Alkasem A.,Abu Dhabi Gas Industries Ltd. GASCO |
Al Zarouni Y.A.,Abu Dhabi Gas Industries Ltd. GASCO |
Slagle J.C.,Bryan Research and Engineering |
Berrouk A.S.,Petroleum Institute |
Satyadileep D.,Petroleum Institute
Society of Petroleum Engineers - Abu Dhabi International Petroleum Exhibition and Conference, ADIPEC 2015 | Year: 2015
As part of its ongoing optimization effort, Abu Dhabi Gas Industries (GASCO) is working with the Petroleum Institute (PI) and Bryan Research and Engineering Inc. (BR&E) to identify opportunities for optimization of the Habshan II amine sweetening unit for a wide range of gas throughput. In a previous study, ProMax®, a process simulation package, was first verified by comparing the model results to operating data for about 300 days and was then used to optimize the facility operating near maximum capacity. Recently, most of the gas has been diverted to another facility resulting in Habshan II operating in the 30-40% capacity range. In the present study, ProMax, is used to re-optimize the facility at the current low throughput. The model results for the new optimum are implemented in the plant and compared to operating data to confirm the predictions. In addition, the plant plans to increase throughput in the coming months. Therefore, the plant has been optimized at various gas flowrates to provide operators with set points at any given gas flowrate. In addition to preparing operators for throughput fluctuations, the results show a reduction of operating costs that amount to roughly 800,000 USD/yr. Copyright 2015, Society of Petroleum Engineers.
Bullin J.A.,Bryan Research and Engineering |
Fitz C.,Bryan Research and Engineering |
Dustman T.,Questar Pipeline Company
GPA Annual Convention Proceedings | Year: 2011
To avoid hydrocarbon liquid dropout in gas transmission lines, most current operating specifications require that the lines be operated above the hydrocarbon dew point (HDP) or cricondentherm hydrocarbon dew point. The GPA Project No. 081 was carried out to determine a practical hydrocarbon dew point specification allowing small amounts of liquids that have no significant impact on operations. Results from the project showed that 0.002 gal of liquid/thousand scf of gas has a negligible effect on pressure drop and should not disrupt pipeline operations. Calculation of an accurate HDP from a GC analysis may be useful but is highly dependent on the characterization of the heavy fraction. An empirical method has been developed to predict the C6, C7, C8, C9 and heavier composition when only a lumped C6+ fraction characterization is available. This is an abstract of a paper presented at the 90th Annual Convention of the GPA (San Antonio, TX 4/3-6/2011).
Addington L.,Bryan Research and Engineering |
Ness C.,Bryan Research and Engineering
GPA Annual Convention Proceedings | Year: 2010
Several "rules of thumb" used in the design and operation of amine sweetening units are described and their usefulness and necessity were evaluated using parametric studies with a steady-state process simulator. The rules evaluated include the 5°C temperature approach in the absorber, the 0.12 kg/L specification for reboiler steam, the 99°C lean/rich exchanger outlet temperature, and the regenerator pressure/reboiler temperature guideline. The four rules showed some flexibility and potential benefits if modified slightly. Each should be considered as a starting point, a first guess. None of four rules represented optimum conditions for all cases. This is an abstract of a paper presented at the 89th Annual Convention of the Gas Processors Association (Austin, TX 3/21-24/2010).
Martinis J.,Bryan Research and Engineering |
Froment G.F.,Texas A&M University
11AIChE - 2011 AIChE Spring Meeting and 7th Global Congress on Process Safety, Conference Proceedings | Year: 2011
A deterministic approach to molecular reconstruction of VGO was combined with single-event kinetics in the simulation of a hydrocracking process unit targeting maximum diesel production. Three different process flow configurations combining pre-treatment, reaction, fractionation, and recycle were studied. At the core of the simulation model, a computer-generated reaction network consisting of 126 million elementary steps and 18 million species described the chemistry of hydrocracking. Rate parameters of the elementary steps were modeled by the Single-Event concept, thus reducing the number of model parameters to be determined from plant data to a realistic level. A rigorous model for trickle-flow in packed-bed reactors was validated for extreme limiting conditions, e.g., local hydrogen depletion and transition to complete vaporization. This is an abstract of a paper presented at the 2011 AIChE Spring Meeting & 7th Global Congress on Process Safety (Chicago, IL 3/13-17/2011).
Addinqton L.,Bryan Research and Engineering |
Ness C.,Bryan Research and Engineering
Hydrocarbon Engineering | Year: 2010
An evaluation of general rules of thumb in amine sweetening unit design and operation is presented. An MDEA regenerator with a constant rich loading was modeled with varying system pressures. The lean quality was set and the reboiler duty was allowed to float. It is most evident for monoethanolamine (MEA) and diethanolamine (DEA) while methyldiethanolamine (MDEA) shows smaller gains, though still quite large on a percentage basis. TEA exhibited similar behavior to MDEA. The benefits also depend very much on the rich feed temperature and the amount of sensible heat required elevating the amine to reboiler temperature. The second model is based on optimal set points, which violate some rules of thumb. A thorough evaluation should be performed to optimize performance, minimize costs, and the benefits of deviating from these guidelines should be weighed against the risks.
Zhang T.,Texas A&M University |
Zhang T.,China University of Petroleum - Beijing |
Leyva C.,Texas A&M University |
Leyva C.,Research Center en Ciencia Applicada y Tecnologia Avancada |
And 2 more authors.
