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A new approach for scheduling of multipurpose batch processes with unlimited intermediate storage policy

Nikolaos Rakovitis, Nan Zhang, Jie Li, Liping Zhang

《化学科学与工程前沿(英文)》 2019年 第13卷 第4期   页码 784-802 doi: 10.1007/s11705-019-1858-4

摘要: The increasing demand of goods, the high competitiveness in the global marketplace as well as the need to minimize the ecological footprint lead multipurpose batch process industries to seek ways to maximize their productivity with a simultaneous reduction of raw materials and utility consumption and efficient use of processing units. Optimal scheduling of their processes can lead facilities towards this direction. Although a great number of mathematical models have been developed for such scheduling, they may still lead to large model sizes and computational time. In this work, we develop two novel mathematical models using the unit-specific event-based modelling approach in which consumption and production tasks related to the same states are allowed to take place at the same event points. The computational results demonstrate that both proposed mathematical models reduce the number of event points required. The proposed unit-specific event-based model is the most efficient since it both requires a smaller number of event points and significantly less computational time in most cases especially for those examples which are computationally expensive from existing models.

关键词: scheduling     multipurpose batch processes     simultaneous transfer     mixed-integer linear programming    

Insights into influence of aging processes on zero-valent iron modified biochar in copper(II) immobilization: from batch solution to pilot-scale investigation

《化学科学与工程前沿(英文)》 2023年 第17卷 第7期   页码 880-892 doi: 10.1007/s11705-022-2282-8

摘要: The zero-valent iron modified biochar materials are widely employed for heavy metals immobilization. However, these materials would be inevitably aged by natural forces after entering into the environment, while there are seldom studies reported the aging effects of zero-valent iron modified biochar. In this work, the hydrogen peroxide and hydrochloric acid solution were applied to simulate aging conditions of zero-valent iron modified biochar. According to the results, the adsorption capacity of copper(II) contaminants on biochar, zero-valent iron modified biochar-1, and zero-valent iron modified biochar-2 after aging was decreased by 15.36%, 22.65% and 23.26%, respectively. The surface interactions were assigned with chemisorption occurred on multi-molecular layers, which were proved by the pseudo-second-order and Langmuir models. After aging, the decreasing of capacity could be mainly attributed to the inhibition of ion-exchange and zero-valent iron oxidation. Moreover, the plant growth and soil leaching experiments also proved the effects of aging treatment, the zero-valent iron modified biochar reduced the inhibition of copper(II) bioavailability and increased the mobility of copper(II) after aging. All these results bridged the gaps between bio-adsorbents customization and their environmental behaviors during practical agro-industrial application.

关键词: zero-valent iron modified biochar     aging processes     copper removal     adsorption     pilot-scale experiments    

基于模糊规划的间歇过程生产调度建模

张虹,李歧强

《中国工程科学》 2004年 第6卷 第10期   页码 65-70

摘要:

通过对现有生产调度模糊模型的分析,针对间歇生产过程,提出了一种新颖的参数模糊的通用模糊规划建模方法,模糊模型采用2种基于普通遗传算法的模糊算法,即模糊模拟和SFA算法。该方法中,参数隶属函数选取灵活,采用合适的模糊表示方式。最后通过实例验证了该模糊建模方法是一种有效的方法。

关键词: 生产调度     模糊规划     间歇生产过程     隶属函数    

A low power, eco-friendly multipurpose thermoelectric refrigerator

N. Jagan Mohan REDDY

《能源前沿(英文)》 2016年 第10卷 第1期   页码 79-87 doi: 10.1007/s11708-015-0380-8

摘要: There has been an immense endeavor to mitigate global warming in spite of which it has only been worse. This paper presents the design and implementation of a low power and eco-friendly refrigeration system using the thermoelectric effect. The conventional refrigerators make use of complex mechanisms which involves synchronous operation of various units, namely the compressor, condensers, expansion valves, evaporator, refrigerant and so on. But a thermoelectric refrigerator exploits the principle of the Peltier effect, thus avoiding the utilization of these complex components. This even helps curb the release of harmful chlorofluorocarbons (CFCs) into the atmosphere which contributes to the increase in global temperature. Moreover, the temperature can be controlled and set to required values with the help of a microcontroller. Hence, this can be used both for domestic and commercial purposes. The unit does not eject any harmful gases. Therefore, the heat expelled from the unit can be tapped for heating utilities, making the use of this device versatile in its application. Thus this proposal aims not only at reducing the air pollutants by not contributing to it but also at reducing the power consumption.

