Aspen Energy Analyzer Research Articles

Kraft lignin-based Vanillin production – Process modification, techno-economic evaluation, and energy analysis

This correspondence outline specific modifications implemented in the vanillin production process derived from kraft lignin, with the primary objective of minimizing the release of chemical substances into the environment and optimizing facility utilization. The processes were meticulously designed using Aspen Plus V12.1 software, followed by a sensitivity analysis conducted on the specifications of the main distillation column for each process. Subsequently, the obtained results underwent techno-economic evaluation and energy analysis, employing Aspen Process Economic Analyzer V12 and Aspen Energy Analyzer V12.1. The calculations reveal that increasing the purity of methanol and water from 95 to 99 wt % during methanol recycling effectively reduces chemical releases into the environment but significantly raises utility costs, thereby diminishing the Net Present Value. Furthermore, the energy analysis demonstrates that the implemented modifications markedly reduce energy consumption, exerting a direct impact on economic parameters. In the process design phase, while Aspen Plus software showed no errors in the results, Aspen Energy Analyzer detected errors in the modified scenario in two heat exchangers because of high temperature at the shell outlet based on its respective criteria, necessitating increasing the cooling flowrates to cover this issue.

Energy efficiency analysis and optimization of heat exchange network under the goal of “double carbon”: a case for production process of isopropyl acetate

ABSTRACT In order to response to the “double carbon” strategy for reducing emissions, chemical production processes were optimized to lower the amount of utility work and equipment investment expenses with increasing the system’s capacity for heat recovery. A sensitivity analysis and the energy efficiency analysis with pinch technique were performed on the distillation and purification of the 30 kt/a isopropyl acetate (IPAC) production process by using process simulation software of Aspen Plus. The IPAC refining tower optimization results show that the purity of the refined IPAC could be reached 99.9% at circumstances of 44 theoretical plates, 19 feed plates, and 0.755 reflux ratio. According to the optimized energy consumption data from Aspen Energy Analyzer (AEA), the cold and heat logistics matching was performed. It can be seen that the heat exchange network was tuned to maximize energy recovery by reducing the amount of utility work. The optimized cold and heat utility usage were 734.69 and 727.81 kW, which meaning that compared with original process, the cold and heat utility usage energy can be save with 10.0%, respectively. The optimized results provide a certain theoretical basis and solution for improving energy saving and reducing investment costs.

Multi-objective optimization of heat exchanger network with disturbances based on graph theory and decoupling

Disturbance poses a significant challenge to highly coupled chemical systems. In this work, a multi-objective optimization framework is developed for reducing the impact of fluctuations on heat exchange networks (HENs) based on graph theory and decoupling. The framework bridges the gap between algebra and structure of HEN through a directed graph (Digraph) and defines the Excitation as a fluctuation impact indicator. The Non-dominated Sorting Genetic Algorithm II (NSGA-II) is improved for generating feasible solutions and global optimality, and the quasi-gradient is applied to select an equilibrium solution from the Pareto Front. Two case studies are conducted, and the equilibrium solution is selected based on quasi-gradient. For the literature case, the Excitation of the equilibrium solution and the total annual cost is reduced by 56.15% and 2.12%, respectively. For the coal-to-methanol system, the utility consumption and Excitation are 29.6% and 264.50% lower than the results of the Aspen Energy Analyzer, respectively.

Total Site Targeting Approach for Heat Recovery at a Paper Factory

The total Site heat integration approach has been used extensively in the industry, including process services and heat exchanger network design integrated with the site service system. This work aims to propose a design for the heat recovery network in the paper factory through Total Site targeting. A procedure that includes the energy analysis and Pinch Analysis methodologies, with the use of Aspen Energy Analyzer is applied. The heat exchanger network design through total site heat integration shows that the rehabilitation of the heat recovery system of the paper machine and boiler blowdown is feasible, with a potential annual saving of 259 t of fuel oil and 116 000 m3 of water, which make it feasible to invest in the factory’s heat recovery system, whose project budget is estimated to recover in a year. Heat exchanger network retrofit design allows to recover 46.2% of the maximum energy recovery.

