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131.
为了适应化工流程模拟软件应用日益普及的现状,我们编写了以强化训练学生计算能力为目标的《化工计算与软件应用》教材。本文分析了传统化工计算教材内容的不足,阐明了选用流程模拟软件作为化工计算主要工具的必要性,介绍了新教材编写过程中内容组织、章节安排、编写风格的考虑,对新教材教学方式的变革提出了意见。本教材在校内使用两年来效果明显,学生应用化工流程模拟软件进行工艺设计的能力大幅增强。 相似文献
132.
Maximilian B. Gorensek John A. Staser Thomas G. Stanford John W. Weidner 《International Journal of Hydrogen Energy》2009
The hybrid sulfur thermochemical cycle has been proposed as a means to produce efficiently massive quantities of clean hydrogen using a high-temperature heat source like nuclear or solar. The cycle consists of two steps, one of which is electrolytic. The reversible cell potential for this step and, hence, the resulting operating potential will depend on the concentrations of dissolved SO2 and sulfuric acid at the electrode. To understand better how these are related as functions of temperature and pressure, an Aspen Plus phase equilibrium model using the OLI Mixed Solvent Electrolyte physical properties method was employed to determine the activities of the species present in the system. These activities were used in conjunction with the Nernst equation to determine the reversible cell potential as a function of sulfuric acid concentration, temperature and pressure. A significant difference between the reversible and actual cell potentials was found, suggesting that there may be considerable room for reducing the operating potential. 相似文献
133.
采用实时数据,利用Aspen流程模拟软件对齐鲁分公司塑料厂HDPE装置循环气冷却器换热效能进行计算,为设备改造提供理论依据。 相似文献
134.
R. Cooper D. Bove E. Audasso M.C. Ferrari B. Bosio 《International Journal of Hydrogen Energy》2021,46(28):15024-15031
This work considers the use of a Molten Carbonate Fuel Cell (MCFC) system as a power generation and CO2 concentrator unit downstream of the coal burner of an existing production plant. In this way, the capability of MCFCs for CO2 segregation, which today is studied primarily in reference to large-scale plants, is applied to an intermediate-size plant highlighting the potential for MCFC use as a low energy method of carbon capture. A technical feasibility analysis was performed using an MCFC system-integrated model capable of determining steady-state performance across varying feed composition. The MCFC user model was implemented in Aspen Custom Modeler and integrated into the reference plant in Aspen Plus. The model considers electrochemical, thermal, and mass balance effects to simulate cell electrical and CO2 segregation performance. Results obtained suggest a specific energy requirement of 1.41 MJ kg CO2?1 significantly lower than seen in conventional Monoethanolamine (MEA) capture processes. 相似文献
135.
Malek Alkasrawi Alex S. Rajangam Muhammad Tawalbeh Feras Kafiah Amani Al-Othman Sameer Al-Asheh Qiang Sun 《国际能源研究杂志》2020,44(15):12602-12613
A novel bioprocess design to convert paper mill sludge (PMS) to biofuels is proposed in this work. The design utilizes cellulosic fiber recovered from the PMS via optimized de-ashing (HCl washing) step. This work specifically provided a technical and economic analysis of paper mill sludge conversion into biofuel production using a novel protocol. The protocol is based on scanning electron microscopy (SEM) analysis to assess the quality of the contained cellulose prior to further processing. The results are crucially important to determine the suitability of the PMS feedstock to produce biofuels. SEM analysis was employed as a preliminary screening tool to evaluate sludge digestibility and conversion. The SEM characterization technique established a direct relationship between the fiber morphology, presence of crystals salts and sugar yield after enzymatic hydrolysis. Substantial structural changes were observed before and after de-ashing the sludge samples, leading to a correlation between the surface morphology and the washing step. The results suggested that de-ashing changes the surface morphology and upon analysis, increased the sugar yield up to about 86% as opposed to 2.2% in sludge sample A as an example. The PMS conversion into biofuel was simulated using Aspen PLUS and compared to a similar process using corn stover as feedstock. The simulation results showed it is 20% cheaper to produce bioethanol from PMS compared to corn stover. The simulation revealed less energy demand by around 13 320 MJ/h compared to that when corn stover was used. 相似文献
136.
M. Shahabuddin Sankar Bhattacharya 《International Journal of Hydrogen Energy》2021,46(47):24051-24059
This process modelling studied the effect of different reactants on syngas composition and gasifier heat duty (heat energy required to carry out the operation) and the downstream treatment of CO rich syngas to maximise hydrogen yield. The process modelling was validated against experimental data obtained from a large bench-scale entrained flow gasifier. Results show that considering the H2/CO ratio, the steam-O2 reactant favours the most compared to those of the pure oxygen and oxygen-CO2 reactants. Under comparable operating conditions, the highest H2/CO ratio of 0.74 was determined using steam-O2 reactant compared to that of 0.31 and 0.33 using steam-CO2 and pure oxygen reactant. The catalytic water-gas shift reaction (WGSR) favours the yield of H2 with complete CO conversion at a temperature of 400 °C using the steam/coal ratio of 1.2. Supplying steam in the gasifier requires more heat energy to be supplied to drive endothermic gasification reaction and maintain the gasifier temperature. Under complete carbon conversion, steam-CO2 and steam-oxygen reactants require 5–65 kW more energy than pure oxygen. 相似文献
137.
