Mathematical Model of Steam Reforming in the Anode Channel of a Molten Carbonate Fuel Cell

The paper presents a mathematical model of a molten carbonate fuel cell with a catalyst in the anode channel. The modeled system is fueled by methane. The system includes a model of the steam reforming process occurring in the anode channel of the MCFC fuel cell and the model of the cell itself. A reduced order model was used to describe the operation of the molten carbonate fuel cell, whereas a kinetic model describes the methane steam reforming. The calculations of the reforming were done in Aspen HYSYS software. Four values of the steam-to-carbon ratio (2.0, 2.5, 3.0, and 3.5) were used to analyze the performance of the reforming process. In the first phase, the reaction kinetics model was based on data from the literature.

Produksi Gas Sintesis Dari Batubara Peringkat Rendah Indonesia Serta Optimasi dan Simulasi Menggunakan Aspen Hysys

Batubara merupakan salah satu potensi sumber energi yang menggantikan minyak bumi sebagai sumber energi dan bahan baku untuk industri kimia di indonesia. Sekarang ini, sumber batubara di indonesia diestimasikan mencapai 61 juta ton dan 80% dari itu adalah batu bara peringkat rendah (low rank coal). Permasalahan pada penelitian ini ialah untuk mengetahui bagaimana pengaruh dari beberapa faktor seperti temperatur, tekanan, serta aliran massa terhadap syngas yang dihasilkan. Selain itu yang ingin diketahui dari penelitian ini ialah untuk menentukan berapa energi yang dapat dihasilkan dari produksi syngas terhadap energi yang diperlukan dalam proses gasifikasi. Proses gasifikasi batubara untuk menghasilkan syngas yang baik memerlukan kondisi dari berbagai parameter tersebut sehingga optimasi sistem gasifikasi perlu dilakukan untuk menghasilkan syngas dengan kualitas yang baik. Syngas yang baik dapat diketahui dari nilai rasio H2 dan CO yang dapat diatur dengan mengubah parameter reaksi. Model yang digunakan pada penelitian ini telah dirancang dengan menggunakan 2 komponen reaktor untuk menjalankan reaksi gasifikasi serta didorong oleh berbagai komponen pendukung seperti kompresor. Metode optimasi yang dilakukan ialah dengan melakukan variasi nilai dari setiap parameter yang ada didalam pemodelan yang dirancang dengan 3 sampel berbeda dengan kode sampel CQ004, CQ005, dan CQ008. Penentuan jumlah energi yang dihasilkan dapat diketahui dengan mengasumsikan produk syngas tersebut digunakan sebagai bahan bakar dengan reaksi pembakaran sehingga dapat diketahui berapakah energi yang diperoleh dari produk syngas tersebut dan akan dibandingkan dengan nilai energi yang diperlukan dalam produksi.

Simulation of Organic Liquid Products Deoxygenation by Multistage Countercurrent Absorber/Stripping Using CO2 as Solvent with Aspen-HYSYS: Process Modeling and Simulation

In this work, the deoxygenation of organic liquid products (OLP) obtained by thermal catalytic cracking of palm oil at 450 °C, 1.0 atmosphere, with 10% (wt.) Na2CO3 as catalyst, in multistage countercurrent absorber columns using supercritical carbon dioxide (SC-CO2) as solvent, with Aspen-HYSYS process simulator was systematically investigated. In a previous study, the thermodynamic data basis and EOS modeling necessary to simulate the deoxygenation of OLP has been presented [Molecules 2021, 26, 4382. https://doi.org/10.3390/molecules26144382]. This work address a new flowsheet, consisting of 03 absorber columns, 10 expansions valves, 10 flash drums, 08 heat exchanges, 01 pressure pump, and 02 make-up of CO2, aiming to improve the deacidification of OLP. The simulation was performed at 333 K, 140 bar, and (S/F) = 17; 350 K, 140 bar, and (S/F) = 38; 333 K, 140 bar, and (S/F) = 25. The simulation shows that 81.49% of OLP could be recovered and the concentrations of hydrocarbons in the extracts of absorber-01 and absorber-02 were 96.95 and 92.78% (wt.) in solvent-free basis, while the bottom stream of absorber-03 was enriched in oxygenates compounds with concentrations up to 32.66% (wt.) in solvent-free basis, showing that organic liquid products (OLP) was deacidified and SC-CO2 was able to deacidify OLP and to obtain fractions with lower olefins content. The best deacidifying conditions was obtained at 333 K, 140 bar, and (S/F) = 17.