A holistic analysis of chemical process performance using pinch technology

ABSTRACT The chemical industry is acquiring new advancement day by day. Previously, quite massive equipment had been used to do heat transferring tasks, but now the industry has been modernised. Heat Integration is a trending area of study that might be applied in several sectors to redesign processes. Heat Integration alludes to any technique in chemical engineering that results in considerably smaller, greener, and more energy-efficient appliances. Heat Integration aims to improve energy transfer, lowering the equipment’s capacity for heat transfer. This paper uses pinch analysis to optimize heat integration and find the best heat-exchange network through case studies. Pinch Technology offers a systematic approach to reducing energy use across all sites and activities. It is feasible to determine the proper alterations to the fundamental process parameters that can result in energy savings by using pinch technology. The Aspen Energy Analyzer tool has been used to compute the heat integration of the case studies. After obtaining the data from the software, they were used in pinch analysis to determine the optimal alternative for the heat exchanger network.

Modeling and exergy analysis of an integrated cryogenic refrigeration system and superconducting magnetic energy storage

Superconducting magnetic energy storage (SMES) systems widely used in various fields of power grids over the last two decades. In this study, a thyristor-based power conditioning system (PCS) that utilizes a six-pulse converter is modeled for an SMES system. The main subject of this research is the generation of required helium for an SMES because for the coil to be at superconducting temperature, it needs to always be immersed in liquid helium. In the conducted simulation, the helium production system provided, in which primarily the gaseous helium temperature was reduced by heat transfer in LNG heat exchangers, and then after the sudden pressure drop, it turned into a liquid. The effect of the various firing angles is investigated, and it is found that at angles lower than 90°, at a specific angle, the output current enhances with time. In the 90°, this current remains constant, and at degrees greater than 90°, the output current reduces with time. The percentage of input flows to the expanders is investigated to find the rate of the maximum liquid helium production amount to the inlet gaseous helium. The diverted ratio of mass flow via expander 1 and expander 2 was 0.46 and 0.35, respectively. The system's work utilization of network, and liquid helium production is 67.18 MW and 12.7 kg/h. Also, the exergy analysis is done and the results show 35.7 % exergy efficiency. The efficiency of helium production has a direct relation to liquid nitrogen mass flow. However, due to the required high power for producing liquid nitrogen, with mass flow rate increment, the total system's efficiency is reduced. The results are evaluated with Aspen HYSYS, Aspen Energy Analyzer, and MATLAB. Specific work obtained from the analysis is 290,097 kW.s/kg which indicates that uses lower power in comparison with the other helium production methods which saves power and electrical costs.

Process Integration Approach to the Methanol (MeOH) Production Variability from Syngas and Industrial Waste Gases

Methanol is expected to be a possible solution for reducing global greenhouse gas emissions and minimizing the dependency on fossil fuels. This paper presents a systematic approach of methanol (MeOH) production from industrial waste gases including flue gas (FG) and coke oven gas (COG) that are considered an important threat to the environment. The impact of process parameters, including dimensional parameters (length, diameter, and number of tubes) and operational parameters (reactor temperature, pressure, and thermal fluid temperature) over the MeOH synthesis, are investigated by Aspen Plus. Firstly, the synthesis process is designed and optimized using syngas (SG) as a feed material. Secondly, by replacing the feed material with FG and COG, methanol production variability is investigated and demonstrated for the same optimized process. Afterward, an efficient heat exchange network system is developed for all three different processes using Aspen Energy Analyzer. The optimized dimensional parameters of the MeOH synthesis reactor are determined to be a length of 12 m, a diameter of 0.06 m, and 5000 tubes for achieving a conversion rate of 75%. Meanwhile, the optimized operational parameters are identified as a reactor temperature of 209 °C, reactor pressure of 70 bar, and thermal fluid temperature of 196 °C. Furthermore, the influence of the stoichiometric number (SN) on the process was observed with higher SN values resulting in increased hydrogen (H2) concentration and an improved forward reaction of MeOH synthesis, leading to higher conversion rates. The findings and insights gained from this study can serve further improvements and advancements in MeOH synthesis processes.

