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Hydrodynamic evaluation of a filter bed of porous material from stratified sedimentary rocks for the removal of turbidity in surface waters

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South African Journal of chemical engineering 2022年 39卷 97-105页

作者： Villabona-Ortíz, Angel Tejada-Tovar, Candelaria López-Barbosa, David Chemical Engineering Department Process Design and Biomass Utilization Research Group (IDAB) Universidad de Cartagena Avenida del Consulado St. 30. Cartagena de Indias 130015 Colombia

In this study, the behavior of a filter bed of stratified sedimentary rocks was evaluated through the analysis of turbidity removal efficiency and head losses. Two types of sands were used as materials, fine and medium, as well as crushed limestone. The materials were characterized to determine the average particle diameter, porosity, and permeability coefficient, obtaining respectively 0.17 mm, 0.39, and 1 × 10⁻³ cm/s for fine sand, 0.33 mm, 0.41, and 3 × 10⁻³ cm/s for medium sand, and 1.26 mm, 0.45, and 1 × 10⁻² cm/s for crushed limestone. Hydrodynamic analyses of the clean filter under conditions of rapid filtration were carried out, by which the different rates of filtration to be used in each experiment were determined, establishing a direct correlation between the rate of filtration and the thickness of the bed;in this way, it was possible to determine the maximum bed thickness that could be used to maintain a rate of rapid filtration higher than 120 m/day. A hydrodynamic study with synthetic turbid water prepared at 8 NTU using tap water and bentonite was also carried out. Total head losses and turbidity removal were studied for each material at a rate of 153 m/day with removal efficiencies of 93.7% for medium sand with a loss of 23 cm and 67.8% for limestone with a loss of 4.5 cm and a rate of 389 m/day. It is recommended to use the medium sand and limestone type material for use in surface water filtration processes. © 2021 The Authors

关键词： Bed Filtration Limestone Sand Stratification Surface water Turbidity

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Oxygen-free oxidative dehydrogenation of ethane over VOx/ γ-Al2O3 catalyst in riser reactor simulator

Oxygen-free oxidative dehydrogenation of ethane over VOx/ γ...

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2011 AIChE Annual Meeting, 11AIChE

作者： Al-Ghamdi, S. De Lasa, H. Volpe, M. Chemical Reactor Engineering Centre University of Western Ontario London ON Canada Process Development Group Research and Development Center Saudi Aramco Oil Company Dhahran Saudi Arabia Bahia Blanca Argentina

A study on the reactivity and stability of prepared 10 wt % VO x/γ-Al 2O 3 catalyst for ethane oxidative dehydrogenation under fluidized bed reaction conditions in CREC Riser Simulator reactor was conducted. Ethane w...

ISBN: (纸本)9780816910700

A study on the reactivity and stability of prepared 10 wt % VO _x/γ-Al ₂O ₃ catalyst for ethane oxidative dehydrogenation under fluidized bed reaction conditions in CREC Riser Simulator reactor was conducted. Ethane was used as a feed for the reaction and air was employed to regenerate the reduced catalyst sample. The prepared catalyst showed very stable reduction behavior over repeated reduction and oxidation cycles with reduction temperature ≈ 500°C and 85% reduction of V ₂O ₅. In the absence of gas-phase oxygen, ethane could be converted selectively to ethylene through the participation of lattice oxygen. The prepared catalyst displayed promising ethane conversions, ethylene selectivity, and catalyst stability during multiple reduction cycles at 550°-600°C. This is an abstract of a paper presented at the 2011 AIChE Annual Meeting (Minneapolis, MN 10/16-21/2011).

