Academic literature on the topic 'Alcohol dehydration'
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Journal articles on the topic "Alcohol dehydration"
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Kostetskyy, Pavlo, Nicholas Athanasis Zervoudis, and Giannis Mpourmpakis. "Carboranes: the strongest Brønsted acids in alcohol dehydration." Catalysis Science & Technology 7, no. 10 (2017): 2001–11. http://dx.doi.org/10.1039/c7cy00458c.
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Budimarwanti, C., and Karim Theresih. "SYNTHESIS OF AMYL VANILLIL ETHER AS WARMING AGENT FROM VANILLIN." Jurnal Sains Dasar 4, no. 2 (May 20, 2016): 100. http://dx.doi.org/10.21831/jsd.v4i2.9084.
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Synthesis of amyl vanillyl ether from vanillin was carried out by two different methods, two-steps reaction method and one-step reaction method. In two-steps reaction method beginning with the first stage reduction of vanillin with NaBH4 to obtain vanillyl alcohol. Then, dehydration vanillyl alcohol and amyl alcohol with concentrated sulfuric acid. Synthesized compound were identification by TLC, IR spectroscopy and GCMS. In one step reaction method the vanillyl alcohol as a result of reduction of vanillin with NaBH4 are not isolated in advance, immediately reacted with amyl alcohol to form amyl vanillyl ether compound with concentrated HCl dehydrator. The results of two-steps reaction method showed that the reduction reaction of vanillin with NaBH4 produced vanillyl alcohol. Vanillyl alcohol compound that produced is white powder and yield 41.28%. Vanillyl amyl ether compound could not synthesis by dehydration from vanillyll alcohol from reduction of vanillin and amyl alcohol. Ether compound from dehydration of vanillyl alcohol from reduction of vanillin and amyl alcohol is diamyl ethers. Method one reaction step successfully synthesized amyl vanilil ether compound. Amyl vanilil ether compound that produced is liquid, colorless and yield 86.42%. Keywords: amyl vanillil ether, vanillin, vanillil alcohol, amyl alcohol
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Volynskii, N. P., S. E. Shevchenko, and A. I. Nekhaev. "Dehydration of ethyl alcohol." Russian Journal of General Chemistry 79, no. 2 (February 2009): 326–27. http://dx.doi.org/10.1134/s1070363209020273.
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Luy, J. C., and J. M. Parera. "Acidity control in alcohol dehydration." Applied Catalysis 26 (January 1986): 295–304. http://dx.doi.org/10.1016/s0166-9834(00)82559-2.
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Klemm, W. R. "Dehydration: A new alcohol theory." Alcohol 7, no. 1 (January 1990): 49–59. http://dx.doi.org/10.1016/0741-8329(90)90060-p.
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Kittur, Arjumandbanu Abdulwahab, Gattumane Motappa Madhu, Sudhina Hulagurmath Rashmi, Sowmya Surapanhalli Rajanna, and Naveenkumar Ashok Yaranal. "Polymeric Nanocomposites for Dehydration of Isopropyl Alcohol–Water Mixtures by Pervaporation." Chemistry & Chemical Technology 12, no. 3 (September 15, 2018): 310–17. http://dx.doi.org/10.23939/chcht12.03.310.
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Gnus, Małgorzata, Gabriela Dudek, Roman Turczyn, Artur Tórz, Dorota Łącka, Mieczysław Łapkowski, and Krystyna Konieczny. "PERVAPORATIVE INVESTIGATION OF ETHYL ALCOHOL DEHYDRATION." Progress on Chemistry and application of Chitin and its Derivatives XX (September 30, 2015): 54–63. http://dx.doi.org/10.15259/pcacd.20.05.
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Kraetz, L. "Dehydration of alcohol fuels by pervaporation." Desalination 70, no. 1 (1988): 487. http://dx.doi.org/10.1016/0011-9164(88)85036-7.
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Kraetz, L. "Dehydration of alcohol fuels by pervaporation." Desalination 70, no. 1-3 (November 1988): 481–85. http://dx.doi.org/10.1016/0011-9164(88)85075-6.
