyrolysis of naphtha

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Frontiers of Chemical Science and Engineering 2022年第12期16卷 1700-1712页

作者： Dongyang Liu Yibo Zhi Yuen Bai Liang Zhao Jinsen Gao Chunming Xu State Key Laboratory of Heavy Oil Processing China University of Petroleum(Beijing)Beijing 102249China

The chain length and hydrocarbon type significantly affect the production of light olefins during the catalytic pyrolysis of naphtha.Herein,for a better catalyst design and operation parameters optimization,the reaction pathways and equilibrium yields for the catalytic pyrolysis of C_(5-8)n/iso/cyclo-paraffins were analyzed thermodynamically.The results revealed that the thermodynamically favorable reaction pathways for n/iso-paraffins and cyclo-paraffins were the protolytic and hydrogen transfer cracking pathways,respectively.However,the formation of light paraffin severely limits the maximum selectivity toward light olefins.The dehydrogenation cracking pathway of n/iso-paraffins and the protolytic cracking pathway of cyclo-paraffins demonstrated significantly improved selectivity for light olefins.The results are thus useful as a direction for future catalyst improvements,facilitating superior reaction pathways to enhance light olefins.In addition,the equilibrium yield of light olefins increased with increasing the chain length,and the introduction of cyclo-paraffin inhibits the formation of light olefins.High temperatures and low pressures favor the formation of ethylene,and moderate temperatures and low pressures favor the formation of propylene.n-Hexane and cyclohexane mixtures gave maximum ethylene and propylene yield of approximately 49.90%and 55.77%,respectively.This work provides theoretical guidance for the development of superior catalysts and the selection of proper operation parameters for the catalytic pyrolysis of C_(5-8)n/iso/cyclo-paraffins from a thermodynamic point of view.

关键词： naphtha catalytic pyrolysis reaction pathway equilibrium yield

Catalyst grading technology for promoting the diesel hydrocracking to naphtha

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Petroleum Science 2023年第6期20卷 3798-3806页

作者： Jia-Qi Ge Peng Zhang Fa-Min Sun Ze-An Xie Zhi-Jie Wu Bai-Jun Liu State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China Petrochemical Research Institute PetroChina Company LimitedBeijing102206China Daqing Petrochemical Research Center PetroChina Company LimitedDaqing163714HeilongjiangChina Institute of Catalysis for Energy and Environment Shenyang Normal UniversityShenyang110034LiaoningChina

This paper reports the application of multi-component hydrocracking catalyst grading technology in diesel hydrocracking system to increase naphtha,and studies the influence of catalyst systems with different number of graded beds on the reaction process of diesel hydrocracking.Three hydrocracking catalysts with different physicochemical properties as gradation components,the diesel hydrocracking reaction on catalyst systems of one-component,two-component and three-component graded beds with different loading sequences are carried out and evaluated,respectively.The catalytic mechanism of the multi-component grading system is analyzed.The results show that,with the increase of the number of grading beds,the space velocity of reaction on each catalyst increases,which can effectively control the overreaction process;along the flow direction of feedstock,the loading sequences of catalysts with acidity decreasing and pore properties increasing can satisfy the demand of different catalytic activity for the conversion of reactant with changing composition to naphtha,which has a guiding role in the conversion of feedstock to target products.Therefore,the conversion of diesel,the selectivity and yield of naphtha all increase significantly on the multi-component catalyst system.The research on the grading technology of multi-component catalysts is of great significance to the promotion and application of catalyst systems in various catalytic fields.

关键词： Grading technology Multi-component catalysts Hydrocracking Diesel naphtha

Application of convolutional neural networks to large-scale naphtha pyrolysis kinetic modeling

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Chinese Journal of Chemical Engineering 2018年第12期26卷 2562-2572页

作者： Feng Hua Zhou Fang Tong Qiu Department of Chemical Engineering Tsinghua University Beijing 100084China Beijing Key Laboratory of Industrial Big Data System and Application Beijing 100084China

System design and optimization problems require large-scale chemical kinetic models. Pure kinetic models of naphtha pyrolysis need to solve a complete set of stiff ODEs and is therefore too computational expensive. On the other hand, artificial neural networks that completely neglect the topology of the reaction networks often have poor generalization. In this paper, a framework is proposed for learning local representations from largescale chemical reaction networks. At first, the features of naphtha pyrolysis reactions are extracted by applying complex network characterization methods. The selected features are then used as inputs in convolutional architectures. Different CNN models are established and compared to optimize the neural network structure.After the pre-training and fine-tuning step, the ultimate CNN model reduces the computational cost of the previous kinetic model by over 300 times and predicts the yields of main products with the average error of less than 3%. The obtained results demonstrate the high efficiency of the proposed framework.

