Modeling and Simulation of Industrial Continuous Naphtha Catalytic Reformer Accompanied with Delumping the Naphtha Feed

Nowadays, with the worldwide, increasing demands of the high qualitative gasoline, it is necessary to establish new naphtha reforming units and develop the traditional units to the high efficiency processes. In this work, according to the recent progresses in naphtha reforming technology, a mathematical modeling of a continuous catalytic reformer with catalyst recirculation is developed for simulation and optimization of the new industrial continuous reformers. The process model uses an extended version of the kinetic model reported by Padmavathi, with some modifications on kinetic constants, and it considers the deactivation rate of the catalyst and pressure drop within the reactor. The process model is based on a 12-lumped kinetics reaction network and has been proved to be quite effective in terms of an industrial application. The naphtha is based on 25-lumped pseudocomponents (including C6 to C10 hydrocarbons) in three categories of n-paraffins, isoparaffins, naphthens, including cyclopentanes and cyclohexanes, and aromatics. The light hydrocarbons product, consisting of C1 to C5 n-paraffins, is taken into account as the products of hydrocracking reaction. First, the kinetic parameters of the reactions are tuned using real results of the outlet temperatures and components in industrial operating conditions. At the next stage, validation of the model was carried out using a new naphtha feed in industrial scale. The final stage of this research was based on splitting a naphtha feed using its only ASTM boiling point and specific gravity, to converting to the components and applying into the process model to predict the outlet temperature and composition, the reformate yield and RON, hydrogen and LPG product, and coke formation at each cycle. The predicted and commercially reported results agreed with each other.

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High-Altitude Matching Characteristic of Regulated Two-Stage Turbocharger With Diesel Engine

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4036283 ◽

2017 ◽

Vol 139 (9) ◽

Cited By ~ 10

Author(s):

Ruilin Liu ◽

Zhongjie Zhang ◽

Surong Dong ◽

Guangmeng Zhou

Keyword(s):

Diesel Engine ◽

High Altitude ◽

Process Model ◽

High Efficiency ◽

Pressure Ratio ◽

Operating Conditions ◽

Boost Pressure ◽

Two Stage ◽

Variable Geometry Turbocharger ◽

Different Altitudes

To improve engine power at high altitude, the regulated two-stage turbocharger (RTST) which was applied to different altitudes was developed by the authors. The working process model of heavy-duty common-rail diesel engine matched with RTST was built to study the regulating characteristic of variable geometry turbocharger (VGT) vane and both turbine bypass valves and also matching performance of RTST with engine at different altitudes. The control scheme of RTST at different altitudes and engine operating conditions was first put forward, and the optimal opening maps of VGT vane and both turbine bypass valves at different altitudes and engine operating conditions were obtained. The results show that the optimal openings of VGT vane and both turbine bypass valves decrease with increase of altitude, and the optimal opening range of VGT vane becomes narrower with increase of altitude. The operating points of both high-pressure (HP) and low-pressure (LP) compressors locate at high-efficiency region of each compressor map, respectively, and compressor efficiency exceeds 70% at altitude of 5500 m. The total boost pressure ratio increases with altitude and reaches the maximum value of 5.1 at altitude of 5500 m. Compared with single-stage turbocharged engine, the rated power, maximum torque, and torques at lower engine speed at altitude of 5500 m increase by 48.2%, 51%, and 65–121% separately, and the minimum fuel consumption decreases by 12.6%.

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Elemental Distribution in Pt-Re:Al2O3 Naphtha Reforming Catalysts

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600000866 ◽

1980 ◽

Vol 38 ◽

pp. 200-201

Author(s):

R. L. Freed ◽

M. J. Kelley

Keyword(s):

Bimetallic Catalyst ◽

Supported Catalysts ◽

Coke Formation ◽

Materials Characterization ◽

Metal Catalyst ◽

Elemental Distribution ◽

Exact Nature ◽

Naphtha Reforming ◽

Reforming Catalysts ◽

Commercial Introduction

The commercial introduction of Pt-Re supported catalysts to replace Pt alone on Al2O3 has brought improvements to naphtha reforming. The bimetallic catalyst can be operated continuously under conditions which lead to deactivation of the single metal catalyst by coke formation. Much disagreement still exists as to the exact nature of the bimetallic catalyst at a microscopic level and how it functions in the process so successfully. The overall purpose of this study was to develop the materials characterization tools necessary to study supported catalysts. Specifically with the Pt-Re:Al2O3 catalyst, we sought to elucidate the elemental distribution on the catalyst.

