Showing posts with label VISBREAKING. Show all posts
Showing posts with label VISBREAKING. Show all posts
Friday, September 16, 2016
Tuesday, October 22, 2013
Improvement of the LUKOIL Neftohim Burgas Visbreaker unit performance by optimisation of process conditions and application of chemical additive treatment programme
CATEGORY: VISBREAKERS
46th International Conference on Petroleum Processing, June 7, 2013, Bratislava, Slovak Republic
Improvement of the LUKOIL Neftohim Burgas Visbreaker unit performance by optimisation of process conditions and application of chemical additive treatment programme
A.Nedelchev, D. Stratiev, G. Stoilov, R. Dinkov, K. Lepidis, R. Sharpe, C. A. Russell, N. Petkova, P. Petkov
Nedelchev.Angel.D@neftochim.bg
Stratiev.Dicho@neftochim.bg
LUKOIL Neftohim Burgas JSC, Bulgaria, Burgas 8104,
Abstract
Nalco’s visbreaker optimisation program (Conversion Plus™ II) was implemented on the visbreaker unit at Lukoil Neftochim Burgas refinery, Bulgaria in 2011. The treatment package was specifically designed by coupling unique laboratory processability characteristics of visbreaker feed with actual unit operational observations. Laboratory processing of visbreaker feeds revealed unique profiles of intrinsic stability degradation and surface fouling with increasing severity. The technique also produced evidence for the effectiveness of chemical additive treatment to decrease surface coke formation, and therefore, increasing removal efficiency.
Transferal of intrinsic stability measurement to the real unit resulted in a dramatic improvement to process monitoring, allowing for a more sensitive measure of severity and therefore a relatively more rapid reaction to operational and feed changes. As a result, the bottleneck for unit throughput was then identified to be the feed inlet zone to the main fractionator, more specifically, the poor design of main distillation trays. The problem was somewhat alleviated by adding a refinery stream to improve the overall asphaltene solvency power of the feed, and by reducing the feed inlet temperature from 380 to 360 °C, with the benefits of the former demonstrated under laboratory conditions. The overall efficiency of the unit increased dramatically as a result of Nalco’s treatment program and the subsequent engineering alterations, with average annual conversion increasing from 14.8 to 16.2 % (products boiling below 360 °C), and unit turnaround time decreasing by nine days. The reduction in cleaning time for both reactor internals and heat exchangers are a direct parallel to laboratory observations when applying the feed specific chemical additive treatment. It is anticipated that a change of distillation tray design from valve to sieve type will further increase the performance of the visbreaker at Lukoil Neftochim Burgas refinery, Bulgaria.
The aim of this work is to discuss the results obtained at the Lukoil Neftochim Burgas, Bulgaria (LNB) VBU during application of the Nalco Conversion Plus II Program.
Free Full Text Source: http://www.vurup.sk/sites/vurup.sk/files/downloads/nedelchev_visbreaker_performance_improvement_by_application_of_chemical_treatment_program_and_optimization_of_process_conditions.pdf
46th International Conference on Petroleum Processing, June 7, 2013, Bratislava, Slovak Republic
Improvement of the LUKOIL Neftohim Burgas Visbreaker unit performance by optimisation of process conditions and application of chemical additive treatment programme
A.Nedelchev, D. Stratiev, G. Stoilov, R. Dinkov, K. Lepidis, R. Sharpe, C. A. Russell, N. Petkova, P. Petkov
Nedelchev.Angel.D@neftochim.bg
Stratiev.Dicho@neftochim.bg
LUKOIL Neftohim Burgas JSC, Bulgaria, Burgas 8104,
Abstract
Nalco’s visbreaker optimisation program (Conversion Plus™ II) was implemented on the visbreaker unit at Lukoil Neftochim Burgas refinery, Bulgaria in 2011. The treatment package was specifically designed by coupling unique laboratory processability characteristics of visbreaker feed with actual unit operational observations. Laboratory processing of visbreaker feeds revealed unique profiles of intrinsic stability degradation and surface fouling with increasing severity. The technique also produced evidence for the effectiveness of chemical additive treatment to decrease surface coke formation, and therefore, increasing removal efficiency.
