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甲醇生产主精馏塔的模拟计算 总被引:3,自引:0,他引:3
对甲醇精馏主塔进行了模拟计算,并以一实际生产装置沿塔身的温度与浓度分布进行了验证。结果表明,水和甲醇的平均偏差为0.9%,微量杂质,不计丁基油,平均偏差为49ppm,温度平均偏差为2.9℃。说明本计算方法及采用的模型参数是可靠的,可用于工程计算。本文进一步指出,为降低废水中醇类含量,较理想的方法是选择合适的精甲醇与丁基油的采出量。 相似文献
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预测聚合物溶液体系的气液平衡数据是热力学模型的一个重要内容.热力学模型大体可分3类,以过量吉布斯自由GF能表示的最为常用.本文选取基于GF的Flory-Huggins(FH)、UNIQUAC、UNIFAC和ENSIC 4种常用模型进行评述,认为FH模型出现较早,形式最简单;UNIQUAC模型发展较完善,应用范围较广,UNIFAC模型弥补了UNIQUAC模型参数缺乏的不足,应用最为;ENSIC模型具有较好的预测效果,但参数难以获得. 相似文献
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采用平衡法测定了丙烯腈+水、己二腈+水、丙腈+水三个二元体系在不同温度(303.15、313.15、323.15、333.15K)下的液-液相平衡数据;并采用NRTL(α=0.2,α=0.3)模型和UNIQUAC模型对液-液平衡数据进行了关联.结果显示,NRTL和UNIQUAC模型对三个二元体系在不同温度下的互溶度关联的目标函数值均小于1×10-17,实验值与计算值吻合较好,绝对偏差小于0.009,关联精度较高.该研究结果可为丙烯腈、丙腈和水三元平衡溶解度数据的模拟和预测提供可靠的基础数据,并对电解二聚法生产己二腈中电解液的分离提纯工艺具有一定的指导意义. 相似文献
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乙酸乙酯-乙醇-水-甘油体系中部分组分之间汽液平衡数据的测定及关联 总被引:1,自引:0,他引:1
生产乙酸乙酯的产物乙醛、乙醚采用精馏容易脱除,乙酸乙酯、乙醇、水形成二元、三元共沸物,则难以分离,共沸法和萃取精制乙酸乙酯,工艺较复杂,能耗大;复合萃取一次可得99%以上乙酸乙酯,同时可得95%以上乙醇,用水量仅为原料量的2倍,工艺简单,能耗低。本文测定乙酸乙酯、乙醇、水在甘油中的γ^∝及二元体系的VLE数据,由三对二元体系模型参数计算乙酸乙酯-水-甘油及乙酸乙酯一乙醇一甘油的VLE数据,为萃取模拟计算及试验提供基础数据。 相似文献
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乙醇水溶液与二乙氧基甲烷的萃取分离 总被引:6,自引:0,他引:6
目前DEM与乙醇水溶液的分离均采用精密精馏法[1],由于DEM的沸点与乙醇水溶液的共沸点接近,很难得到98%以上的DEM,本文以二甘醇为萃取剂,以UNIQUAC方程为模型[6],采用微机模拟逆流萃取分离结果,并进行逆流萃取试验。1 逆流萃取模拟计算以UNIQUAC方程为模型,采用二甘醇为逆流图1 液液萃取工艺流程Fig.1 liquid liquidextractiontechnicalchart萃取剂模拟计算DEM与乙醇水溶液的分离结果,工艺流程如图1所示,塔顶为萃余相③,含高纯度的DEM,塔底为富含乙醇和水的萃取相②,萃取相送精馏塔分离,精馏塔底溶剂循环使用,塔顶可得到… 相似文献
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水合物反应液中水活度系数的计算对水合物相平衡特性的研究及水合物技术的应用具有重要意义。 通过调研大量的国内外资料,概括了Margules、Wilson、NRTL、UNIQUAC及UNIFAC活度系数方程及其关联式等模型及其应用,结果表明,Margules模型常用于二元体系活度系数的计算,但对高温高压体系条件下的溶液适用性较差;Wilson模型参数回归误差稍大且不适于溶质与离子不能完全互溶体系;UNIQUAC模型在含水或咪唑类离子反应液体系中误差较大;多元离子体系相平衡的研究中常选择NRTL模型;UNIFAC模型拟合效果较好,可实现较高浓度体系活度系数的精确计算,应用较广泛。 水活度关联方程参数拟合效果好,且准确度高,但在高温高压水合物反应液体系中的计算仍是一个技术难点,是今后的研究方向。 相似文献
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用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
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《Tetrahedron》2014,70(21):3377-3384
The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative. 相似文献
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Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献