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Larsen, Gustavo, Edgar Lotero, Lucı́a M. Petkovic, and David S. Shobe. "Alcohol Dehydration Reactions over Tungstated Zirconia Catalysts." Journal of Catalysis 169, no. 1 (July 1997): 67–75. http://dx.doi.org/10.1006/jcat.1997.1698.
Full textDissertations / Theses on the topic "Alcohol dehydration"
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Bukusoglu, Emre. "Dehydration Of Alcohol Solutions Obtained From A Solvent Recovery Process By Pervaporation." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612196/index.pdf.
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Solvent recovery is gaining importance in the chemical production processes to reduce the costs and because of environmental concerns. Therefore separation schemes for recovery and recycle of solvents used in printing and packaging industry were developed. However, a low value by-product, mainly ethyl alcohol and isopropanol, is obtained during the solvent recovery process. If the water concentration of this mixture is decreased below 0.1% by weight, the value of it increases significantly. To dehydrate this stream, a pervaporation-adsorption separation scheme is developed in this study.
The effect of pervaporation process parameters, such as temperature, feed flow rate, permeate side pressure, feed water and ethyl acetate concentration, on the performance of the PERVAP 2211 and 2201 membranes of Sulzer Chem-tech®using the real industrial by-product solution obtained from a local company are investigated. Pervaporation tests were conducted using a home made experimental setup equipped with 148 cm2 rectangular shaped membrane module. Permeates obtained from these experiments were analyzed using a gas chromatograph equipped with FID and the water concentration of the feed solutions were analyzed using Karl-Fisher titration. Besides, adsorption studies were conducted using zeolite 3A in a fixed bed column. As a result of this study, PERVAP 2201 membranes showed higher fluxes with a slightly lower permeate water concentration compared to PERVAP 2211 at the at ranges studied. The increase in the pervaporation performance was observed with an increase in the temperature, permeate side vacuum and feed flow rate over the membrane. Therefore, concentrated-mode experiments were conducted at 70°
C, 2 torr permeate side pressure and 1.6 L/min of feed flow rate using the findings of the parametric studies and the retentate of this experiments were further dehydrated using liquid phase adsorption. Finally, the water concentration of the solution was decreased to 0.04% by weight.
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Benson, Tracy John. "Dehydration of an ethanol/water mixture using lignocellulosic based adsorbents." Master's thesis, Mississippi State : Mississippi State University, 2003. http://library.msstate.edu/etd/show.asp?etd=etd-11102003-171312.
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Pera, Titus Marc. "Preparation, characterization and modeling of zeolite NaA membranes for the pervaporation dehydration of alcohol mixtures." Doctoral thesis, Universitat de Barcelona, 2006. http://hdl.handle.net/10803/1530.
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Zeolite NaA membranes have attracted special attention in the last years in light of their high selectivities (>40000) and fluxes in the dehydration of alcohol/water mixtures. This Ph.D. thesis is aimed at developing new methods for zeolite NaA membrane synthesis together with the characterization of their mass transfer mechanisms for their further application in membrane reactors.The membranes have been prepared onto the outer and inner surface of ceramic tubular supports by in situ and seeded hydrothermal synthesis. To avoid the shortcoming of low accessibility to the lumen of the tubes in inner-side membrane synthesis, a new seeding technique is here presented that relies on a controled filtration of a zeolite particle suspension. The seeding weight gain strongly depends on the retentate flow rate, transmembrane pressure and pH. On the other hand, for the hydrothermal syntheses, four different techniques have been used: (1) synthesis in a batch system, (2) synthesis in a centrifugal force field, (3) semi-continuous synthesis and (4) continuous synthesis. The as-synthesized membranes have been characterized by gas permeance, PV of ethanol/water mixtures, XRD and SEM. The results reveal that techniques (3) and (4) that involve gel renewal improve the PV performance, with selectivities and fluxes up to 16000 and 1.2 kg m-2 h-1, respectively, for ethanol/water mixtures 92:8 wt.% at 323 K. Moreover, despite the presence of a certain amount of intercrystalline defects in the layers, their use is suitable for dehydrating long-chain alcohols and ethers, which opens up the possibility of being used in membrane reactors to carry out etherificarion reactions.
