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Porous frozen material approach to freeze-drying of instant coffee
Freeze-drying desorption drying time initial saturation sublimation
2023/6/19
Porous frozen material with a certain initial porosity was prepared to explore its influence on freeze-drying experimentally. Soluble coffee was selected as the solute in aqueous solution and liquid n...
采用计算流体动力学(CFD)方法对通气强化气隙式膜蒸馏(AGMD)过程进行了数值模拟,并探讨了强化过程的传质机理.利用FLUENT软件结合流体体积函数(VOF)模型,以通气强化过程膜管内的气液两相流体为研究对象,设定氯化钠溶液为分离介质,氮气为强化介质进行模型建立与模拟分析.结果表明:渗透通量模拟数据与实验数据基本吻合;通气可增大渗透通量(J)与传质系数(k),降低浓度极化率(CPC),有利于膜蒸...
换热器网络在化工生产过程中起着能量回收、节能降耗的重要作用.常规换热器网络综合方法以经济性为目标进行参数和结构优化,导致换热设备之间的强烈耦合从而引起潜在的控制困难.此外,在实际生产中,无论是单个换热设备还是整个网络都不可避免地受到一些不确定性因素的干扰,故能够抵御这些扰动的可控性换热器网络是至关重要的.通过考虑网络结构与可控性之间的相互作用,提出可控性换热器网络综合方法,并基于多工况优化探究了决...
为了研究小型相变蓄冷系统操作参数、环境因素对系统性能的影响,在实验研究的基础上,建立系统的稳态数学模型,研究了系统性能与各参数的关系.蓄冷系统实验证明了所建模型的可靠性.模拟研究发现,增加冷凝器进口风温会提高压缩机功率、降低系统的COP(性能系数);增加冷凝器迎面风速对系统性能的提升存在上限;增加压缩机转数是提高制冷量、缩短蓄冷时间的最有效方法.
针对管状煤基炭膜气隙式膜蒸馏过程通量低的问题,进行膜蒸馏氯化钠溶液气液两相流强化实验及CFD模拟研究,探讨两相流流型和气含率对强化过程的影响.实验结果表明:N2流量对渗透通量影响的模拟结果与实验结果吻合较好.当进料流量为40 L·h-1、N2流量为50 L·h-1(气含率0.56)时,对应团状流,此时强化传质效果最好.模拟结果中强化过程的膜壁剪应力(约1.77 N·m-2)明显大于无强化过程(约0...
乳化剂对动态膜分离油水乳化液过程的影响
膜分离 乳化剂 分子模拟 渗透通量
2023/6/19
利用管状陶瓷膜基氧化锆动态膜分离油水乳化液,研究了4种工业常见乳化剂[斯盘80(SP-80)、十二烷基磺酸钠(SDS)、十二烷基硫酸钠(SLS)和十二烷基苯磺酸钠(SDBS)]对分离过程的影响.利用正交实验方法考察了乳化剂种类和浓度、乳化液温度和流量以及操作压力对过程的影响.正交实验结果表明,在SDS、1.0 g/L、50℃、120L/h和0.14MPa操作条件下,油水混合物稳定渗透通量最大.单因...
Superstructure-Based Simultaneous Optimization of a Heat Exchanger Network and a Compression-Absorption Cascade Refrigeration System for Heat Recovery
Heat Exchanger Network Refrigeration System Heat Recovery
2023/6/19
A heat exchanger network (HEN) plays an important role in the chemical process industry owing to its significant effect in energy recovery. A compression-absorption cascade refrigeration system (CACRS...
Molecular simulation and optimization on the microporous structure in carbon molecular sieve membrane for CO2/CH4 separation
Carbon molecular sieve membrane Gas separation Molecular simulation Pore size Structure optimization
2023/6/19
Zigzag-type pore model with a modified structure was proposed to evaluate the effect of micropore structure on the gas separation performance of carbon molecular sieve membranes (CMSM). Molecular simu...
Highly selective production of renewable p-xylene from bio-based2,5-dimethylfuran and ethylene over Al-modified H-Beta zeolites
p-xylene ethylene Al-modified H-Beta zeolites
2023/6/19
Highly selective synthesis of renewable p-xylene (PX) from bio-based 2,5-dimethylfuran (DMF) and ethylene was successfully realized on H-Beta zeolite catalysts with further Al-modifications. The influ...
Post-modification of desilicated MFI zeolites by phosphorous promoter
Desilicated zeolites Acidity tailoring Phosphorous modification Glycerol dehydration
2023/6/19
Developments in microporous zeolites-base catalysts have evidenced the necessity of acidity tailoring in order to meet the exact requirements of specific reactions, which can be achieved by the post-m...
Fuzzy comprehensive assessment of running condition for a large-scale centrifugal compressor set
Compressor Condition assessment Mathematical modeling Maximal information coefficient Dynamic deterioration degree Prediction
2023/6/19
A fuzzy comprehensive assessment method of running condition was constructed and applied to a large-scale centrifugal compressor set in a petrochemical corporation aiming at the monitoring and early w...
Low-cost electrochemical filtration carbon membrane prepared from coal via self-bonding
Electrochemical filtration carbon membrane Caking coal Self-bonding Organic pollutants Oxidation mechanism
2023/6/19
Electrochemical filtration membranes are highly effective for wastewater treatment. However, their relatively high production cost may limit their large-scale production and industrial application. In...
Pyrolysis behaviors of coal-related model compounds catalyzed by pyrite
Pyrite Catalytic pyrolysis Coal-related model compounds Tetrahydronaphthalene
2023/6/19
The pyrolysis behaviors of coal-related model compounds (bibenzyl and benzyloxybenzene) were investigated on a fixed-bed reactor catalyzed by pyrite (main component is FeS2). The pyrolysis products we...
草酸溶液处理对SAPO-34分子筛物性和催化性能的影响
SAPO-34 分子筛 草酸溶液 MTO反应
2023/6/19
用XRD、SEM、N2物理吸附、XRF、ICP-AES以及NH3-TPD、FT-IR、固体NMR和固定床甲醇制烯烃技术(MTO)反应评价等表征手段,研究了草酸溶液处理对SAPO-34分子筛的改性作用.结果表明,用草酸溶液对SAPO-34分子筛进行后处理可以通过刻蚀骨架在晶体中产生大孔,调变孔道结构,改善微孔扩散性能;选择性地降低分子筛的骨架硅含量,从而降低分子筛的酸强度和酸中心密度.将改性前后的分...
Desulfurization of 2-phenylcyclohexanethiol over transition-metal phosphides
2-Phenylcyclohexanethiol Cycloalkyl C-S bond Desulfurization Ni2P MoP WP Transition-metal phosphosulfide Piperidine
2023/6/19
The desulfurization of 2-phenylcyclohexanethiol (2-PCHT) was studied over Ni2P, MoP, and WP under 4.0 MPa H-2 or Ar at 240 degrees C. The hydrodesulfurization of 2-PCHT proceeded through three paralle...