Energy saving in Cu-Cl thermochemical cycle for green hydrogen production: Use of heat integration approach and simulation tools

Hydrogen, both green and blue, is a crucial fuel as it carries energy from sustainable sources and has no impact on global warming. Thermochemical methods for green hydrogen generation are promising alternative technologies to previous technologies for the commercial-scale generation of hydrogen gas without fossil fuel. In the present work, ICT-OEC six-step copper-chlorine (Cu-Cl) thermochemical cycle is explored, its efficiency is investigated using the Aspen Plus simulation software, and probable efficiency enhancements are addressed. Using the Aspen energy analyzer, different design configurations for the heat exchanger network were proposed, and thermal management within the cycle was studied. The implementation of thermal management strategies yielded a substantial enhancement in the efficiency of the Cu-Cl cycle, elevating it from 38.68% to 51.54%. The comparative analysis of the 6-step Cu-Cl cycle with other 3-, 4-, and 5-step cycles revealed that the 4-step Cu-Cl cycle (UOIT-CERL, Canada) exhibited higher energy efficiency. However, the 6-step Cu-Cl cycle shows greater promise for commercialization.

Heat Exchanger Network (HEN) Analysis of The Power Plant Industry Using Aspen Energy Analyzer Software

Heat recovery is considered as the key to improve energy efficiency in the process design. An appropriate heat exchanger network (HEN) design is an effective tool to maximize heat recovery from the process streams and to minimize energy consumption. The objectives of this study were arranging optimum HEN based on the annual cost in the power industry. HEN in the Paiton Steam Power Plant, East Java, Indonesia, was designed using spreadsheet and Aspen Energy Analyzer with Peng-Robinson equation. Pinch analysis was conducted by comparing Tmin (10°C - 19°C) to obtain Maximum Energy Recovery (MER) and Heat Exchanger Area (HEA). The HEN design was optimized using grid diagram. Simulation in this study succeeded to reduce the annual cost the most effectively at ∆Tmin 16°C. This design optimized the process integration and contributed to the capital, operation, and total annual cost reduction of 14.3%. The maximum energy recovery was 286,706 kW and HEA 138.790 m2. This result is a solution for Steam Power Plant as an effort for enhancing energy efficiency and the company competitiveness.

Design and analysis of cryogenic CO2 separation from a CO2‐rich mixture

AbstractIn this study, we designed and optimized the main process for CO2 cryogenic separation and purification as well as the auxiliary process of refrigeration with ammonia, both these processes are modeled using Aspen HYSYS V11. The energy‐saving potential and greenhouse gas emission reduction potential of the process flow were analyzed using the Aspen Energy Analyzer V11. The effects of the plant inlet pressure, cooling temperature, tower pressure, and number of stages on two key parameters (energy consumption per unit of product and CO2 recovery rate) were studied in detail. Simultaneously, the appropriate design parameters of the plant were obtained, and the reason for the variation law was analyzed. Finally, grey relational analysis was used to explore the correlation between the influence factors and key parameters, indicating that the number of stages has the largest impact on the CO2 recovery rate and the energy consumption per unit of product, whereas tower pressure and cooling temperature have the least impact on the CO2 recovery rate and energy consumption per unit of product, respectively.

Critique – Comparison between P-HENS and Aspen Energy Analyzer for heat exchanger network synthesis

This critique evaluates the use of the P-HENS software for developing recommended heat exchanger network designs compared to the commercial simulator Aspen Energy Analyzer. The similarities between the two software when carrying out an energy integration are discussed, as well as their advantages and possible improvements to be implemented in the tool.