The PV process in zeolite NaA membranes has been modeled using the generalized Maxwell-Stefan diffusional theory, including the explicit contribution of intercrystalline porosity and the binary adsorption isotherm of water and ethanol. The surface diffusivities of water obtained from the fittings to PV fluxes are ca. 3-5 orders of magnitud higher than those obtained from adsorption kinetics experiments. This apparent contradiction might be ascribed to the role of grain boundaries between adjacent zeolite grains as fast diffusion paths.
Les membranes zeolítiques hidrofíliques, caracteritzades per les seves elevades relacions Al/Si, constitueixen una camp de recerca prometedor per a la deshidratació de mescles orgàniques mitjançant pervaporació (PV). Més específicament, les membranes de zeolita NaA han rebut especial atenció per les seves altes selectivitats (>40000) y fluxos en la deshidratació de mescles alcohol/aigua. En aquest context, l'objectiu principal d'aquesta tesi doctoral ha estat el desenvolupament de nous mètodes de preparació d'aquestes membranes, juntament amb la caracterització dels seus mecanismes de transport per a la seva posterior aplicació en reactors de membrana.
En els capítols IV i V de la memòria es descriu la preparació de membranes de zeolita NaA sobre suports tubulars ceràmics, tant a la seva superficie externa com interna, mitjançant síntesi hidrotèrmica in situ y creixement secundari. En aquesta configuració, la sembra del suport és complexa a causa de la poca accessibilitat a la seva superficie interior. Per a paliar aquesta limitació, en esta tesi s'ha desenvolupat un mètode de sembra basat en la filtració controlada d'una suspensió de partícules de zeolita NaA. S'ha observat que el guany de de sembra [mg cm-2] depèn fortament del cabal de retingut, pressió transmembranal y pH. D'altra banda, la síntesi hidrotèrmica de les capes s'ha realizat mitjançant quatre tècniques diferents: (1) síntesi en un sistema batch, (2) síntesi sota l'acció d'un camp centrífug, (3) síntesi en un sistema semi-continu i (4) síntesi en un sistema continu. Les capas sintetizades s'han caracteritzat mitjançant permeació de gasos, PV de mescles etanol/aigua, DRX y SEM. Els resultats obtinguts indiquen que la renovació del gel a l'interior dels tubs millora la qualitat pervaporativa de les membranes, amb selectivitats y fluxos de fins a 16000 y 1.2 kg m-2 h-1, respectivament, per a mescles etanol/aigua 92:8 wt.% a 323 K. Les membranes també mostren bones prestacions en la deshidratació d'alcohols primaris C1-C5 i mescles ternàries 1-pentanol/DNPE/aigua. Els resultats també reflecteixen que, a pesar de la presència de defectes en les capes, el seu ús sembla adequat per a deshidratar alcohols y èters de cadena llarga, la qual cosa en possibilitaria l'ús en reactors de membrana per a dur a terme reaccions d'eterficació. Aquesta possibilitat s'il·lustra a partir de la simulació d'un reactor de membrana de zeolita NaA per a la reacció de l'1-pentanol a di-n-pentil éter (DNPE) en fase líquida catalitzada per resines àcides de bescanvi iònic.
En el capítol VI es presenta un model matemàtic per a la predicció de distribucions de tamanys de porus en membranes de MF, UF i NF a partir de la teoria de moments a partir de tres experiments independients: (1) permeació de N2 en règim Knudsen, (2) permeació d'agua pura, i (3) difusió iònica no impedida. Posteriorment, aquest mètode s'ha extès a la caracterització de defectes meso- i macroporosos en capes zeolítiques a partir d'una col·lecció d'experiments de PV. S'observa que les membranes de zeolita NaA perden parcialment la seva capacitat deshidratadora per a porositats intercristal·lines >10-4.
Finalment, en els capítols VII y VIII es descriu la modelització del procés de PV en membranes de zeolita NaA mitjançant la teoria generalitzada de Maxwell-Stefan. La modelització inclou explícitament la contribució de la porositat intercristal·lina i la informació de l'adsorció binària d'aigua i etanol. La modelització de l'equilibri d'adsorció binari s'ha realitzat a partir de la teoria IAST i la versió modificada PRAST. Els models resultants representen satisfactòriament les tendències experimentals. Les difusivitats superficials de l'aigua obtingudes a partir dels ajustos a fluxos de PV són 3-5 ordres de magnitud superiors als obtinguts a partir de cinètiques d'adsorció. Aquesta aparent contradicció s'argumenta a partir de la contribució dels límits de gra en les capes, el quals podrien actuar com a camins de difusió ràpida.