关键词： Convolutional neural network Network motif naphtha pyrolysis Kinetic modeling

An Extraction Process for Optimal Utilization of naphtha Based on Molecule Management

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China Petroleum Processing & Petrochemical Technology 2016年第3期18卷 91-101页

作者： Wang Tianxiao Shen Benxian Sun Hui State Key Laboratory of Chemical Engineering East China University of Science and Technology

In this paper, the separation of aromatics from light naphtha by using extraction process was investigated for improving the utilization efficiency of naphtha. It is indicated that, using a mixture of propylene carbonate-diethylene glycol as the solvent, the optimal extraction conditions cover: a volume fraction of propylene carbonate in the mixed solvent of 0.3, a solvent to feed ratio of 8, and an extraction temperature of 308 K. Through the extraction process, the aromatics mass fraction increases from 10.05% in naphtha to 27.74% in extract oil. It is found that the aromatics yield of extract oil, R_A, reaches 92.11%. As a result, in comparison with naphtha, the potential aromatics content of extract oil increases impressively by 18.03%. Meanwhile, the aromatics content of raffinate oil decreases to 1.33%, and the normal paraffin yield of raffinate oil, Rp, is 76.61%. Accordingly, higher total olefins yields can be obtained when using raffinate oil as the raw material for steam cracking. The present results show that the utilization efficiency of naphtha is improved through extraction process.

关键词： optimal utilization naphtha extraction aromatics separation

Study and Analysis on naphtha Catalytic Reforming Reactor Simulation

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China Petroleum Processing & Petrochemical Technology 2004年第4期6卷 49-56页

作者： Liang Ke min1 Song Yongji2 Pan Shiwei3( 1 School of Petrochemical Engineering, Shenyang University of Technology, Liaoyang 111003 2 Department of Chemical Engineering, Beijing Institute of Petrochemical Technology, Beijing102617 3 School of Advanced Professional Technology, Shenyang University of Technology,Liaoyang 111003) School of Petrochemical Engineering Shenyang University of Technology Liaoyang 111003 China Department of Chemical Engineering Beijing Inst. of Petrochem. Technol. Beijing 102617 China Sch. of Adv. Professional Technology Shenyang University of Technology Liaoyang 111003 China

A naphtha catalytic reforming unit with four reactors connected in series is analyzed. A physicalmodel is proposed to describe the catalytic reforming radial flow reactor. Kinetics and thermodynamicsequations are selected to describe the naphtha catalytic reforming reaction characteristics based on idealiz-ing the complex naphtha mixture to represent the paraffin, naphthene, and aromatic groups with individualcompounds. The simulation results based on above models agree very well with actual operating data ofprocess unit.

关键词： naphtha catalytic reforming kinetics simulation and analysis

Experimental study of Iranian heavy crude oil viscosity reduction by diluting with heptane, methanol, toluene, gas condensate and naphtha

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Petroleum 2016年第4期2卷 415-424页

作者： Amir Hossein Saeedi Dehaghani Mohammad Hasan Badizad Petroleum Engineering Group Faculty of Chemical EngineeringTarbiat Modares UniversityTehranIran

Due to the high viscosity of heavy crude oils,production from these reservoirs is a demanding task.To tackle this problem,reducing oil viscosity is a promising approach.There are various methods to reduce viscosity of heavy oil:heating,diluting,emulsification,and core annular flow.In this study,dilution approach was employed,using industrial solvents and gas condensate.The viscosity of two Iranian heavy crude oils was measured by mixing with solvents at different temperatures.Dilution of both oil samples with toluene and heptane,resulted in viscosity reduction.However,their effect became less significant at higher concentrations of diluent.Because of forming hydrogen bonds,adding methanol to heavy crude oil resulted in higher viscosity.By adding condensate,viscosity of each sample reduced.Gas condensate had a greater impact on heavier oil;however,at higher temperatures its effect was reduced.Diluting with naphtha decreased heavy oil viscosity in the same way as n-heptane and toluene.Besides experimental investigation,different viscosity models were evaluated for prediction of heavy oil/solvent viscosity.It was recognized that Lederer'model is the best one.