Graphical Prediction of Optimum Pinch Point Value with AEA Software Simulation and Validation Applied in Closed Cycle Gas Power Plant

Studying industries energy saving is very important prospect for many researchers in the last four decades. In this respect, better process heat transfer can be achieved to improve process operating and capital cost. Thereafter, obtaining higher amount of heat recovery, which will help to reach system optimum heat exchanger network design. Application of Pinch analysis (PA) in our current study, was found to be as an effective method towards economic solution and assessment for all system thermal processes. Whereby, minimizing energy losses, and thus, prediction of maximum energy saving. In addition, application of "Aspen Energy Analyzer (AEA)" simulation software assist our effort to optimize Heat Exchanger Network design (HEN), with various application scenario towards best design. This study represents a "Case study" as a Brayton closed cycle gas turbine power plant in Al-khairat district, which is one of a number of sites used to generate electricity for Iraq national grid. However, the plant original design is open cycle. This study, represent an attempt to apply (PA) in system closed cycle model with the same working conditions. The results predicted, on the contrary of open cycle, that using closed cycle (PA) with temperature difference ∆Tmin can be acceptable with several design propositions. The optimum (∆Tmin = 15℃) were evaluated in the closed cycle system pinch analysis, thereby the maximum Qrec. process that minimize the QHmin & QCmin requirement were identified by the software simulation for the best HEN design. These results were found as Qrec. = 318.330 MW, QHmin = 88.607 MW and QCmin =39.564 MW.

Heat Integration and Heat Exchanger Network Design with Aspen Energy Analyze

The considerable amount of energy used in industrial processes is typically used for heating and cooling. The synthesis of heat ex-changer networks (HEN) is a critical topic in this industry in order to reduce energy and capital costs in chemical plants. Heating and cooling systems in industry must be designed efficiently, which can be done using technologies like pinch analysis to create an optimal heat recovery network. Heat pinch analysis is a systematic method for designing thermally efficient systems. A designer can determine the minimum heating and cooling requirements as well as the maximum heat recovery (MHR) potential by locating a thermodynamic bottleneck, or the pinch point for heat recovery. This Paper uses Aspen Energy Analyzer for HEN Design.Heat integration network design is a cost-effective strategy that helps industries to cut costs by reducing the number of external utilities needed and increase profitability by lowering energy consumption. The HENs’ composite curves, grand composite curves, grid representation, and target reports were created using the Aspen Energy Analyzer. The software suggested ten designs, which were then optimized based on total annualized cost. By comparing it to other optimized designs, the best design is determined.

Thermal Energy Consumption Assessment in a Fluid Milk Plant

The main energy conservation opportunities in a dairy plant are in refrigeration, and steam generation. This paper aims to identify potential energy and water savings and opportunities to improve the thermal efficiency of a fluid milk processing plant, using energy analysis and Heat Integration methods. Methodologies for energy analysis and Pinch Analysis with the use of HENSAD and Aspen Energy Analyzer are applied. The main specific energy consumptions are defined as indicators of the progress of improved energy efficiency. The determination of energy performance indicators and energy targets of the heat exchanger network, as well as its design, allowed identifying opportunities for improvement to reduce fuel and water consumption through heat recovery in the milk pasteurization process. Current hot and cold utilities duties are satisfied, for a minimum allowable temperature difference of 20 °C. Total annual savings of 60 t of fuel oil and 15,800 m3 of water allow assessing the feasibility of an investment project for improved heat recovery.

Process simulation and optimization of dodecyl benzene sulfonic acid production plant

