Process Simulation Tools Research Articles

Process simulation and optimization of oxygen enriched combustion using thin polymeric membranes: effect of thickness and temperature dependent physical aging

AbstractBACKGROUNDLimited work has been available to model thickness and temperature dependent physical aging encountered in polymeric membranes for gas separation to provide physically intuitive interpretation underlying the process. The Tait equation of states has been integrated within conventional dual mode mathematical model to characterize the physical aging mechanism, whereby the model requires merely temperature dependent parameters. Subsequently, the Tait‐dual mode mechanism model has been incorporated within a succession of states methodology that quantifies transport mechanism in a countercurrent hollow fiber membrane. Finally, the developed mathematical model has been implemented in Aspen HYSYS to constitute an oxygen enrichment plant.RESULTSThe simulation model has been validated with experimental observation with an acceptable error of < 6.5%. The process simulation tool has been used to evaluate the separation performance of oxygen enrichment plant using polymeric membrane with consideration of operating temperature (35–55 °C) and thickness dependent (400–1000 nm) physical aging. It is found that the optimal membrane design that generates highest profitability with physical aging consideration is at film thickness of ∼400 nm and operating temperature of 55 °C. Under such operating condition, the deviation between ideal and non‐ideal simulation model is also the smallest at ∼6%, which implies that physical aging has the least impact to the operability of the plant.CONCLUSIONThe developed simulation model has the potential to be applied for complex membrane system design (multiple membranes or hybrid system), scale up and optimization study that is essentially required for industrial scale application. © 2019 Society of Chemical Industry

Analysis of germanium-doped silicon vertical PN junction optical phase shifter

In this paper, the performance of a germanium-doped silicon optical phase shifter with vertical PN junction has been investigated. The proposed phase shifter is simulated using a process simulation tool, and 2D carrier distribution has been used to calculate the phase shifter performance metrics. The designed phase shifter is integrated into a Mach–Zehnder interferometer structure, and the transfer characteristics are plotted. The proposed phase shifter has a phase shift of ∼141°/mm, VπLπ of ∼0.64 V·cm, insertion loss of ∼1.23 dB, and 3 dB bandwidth of ∼37 GHz at 5 V reverse bias.

Novel AGR-EOR Compression Integration for Process Optimization

Summary In this work we aim to enhance the sour-gas loading in acid-gas removal (AGR) systems, maximizing oil-production rate at the tertiary phase and enhanced oil recovery (EOR), and mitigating vented carbon dioxide (CO2) with minimal modification to the existing systems. We conducted a simulation study on the basis of a real natural-gas liquids (NGLs) plant and Qatari oil wells with a 390-MMscf/D feed of sour gas using HYSYS and ProMax process simulation tools to evaluate the novel configurations compared with a conventional AGR system. The results show that the acid-gas loading improved from 0.48 to 0.81, and the amine circulation rate decreased by 40%, while maintaining the treated-gas quality specifications (4 ppm H2S, 1 mol% CO2). The required CO2 compression power for CO2-EOR decreased by 15.49%, and the oil production was enhanced by 1,360 B/D. In addition, 13.6 MMscf/D of CO2 is mitigated and used rather than vented.

Analysis of a process simulated graded-index strained silicon-germanium optical phase shifter

This paper analyzes the effect of germanium doping on the performance of an optical PN phase shifter in silicon photonics platform. The fabrication process flow is defined using a 2D process simulation tool to create the phase shifter structure. The mode, material, and loss parameters of the designed phase shifter are calculated and the performance is compared with a silicon phase shifter. A 1.84× higher phase shift, 1.27× lower absorption, and 1.50× lower insertion loss is obtained for the silicon-germanium phase shifter compared to silicon.

Usability and Usefulness of Non-Conventional Building Performance Simulation Tools in Architectural Design Processes

Simulation tools have been suggested to have the potential to support the design of high-performance buildings. However, sophisticated simulation environments are frequently utilized in the later stages of building planning. This might be due, in part, to the lack of sufficient and reliable input data during the early stages of design. Moreover, advanced tools appear to be geared toward consultants and specialists (expert users) rather than primary building designers. In recent years, tools in the CAD and BIM areas have introduced new features for parametric design and interfaces to different calculation and simulation engines. If properly deployed, such tools could offer effective early-design performance evaluation support, for instance via pre-rationalization of building forms and morphologies. Surprisingly, few studies have assessed the usefulness and usability of these new opportunities. In this context, the present contribution documents the background, method, and results of a tool potential assessment study regarding two specific environments, namely Ladybug and Honeybee. These are plugins for the parametrization environment grasshopper. The outcome of this effort provides not only a specific snapshot of the standing of these tools in the context of realistic performance assessment scenarios, but provides also a detailed framework for future critical evaluation of the usability and usefulness of computational solutions for early stage design optimization.