关键词: low power     eco-friendly     multipurpose     TEC-12706     Peltier effect     microcontroller (P89V51RD2BN)     temperature control    

Functional flax fiber with UV-induced switchable wettability for multipurpose oil-water separation

《环境科学与工程前沿(英文)》 2022年 第16卷 第12期 doi: 10.1007/s11783-022-1588-6

摘要:

● A PAA-ZnO-HDTMS flax fiber with UV-induced switchable wettability was developed.

关键词: Flax fiber     Switchable wettability     ZnO-HDTMS coating     Oil-water separation    

The energy consumption in a batch stripper and a batch rectifier

Xianbao CUI, Tianyang FENG, Ying ZHANG, Zhicai YANG,

《化学科学与工程前沿(英文)》 2009年 第3卷 第4期   页码 443-452 doi: 10.1007/s11705-009-0266-6

摘要: The energy consumption in a batch rectifier and a batch stripper was investigated with a shortcut mathematical model. The minimum energy consumption of a batch stripper was compared to that of a batch rectifier under “general constant reflux” and “general constant distillate composition” with the ratio of minimum energy consumption /. When the feed contains a large amount of light component, the product purity specification is low and the relative volatility is small, the minimum energy consumption of a batch stripper is less than that of a batch rectifier under “general constant reflux” and “general constant distillate composition”. When the feed contains a small amount of light component, the product purity specification is very high and the relative volatility is low, a batch stripper can also consume less energy only in the “general constant distillate composition” operation mode. In other cases, a batch rectifier can consume less energy.

关键词: constant reflux     feed     energy consumption     general constant     product purity    

Influence of entrainer recycle for batch heteroazeotropic distillation

Laszlo Hegely, Peter Lang

《化学科学与工程前沿(英文)》 2018年 第12卷 第4期   页码 643-659 doi: 10.1007/s11705-018-1760-5

摘要:

Dehydration of isopropanol applying batch heteroazeotropic distillation with toluene as entrainer (E) is investigated. The composition of the feed is near to that of the isopropanol (A)-water (B) azeotrope. The effects of recycling the entrainer and the off-cut are studied by dynamic simulation with a professional flow-sheet simulator. Three consecutive batches (one production cycle) is studied. Both operational modes (Mode I: decantation after distillation and Mode II: decantation during distillation) are simulated. For Mode II, calculations are performed both for Strategy A (distillate from the aqueous (E-lean) phase only) and Strategy B (partial withdrawal of the organic (E-rich phase), as well). The E-rich phase, the final column hold-up and the off-cut (Mode II only) are recycled to the next batch. The influence of the following parameters are determined: quantity of entrainer, reflux ratios of the steps. The variations caused by the recycling in the 2nd and 3rd batches are also shown. The best results (lowest specific energy demand and highest recovery of A) are obtained by Mode II, Strategy A. Recycling increases the recovery, and drastically diminishes the entrainer consumption. However, it makes the production slower and decreases the quantity of fresh feed that can be processed.