The aim of work is to design sulfonating plant on the basis of a hydrophilic sulfonate head-group and a hydrophobic alkyl benzene tail-group reaction mechanism, study of kinetics and thermodynamics followed by a steady-state simulation for the process was done by ASPEN HYSYS (V8.8) through using Peng-Robinson fluid package. Then heat integration of the process, done by using Aspen Energy Analyzer and studies of the influence parameters on the simulated process of dodecyl benzene sulfonic acid. Alkyl benzene sulphonate is produced due to the sulphonation reaction of an alkylbenzene (LAB) plus a sulphonating agent in a falling film sulphonator to produce sulfonic acid (LABSA).The modeling of dodecyl benzene sulfonic acid plant depends on : Air drying, Sulphur melting and proportioning, Sulphur combustion and SO3 production, Film sulfonation. Dodecyl benzene sulfonic acid production rate is influenced by changing of the following factors: the sulfur molar flow rate, molar flow rate of air and pressure of dodecyl benzene, the results of optimization shows that : The optimum operating Molar flow rate of sulfur is lies in the range of [3:3.5] Kg.mol/h, The optimum operating Molar flow rate of Air is 25 Kg.mol/h, The optimum operating Molar flow rate of Dodecyl Benzene is 3.1 Kg.mol/h and The optimum operating Pressure of Dodecyl Benzene is 70 KPa. For heat integration, a proposed heat exchanger network is generated which made the process functional without external heating. Generation of the top 10 heat exchanger network (HEN) leads to: the best case scenario from the top 10 scenarios from the point of cost and also from the point of cooling and heating required was design (9). After heat integration, the total amount of cooling demand decreased from 912620.50 KJ/h to 890261.56 KJ/h and the total amount of heating demand decreased from 22358.94 KJ/h to 0KJ/h.

A new approach for energy optimization in dairy industry

Energy carriers as fuel, are one of the essential needs of various industries. The cost of these carriers persuades us to find solutions to prevent waste of energy consumption. Among the various industries, dairy industry is one of the most energy intensive of them. By considering the importance of energy consumption in the dairy sector, in this study first the types of technologies available in the milk drying industry is discussed and then this technology is investigated economically and its disadvantages and advantages are expressed. This paper's main goal is to optimize energy consumption in the process of milk powder production using pinch technology. Therefore, it provides a brief description of pinch technology and after providing data table consist of streams information, the desired cycle (milk spray dryer) is optimized from a technical and economic point of view by Aspen Energy analyzer (AEA). The modeling assumptions and the desired scenario are also given. Finally, four scenarios about how to apply a connection among heat exchangers and discuss about cost of investment for each scenario is presented. The results show that temperature of pinch point, hot utility and cold utility is 85 °C, 25.3 kW and 66.36 kW respectively and MER-3 networking is chosen as the best option in terms of initial cost (81,304.42 $), number of units (7), area (65.27 m 2 ) and final cost (7.28 × 10 4 $/S) that this amount is close to the target mode but it is not in a good position in terms of the required area, which is a weakness in the desired networking.

Pyrolysis and gasification integrated process of empty fruit bunch for multi-biofuels production: Technical and economic analyses

The use of renewable energy sources has been promoted with concern about limited fossil fuels and increased environmental impact. Empty fruit bunch (EFB), which is a valuable biomass residual from palm oil milling processes, is one of the most promising renewable energy sources that can be used to increase the monetary value of EFB through the pyrolysis and gasification integrated process for multi-biofuels production. This work aims to perform technical and economic analyses of the pyrolysis and gasification integrated process using EFB for multi-biofuels production. Firstly, the pyrolysis and gasification integrated process model is developed by using Aspen Plus simulator and employed to determine optimal conditions through a parametric analysis. Then, the design of a heat exchanger network is also incorporated to enhance the energy efficiency of the process using Aspen Energy Analyzer. Finally, the key economic performance indicators, i.e., payback period (PB), net present value (NPV), and internal rate of return (IRR), of the process are analyzed using Aspen Process Economic Analyzer. The results show that the integrated process should be operated at steam to biochar mass ratio of 2.7, gasifier temperature of 900 °C, steam to syngas mass ratio of 3.0, and WGS temperature of 240 °C to produce the maximum hydrogen, gases, gasoline, naphtha, kerosene and diesel at 140, 290, 657, 729, 298 and 811 kg h−1, respectively. Furthermore, in terms of heat integration, the minimum hot and cold utilities are required at 21,554 and 5,247 MJ h−1, respectively. The economic analysis results indicate that the proposed process is economically feasible and attractive with 5.98 years of PB, $ 249,951,964 of NPV, and 22% of IRR.