Data Exchange for Process Engineering – Challenges and Opportunities

AbstractThe ideas and requirements for digitization in the process industry are manifold – the interoperability of the tools in use by engineers is an important prerequisite. The strong heterogeneity of existing data formats and standards as well as the variety of proprietary and company‐specific solutions confronts the process industry with huge challenges. This paper deals with the data exchange between process simulation, 2D CAD, and 3D CAD tools, provides an overview of existing standards and formats as well as initial experiences gained in a case study.

Eco-Efficiency Applied to Dairy Processing: From Concept to Assessment

Eco-efficiency is a concept which aims at decoupling economic growth from resource use and pollution. The objective of this paper is to review how the application of this concept to dairy processing has evolved over time. Following the introduction of the concept, guidelines and recommendations were introduced in the dairy sector. The absence of a lifecycle perspective and means of measuring improvement led to a subsequent addition of efficiency and intensity assessments. As restrictive regulations and comprehensive methodologies integrating the life-cycle perspective in eco-efficiency assessments were virtually non-existent, the ISO 14045 standard was developed. However, as of yet the dairy processing sector does not appear to have embraced the ISO methodology. Nonetheless, process simulation tools may help and could therefore contribute to the implementation of the eco-efficiency assessments in the dairy processing sector.

Development and validation of extrusion deposition additive manufacturing process simulations

The process simulation tool Additive3D has been developed in Abaqus© 2017 to model the Extrusion Deposition Additive Manufacturing (EDAM) process for fiber-reinforced thermoplastic composites. This additive manufacturing (AM) method encompasses material deposition processes where geometries are constructed layer by layer and the resulting layer properties are highly anisotropic.The goal is to predict final deformed shapes and residual stresses of printed geometries due to the printing process and the material anisotropy. The resulting design tool allows to assess the outcomes of the printing process based on the part geometry, the printing material and the position control parameters.Material properties were characterized, and validation experiments, without additional calibration, show an excellent agreement between modeled and measured part deformation states with relative deviations below 7%. Due to the physics-based nature of the developed simulation tools, the simulations can be extended to account for different part scales, printing materials and printing histories.

Thermodynamic analysis of an integrated gas turbine power plant utilizing cold exergy of LNG

The main concerns in energy from petroleum-based fuels are the scarcity, cost, and pollution the fuels. Now, natural gas is considered as a better alternative. The process of converting natural gas into liquefied natural gas (LNG) is highly energy intensive and consumes about 10–15% of the total energy spent on natural gas production. Novel methods for regasification of LNG (converting back to NG) exist and are being used in various applications; mainly in power generation and refrigeration. One such method in power generation, the cold associated with LNG (cold exergy) can be utilized efficiently for improving the performance of power plants based on the Brayton cycle by precooling the working fluid. The study investigated such a possibility of precooling the inlet working fluid and to bring out the various factors influencing the overall efficiency of the power plant and regasification of LNG. Exergy analysis is the tool used for this study. The combined power plant is modeled using Aspen Hysys process simulation tool, and the results show that there is 35-135% improvement in the exergy efficiency of the power plant. This study also intends to find a suitable working fluid based on the objective functions such as exergy efficiency of the power plant and a regasification parameter (mass flow ratio). The gas turbine cycle gives maximum exergy efficiency when air is used as working fluid and Helium is the best working fluid candidate where regasification is the prime objective. Helium can gasify LNG about ten times more than other three working fluids

Modeling approaches for electron beam lithography

In this paper, a study based on the mathematical modelling, applying different process simulation tools (CASINO, TREM, SELID) for characterization of PMMA resist and for the improvement of the resolution concerning the critical dimensions of nano-patterning by electron beam lithography (EBL) is presented. Data for important EBL characteristics (energy deposition function, proximity effect parameters, solubility rate, etc.) are obtained by applying different approaches (Monte Carlo methods, regression models, etc.).