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"Recent Patents on the Triboelectrostatic Separation of Fly Ash"

Recent Patents on Engineering ◽

10.2174/1872212113666190923100018 ◽

2019 ◽

Vol 13 ◽

Author(s):

Haisheng Li ◽

Wenping Wang ◽

Yinghua Chen ◽

Xinxi Zhang ◽

Chaoyong Li

Keyword(s):

Fly Ash ◽

Power Plants ◽

High Efficiency ◽

Separation Efficiency ◽

High Reliability ◽

Operating Conditions ◽

Security Requirements ◽

Unburned Carbon ◽

Efficient Operation ◽

Triboelectrostatic Separation

Background: The fly ash produced by coal-fired power plants is an industrial waste. The environmental pollution problems caused by fly ash have been widely of public environmental concern. As a waste of recoverable resources, it can be used in the field of building materials, agricultural fertilizers, environmental materials, new materials, etc. Unburned carbon content in fly ash has an influence on the performance of resource reuse products. Therefore, it is the key to remove unburned carbon from fly ash. As a physical method, triboelectrostatic separation technology has been widely used because of obvious advantages, such as high-efficiency, simple process, high reliability, without water resources consumption and secondary pollution. Objective: The related patents of fly ash triboelectrostatic separation had been reviewed. The structural characteristics and working principle of these patents are analyzed in detail. The results can provide some meaningful references for the improvement of separation efficiency and optimal design. Methods: Based on the comparative analysis for the latest patents related to fly ash triboelectrostatic separation, the future development is presented. Results: The patents focused on the charging efficiency and separation efficiency. Studies show that remarkable improvements have been achieved for the fly ash triboelectrostatic separation. Some patents have been used in industrial production. Conclusion: According to the current technology status, the researches related to process optimization and anti-interference ability will be beneficial to overcome the influence of operating conditions and complex environment, and meet system security requirements. The intelligent control can not only ensure the process continuity and stability, but also realize the efficient operation and management automatically. Meanwhile, the researchers should pay more attention to the resource utilization of fly ash processed by triboelectrostatic separation.

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Comprehensive Parameters Identification and Dynamic Model Validation of Interior-Mount Line-Start Permanent Magnet Synchronous Motors

Machines ◽

10.3390/machines7010004 ◽

2019 ◽

Vol 7 (1) ◽

pp. 4 ◽

Cited By ~ 3

Author(s):

Luqman S. Maraaba ◽

Zakariya M. Al-Hamouz ◽

Abdulaziz S. Milhem ◽

Ssennoga Twaha

Keyword(s):

Mathematical Model ◽

Permanent Magnet ◽

High Efficiency ◽

Experimental Tests ◽

Induction Machines ◽

Test Methods ◽

Operating Conditions ◽

Test Method ◽

Permanent Magnet Synchronous Motors ◽

Synchronous Motors

The application of line-start permanent magnet synchronous motors (LSPMSMs) is rapidly spreading due to their advantages of high efficiency, high operational power factor, being self-starting, rendering them as highly needed in many applications in recent years. Although there have been standard methods for the identification of parameters of synchronous and induction machines, most of them do not apply to LSPMSMs. This paper presents a study and analysis of different parameter identification methods for interior mount LSPMSM. Experimental tests have been performed in the laboratory on a 1-hp interior mount LSPMSM. The measurements have been validated by investigating the performance of the machine under different operating conditions using a developed qd0 mathematical model and an experimental setup. The dynamic and steady-state performance analyses have been performed using the determined parameters. It is found that the experimental results are close to the mathematical model results, confirming the accuracy of the studied test methods. Therefore, the output of this study will help in selecting the proper test method for LSPMSM.

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An In-Depth Process Model for Fuel Production via Hydrothermal Liquefaction and Catalytic Hydrotreating

Processes ◽

10.3390/pr9071172 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1172

Author(s):

Leonard Moser ◽

Christina Penke ◽

Valentin Batteiger

Keyword(s):

Process Model ◽

Reaction Network ◽

Hydrothermal Liquefaction ◽

Process Chain ◽

Fuel Production ◽

Model Compounds ◽

Point Distribution ◽

Process Step ◽

Elemental Analyses ◽

Made In

One of the more promising technologies for future renewable fuel production from biomass is hydrothermal liquefaction (HTL). Although enormous progress in the context of continuous experiments on demonstration plants has been made in the last years, still many research questions concerning the understanding of the HTL reaction network remain unanswered. In this study, a unique process model of an HTL process chain has been developed in Aspen Plus® for three feedstock, microalgae, sewage sludge and wheat straw. A process chain consisting of HTL, hydrotreatment (HT) and catalytic hydrothermal gasification (cHTG) build the core process steps of the model, which uses 51 model compounds representing the hydrolysis products of the different biochemical groups lipids, proteins, carbohydrates, lignin, extractives and ash for modeling the biomass. Two extensive reaction networks of 272 and 290 reactions for the HTL and HT process step, respectively, lead to the intermediate biocrude (~200 model compounds) and the final upgraded biocrude product (~130 model compounds). The model can reproduce important characteristics, such as yields, elemental analyses, boiling point distribution, product fractions, density and higher heating values of experimental results from continuous experiments as well as literature values. The model can be applied as basis for techno-economic and environmental assessments of HTL fuel production, and may be further developed into a predictive yield modeling tool.