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Pienaar, Cornelia. "Evaluation of entrainers for the dehydration of C2 and C3 alcohols via azeotropic distillation." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/20357.
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Thesis (MScEng)--Stellenbosch University, 2012.ENGLISH ABSTRACT: Distillation is the most widely used separation technique in the chemical process industry and typically accounts for approximately one-third of the total capital cost and more than half of the total energy consumption of a typical petrochemical-chemical plant. Therefore, the design and optimization of the distillation sequence are of critical importance to the economics of the entire process. Azeotropic mixtures cannot be separated into their pure components via normal distillation. Enhanced distillation techniques such as heterogeneous azeotropic distillation should be considered for these mixtures. Isobaric vapour-liquid-liquid equilibrium (VLLE) data are highly important for the design and analysis of heterogeneous distillation columns. However, limited VLLE data are available in literature due to the difficulties involved with measuring such data. The objective of this work was to systematically evaluate and compare the performance of selected entrainers (including benzene, DIPE and cyclohexane) for the dehydration of C2 and C3 alcohols. To meet this objective, phase equilibrium data had to be measured. Isobaric VLLE at standard atmospheric conditions were measured with a dynamic Guillespie unit equipped with an ultrasonic homogenizer, which prevented liquid-liquid separation. Vapour-liquid equilibrium (VLE) and VLLE data were measured for ethanol/water/di-isopropyl ether (DIPE), n-propanol/water/DIPE and n-propanol/water/isooctane. The VLE data were found to be thermodynamically consistent according to the L-W (Wisniak 1993) and McDermott-Ellis consistency tests. No thermodynamic consistency test, specifically for VLLE data, could be found in literature, but the LLE part of the data followed a regular profile according to the Othmer-Tobias correlation. The binary DIPE/water and isooctane/water azeotropes, as well as ternary ethanol/DIPE/water and n-propanol/isooctane/water azeotropes, as measured in this work, agree well with those found in literature. Regressed parameters for the NRTL, UNIQUAC, and UNIFAC models, generally improved the model predictions compared with built-in Aspen parameters. This confirmed the importance of having actual measured VLLE data available for evaluation and improvement of estimations by thermodynamic models. NRTL predicted the ethanol/DIPE/water and n-propanol/DIPE/water VLLE most accurately. Despite the improved regressed parameters for n-propanol/isooctane/water predictions, the models are still considered unsuitable for accurate prediction of the VLLE behaviour of this system. Separation sequences were simulated in Aspen with built-in and regressed parameters, respectively, to illustrate the significant effect such inaccurate parameters have on these simulations. Phase diagram (VLLE data) evaluation of ethanol and isopropanol (IPA) with various entrainers, as found in literature, indicated that DIPE might be a good entrainer for the dehydration of these alcohols. Benzene and cyclohexane are generally used as entrainers in industry for these processes. Benzene is however carcinogenic and therefore an alternative has to be found (United States Department of Labour - Occupational Safety & Health Administration 2011). Separation sequences were simulated for ethanol dehydration with benzene and DIPE as entrainers, respectively. Taking cost and safety into account, DIPE can be considered an acceptable replacement for benzene as entrainer for ethanol dehydration. A separation sequence was also simulated for the dehydration of IPA with DIPE as entrainer and compared to a simulation with cyclohexane (Arifin, Chien 2007) as entrainer. DIPE was found to be a reasonable alternative to cyclohexane as entrainer for IPA dehydration. Two other separation sequences were simulated as practical examples where DIPE could be used as entrainer for the recovery of ethanol or n-propanol from aqueous Fischer Tropsch waste streams. DIPE is therefore found to be a feasible alternative entrainer to benzene and cyclohexane for the dehydration of ethanol and IPA via heterogeneous azeotropic distillation, based on pre-liminary cost considerations, separation ability and safety. Better entrainers than DIPE may exist, but from the data available in literature and the measurements made in this work DIPE appears to be superior to benzene, cyclohexane and isooctane.