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Efficient conversion of benzene and syngas to toluene and xylene over ZnO-ZrO_(2)&H-ZSM-5 bifunctional catalysts

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Chinese Journal of chemical engineering 2022年第5期35卷 203-210页

作者： Xiao Zhao Xuan Shi Zhongshun Chen Long Xu Chengyi Dai Yazhou Zhang Xinwen Guo Dongyuan Yang Xiaoxun Ma School of Chemical Engineering Northwest UniversityXi’an 710069China International Science&Technology Cooperation Base for Clean Utilization of Hydrocarbon Resources Chemical Engineering Research Center of the Ministry of Education for Advanced Use Technology of Shanbei EnergyCollaborative Innovation Center for Development of Energy and Chemical Industry in Northern ShaanxiNorthwest UniversityXi’an 710069China School of Chemical Engineering Dalian University of TechnologyDalian 116024China Shaanxi Key Laboratory of Energy Chemical Process Intensification School of Chemical Engineering and TechnologyXi’an Jiaotong UniversityXi’an 710049China Shanxi yanchang Petroleum(Group)Corp.LtdXi’an 710000China

A series of ZnO-ZrO_(2) solid solutions with different Zn contents were synthesized by the urea coprecipitation method,which were coupled with H-ZSM-5 zeolite to form bifunctional *** a new benzene alkylation reagent,syngas was used instead of methanol to realize the efficient conversion of syngas and benzene into toluene and xylene.A suitable ratio of ZnO-ZrO_(2) led to the significant improvement in the catalytic performance,and a suitable amount of acid helped to increase the selectivity of toluene/xylene and reduce the selectivity of the by-products ethylbenzene and C^(9+) *** highest benzene conversion of 89.2%and toluene/xylene selectivity of 88.7%were achieved over 10%ZnO-ZrO_(2)&H-ZSM-5(Si/Al=23)at a pressure of 3 MPa and a temperature of 450℃.In addition,the effect of the zeolite framework structure on product distribution was *** to the molecular dynamics of aromatic hydrocarbons,H-ZSM-5 zeolites comprise 10-membered-ring pores,which are beneficial to the activation of benzene;hence,the conversion of benzene is higher.H-ZSM-35 and HMOR zeolites exhibited small eight-membered-ring channels,which were not conducive to the passage of benzene;hence,the by-product ethylbenzene exhibits a higher *** distance between the active centers of the bifunctional catalysts was the main factor affecting the catalytic performance,and the powder mixing method was more conducive to the conversion of syngas and benzene.

关键词： ZnO-ZrO_(2) Bifunctional catalysts Aromatics Alkylation of benzene Syngas

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The dissolution kinetics of industrial brine sludge wastes from a chlor-alkali industry as a sorbent for wet flue gas desulfurization (FGD)

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Journal of the Air & Waste Management Association 2018年第2期68卷 93页

作者： Masilela, E Lerotholi, L Seodigeng, T Rutto, H Product and Process Design Research Group Chemical Engineering Department Vaal University of Technology Vanderbijlpark South Africa

The disposal of industrial brine sludge waste (IBSW) in chlor-alkali plants can be avoided by utilization of IBSW as a sorbent in wet flue gas desulfurization (FGD). The shrinking core model was used to determine the dissolution kinetics of IBSW, which is a vital step in wet FGD. The effects of solid-to-liquid ratio (m/v), temperature, pH, particle size, and stirring speed on the conversion and dissolution rate constant are determined. The conversion and dissolution rate constant decreases as the pH, particle size, and solid-to-liquid ratio are increased and increases as the temperature, concentration of acid, and stirring speed are increased. The sorbents before and after dissolution were characterized using x-ray fluorescence (XRF), x-ray diffraction (XRD), and scanning electron microscopy (SEM). An activation energy of 7.195 kJ/mol was obtained and the product layer diffusion model was found to be the rate-controlling ***: The use of industrial brine sludge waste as an alternative sorbent in wet flue gas desulfurization can reduce the amounts of industrial wastes disposed of in landfills. This study has proved that the sorbent can contain up to 91% calcium carbonate and trace amounts of sulfate, magnesium, and so on. This can be used as new sorbent to reduce the amount of sulfur dioxide in the atmosphere and the by-product gypsum can be used in construction, as a plaster ingredient, as a fertilizer, and for soil conditioning. Therefore, the sorbent has both economic and environmental benefits.

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Distributed model predictive control for UK CO2 capture, transport and storage network

Distributed model predictive control for UK CO2 capture, tra...