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A Comparative Study on Fault Detection Methods for Gas Turbine Combustion Systems

Energies ◽

10.3390/en14020389 ◽

2021 ◽

Vol 14 (2) ◽

pp. 389

Author(s):

Jinfu Liu ◽

Zhenhua Long ◽

Mingliang Bai ◽

Linhai Zhu ◽

Daren Yu

Keyword(s):

Fault Detection ◽

Gas Turbine ◽

Gas Turbines ◽

Operating Conditions ◽

Detection Methods ◽

Distribution Model ◽

Outlet Temperature ◽

Combustion System ◽

Comparison Results ◽

Gas Turbine Combustion

As one of the core components of gas turbines, the combustion system operates in a high-temperature and high-pressure adverse environment, which makes it extremely prone to faults and catastrophic accidents. Therefore, it is necessary to monitor the combustion system to detect in a timely way whether its performance has deteriorated, to improve the safety and economy of gas turbine operation. However, the combustor outlet temperature is so high that conventional sensors cannot work in such a harsh environment for a long time. In practical application, temperature thermocouples distributed at the turbine outlet are used to monitor the exhaust gas temperature (EGT) to indirectly monitor the performance of the combustion system, but, the EGT is not only affected by faults but also influenced by many interference factors, such as ambient conditions, operating conditions, rotation and mixing of uneven hot gas, performance degradation of compressor, etc., which will reduce the sensitivity and reliability of fault detection. For this reason, many scholars have devoted themselves to the research of combustion system fault detection and proposed many excellent methods. However, few studies have compared these methods. This paper will introduce the main methods of combustion system fault detection and select current mainstream methods for analysis. And a circumferential temperature distribution model of gas turbine is established to simulate the EGT profile when a fault is coupled with interference factors, then use the simulation data to compare the detection results of selected methods. Besides, the comparison results are verified by the actual operation data of a gas turbine. Finally, through comparative research and mechanism analysis, the study points out a more suitable method for gas turbine combustion system fault detection and proposes possible development directions.

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Octane Index Applicability over the Pressure-Temperature Domain

Energies ◽

10.3390/en14030607 ◽

2021 ◽

Vol 14 (3) ◽

pp. 607

Author(s):

Tommy R. Powell ◽

James P. Szybist ◽

Flavio Dal Forno Chuahy ◽

Scott J. Curran ◽

John Mengwasser ◽

...

Keyword(s):

High Efficiency ◽

National Laboratory ◽

Operating Conditions ◽

Dominant Factor ◽

Compression Ignition ◽

Oak Ridge ◽

Operating Modes ◽

Wide Range ◽

Thermodynamic Conditions ◽

Si Engines

Modern boosted spark-ignition (SI) engines and emerging advanced compression ignition (ACI) engines operate under conditions that deviate substantially from the conditions of conventional autoignition metrics, namely the research and motor octane numbers (RON and MON). The octane index (OI) is an emerging autoignition metric based on RON and MON which was developed to better describe fuel knock resistance over a broader range of engine conditions. Prior research at Oak Ridge National Laboratory (ORNL) identified that OI performs reasonably well under stoichiometric boosted conditions, but inconsistencies exist in the ability of OI to predict autoignition behavior under ACI strategies. Instead, the autoignition behavior under ACI operation was found to correlate more closely to fuel composition, suggesting fuel chemistry differences that are insensitive to the conditions of the RON and MON tests may become the dominant factor under these high efficiency operating conditions. This investigation builds on earlier work to study autoignition behavior over six pressure-temperature (PT) trajectories that correspond to a wide range of operating conditions, including boosted SI operation, partial fuel stratification (PFS), and spark-assisted compression ignition (SACI). A total of 12 different fuels were investigated, including the Co-Optima core fuels and five fuels that represent refinery-relevant blending streams. It was found that, for the ACI operating modes investigated here, the low temperature reactions dominate reactivity, similar to boosted SI operating conditions because their PT trajectories lay close to the RON trajectory. Additionally, the OI metric was found to adequately predict autoignition resistance over the PT domain, for the ACI conditions investigated here, and for fuels from different chemical families. This finding is in contrast with the prior study using a different type of ACI operation with different thermodynamic conditions, specifically a significantly higher temperature at the start of compression, illustrating that fuel response depends highly on the ACI strategy being used.