AFRIKAANSE OPSOMMING: Distillasie is die mees algemeen-gebruikte skeidingstegniek in die chemiese proses-industrie. Dit is tipies verantwoordelik vir ʼn derde van die totale kapitaalkoste en meer as die helfte van die totale energie verbruik op ʼn tipiese petrochemiese chemiese aanleg. Daarom is die ontwerp en optimering van ʼn distillasie trein van kardinale belang vir die winsgewendheid van die proses. Azeotropiese mengsels kan nie slegs deur normale distillasie in suiwer komponente geskei word nie. Gevorderde distillasie tegnieke soos heterogene azeotropiese distillasie moet dus oorweeg word vir sulke mengsels. Isobariese damp-vloeistof-vloeistof ewewigsdata is een van die belangrikste fisiese eienskappe vir die ontwerp van heterogene distillasie kolomme. Die hoeveelheid damp-vloeistof-vloeistof ewewigsdata wat beskikbaar is in die literatuur is egter baie beperk omdat dit moeilik is om die data te meet. In hierdie werk is isobariese damp-vloeistof-vloeistof ewewigsdata met ʼn dinamiese Guillespie eenheid, by standaard atmosferiese druk gemeet. Die eenheid is toegerus met ʼn ultrasoniese homogeniseerder om vloeistof-vloeistof skeiding te voorkom. Temperatuur is gemeet met ʼn akkuraatheid van 0.03oC by 0oC. Die sisteem se druk is konstant gehou op 101.3 kPa met ʼn akkuraatheid van 0.35 % VSU (Vol Skaal Uitset). Die ewewigsamestellings is met ʼn relatiewe akkuraatheid van 2 % gemeet. Daar is damp-vloeistof en damp-vloeistof-vloeistof ewewigsdata van etanol/water/di-isopropiel eter (DIPE), npropanol/ water/ DIPE en n-propanol/water/iso-oktaan gemeet. Die damp-vloeistof ewewigsdata is deur die LW (Wisniak 1993) en McDermott-Ellis termodinamiese konsistensie toetse getoets en konsistent bevind. Geen termodinamiese konsistensie toets spesifiek vir damp-vloeistof-vloeistof ewewigsdata kon gevind word nie. Die Othmer-Tobias korrelasie dui egter aan dat die vloeistof-vloeistof ewewig gedeelte van die data ʼn reëlmatige gang volg. Die binêre DIPE/water en iso-oktaan/water azeotrope en ternêre etanol/DIPE/water en n-propanol/iso-oktaan/water fase-ewewigte wat in hierdie werk gemeet is, stem ooreen met die wat in die literatuur te vind is. Die parameters vir die modelle (NRTL, UNIQUAC en UNIFAC) wat in hierdie werk bestudeer is, is in die algemeen verbeter deur regressie van die eksperimentele data. Dit dui daarop dat dit belangrik is om eksperimentele damp-vloeistof-vloeistof ewewigsdata te hê om die voorspellings van termodinamiese modelle mee te evalueer en te verbeter. Die etanol/water/ DIPE en n-propanol/water/DIPE damp-vloeistof-vloeistof ewewigsdata is die akkuraatste deur NRTL voorspel. Ten spyte van die verbeteringe wat deur regressie behaal is met die NRTL en UNIQUAC parameters vir n-propanol/water/isooktaan, word hierdie modelle steeds nie as gepas vir die voorspelling van hierdie datastel beskou nie. Skeidingsreekse is gesimuleer met die ingeboude Aspen parameters en regressie parameters, onderskeidelik, om te illustreer dat onakkurate parameters ʼn beduidende effek op sulke simulasies het. Die evaluasie van fase diagramme van etanol en IPA met verskeie skeidingsagente, wat in die literatuur te vind is, dui aan dat DIPE ʼn goeie skeidingsagent kan wees vir die dehidrasie van hierdie alkohole. Skeidingsreekse vir die dehidrasie van etanol met benseen en DIPE, onderskeidelik, is gesimuleer. Met koste en veiligheid in ag geneem, is daar gevind dat DIPE ʼn aanvaarbare plaasvervanger vir benseen as skeidingsagent vir etanol dehidrasie kan wees. Daar is ook ʼn skeidingsreeks vir die dehidrasie van IPA met DIPE as skeidingsagent gesimuleer en met ʼn simulasie (Arifin, Chien 2007) wat sikloheksaan as skeidingsagent gebruik, vergelyk. Daar is bevind dat DIPE ʼn redelike alternatief vir sikloheksaan kan wees as skeidingsagent vir IPA dehidrasie. Nog twee skeidingsreekse is gesimuleer om as praktiese voorbeelde te dien van die gebruik van DIPE as skeidingsagent om etanol of n-propanol vanaf waterige Fischer-Tropsch afvalstrome te herwin. Daarom is daar bevind dat DIPE ʼn geldige alternatiewe skeidingsagent vir benseen en sikloheksaan is, gebaseer op koste, skeidingsvermoë en veiligheid. Daar kan beter skeidingsagente as DIPE bestaan, maar vanuit die data beskikbaar in literatuur en die metings geneem in hierdie werk, is DIPE die beste.