关键词: batch distillation     heteroazeotropic distillation     operational policies     off-cut recycle     entrainer    

Micromixing performance of the teethed high shear mixer under semi-batch operation

《化学科学与工程前沿(英文)》 2022年 第16卷 第4期   页码 546-559 doi: 10.1007/s11705-021-2069-3

摘要: Semi-batch operated reaction processes are necessary for some competitive reaction systems to achieve a desirable process selectivity and productivity of fine chemical products. Herein the structural and operating parameters of the teethed high shear mixers were adjusted to study the micromixing performance in the semi-batch operated system, using the Villermaux/Dushman reaction system. The results indicate that the rising of the rotor speed and the number of rotor teeth, the decrease of the width of the shear gap and the radial distance between the feed position and the inner wall of stator can enhance the micromixing level and lead to the decrease of the segregation index. Additionally, computational fluid dynamics calculations were carried out to disclose the evolution of the flow pattern and turbulent energy dissipation rate of the semi-batch operated high shear mixer. Furthermore, the correlation was established with a mean relative error of 8.05% and R2 of 0.955 to fit the segregation index and the parameters studied in this work, which can provide valuable guidance on the design and optimization of the semi-batch operated high shear mixers in practical applications.

关键词: high shear mixer     semi-batch operation     micromixing performance     Villermaux/Dushman system     segregation index    

Two-stage scheduling on batch and single machines with limited waiting time constraint

Zhongshun SHI, Zewen HUANG, Leyuan SHI

《工程管理前沿(英文)》 2017年 第4卷 第3期   页码 368-374 doi: 10.15302/J-FEM-2017034

摘要: This study addresses the problem of two-stage scheduling on batch and single machines with limited waiting time constraint; thus, the makespan is minimized. A mixed-integer linear programming model is proposed for this problem. Three tight lower bounds and a heuristic algorithm are developed. The worst-case performance of the proposed algorithm is discussed. A hybrid differential evolution algorithm is also developed to improve the solution quantity. Numerical results show that the hybrid algorithm is capable of obtaining high-quality solutions and exhibits a competitive performance

关键词: batch machine     flow shop     makespan     limited waiting time    

Repeated batch fermentation with water recycling and cell separation for microbial lipid production

Yumei WANG, Wei LIU, Jie BAO

《化学科学与工程前沿(英文)》 2012年 第6卷 第4期   页码 453-460 doi: 10.1007/s11705-012-1210-8

摘要: Large waste water disposal was the major problem in microbial lipid fermentation because of low yield of lipid. In this study, the repeated batch fermentation was investigated for reducing waste water generated in the lipid fermentation of an oleaginous yeast CX1 strain. The waste fermentation broth was recycled in the next batch operation after the cells were separated using two different methods, centrifugation and flocculation. Two different sugar substrates, glucose and inulin, were applied to the proposed operation. The result showed that at least 70% of the waste water was reduced, while lipid production maintained satisfactory in the initial four cycles. Furthermore, it is suggested that CX1 cells might produce certain naturally occurring inulin hydrolyzing enzyme(s) for obtaining fructose and glucose from inulin directly. Our method provided a practical option for reducing the waste water generated from microbial lipid fermentation.

关键词: batch fermentation     microbial lipid     Trichosporon cutaneum CX1     flocculation     waste water recycle    

Multistage-batch bipolar membrane electrodialysis for base production from high-salinity wastewater

《化学科学与工程前沿(英文)》 2022年 第16卷 第5期   页码 764-773 doi: 10.1007/s11705-021-2114-2

摘要: Bipolar membrane electrodialysis (BMED) is considered a state-of-the-art technology for the conversion of salts into acids and bases. However, the low concentration of base generated from a traditional BMED process may limit the viability of this technology for a large-scale application. Herein, we report an especially designed multistage-batch (two/three-stage-batch) BMED process to increase the base concentration by adjusting different volume ratios in the acid (Vacid), base (Vbase), and salt compartments (Vsalt). The findings indicated that performance of the two-stage-batch with a volume ratio of Vacid:Vbase:Vsalt = 1:1:5 was superior in comparison to the three-stage-batch with a volume ratio of Vacid:Vbase:Vsalt = 1:1:2. Besides, the base concentration could be further increased by exchanging the acid produced in the acid compartment with fresh water in the second stage-batch process. With the two-stage-batch BMED, the maximum concentration of the base can be obtained up to 3.40 mol∙L–1, which was higher than the most reported base production by BMED. The low energy consumption and high current efficiency further authenticate that the designed process is reliable, cost-effective, and more productive to convert saline water into valuable industrial commodities.