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Improvement Effect of Green Remodeling and Building Value Assessment Criteria for Aging Public Buildings

Energies ◽

10.3390/en14041200 ◽

2021 ◽

Vol 14 (4) ◽

pp. 1200

Author(s):

Yong-Joon Jun ◽

Seung-ho Ahn ◽

Kyung-Soon Park

Keyword(s):

High Efficiency ◽

Energy Performance ◽

Operating Conditions ◽

Energy Usage ◽

Public Buildings ◽

Value Judgment ◽

Relationship Analysis ◽

Improvement Effect ◽

The Relationship ◽

Usage Data

The Green Remodeling Project under South Korea’s Green New Deal policy is a government-led project intended to strengthen the performance sector directly correlated with energy performance among various elements of improvement applicable to building remodeling by replacing insulation materials, introducing new and renewable energy, introducing high-efficiency equipment, etc., with public buildings taking the lead in green remodeling in order to induce energy efficiency enhancement in private buildings. However, there is an ongoing policy that involves the application of a fragmentary value judgment criterion, i.e., whether to apply technical elements confined to the enhancement of the energy performance of target buildings and the prediction of improvement effects according thereto, thus resulting in the phenomenon of another important value criterion for green remodeling, i.e., the enhancement of the occupant (user) comfort performance of target buildings as one of its purposes, being neglected instead. In order to accurately grasp the current status of these problems and to promote ‘expansion of the value judgment criteria for green remodeling’ as an alternative, this study collected energy usage data of buildings actually used by public institutions and then conducted a total analysis. After that, the characteristics of energy usage were analyzed for each of the groups of buildings classified by year of completion, thereby carrying out an analysis of the correlation between the non-architectural elements affecting the actual energy usage and the actual energy usage data. The correlation between the improvement performance of each technical element and the actual improvement effect was also analyzed, thereby ascertaining the relationship between the direction of major policy strategies and the actual energy usage. As a result of the relationship analysis, it was confirmed that the actual energy usage is more affected by the operating conditions of the relevant building than the application of individual strategic elements such as the performance of the envelope insulation and the performance of the high-efficiency system. In addition, it was also confirmed that the usage of public buildings does not increase in proportion to their aging. The primary goal of reducing energy usage in target buildings can be achieved if public sector (government)-led green remodeling is pushed ahead with in accordance with biased value judgment criteria, just as in the case of a campaign to refrain from operating cooling facilities in aging public buildings. However, it was possible to grasp through the progress of this study that the remodeling may also result in the deterioration of environmental comfort and stability, such as the numerical value of the indoor thermal environment. The results of this study have the significance of providing basic data for pushing ahead with a green remodeling policy in which the value judgment criteria for aging existing public buildings are more expanded, and it is necessary to continue research in such a direction that the quantitative purpose of green remodeling, which is to reduce energy usage in aging public buildings, and its qualitative purpose, which is to enhance their environmental performance for occupants’ comfort, can be mutually balanced and secured at the same time.

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Dynamic Modeling of CATOFIN® Fixed-Bed Iso-Butane Dehydrogenation Reactor for Operational Optimization

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2015-0087 ◽

2016 ◽

Vol 14 (1) ◽

pp. 491-515 ◽

Cited By ~ 3

Author(s):

Zeeshan Nawaz

Keyword(s):

Coke Formation ◽

Fixed Bed ◽

Process Intensification ◽

Operating Conditions ◽

Catalytic Dehydrogenation ◽

Heating Rates ◽

Reactor Model ◽

Fuel Gas ◽

Bed Temperature ◽

Operational Optimization

AbstractThe catalytic dehydrogenation of iso-butane to iso-butylene is an equilibrium limited endothermic reaction and requires high temperature. The catalyst deactivates quickly, due to deposition of carbonaceous species and countered by periodic regeneration. The reaction-engineering constraints are tied up with operation and/or technology design features. CATOFIN® is a sophisticated commercialized technology for propane/iso-butane dehydrogenation using multiple adiabatic fixed-bed reactors having Cr2O3/Al2O3 as catalyst, that undergo cyclic operations (~18–30m); dehydrogenation, regeneration, evacuation, purging and reduction. It is always a concern, how to maintain CATOFIN® reactor at an optimum production, while overcoming gradual decrease of heat in catalyst bed and deactivation. A homogeneous one-dimensional dynamic reactor model for a commercial CATOFIN® fixed-bed iso-butane dehydrogenation reactor is developed in an equation oriented (EO) platform Aspen Custom Modeler (ACM), for operational optimization and process intensification. Both reaction and regeneration steps were modeled and results were validated. The model predicts the dynamic behavior and demonstrates the extent of catalyst utilization with operating conditions and time, coke formation and removal, etc. The model computes optimum catalyst bed temperature profiles, feed rate, pre-heating, rates for reaction and regeneration, fuel gas requirement, optimum catalyst amount, overall cycle time optimization, and suggest best operational philosophy.

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