Flare Gas Recovery from an Existing Oil Plant using Gas Compressors

Global warming is nowadays one of the main and important issues. As the increase in the concentration of carbon dioxide and other greenhouse gases in the atmosphere as a result of the combustion of these gases causes such phenomena. Therefore, oil and gas plants need to be constantly reviewed over time to maintain high performance and operability, especially while changing feed composition and rate to meet standard product specifications. The aim of this study is to study the effect of flare gases recovery using gas compressors on the economic and environmental performance of an existing oilfield plant. A commercial simulation program aspen HYSYS Version 11 was used. The Kalabsha Central Processing Facility (KCPF) in the Western Desert of Egypt is the studied plant. This plant handles 30 million standard cubic feet per day (MMSCFD) from free water knock out drum and 1.6 MMSCFD of gases from heaters. 20 MMSCFD from gas is charged to the gas pipeline and 10 MMSCFD is sent to the flare with the 1.6 MMSCFD. It is proposed to install gas compressors to capture the gases from the free water knock out drum and heaters before sending them to the flare. Such technology can be used as a guide in upgrading existing and new oil and gas plants to reduce gas flaring. In addition, environmental protection also adds more economic profits from burning the recovered gas besides increasing the life of the flare equipment.

Techno Commercial Analysis of Liquefied Petroleum Gas Recovery From Natural Gas Using Aspen HYSYS

Liquefied petroleum gas is an alternative, relatively clean and a supreme source of energy, which is being used as a key component in the global energy supply. The international trade agreements and the chemical and non-chemical demand of liquefied petroleum gas with the increase in the world’s population have brought its production from the processing of natural gas to the limelight. During its processing, a variety of different components are extracted from it, including methane and ethane which remains in the bulk as natural gas. The objective of this research work is to find the capability of investigating the liquefied petroleum gas recovery performance to make the process economical by saving the processing cost and energy. The novelty of this work is to deal with the design and simulation of a liquefied petroleum gas plant using Aspen HYSYS. To make this process energy efficient and economical, different schemes of process alternatives were applied by reducing the sizes of the exchanger and other pieces of equipment. Three cases are studied in which feed is precooled by rerouting the stream and/or by repositioning of the chiller for the recovery of liquefied petroleum gas from natural gas by analyzing their cost and process parameters. The modelling and simulation base case and three different case studies are realized in Aspen HYSYS. It has been observed that case study 2 results in about 10% increase in LPG production where the chiller is repositioned in the separation section of the LPG production flowsheet. Case study 3 shows a maximum decrease in hot side utilities in the flowsheet of about 20% while 10 and 14% decreases are observed for case studies 1 and 2, respectively. Furthermore, economic analysis indicates about 18 and 22% in the capital cost for case studies 2 and 3, respectively, due to the lower size of process units. The outcome of this investigation is to present plenty of suggestions to improve the process efficiency and minimize the requirement to over design the plant components.

Ammonia converter Simulation and Optimization Based on an Innovative Correlation for (KP) Prediction

In this paper, the simulation and optimization of an industrial ammonia synthesis reactor is illustrated. The converter under study is of a vertical design, equipped with three radial-flow catalyst beds with inter-stage cooling and two quenching points. For building the model, a modified kinetic equation of ammonia synthesis reaction, based on Temkin- Pyzhev equation and an innovative correlation for (KP) prediction, was developed in suitable form for the implementation in Aspen HYSYS plug flow reactor using the spreadsheet embedded in the software with the introduction of some invented simulation techniques. A new parameter, which is a function of (T, P and α), was introduced into the reaction rate equation to account for the variation of KP with pressure. The simulation model is able to describe the converter behavior with acceptable accuracy. A case study was done, using Aspen HYSYS Optimizer, illustrated the optimum reactor temperature profile, after 12 years of operation, to achieve maximum production. The result predicts an increase of 8 tons ammonia per day accompanied with an increase of steam production of 12 tons per day.