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Brits, Leanne. "Vapour-liquid-liquid equilibria measurements for the dehydration of low molecular weight alcohols via heterogeneous azeotropic distillation." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96850.
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Thesis (MEng)--Stellenbosch University, 2015.ENGLISH ABSTRACT: The operation and optimisation of a distillation train directly effects the total energy consumption of a typical processing plant. With this in mind, the efficient separation of low molecular weight alcohol azeotropes, using heterogeneous azeotropic distillation, is of great economic and environmental importance. Heterogeneous azeotropic distillation involves the addition of an extraneous component, known as an entrainer, to the mixture to facilitate separation. Benzene has long been replaced as the entrainer of choice, due to its carcinogenic nature, and research into finding a more suitable entrainer has commenced. To determine if an entrainer is suitable for a particular separation, detailed phase behaviour information of the ternary alcohol/entrainer/water system is required; vapour-liquid (VLE), vapour-liquid-liquid (VLLE) equilibria data and the composition of all azeotropes present. This is complicated by the fact that thermodynamic models (like the nonrandom two-liquid (NRTL), universal functional (UNIFAC) and universal quasichemical (UNIQUAC) activity coefficient models) often fail to predict the phase equilibria of ternary systems. The lack of available experimental phase equilibria data, and the inability of thermodynamic models to predict phase equilibria data, has fueled the need for the experimental determination of accurate, repeatable isobaric VLE, VLLE and azeotropic data. With this in mind, this research is focused on the experimental determination of VLE, VLLE and azeotropic data for three low molecular weight alcohol/entrainer/water systems at 101.3 kPa. Following an extensive literature study on azeotropes, applicable separation techniques and available VLE and VLLE data in literature, the ethanol/2-butanone/water, n-propanol/2-butanone/water and iso-propanol/2-butanone/water systems were chosen for experimental investigation. The experimental determination was carried out in a Gillespie type still, equipped with an ultrasonic homogenizer. The temperature and pressure accuracies of the equipment were found to be 0.03°C and 2mbar respectively. The chosen experimental methodology was verified, and its repeatability tested, through the measurement of isobaric VLE and VLLE data of ethanol/isooctane, ethanol/n-butanol/water and n-propanol/isooctane/water systems at 101.3 kPa and subsequent comparison of the measured data with literature data. The compositional error reported, taking into account experimental and analysis effects, is ±0.014 mole fraction. All experimentally determined data sets, verification and new data, were tested for thermodynamic consistency by using the Wisniak modification of the Herrington test, the L/W consistency test, as well as the McDermott-Ellis consistency test, and found to be consistent. The Othmer-Tobias correlation was used to ensure the measured LLE data followed a steady trend, with all R-values larger than 0.910. For all three of the new systems chosen, the absence of ternary heterogeneous azeotropes was noted. The presence of a ternary homogeneous azeotrope was found for both the ethanol/2-butanone/water and iso-propanol/2-butanone/water systems. No ternary azeotropes are present for the n-propanol/2-butanone/water system. Suitable entrainers were compared to 2-butanone (MEK) by plotting measured data and literature information of five similar alcohol/entrainer/water systems on a ternary phase diagram. It was found that MEK could not be considered as a suitable entrainer for heterogeneous azeotropic distillation of ethanol, n-propanol and IPA. This is due to the absence of a ternary heterogeneous azeotrope for the aforementioned alcohol/MEK/water systems. Finally, the ability of thermodynamic models (NRTL, UNIFAC and UNIQUAC) to predict experimental data was determined both visually and through descriptive statistics. This entailed the inspection of ternary phase diagrams and the calculation and evaluation of average absolute deviation (AAD) and and average absolute relative deviation (AARD%) values. The measured data were modelled in Aspen Plus®. It was found that none of the models could predict the ternary systems with acceptable accuracy and the data were regressed. In general, the regressed parameters for the NRTL, UNIFAC and UNIQAC models improved the model predictions when compared to the built-in Aspen parameters. The UNIFAC model predicted the ethanol/MEK/water and n-propanol/MEK/water systems most accurately while none of the models could predict the IPA/MEK/water systems with acceptable accuracy.