Application of Computational Fluid Dynamics in Industrial Crystallization

Computational Fluid Dynamics (CFD) simulates a multi-phase flow field by means of numerical calculations and becomes a knot.A powerful tool for crystal process simulation. This paper summarizes the application of CFD technology in the coupling of solving methods, crystallization phenomenon, reaction crystallization process, different operation modes and proportional amplification in the simulation of industrial crystallization, and points out that the development of a suitable model will have a high application value.

Closed-Loop Self-Cooling Recuperative N2 Expander Cycle for the Energy Efficient and Ecological Natural Gas Liquefaction Process

Liquefied natural gas (LNG) has attracted global attention as a more environmentally friendly energy source when compared to other fossil fuels. The nitrogen (N2) expander liquefaction is the most green and safe process among the different types of commercial natural gas liquefaction processes, but its relatively low energy efficiency is a major issue. In this study, an innovative closed-loop self-cooling recuperation technology was proposed to reduce the exergy losses of the N2 expander LNG process. The LNG process with the implementation of the proposed technology was modeled using a commercial process simulation tool, ASPEN HYSYS v9. Subsequently, a modified coordinate descent optimization algorithm was employed to achieve maximum potential benefits of the proposed technology. The energy efficiency of the proposed LNG process was further improved by energy recovery from end flash gas and high-pressure natural gas feed. Finally, the energy efficiency of the proposed closed-loop self-cooling recuperative...

Simulation of Cogeneration-Combined Cycle Plant Flexibilization by Thermochemical Energy Storage

In the course of the “Energiewende,” the German electricity market is undergoing major changes. The state-aided priority of renewable generation has led to a significant decline in electricity prices. This reduces the profit margin of cogeneration units and increases the necessity of flexible operation to avoid electricity production when spot prices drop below marginal costs. In this work, a 100 MWel combined-cycle (CC) power plant supplying heat and power to a paper mill is investigated. Currently, the plant is operated heat-controlled and is therefore unable to react to changing electricity spot prices. With the integration of heat storage, the plant is enabled to switch to power-controlled mode. To evaluate the technical impact of the storage, the plant and a thermochemical MgO/Mg(OH)2 storage are modeled using the stationary process simulation tool ebsilon professional. Different operation modes are investigated and results are used to derive a mixed integer linear programming (MILP) model to optimize the operation of the plant/storage system. Using this method, the overall economic impact of the storage on the plant operation is quantified.

Preparation of Papers for IFAC Conferences & Symposia: Computer-aided Processing of Manual Assembly Operations with Integration of Simulation Tools in Production Processes

In this paper, we describe the development of a simulation model. The model deals with the role of an assembly worker in the virtual environment. He performs sequences of common tasks in manufacturing processes like reaching, grasping, walking, lifting etc. We compare time reports by the analytical MTM method and reports automatically generated by the Siemens JACK 8.4 tool. The methodology gives an insight into influential parameters, dimensions and mass of object, which have an impact on the time reports. Results of our research show that the parameters differ in importance in the MTM and JACK analyses. For one combination of influential parameters, we perform a practical experiment and compare the obtained time analysis with previous results.

Study the Effects of Photon Radiation on Power MOSFET for Harsh Environment Application

The rapid growth of the advanced technologies in power electronics system gives a challenge to the electronic device to sustain with the modern technologies nowadays. The challenges are also including the place where the system was installed for example the application in the harsh environment. Harsh environment application requires an electronic device deals with radiation pollution. Hence, the electronic device will suffer from this phenomenon and make the whole system to malfunction and break down. Power Metal Oxide Semiconductor Field Effect Transistor (MOSFET) is one type of electronic device that is the most broadly for high voltage and high switching speed application. The aim of this paper is to studies the photon radiation effect toward the Power MOSFET performance. The study focus on the changing of the electrical characteristics of the device after radiated with photon radiation. Process simulation and Device simulation tools in Sentaurus Synopsys Software used for the research to validate all the theory.

Design and Ergonomic Analysis of the Waste Electrical and Electronic Equipment (WEEE) Remanufacturing Workcell Fixture Using Digital Mock-up Environment

Traditionally, operations in recycling industry such as WEEE (Waste Electrical and Electronic Equipment) are labour intensive and time consuming due to the nature of discrete / non-standards product states. Hence, small-mid scale WEEE recycling companies require significant product state assessment, process design and technology commitment in order to bid for mass refurbishment projects. Employing digital process simulation tools (which is prevalent in automotive and aircraft manufacturing industries) will result in design of ergonomically viable workstations. This paper introduces design and ergonomic assessment for remanufacturing workcell for light weight, hull shaped free-formed components. It demonstrates that the use of digital process simulation is a valuable tool and leads pathways towards establishing better workplaces where work related disorders are frequently reported in such industries.