Increasing the efficiency of liquefied natural gas production plant with considering appropriate refrigerant components

AbstractIn liquefied natural gas (LNG) production, the total efficiency of the system increased by using mixed refrigerants for the liquefaction process. In this study, the mixing of the effective refrigerants is considered as one of the most important factors in the optimization of liquefaction process of natural gas. In this regard, three mixed refrigerants with different compositions and conditions were selected. The refrigerants were selected based on optimization of power and electrical efficiency, overall thermal efficiency, heat exchanged with refrigeration cycle, and mass flow rate of Refrigerants in cycle. The optimized chemical process with related energy integrations were simulated and evaluated by Aspen HYSYS and Aspen energy analyzer (HX‐Net), respectively. Furthermore, the Aspen Capital Cost Estimator (Icarus) was employed for the economic analysis of these processes. The investment and operating costs of the optimized process (in the process with considering the MR3 refrigerant) are less than other processes. The calculated capital, operating, and equipment costs are about 22.6, 20.1, and 10.3 million US Dollars in the process with MR3 refrigerant. The mixed refrigerant 3 (MR3) contains the CH4, C2H6, C3H8, and N2with the mole fraction of 0.1316, 0.1317, 0.0299, and 0.7098, respectively. Modeling and cost estimation techniques can be used as a useful tool for the design and optimization of appropriate gas liquefaction and refrigeration processes with an effective performance for various industrial applications.

Process simulation and economic and environmental evaluation of a corncob-based biorefinery system

A new biorefinery system of producing bioethanol, xylose, electricity and steam from corncob was analyzed by a systematic methodology of process simulation, pinch analysis, economic analysis and life cycle assessment (LCA). The biorefinery system processing 875 kt/a corncob and operating 8400 h/a was first simulated in Aspen Plus. Through process integration in Aspen Energy Analyzer, the biorefinery system reduced 36.8% of cooling utilities and 60.6% of heating utilities, achieved by the installation of 10 heat exchangers. The yield of bioethanol, 194.2 L/t dry corncob, was lower than other biorefineries because hemicellulose in corncob was employed to produce high-valued xylose. However, the production cost, 0.50 $/L bioethanol, made it quite competitive due to the sale price of xylose being more than two times higher than bioethanol. Lastly, the new biorefinery system was evaluated by environmental performance of using LCA method in SimaPro software. Two other biorefinery systems involved with same feedstock and capacity, but different conversion routes were conducted as base cases. The results showed that pretreatment, bioethanol production and wastewater treatment contributed most to the fossil fuels depletion (FDP) and global warming potential (GWP) impacts. The new biorefinery system showed significantly better performance compared with other cases, FDP 25.5 MJ/t dry corncob (0.05 MJ/MJ bioethanol) and GWP 0.45 t CO2 eq/t dry corncob (0.11 kg CO2 eq/MJ bioethanol).

Environmental and thermodynamic performance assessment of biomass gasification process for hydrogen production in a downdraft gasifier

AbstractGasification is one of the most efficient techniques for sustainable hydrogen production from biomass. In this study, a comparative performance analysis of the gasification process using various types of biomass materials was undertaken via thermodynamic approach. Air, steam, and air/steam as the traditional gasifying agents were applied to provide an opportunity to choose the most proper agent in the process. This paper also evaluates the environmental impacts of the process in terms of CO2emission by using Aspen Energy Analyzer. The effects of agent to biomass molar ratio, agent inlet temperature, moisture content of biomass material, and gasification temperature were estimated based on the producer gas compositions, hydrogen yield and heating values. The results indicate that the highest hydrogen yield (0.074 g H2/g biomass) was obtained in the steam gasification of plastic, while air gasification of paper generates the lowest one. It was also observed that manure is the most beneficial from environmental perspectives, while tire and plastic have the highest contribution to CO2emission and consequently global warming. The higher values of hydrogen production and LHV of produced gas are associated respectively with using steam, air/steam, and air as the gasification agents. The lowest value of CO2emission is obtained for air, air/steam, and steam as the gasifying agents, respectively.