AFRIKAANSE OPSOMMING: Die ontwerp en optimering van 'n distillasietrein het ‘n duidelike effek op die totale energieverbruik van ‘n tipiese prosesaanleg. Met dit in gedagte, is ‘n meer doeltreffende skeiding van lae molekulêre massa alkohol aseotrope, met behulp van heterogene aseotropiese distillasie, voordelig vir die ekonomie en die omgewing. Heterogene aseotropiese distillasie behels die toevoeging van 'n eksterne komponent, wat bekend staan as 'n skeidingsagent, om uiteindelik die skeiding te fasiliteer deur die komponente se dampdrukke te verander. Benseen was in die verlede ‘n gewilde skeidingsagent, maar dit is a.g.v. sy karsenogeniese eienskappe nie meer aanvaarbaar om te gebruik nie. Nuwe navorsing in hierdie veld fokus dus onder andere op die identifisering van meer geskikte skeidingsagente. Om te bepaal of 'n skeidingsagent geskik is, word indiepte fasegedrag inligting benodig, i.e. damp-vloeistof en damp-vloeistof-vloeistof ewewigsdata en die samestelling van alle aseotrope teenwoordig. Ongelukkig kan termodinamiese modelle dikwels nie die fasegedrag van ternêre stelsels voorspel nie. Dit, sowel as die beperkte beskikbaarheid van eksperimentele ewewigsdata in die literatuur, het dus hierdie navorsing aangevuur. Die projek het gefokus op die experimentele bepaling van damp-vloeistof en damp-vloeistof-vloeistof ewewigsdata en aseotropiese data vir drie alkohol/skeidingsagent/water-stelsels by 101.3 kPa. Na ‘n indiepte literatuurstudie van aseotrope, gepaste skeidingstegnieke en beskikbare damp-vloeistof en damp-vloeistof-vloeistof ewewigsdata, is 2-butanone (MEK) gekies as ‘n moontlike skeidingsagent en die etanol/MEK/water-, n-propanol/MEK/water- en iso-propanol/MEK/water-stelsels gekies vir eksperimentele ondersoek. Die data is met ‘n dinamiese Gillespie eenheid gemeet, toegerus met ‘n ultrasoniese homogeniseerder om vloeistof-vloeistof skeiding te voorkom. Die akkuraatheidsbande van temperatuur- en druk meetinstrumente was 0,03°C en 2 mbar, onderskeidelik. Die eksperimentele metode en die herhaalbaarheid van metings is bevesting, deur die isobariese damp-vloeistof en damp-vloeistof-vloeistof ewewigsdata van etanol/iso-oktaan, etanol/n-butanol/water en n-propanol/iso-oktaan/water te vergelyk met onafhanklike stelle ooreenstemmende data uit die literatuur. Die gesamentlike eksperimentele en analitiese fout wat gemaak kon word tydens bepaling van molfraksie samestellings was ±0.014 molfraksie. Alle gemete eksperimentele data is getoets vir termodinamiese samehang deur middel van beide die L/W en McDermott-Ellis konsekwentheidstoetse. Die Othmer-Tobias korrelasie is gebruik om seker te maak dat die gemete LLE data ‘n konstante tendens volg, met alle R-waardes groter as 0.910. Vir al drie van die nuwe stelsels wat gekies is, was ‘n drieledige heterogene aseotroop afwesig. Die teenwoordigheid van drieledige homogene aseotrope is egter waargeneem vir die etanol/MEK/water- en IPA/MEK/water-stelsels. Geen drieledige aseotrope is vir die n-propanol/MEK/water-sisteem gevind nie. Alle gemete data, asook literatuur inligting van vyf soortgelyke alkohol/skeidingsagent/water sisteme, is op ‘n drieledige fase diagram voorgestel om die skeidingsagente met mekaar te vergelyk. Hiervolgens word dit getoon dat MEK nie as ‘n gepaste skeidingsagent vir heterogene aseotropiese distillase beskou kan word nie a.g.v. die afwesigheid van ‘n drieledige heterogene aseotroop in die voorgenoemde alkohol/MEK/waterstelsels. Die vermoë van die termodinamiese modelle (NRTL, UNIFAC en UNIQUAC) om die eksperimentele data te voorspel is visueel (per grafiek) sowel as deur beskrywende statistiek