《International Journal of Hydrogen Energy》2022,47(63):26891-26900
The plasma gasification process is one of the newest and most innovative approaches to meet the needs of waste management but requires assessment and research on operational conditions prior to installation. In this work, a model based on Gibbs free energy minimization was developed and implemented in Aspen Plus®. A combination of municipal solid waste (MSW) and coal has been used as feedstocks. The model's performance was compared with the results of the literature and found to be in good agreement. The effect of various parameters such as temperature, equivalence ratio, MSW/coal blending ratio, and steam-to-feedstock ratio on the composition of syngas and hydrogen production were assessed. Very interesting results were obtained concerning the mixture of the feedstocks that maximize the hydrogen production besides that using steam as a gasifying agent allows higher hydrogen production than using air. When using high amounts of coal in the feedstock mixture, low steam ratios are preferred. When using high amounts of MSW in the feedstock mixture high steam ratios are preferred. The use of pure oxygen as the gasifying agent increases the hydrogen percentage but requires an air separation unit to be included in the process. The results obtained in this study are particularly relevant for countries with coal reserves. 相似文献
138.
Maximilian Hauck Stephan Herrmann Hartmut Spliethoff 《International Journal of Hydrogen Energy》2017,42(15):10329-10340
A thermodynamic Aspen Plus simulation model for a reversible solid oxide fuel cell (RSOFC) is presented and evaluated. It is composed of an electrolysis and a fuel cell module. The latter is based on an existing non reversible SOFC model. The electrolysis model simulates water electrolysis as well as catalytic reactions of inlet gases. The model has been validated using data from literature. It has been found that the support layer on fuel electrode supported cells has to be treated differently in terms of diffusion than the active layer. Simulation results show that for the investigated cell parameters, the positive effect of adding CO2 to the steam feed on the electrolysis process is due to water–gas-shift reactions and not CO2 electrolysis. An analysis of outlet gas compositions in electrolysis mode showed that the assumption of the cell as an equilibrium reactor was justified. A parameter study has been conducted, showing that increasing the operation temperature and pressure can improve the overall performance, while changing the inlet gas compositions in general improves either fuel cell or electrolysis mode and deteriorates performance for the other mode. 相似文献
139.
140.
Umberto Desideri Stefania Proietti Paolo Sdringola Giovanni Cinti Filippo Curbis 《International Journal of Hydrogen Energy》2012
Carbon dioxide emissions into the atmosphere are considered among the main reasons of the greenhouse effect. The largest share of CO2 is emitted by power plants using fossil fuels. Nowadays there are several technologies to capture CO2 from power plants' exhaust gas but each of them consumes a significant part of the electric power generated by the plant. The Molten Carbonate Fuel Cell (MCFC) can be used as concentrator of CO2, due to the chemical reactions that occurs in the cell stack: carbon dioxide entering into the cathode side is transported to the anode side via CO3= ions and is finally concentrated in the anodic exhaust. MCFC systems can be integrated in existing power plants (retro fitting) to separate CO2 in the exhaust gas and, at the same time, produce additional energy. The aim of this study is to find a feasible system design for medium scale cogeneration plants which are not considered economically and technically interesting for existing technologies for carbon capture, but are increasing in numbers with respect to large size power plants. This trend, if confirmed, will increase number of medium cogeneration plants with consequent benefit for both MCFC market for this application and effect on global CO2 emissions. System concept has been developed in a numerical model, using AspenTech engineering software. The model simulates a plant, which separates CO2 from a cogeneration plant exhaust gases and produces electric power. Data showing the effect of CO2 on cell voltage and cogenerator exhaust gas composition were taken from experimental activities in the fuel cell laboratory of the University of Perugia, FCLab, and from existing CHP plants. The innovative aspect of this model is the introduction of recirculation to optimize the performance of the MCFC. Cathode recirculation allows to decrease the carbon dioxide utilization factor of the cell keeping at the same time system CO2 removal efficiency at high level. At anode side, recirculation is used to reduce the fuel consumption (due to the unreacted hydrogen) and to increase the CO2 purity in the stored gas. The system design was completely introduced in the model and several analyses were performed. CO2 removal efficiency of 63% was reached with correspondent total efficiency of about 35%. System outlet is also thermal power, due to the high temperature of cathode exhaust off gases, and it is possible to consider integration of this outlet with the cogeneration system. This system, compared to other post-combustion CO2 removal technologies, does not consume energy, but produces additional electrical and thermal power with a global efficiency of about 70%. 相似文献