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Computing and Systems Technology Division - Core Programming Topic at the 2011 AIChE Annual Meeting

作者： Arce, Alicia Dowell, Niall Mac Del Real, Alejandro J. Shah, Nilay Vega, Lourdes F. MATGAS Research Center Barcelona Spain Chemical Engineering Imperial College London London United Kingdom Research and Development IDENER Seville Spain Centre for Process Systems Engineering Department of Chemical Engineering Imperial College London London United Kingdom MATGAS Research Center and Carburos Metlicos Air Products Group Barcelona Spain

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Slag-coke interactions in the lead blast furnace 10

Slag-coke interactions in the lead blast furnace

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10th European Metallurgical Conference, EMC 2019

作者： Vanparys, Robin Brooks, Geoff Rhamdhani, Akbar Crivits, Tijl Swinburne University of Technology Dept. of Mechanical and Product Design Engineering Fluid and Process Dynamics Group John Street HawthornVIC3122 Australia Umicore Research and Development Watertorenstraat 33 Olen2250 Belgium

ISBN: (纸本)9783940276872

The interaction between metallurgical coke and slag is an important aspect of furnace operation in both lead production and ironmaking. This interaction occurs in the dripping zone of the blast furnace, where molten phases trickle through a bed of metallurgical coke. The impact on productivity is significant, as the majority of PbO reduction takes place in this zone of the lead blast furnace, and the reduction of FeO to Fe occurs in this zone of the iron blast furnace. The relative importance of direct and indirect reduction reactions in the dripping zone are not yet fully understood. The conditions of this zone are hard also to replicate in a laboratory experiment. In this work, a literature review on the conditions of the lead blast furnace and on the reduction kinetics of slags with metallurgical coke is included. Current studies on coke-slag interactions are performed either by sessile drop experiments or by submersion of coke into a molten slag. Using the sessile drop technique, the mechanism for direct reduction of oxides in a slag phase with solid carbonaceous material was found to be one of two gas-ferrying mechanisms for the case of FeO reduction. For PbO reduction, a gas-ferrying mechanism or a series of electrochemical reactions can be active. The different mechanisms are simultaneously operating, but the dominating mechanism depends on the wetting behaviour of the slag-carbon couple. Using the submersion technique, mass transfer was found to be rate determining for low lead or iron oxide activities, whereas for higher activities, the chemical reaction becomes rate limiting. These test methods have their merit when discussing bath smelting reactors or the hearth of the blast furnace, but both of these techniques are insufficient to represent the dripping zone of the furnace accurately. A new, dynamic, method of testing is therefore proposed. Copyright © European Metallurgical Conference, EMC *** rights reserved.

关键词： Slags

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Studies on polyoxymethylene dimethyl ethers production from dimethoxymethane and 1,3,5-trioxane over SO_(4)^(2-)/ZrO_(2)-TiO_(2)

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Chinese Journal of chemical engineering 2023年第9期61卷 24-36页

作者： Haoyu Yao Jiangcheng Li Jiangyan Li Xiangfeng Liang Gang Wang Haiyan Luo Environmental Resources Green Chemical Separation GroupQingdao Institute of BioenergyBioprocess TechnologyChinese Academy of SciencesQingdao 266101China Beijing Insight Chemistry Co. LtdBeijing 101121China Merck Sharp&Dohme Research and Development(China)Co. LtdBeijing 100101China Institute for Catalysis Hokkaido UniversityN-21W-10Sapporo 001-0021Japan CAS Key Laboratory of Green Process and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

Polyoxymethylene dimethyl ethers(OMEs)with physical properties similar to those of diesel has received significant attention as green additives for soot emission ***,series of SO_(4)^(2-)/ZrO_(2)-TiO_(2)catalysts were developed for OMEs production from dimethoxymethane(DMM)and1,3,5-trioxane through sequential formaldehyde monomer insertion into C-O bond of *** Lewis but Bronsted acid sites were identified to be active for the decomposition of 1,3,5-trioxane into formaldehyde unit,however,both of them are effective for the chain propagation of DMM via formaldehyde unit insertion into C-O *** studies indicated each chain growth step exhibited the same parameters and activation barrier on corresponding Bronsted and Lewis acid sites due to the same reaction mechanism and very similar chemical structure of ***,the catalytic stability investigation suggested the deactivation behavior was derived from the carbon deposition,and the decay factor could be exponentially correlated with the amount of coke accumulation.