Device-Technological Modeling of Integrated Circuit Elements with Improved Resilience to External Influences

This paper analyzes some features of the process and device simulation tools. The tools are analyzed as applied to the calculation of electrical characteristics for several integrated circuit (IC) devices operating under different external conditions. The model features having the maximum effect on the simulation results are identified.

Dynamic simulation of a biogas plant providing control energy reserves

The increasing integration of renewable energy sources leads to challenges for the power grid balance. The share of power plants with intermittent energy production is rising. The increasing volatility of supply and demand has to be compensated by more flexibility in the energy system. Biomass-based plants are qualified for providing flexibility due to the almost infinite storability of the energy carrier. In this work dynamic models for the simulation of flexible operation of an Austrian biogas plant with biomethane production using the process simulation tool IPSEpro are presented. The models base on data collected during a one-year-monitoring. The plants main focus lies on biogas upgrading with two additional CHP units for production of heat and power on demand. For the simulation detailed models of the CHP units and various dynamic models including a gas storage model were developed and are described in this work. Additionally the effects of providing positive secondary control reserves on the needed gas and heat storage capacities were investigated in a case study. For this purpose one month of operation was simulated ex-post. The results show that the existing gas storage capacities are sufficient to provide control reserves while upgrading biogas steadily and simultaneously. Furthermore, the results of a cost efficiency analysis regarding optimal heat storage capacity are used to identify the most economic size of a hot water tank for short-term storage of heat for the investigated case.

3D numerical modelling of the thermal state of deep geological nuclear waste repositories

One of the important aspects of the high-level radioactive waste (HLW) disposal in deep geological repositories is ensuring the integrity of the engineered barriers which is, among other phenomena, considerably influenced by the thermal loads. As the HLW produce significant amount of heat, the design of the repository should maintain the balance between the cost-effectiveness of the construction and the sufficiency of the safety margins, including those imposed on the thermal conditions of the barriers. The 3D finite-element computer code FENIA was developed as a tool for simulation of thermal processes in deep geological repositories. Further the models for mechanical phenomena and groundwater hydraulics will be added resulting in a fully coupled thermo-hydro-mechanical (THM) solution. The long-term simulations of the thermal state were performed for two possible layouts of the repository. One was based on the proposed project of Russian repository, and another features larger HLW amount within the same space. The obtained results describe the spatial and temporal evolution of the temperature filed inside the repository and in the surrounding rock for 3500 years. These results show that practically all generated heat was ultimately absorbed by the host rock without any significant temperature increase. Still in the short time span even in case of smaller amount of the HLW the temperature maximum exceeds 100 °C, and for larger amount of the HLW the local temperature remains above 100 °C for considerable time. Thus, the substantiation of the long-term stability of the repository would require an extensive study of the materials properties and behaviour in order to remove the excessive conservatism from the simulations and to reduce the uncertainty of the input data.

Product diversification in the sugarcane biorefinery through algae growth and supercritical CO 2 extraction: Thermal and economic analysis

The sugarcane sector in Brazil has undergone a major modernization in the last thirty years. Embracing the biorefinery concept, this sector is investigating bioproduct diversification and mostly putting a lot of effort and investment on second generation ethanol production. In this context, the investigation of the integration of a third generation biofuel production using microalgae to the sugarcane biorefinery seems an important starting point. This study evaluates the integration of microalgae growth and processing to a sugarcane biorefinery producing first and second generation ethanol using process simulation tools. Microalgae are cultivated using CO2 produced during fermentation of ethanol and it is processed using supercritical fluid extraction technology in order to obtain lipids rich in high added-value compounds, carotenoids. The results showed that the integration of microalgae biomass processing without previously drying with the sugarcane biorefinery is not attractive from the thermo-economic point. When considering the extraction of dried microalgae the extraction process could be thermal integrated to the sugarcane biorefinery producing ethanol without the need of buying external fuel. The amount of CO2 used as solvent to the supercritical fluid extraction was the main factor that influenced the economic viability of the process. When microalgae pretreatment by cell disruption or co-solvent extraction was considered, it was possible to decrease the amount of CO2 used in the process and an increase in process yields was consequently achieved. The use of a co-solvent in the extraction increased in 1.4 and 2.4 times lipids and carotenoids extraction, respectively, and presented a lower investment when comparing with microalgae extraction without cell disruption.