Comparative Techno-Economic Analysis of Carbon Capture Processes: Pre-Combustion, Post-Combustion, and Oxy-Fuel Combustion Operations

Evaluation of economic aspects is one of the main milestones that affect taking rapid actions in dealing with GHGs mitigation; in particular, avoiding CO2 emissions from large source points, such as power plants. In the present study, three kinds of capturing solutions for coal power plants as the most common source of electricity generation have been studied from technical and economic standpoints. Aspen HYSYS (ver.11) has been used to simulate the overall processes, calculate the battery limit, and assess required equipment. The Taylor scoring method has been utilized to calculate the costliness indexes, assessing the capital and investment costs of a 230 MW power plant using anthracite coal with and without post-combustion, pre-combustion, and oxy-fuel combustion CO2 capture technologies. Comparing the costs and the levelized cost of electricity, it was found that pre-combustion is more costly, to the extent that the total investment for it is approximately 1.6 times higher than the oxy-fuel process. Finally, post-combustion, in terms of maturity and cost-effectiveness, seems to be more attractive, since the capital cost and indirect costs are less. Most importantly, this can be applied to the existing plants without major disruption to the current operation of the plants.

Algorithm and software for the optimal technological design of a system of simple distillation columns

Objectives. The formalized problem of the optimal design of distillation column systems belongs to the class of mixed integer nonlinear program problems. Discrete search variables are the number of trays in the rectifying and stripping sections of columns, whereas the continuous ones are the operating modes of columns. This study aimed to develop an algorithm and a software package for the optimal technological design of a system of simple distillation columns based on the criterion of total reduced capital and energy costs using rigorous mathematical distillation models.Methods. The solution to this problem is based on the branch and bound method. A computer model of the distillation column system was developed in the environment of the Aspen Hysys software package. The Inside–Out module was used as the distillation model. The developed algorithm is implemented in the software environment of the Matlab mathematical package. To solve the conditional optimization problem, a sequential quadratic programming method-based model was used. The interaction between software add-ins in Matlab and Aspen Hysys is implemented using a Component Object Model interface.Results. Approaches to obtain the lower and upper bounds of the optimality criterion and the branching method for the implementation of the branch and bound method have been developed. In addition, an algorithm for the optimal design of a distillation column of a given topology based on the branch and bound method has been developed. Furthermore, using Matlab, a software package that implements the developed algorithm and is integrated with the universal modeling software AspenHysys has been created.Conclusions. An algorithm and a software package have been developed and implemented that allows automating the design process of distillation column systems and integration with advanced mathematical programming packages, respectively. The performance of the algorithm and software package has been evaluated using the optimal design of the debutanization column as an example.

Evaluación de arcillas pilareadas impregnadas con Fe/Mo para la obtención de acetaldehído a partir de etanol en un reactor de lecho fijo

El presente trabajo de investigación tiene como objetivo, preparar una bentonita pilareada con hierro, para ser utilizado como soporte catalítico, impregnada con Fe/Mocomo fase activa del catalizador para la obtención de acetaldehído a partir de etanol en un reactor de lecho fijo. El catalizador de hierro, molibdeno soportado en montmorillonita(Fe/Mo-Mt) se sintetizó de acuerdo al procedimiento recomendado por Qiuqiang, Wu, Li, Zhu, & Dang (2009). En primer lugar, se consideró la relación Fe/Mo = 1.5. Este producto se desarrolló como un catalizador estructurado en piedra pómez para luego hacer las pruebas experimentales en un reactor catalítico de lecho fijo el cual consta de un evaporador, un precalentador un reactor, un condensador y una trampa. Las variables a controlar fueron la temperatura del reactor y el flujo de aire. La evaluación de los parámetros termodinámicos, así como, el balance de materia y energía en el reactor catalítico de lecho fijo, se han realizado mediante el Aspen Hysys, versión 8.4. Se obtuvo acetaldehído a partir de etanol, en un reactor catalítico de lecho fijo, a una temperatura en el precalentador de 250 °C y de 300 °C en el reactor, en donde la primera fracción de la mezcla alcanzó la temperatura de 47.6 °C, y que de acuerdo al diagrama de equilibrio líquido-vapor determinado mediante el método de contribución de grupos UNIFAC la composición correspondeal 0.55 fracción molar del acetaldehído.