关键词： Polyoxymethylene dimethylethers SO_(4)^(2-)/ZrO_(2)-TiO_(2) Chain propagation Kinetics Deactivation behavior

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MICROBIAL CATABOLITES AS chemical SYNTHESIS INTERMEDIATES - A COST-BENEFIT-ANALYSIS

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BIOTECHNOLOGY PROGRESS 1987年第3期3卷 127-130页

作者： JOHNSTON, JB WINICOV, H CUNNINGHAM, VL Chemical Engineering Department Smith Kline and French Laboratories Swedeland PA 19479 James B. Johnston is Senior Investigator in Chemical Engineering at Smith Kline and French Laboratories where he conducts research on biocatalytic transformations of organic compounds. Herbert Winicov recently retired from his position as Senior Investigator in Chemical Engineering at Smith Kline and French Laboratories. He specialized in cost estimation and costing of chemical processes under development. Virginia L. Cunningham is Assistant Director Chemical Engineering Smith Kline and French Laboratories. She heads a group responsible for process engineering and related environmental process analytical and costing issues. Dr. Cunningham is the author of ECAS—Environmental Cost Analysis System an expert system for estimating the costs of waste treatment in chemical processes.

Cost projections have been developed for a biologically mediated synthesis. Significant cost advantages can be realized using the biochemical approach.

关键词： BIOSYNTHESIS

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design of tundish nozzles alignment system for multistrand billet casters in continuous casting shop 14

Design of tundish nozzles alignment system for multistrand b...

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14th National Conference on Machines and Mechanisms, NaCoMM 2009

作者： Verma, Amresh Kumar Selvam, Sambandham Thirumalai Chaudhuri, Subhasis Mishra, Pradeep Kumar Singh, Arun Kumar Prasad Process Engineering Group Design and Engineering Division Research and Development Centre for Iron and Steel Steel Authority of India Limited Ranchi834002 India Continuous Casting Plant Durgapur Steel Plant Steel Authority of India Limited Durgapur West Bengal India

The Continuous Casting Shop in Durgapur Steel Plant has two 6-strand billet casters where the molten steel is brought in ladles and poured into tundish. The nozzles in the tundish need to be accurately aligned with respect to the moulds for smooth casting. In the earlier system, the alignment stands had fixed templates. Alignment of tundish nozzles with respect to the fixed template was difficult to achieve due to the inaccurate placement of tundish in the alignment stands and geometrical incorrectness of the tundish holes. Also the cranes were engaged for lengthy durations for aligning the tundish in the alignment stands. The new tundish nozzles alignment system comprises alignment mechanism having a movable template with precise guided motion, tundish holes alignment checking template for checking geometrical correctness of tundish holes, alignment fixtures and nozzle setting rods for aligning the nozzles and a PLC controlled hydraulic system for precise movement of alignment mechanism. The tundish alignment mechanism is a user friendly method to align the template with respect to tundish and place the nozzles accurately in the nozzle seating holes in the tundish during relining. It has also reduced the crane engagement time. This system has helped in increasing production by eliminating misalignment of the tundish nozzles. © 2009 14th National Conference on Machines and Mechanisms, NaCoMM 2009. All rights reserved.

关键词： Continuous casting

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Ultrasonic sludge disintegration in the presence of iron (II) as catalyst

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International Journal of Environment and Waste Management 2013年第1期12卷 65-76页

作者： Rai, Chockalingam Lajapathi Sivasamy, Arumugam Rekha, Subramani Process Development and Scale-up Group Chemical Engineering Division Central Leather Research Institute Adyar Chennai 600020 India

Increasing environmental awareness worldwide and subsequent regulations have led to the application of improved and novel technologies in excess sludge treatment. Sludge is the by-product of wastewater treatment plants rich in organic carbons, pathogens and metals. To enhance the ultrasonic sludge disintegration, a new method by introducing (Fe (II)) as a catalyst in the process has been explored. Studies were conducted to elucidate the parameters governing the disintegration process. The disintegration profiles show two phases distuption of micro-organisms resulting release of organic-substances and mineralisation of dissolved organic substances. The optimal level of process parameters results in better solubilisation and mineralisation. © 2013 Inderscience Enterprises Ltd.

关键词： Microorganisms

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