Industrial and Engineering Chemistry Research | Year: 2014
A bench-scale experimental unit based on a Robinson-Mahoney reactor with completely mixed gas and liquid phases was used to study the hydrocracking of a light vacuum gas oil on two base metal sulfide containing acid catalysts, characterized by their textural properties, NH3-TPD and pyridine-adsorbed Fourier-transformed infrared (Py-FTIR) acidity. The reactor effluent was analyzed in great detail by means of online gas chromatography and gas chromatography-mass spectrometry which evidenced the role of the catalyst acidity. The detailed analysis allowed the reaction scheme to be expressed at the level required by the kinetic analysis in terms of the fundamental Single Event Kinetics approach and thus drastically reduce the number of independent kinetic parameters to be determined from the experimental data. Reactor simulations illustrate the detailed predictions made possible by this approach. © 2014 American Chemical Society.
Davila G. Y.O.,Pdvsa |
Martinis C. J.M.,Pdvsa |
Martinis C. J.M.,Bryan Research and Engineering
Industrial and Engineering Chemistry Research | Year: 2011
A method based on graph theory has been formulated to estimate some key thermochemical properties commonly utilized in modeling acid-catalyzed transformations of hydrocarbons at the elementary step level. Presently, modeling techniques for these transformations frequently convey the computer-aided generation of reaction networks involving a very large number of molecules and intermediate species such as carbenium ions. Although quantum mechanical calculations have been widely used to estimate thermodynamic properties of carbenium ions accurately, the current performance of such techniques is yet insufficient for very large sets of species. The proposed method handles this problem by simply analyzing the connectivity of the carbon atoms within a molecule, which is less demanding from a computational point of view. Thus, it is possible to obtain information on the contributions from different structural groups and their indistinguishability, making property estimation straightforward. This work presents a set of rules for calculating the symmetry numbers of hydrocarbons with up to 2 rings, and Benson-like structural contribution groups for estimating the enthalpy of carbenium ions. © 2011 American Chemical Society.
Martinis J.M.,Bryan Research and Engineering
12AIChE - 2012 AIChE Spring Meeting and 8th Global Congress on Process Safety, Conference Proceedings | Year: 2012
A series of algorithms were formulated to solve the formidable problem of generating detailed reaction networks for a given set of species following well-established rules governing the underlying chemistry of the process. In the particular case of hydroprocessing, computer science fundamentals, e.g., object-orientation, functional programming, and recursive operations, on relational sets are applied to generate consistent reaction networks starting from the fundamentals of transition-metal catalysis and carbenium ion chemistry. As a result, reaction networks at the elementary step level are generated for catalytic reforming, hydroisomerization, hydrodewaxing, and hydrocracking. This is an abstract of a paper presented at the 2012 AIChE Spring Meeting and 8th Global Congress on Process Safety (Houston, TX 4/1-5/2012).
Burr B.L.,Bryan Research and Engineering |
Georgeson A.M.,Bryan Research and Engineering |
Mach K.,Chesapeake Energy Co.
Proceedings, Annual Convention - Gas Processors Association | Year: 2014
Hydrocarbon processing systems and storage tanks are a significant source of volatile organic compound (VOC) emissions in the United States. Emissions rates from process units and tanks have historically been calculated individually for permit applications and at a single operating point once design engineering is complete. Now with EPA's new NSPS OOOO rule, operating companies must perform far more VOC emissions calculations than ever before to comply with increased reporting requirements. With more focus on the quantities emitted and possible control alternatives, there is more interest in using the emission calculation methods during the oil and gas production site design stage. More sophisticated modeling systems using chemical process simulators permit more accurate emissions estimation over a wider range of conditions and configurations. Recent advances in simulation interface technology permit automation of these modeling tasks for more efficient enterprise-wide reporting.
Martinis J.,Bryan Research and Engineering |
Froment G.F.,Texas A&M University
10AIChE - 2010 AIChE Spring Meeting and 6th Global Congress on Process Safety | Year: 2010
A 19 KBPD commercial catalytic reforming unit using a 4-bed stacked reactor for the production of BTX was simulated. The underlying chemistry of catalytic reforming on noble metal-loaded acid catalysts was modeled by means of a computer-generated reaction network consisting of 50,000+ elementary steps and containing 4700 species within the C1-C10 carbon range. The Single-Event Kinetics approach allowed the reduction in the number of independent kinetic parameters to 44. Material and Energy conservation equations were applied to formulate a model for the radial flow of species in a packed-bed adiabatic reactor. The resulting model also accounted for pore diffusion limitations and catalyst deactivation by coke formation. Equilibration of fast elementary steps such as alkene (de)protonations and methyl-/Ethyl-shifts led to a reduction in the number of non-intermediate species from 326 pure species to 68 groups of isomeric species in equilibrium, making the resulting number of compound species suitable for process simulation purposes. Molecular reconstruction of naphtha cuts by group contributions from typical operational follow-up data such as specific gravity, C/H elemental analysis, and GC simulated distillation was applied to predict the most likely composition of the feedstock. By their very essence, the Single-Event Kinetic parameters were invariant from the naphtha composition. This enabled a series of simulations for different blends from a pool of 62 naphtha cuts aiming to maximum Hydrogen and BTX production. This is an abstract of a paper presented at the AIChE 2010 Spring National Meeting (San Antonio, TX 3/21-25/2010).