关键词： Heavy oil Viscosity reduction Dilution Toluene Methanol n-Heptane naphtha Gas condensate

naphtha Importers Can Enjoy Returned Tax

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China Chemical Reporter 2009年第24期20卷 5-5页

Recently the Ministry of Finance, the General Administration of Cus-toms and the State Administration of Taxation of China jointly issueda policy that the domestic enterprises who import naphtha, after theimported nap... 详细信息

关键词： naphtha propylene jointly processed import butadie

First Evidence of Fungal Strains Isolated and Identified from naphtha Storage Tanks and Transporting Pipelines in Venezuelan Oil Facilities

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Advances in Microbiology 2015年第2期5卷 143-154页

作者： Leopoldo Naranjo Beatriz Pernía Ysvic Inojosa Diego Rojas Lucia Sena D’Anna Meralys González ángela De Sisto Área de Energía y Ambiente Instituto de Estudios Avanzados (IDEA) Caracas Venezuela

Biocorrosion, as well as the biodeterioration of crude oil and its derivatives, is one of the major environmental, operational and economic problems in the Venezuelan oil industry. Fungal contaminants are able to produce large quantities of biomass and synthesize peroxides and organic acids, causing severe damage on metal surfaces and promoting the contamination and biodeterioration of fuels. No evidences regarding fungal strains have been reported to be associated to petroleum naphtha, widely used as a diluent of extra heavy crude oil (EHCO) in the exploitation processes of the Orinoco Oil Belt, the biggest proven reserve of EHCO worldwide. The aims of this paper were to isolate and identify fungal strains from the naphtha storage tank and the naphtha distribution network from an oil field operator in Venezuela. The results showed the isolation of four different fungal strains. The molecular identification by 28S rRNA sequencing and phylogenetic tree analysis allowed us to identify the presence of: 1) a new uncultured Ascomycota fungus species BM-103, with high identity to novel hyphomycetes Noosia banksiae and Sporidesmium tengii, in the naphtha storage tank;2) two yeasts, Rhodotorula mucilaginosa BM-104 (Phylum Basidiomycota) and Wickerhamia sp. BM-105 (Phylum Ascomycota), in a highly damaged naphtha pipeline branch and;3) Cladosporium cladosporioides BM-102 (Phylum Ascomycota) in a cluster oil well. DNA fingerprinting analysis using ERIC-PCR primers pairs also allowed us to detect the presence of R. mucilaginosa BM-104 right in the access of the studied naphtha system. Interestingly, R. mucilaginosa and C. cladosporioides were previously reported as predominant fungal contaminants of diesel and jet fuel and of kerosene and fuel storage systems, respectively. This paper represents the first evidence of fungal strains isolated and identified from the naphtha systems in the Venezuelan oil industry. The results obtained are discussed.

关键词： Fungi Biocorrosion Biodeterioration naphtha Pipelines Extra Heavy Crude Oil Orinoco Oil Belt

A New Kind of Renewable Energy: Production of Aromatic Hydrocarbons naphtha Chemical by Thermal Degradation of Polystyrene (PS) Waste Plastic

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American Journal of Climate Change 2012年第3期1卷 145-153页

作者： Moinuddin Sarker Mohammad Mamunor Rashid Muhammad Sadikur Rahman Mohammed Molla Natural State Research Inc. Department of Research and Development 37 Brown House Road (2nd Floor) Stamford CT 06902 USA

Polystyrene (PS) waste plastic to renewable energy or naphtha grade fuel production through fractional distillation process was applied and PS liquefaction temperature range was 250?C - 430?C and fractional column temperature was 110?C - 135?C for naphtha grade fuel separation. The thermal degradation of PS waste plastic to renewable energy or naphtha grade chemical production was without adding any kind of cracking catalyst and without vacuum system. Polystyrene waste plastic is not bio-degradable and its can remain long period of landfill and creating gas emission for that reason its major cause climate change. For experimental purpose raw sample was use 1 kg of PS waste plastic and experiment was performed under Labconco fume hood and experiment was fully closed system, whole experiment was performed into stainless steel reactor. Produced fuel was analysis by gas chromatography and mass spectrometer, FT-IR and DSC. Analysis result indicate for fuel compounds chemical structure, compound band energy and enthalpy, delta H value. Produced fuel sulfur content less then environmental protection agency (EPA) level and fuel could be use for chemical feedstock refinery for further modification. By using this technology can reduce some foreign oil dependency and boost up renewable energy sector all over the world.

关键词： Renewable Energy Climate Change Polystyrene Aromatic naphtha Waste Plastic Thermal Degradation GC/MS