Transferal of intrinsic stability measurement to the real unit resulted in a dramatic improvement to process monitoring, allowing for a more sensitive measure of severity and therefore a relatively more rapid reaction to operational and feed changes. As a result, the bottleneck for unit throughput was then identified to be the feed inlet zone to the main fractionator, more specifically, the poor design of main distillation trays. The problem was somewhat alleviated by adding a refinery stream to improve the overall asphaltene solvency power of the feed, and by reducing the feed inlet temperature from 380 to 360 °C, with the benefits of the former demonstrated under laboratory conditions. The overall efficiency of the unit increased dramatically as a result of Nalco’s treatment program and the subsequent engineering alterations, with average annual conversion increasing from 14.8 to 16.2 % (products boiling below 360 °C), and unit turnaround time decreasing by nine days. The reduction in cleaning time for both reactor internals and heat exchangers are a direct parallel to laboratory observations when applying the feed specific chemical additive treatment. It is anticipated that a change of distillation tray design from valve to sieve type will further increase the performance of the visbreaker at Lukoil Neftochim Burgas refinery, Bulgaria.
The aim of this work is to discuss the results obtained at the Lukoil Neftochim Burgas, Bulgaria (LNB) VBU during application of the Nalco Conversion Plus II Program.
Free Full Text Source: http://www.vurup.sk/sites/vurup.sk/files/downloads/nedelchev_visbreaker_performance_improvement_by_application_of_chemical_treatment_program_and_optimization_of_process_conditions.pdf
Monday, July 29, 2013
Optimization of Furnace Operation Conditions in an Industrial Visbreaking Process
CATEGORY: VISBREAKING
European Chemical Bulletin, Vol. 2, No. 3 (2013)
Optimization of Furnace Operation Conditions in an Industrial Visbreaking Process
Reza Seif Mohaddecy, Sepehr Sadighi
Abstract
Reports results of a study of the visbreaking unit of a Tehran refinery using simulation and a parametric sensitivity analysis to determine optimum temperature. Researchers employed a Petro-Sim simulator, which specializes in the simulation of refinery processes.
The simulator was validated using actual plant test runs. After tuning, the simulations provided errors less than 3%. Using the validated simulator the sensitivity of yield of fuel oil, gasoline and fuel oil viscosity with the variation of furnace temperature was studied. The validated simulator was used to optimize the unit operating conditions to obtain the desired product specifications.
Full Text Source (Subscription or Fee): http://www.eurchembull.com/index.php/ECB/article/view/259
Modeling of thermal cracking process in a crude oil refinery
CATEGORY: VISBREAKING
Journal of Petroleum and Gas Engineering, Vol. 4(4), pp. 81-90, April, 2013
Modeling of thermal cracking process in a crude oil refinery
Sepehr Sadighi and S. Reza. Seif Mohaddecy*
Project Manager, Catalysis and Nanotechnology Division, Catalytic Reaction Engineering Department, Research
Institute of Petroleum Industry (RIPI) Iran
In a thermal cracking process, the molecular bonds of the liquid are broken to the lighter ones. Recently due to the availability of more heavy oils, the process interest was to yield light and middle distillate products. In this research, thermal cracking of vacuum residue in a commercial soaker-visbreaking plant is studied. The product of the process is characterized to the light gas (C1, C2), liquefied petroleum gases (C3, C4), gasoline (IBP-180°C), gas oil (180 to 320°C) and fuel (320+°C). Then to model the visbreaking process, a six-lump kinetic network with fifteen reactions and thirty kinetic parameters is developed. In this model, visbreaking process is modeled as an equal distributed heater, and the soaker is modeled as a complete stirred tank reactor. After evaluating the rate of reactions by estimated kinetic parameters, it is confirmed that a reduced reaction network with seven reaction paths and fourteen kinetic parameters is reliable enough to simulate the performance of the reactor with the absolute average deviation ( AAD%) of 4.75%
The aim of this research is developing a simple yield predictor model, according to a six-lump reaction approach, to predict the most added value products consists of gas, LPG, gasoline, diesel and fuel oil in a commercial soaker unit. The main advantage of this work is presenting a simple approach for the commercial visbreaking process in which the temperature profile of the furnace is also included in the model.
Free Full Text Source: http://www.academicjournals.org/JPGE/PDF/pdf2013/Apr/Sadighi%20and%20Mohaddecy.pdf
Friday, January 11, 2013
Sensitivity analysis and determination of optimum temperature of furnace for commercial visbreaking unit
CATEGORY: VISBREAKING
Journal of Petroleum and Gas Engineering Vol. 3 (7), pp. 128-134, December 2012
DOI: 10.5897/JPGE11.002
Sensitivity analysis and determination of optimum temperature of furnace for commercial visbreaking unit
S. Reza Seif Mohaddecy*, Mehrdad Alibouri and Sepehr Sadighi
Catalytic Reaction Engineering Department, Catalysis and Nanotechnology Division, Research Institute of Petroleum Industry (RIPI), Iran.