关键词: bipolar membrane electrodialysis     multistage-batch     base production     high-salinity wastewater    

Emerging electrochemical processes for materials recovery from wastewater: Mechanisms and prospects

Lingchen Kong, Xitong Liu

《环境科学与工程前沿(英文)》 2020年 第14卷 第5期 doi: 10.1007/s11783-020-1269-2

摘要: Abstract • Mechanisms for selective recovery of materials in electrochemical processes are discussed. • Wastewaters that contain recoverable materials are reviewed. • Application prospects are discussed from both technical and non-technical aspects. Recovering valuable materials from waste streams is critical to the transition to a circular economy with reduced environmental damages caused by resource extraction activities. Municipal and industrial wastewaters contain a variety of materials, such as nutrients (nitrogen and phosphorus), lithium, and rare earth elements, which can be recovered as value-added products. Owing to their modularity, convenient operation and control, and the non-requirement of chemical dosage, electrochemical technologies offer a great promise for resource recovery in small-scale, decentralized systems. Here, we review three emerging electrochemical technologies for materials recovery applications: electrosorption based on carbonaceous and intercalation electrodes, electrochemical redox processes, and electrochemically induced precipitation. We highlight the mechanisms for achieving selective materials recovery in these processes. We also present an overview of the advantages and limitations of these technologies, as well as the key challenges that need to be overcome for their deployment in real-world systems to achieve cost-effective and sustainable materials recovery.

关键词: Materials recovery     Electrosorption     Capacitive deionization     Redox processes     Electrochemical precipitation    

Effect of different gas releasing methods on anaerobic fermentative hydrogen production in batch cultures

Sheng CHANG, Jianzheng LI, Feng LIU, Ze YU

《环境科学与工程前沿(英文)》 2012年 第6卷 第6期   页码 901-906 doi: 10.1007/s11783-012-0403-1

摘要: Decreasing hydrogen partial pressure can not only increase the activity of the hydrogen enzyme but also decrease the products inhibition, so it is an appropriate method to enhance the fermentative hydrogen production from anaerobic mixed culture. The effect of biogas release method on anaerobic fermentative hydrogen production in batch culture system was compared, i.e., Owen method with intermediately release, continuous releasing method, and continuous releasing+ CO absorbing. The experimental results showed that, at 35°C, initial pH 7.0 and glucose concentration of 10 g·L , the hydrogen production was only 28 mL when releasing gas by Owen method, while it increased two times when releasing the biogas continuously. The cumulative hydrogen production could reach 155 mL when carbon dioxide in the gas stream was continuously absorbed by 1 mol·L NaOH. The results showed that acetate was dominated, accounting for 43% in the dissolved fermentation products in Owen method, whereas the butyrate predominated and reached 47%–53% of the total liquid end products when releasing gas continuously. It is concluded that the homoacetogenesis could be suppressed when absorbing CO in the gas phase in fermentative hydrogen production system.

关键词: batch fermentation     hydrogen production     biogas releasing     hydrogen pressure     homoacetogenesis    

Nitrifying and denitrifying bacteria in aerobic granules formed in sequencing batch airlift reactors

WANG Fang, YANG Fenglin, QI Aijiu

《环境科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 184-189 doi: 10.1007/s11783-007-0032-2

摘要: The purpose of this study was to investigate nitrifying bacteria and denitrifying bacteria isolated from aerobic granules. Aerobic granules were formed in an internal-circulate sequencing batch airlift reactor (SBAR) and biodegradation of NH3--N was analyzed in the reactor. Bacteria were isolated and determined from aerobic granules using selected media. The growth properties and morphology of bacteria colonies were observed by controlling aerobic or anaerobic conditions in the culture medium. It was found that bacteria in aerobic granules were diverse and some of them were facultative aerobes. The diversity of bacteria in aerobic granules was a premise of simultaneous nitrification and denitrification.