Abstract
Authors describe simulation of the visbreaking unit of a Tehran refinery, after which a parametric sensitivity analysis was conducted to determin optimum temperature. They employed the Petro-Sim simulator, which specializes in the simulation of refinery processes. The simulator was validated using actual plant test runs and after tuning, the simulations provided errors less than 3%. Using the validated simulator the sensitivity of yield of fuel oil, gasoline and fuel oil viscosity with the variation of furnace temperature (reaction temperature) was investigated. The validated simulator was used to optimize the unit operating conditions to obtain the desired product specifications.
INTRODUCTION
Visbreaking appears like an alternative for the conversion or transportation of heavy crudes. It is a relatively mild thermal cracking process mainly used to reduce vacuum tower bottoms viscosities and pour points and to reduce the amount of cutting stock required for residue dilution to meet fuel oil specifications (Benito et al., 1995; Kataria et al., 2004; Wiehe, 2008). Heavy fuel oil production can be reduced from 20 to 35% and cutter stock for dilution by 20 to 30% by visbreaking. This increases the yield of more valuable distillates directly converted from visbreaking or used as catalytic cracker feedstocks. In a refinery, this one process allows the production of fuel oil and feed for the catalytic cracking units (Joshi et al., 2008) (Upgradin Process of Heavy Oil, Japan Corporation Center, Petroleum (JCCP) Seminar, Technical Training Course, June, 2005).
The aim of this research is developing a simple yield predictor model, according to a process simulation; to predict the most added value products consists of gas, LPG, gasoline, diesel and visbroken fuel oil in a commercial soaker unit. The main advantage of this work is investigation of influence of operation conditions on the products yield such as fuel oil and gasoline.
Free Full Text Source: http://www.academicjournals.org/JPGE/PDF/pdf2012/Dec/Mohaddecy%20et%20al.pdf
Journal of Petroleum and Gas Engineering Vol. 3 (7), pp. 128-134, December 2012
DOI: 10.5897/JPGE11.002
Sensitivity analysis and determination of optimum temperature of furnace for commercial visbreaking unit
S. Reza Seif Mohaddecy*, Mehrdad Alibouri and Sepehr Sadighi
Catalytic Reaction Engineering Department, Catalysis and Nanotechnology Division, Research Institute of Petroleum Industry (RIPI), Iran.
Abstract
Authors describe simulation of the visbreaking unit of a Tehran refinery, after which a parametric sensitivity analysis was conducted to determin optimum temperature. They employed the Petro-Sim simulator, which specializes in the simulation of refinery processes. The simulator was validated using actual plant test runs and after tuning, the simulations provided errors less than 3%. Using the validated simulator the sensitivity of yield of fuel oil, gasoline and fuel oil viscosity with the variation of furnace temperature (reaction temperature) was investigated. The validated simulator was used to optimize the unit operating conditions to obtain the desired product specifications.
INTRODUCTION
Visbreaking appears like an alternative for the conversion or transportation of heavy crudes. It is a relatively mild thermal cracking process mainly used to reduce vacuum tower bottoms viscosities and pour points and to reduce the amount of cutting stock required for residue dilution to meet fuel oil specifications (Benito et al., 1995; Kataria et al., 2004; Wiehe, 2008). Heavy fuel oil production can be reduced from 20 to 35% and cutter stock for dilution by 20 to 30% by visbreaking. This increases the yield of more valuable distillates directly converted from visbreaking or used as catalytic cracker feedstocks. In a refinery, this one process allows the production of fuel oil and feed for the catalytic cracking units (Joshi et al., 2008) (Upgradin Process of Heavy Oil, Japan Corporation Center, Petroleum (JCCP) Seminar, Technical Training Course, June, 2005).
The aim of this research is developing a simple yield predictor model, according to a process simulation; to predict the most added value products consists of gas, LPG, gasoline, diesel and visbroken fuel oil in a commercial soaker unit. The main advantage of this work is investigation of influence of operation conditions on the products yield such as fuel oil and gasoline.
Free Full Text Source: http://www.academicjournals.org/JPGE/PDF/pdf2012/Dec/Mohaddecy%20et%20al.pdf
Tuesday, November 13, 2012
Fault detection and isolation of Visbreaker unit in oil refinery using multistage Gath-Geva clustering
CATEGORY: VISBREAKER
2012 20th Iranian Conference on Electrical Engineering (ICEE), 15-17 May 2012, Page(s): 1018 - 1022
Fault detection and isolation of Visbreaker unit in oil refinery using multistage Gath-Geva clustering
Mokhtare, M., Hekmati Vahed, S. ; Aliyari Shoorehdeli, M. ; Fatehi, A.