Influence of aeration intensity on the performance of A/O-type sequencing batch MBR system treating azo

Xinhua WANG, Jingmei LI, Xiufen LI, Guocheng DU

《环境科学与工程前沿(英文)》 2011年 第5卷 第4期   页码 615-622 doi: 10.1007/s11783-011-0362-y

摘要: Among the numerous parameters affecting the membrane bioreactor (MBR) performance, the aeration intensity is one of the most important factors. In the present investigation, an anoxic/aerobic-type (A/O-type) sequencing batch MBR system, added anoxic process as a pretreatment to improve the biodegradability of azo dye wastewater, was investigated under different aeration intensities and the impact of the aeration intensity on effluent quantity, sludge properties, extracellular polymeric substances (EPS) amount generated as well as the change of permeation flux were examined. Neither lower nor higher aeration intensities could improve A/O-type sequencing batch MBR performances. The results showed 0.15 m ·h aeration intensity was promising for treatment of azo dye wastewater under the conditions examined. Under this aeration intensity, chemical oxygen demand (COD), ammonium nitrogen and color removal as well as membrane flux amounted to 97.8%, 96.5%, 98.7% and 6.21 L·m ·h , respectively. The effluent quality, with 25.0 mg·L COD, 0.84 mg·L ammonium nitrogen and 8 chroma, could directly meet the reuse standard in China. In the meantime, the sludge relative hydrophobicity, the bound EPS, soluble EPS and EPS amounts contained in the membrane fouling layer were 70.3%, 52.0 mg·g VSS, 38.8 mg·g VSS and 90.8 mg·g VSS, respectively, which showed close relationships to both pollutant removals and membrane flux.

关键词: batch membrane bioreactor     azo dye     aeration intensity     extracellular polymeric substances     sludge properties    

标题 作者 时间 类型 操作

A new approach for scheduling of multipurpose batch processes with unlimited intermediate storage policy

Nikolaos Rakovitis, Nan Zhang, Jie Li, Liping Zhang

期刊论文

Insights into influence of aging processes on zero-valent iron modified biochar in copper(II) immobilization: from batch solution to pilot-scale investigation

期刊论文

基于模糊规划的间歇过程生产调度建模

张虹,李歧强

期刊论文

A low power, eco-friendly multipurpose thermoelectric refrigerator

N. Jagan Mohan REDDY

期刊论文

Functional flax fiber with UV-induced switchable wettability for multipurpose oil-water separation

期刊论文

The energy consumption in a batch stripper and a batch rectifier

Xianbao CUI, Tianyang FENG, Ying ZHANG, Zhicai YANG,

期刊论文

Influence of entrainer recycle for batch heteroazeotropic distillation

Laszlo Hegely, Peter Lang

期刊论文

Micromixing performance of the teethed high shear mixer under semi-batch operation

期刊论文

Two-stage scheduling on batch and single machines with limited waiting time constraint

Zhongshun SHI, Zewen HUANG, Leyuan SHI

期刊论文

Repeated batch fermentation with water recycling and cell separation for microbial lipid production

Yumei WANG, Wei LIU, Jie BAO

期刊论文

Multistage-batch bipolar membrane electrodialysis for base production from high-salinity wastewater

期刊论文

Emerging electrochemical processes for materials recovery from wastewater: Mechanisms and prospects

Lingchen Kong, Xitong Liu

期刊论文

Effect of different gas releasing methods on anaerobic fermentative hydrogen production in batch cultures

Sheng CHANG, Jianzheng LI, Feng LIU, Ze YU

期刊论文

Nitrifying and denitrifying bacteria in aerobic granules formed in sequencing batch airlift reactors

WANG Fang, YANG Fenglin, QI Aijiu

期刊论文

Influence of aeration intensity on the performance of A/O-type sequencing batch MBR system treating azo

Xinhua WANG, Jingmei LI, Xiufen LI, Guocheng DU

期刊论文