Dept. of Mechatron., Sci. & Res. Branch, Islamic Azad Univ., Tehran, Iran
Abstract
Authors show that Fault Detection and Isolation (FDI) is a pattern classification problem which can be solved using clustering techniques. They use Gath-Geva clustering (GGC) as optimal form by a performance assessment rule for fault detection, while using multistage Gath-Geva clustering fault isolation.
Because a Visbreaker unit is a large scale process, they also propose a novel hybrid method on the basis of Principle Component Analysis and Genetic Algorithm optimization in order to cope with the problem of dimensionality and complexity of computation problems. The proposed FDI approaches have been evaluated using experimental Visbreaker process unit data collected in an oil refinery.
Full Text Source (Subscription or Fee): http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6292502&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D6292502
2012 20th Iranian Conference on Electrical Engineering (ICEE), 15-17 May 2012, Page(s): 1018 - 1022
Fault detection and isolation of Visbreaker unit in oil refinery using multistage Gath-Geva clustering
Mokhtare, M., Hekmati Vahed, S. ; Aliyari Shoorehdeli, M. ; Fatehi, A.
Dept. of Mechatron., Sci. & Res. Branch, Islamic Azad Univ., Tehran, Iran
Abstract
Authors show that Fault Detection and Isolation (FDI) is a pattern classification problem which can be solved using clustering techniques. They use Gath-Geva clustering (GGC) as optimal form by a performance assessment rule for fault detection, while using multistage Gath-Geva clustering fault isolation.
Because a Visbreaker unit is a large scale process, they also propose a novel hybrid method on the basis of Principle Component Analysis and Genetic Algorithm optimization in order to cope with the problem of dimensionality and complexity of computation problems. The proposed FDI approaches have been evaluated using experimental Visbreaker process unit data collected in an oil refinery.
Full Text Source (Subscription or Fee): http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6292502&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D6292502
Thursday, July 19, 2012
Head Pressure minimization of a Visbreaking column through an advanced PID controllers architecture
IFAC Conference on Advances in PID Control PID'12, Brescia (Italy), March 28-30, 2012
S.M. Zanoli*, D. Barchiesi*, G. Astolfi*
*D.I.I, Università Politecnica delle Marche, Ancona, Italy
Abstract:
INTRODUCTION
Visbreaking is a non-catalytic thermal process that converts atmospheric or vacuum residues via thermal cracking to gas, naphtha, distillates, and visbroken residue. Atmospheric and vacuum residues are typically charged to a visbreaker to reduce fuel oil viscosity and increase distillate yield in the refiner. The process name of "visbreaking" refers to the fact that the process reduces (i.e. breaks) the viscosity of the residual oil.
The objectives of visbreaking are to:
• Reduce the viscosity of the feed stream: typically this is the residue from either the refinery's atmospheric or vacuum distillation of crude oil but can also be used to reduce the viscosity of oils produced in the processing of tar sands, certain high viscosity crude oils and other high viscosity oils.
• Reduce the amount of endproduct residual fuel oil produced by a refinery: Residual fuel oil is generally regarded as a low value product.
• Increase the proportion of middle distillates in the refinery output: middle distillates are used as a diluent with residual oils to bring their viscosity down to a marketable level. By reducing the viscosity of the residual stream in a visbreaker, a fuel oil can be made using less diluent and the middle distillate saved can be diverted to higher value diesel or heating oil manufacture.
Basically, a visbreaker thermally cracks large hydrocarbon molecules into smaller molecules by heating residuals oil thus reducing its viscosity. Typically the feed stream is the residue from either the refinery's atmospheric or vacuum distillation of crude oil but can also be oils produced in the processing of tar sands, certain high viscosity crude oils and other high viscosity oils. Visbreaker produces naphtha and fuel oils as well as refinery fuel gas (see Figure 1).
There are two types of visbreaking technology that are commercially available: the ‘coil’ or ‘furnace’ type and the ‘soaker’ process. In the coil process, conversion is achieved by high temperature cracking for a predetermined, relatively short period of time in the heater. In the soaker process, which is a low temperature/high residence time process, the majority of conversion occurs in a reaction vessel or soaker drum, where the two-phase heater effluent is held at a lower temperature for a longer period of time. In this work a soaker visbreaking column of a refinement plant has been considered. The scope of this unit is the production of gas, gasoline, kerosene, Light GasOil (LGO)
Free Full Text Full Text Source (Subscription or Fee): http://www.nt.ntnu.no/users/skoge/prost/proceedings/PID-12/papers/0087.pdf
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