bepaal. Dit behels die inspeksie van drieledige fasediagrame en die berekening en evaluasie van die gemiddelde absolute afwyking en gemiddelde absolute relatiewe afwykingswaardes. Hierdie teoretiese data is met Aspen Plus® bepaal. Nie een van die modelle kon die drieledige stelsels se fasegedrag met aanvaarbare akkuraatheid voorspel nie. Die parameters vir die NRTL-,UNIFAC- en UNIQUAC-modelle kan verbeter word deur middel van regressie, in vergelyking met die ingeboude Aspen parameters. Dit is bevind dat die UNIFAC model die etanol/MEK/water- en n-propanol/MEK/water-stelsel die beste kan voorspel. Nie een van die bogenoemde modelle kon egter die fasegedrag van die IPA/MEK/water-stelsel voorspel nie.
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Morais, Marcilio Machado. "Estudo da retenção de aroma de abacaxi na secagem em atmosfera normal e modificada." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267670.
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Orientador : Maria Aparecida SilvaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: Na secagem de determinados alimentos como frutas, juntamente com a água há também a evaporação de outras substâncias voláteis presentes em quantidades menores. Quando essas substâncias possuem características odoríferas, a qualidade do produto final seco pode ser prejudicada devido à diminuição do aroma. Por isso, torna-se interessante considerar nos estudos de secagem a evaporação, além da água, desses outros componentes voláteis. A modificação da atmosfera tem sido utilizada somente em armazenamento, principalmente de vegetais, mas pode também ser estendida à secagem, pois pode influenciar a perda de voláteis responsáveis pelas características sensoriais do produto final. No presente trabalho, desenvolveu-se um sistema de secagem, no qual a atmosfera de secagem pode ser modificada pela adição de gases ou líquidos. O referido sistema é composto por um túnel de secagem, feito de paredes de policarbonato e de um sistema de aquisição e controle de dados, onde se pode acompanhar continuamente o peso da amostra e controlar a temperatura do gás de secagem. As amostras submetidas à secagem foram um sistemamodelo e o abacaxi (Smooth Cayenne). O primeiro foi desenvolvido a partir da composição química básica do abacaxi e da adição de outros compostos, contendo um dos principais componentes do aroma desta fruta (hexanoato de etila). A atmosfera de secagem foi modificada pela adição de etanol (0,5% v/v) ao ar por meio de um bico atomizador, localizado na parte superior do túnel de secagem. Nos experimentos de secagem (temperatura: 40 e 60ºC; velocidade do gás de secagem: 0,42 e 0,84 m/s; umidade relativa do gás de secagem: 8 e 23%), acompanhou-se a variação do teor de água com o tempo e a variação do teor dos componentes do aroma, sendo estes últimos determinados por cromatografia gasosa. Desenvolveu-se a metodologia analítica de determinação do aroma em ambos os sistemas, a partir dos estudos de extração de aromas e de análise cromatográfica gasosa. O aroma presente no sistema-modelo foi extraído em hexano e os componentes voláteis do aroma do abacaxi foram extraídos em éter etílico. A modificação da atmosfera de secagem do sistema-modelo com etanol, promoveu uma evaporação menos intensa de água e do componente do aroma. Já nos experimentos de secagem de abacaxi, aparentemente a evaporação do aroma foi mais intensa em atmosfera modificada do que em atmosfera normal
Abstract: In the drying of some foods such as fruits, along with water removal there is also the evaporation of other volatile substances present in lesser amounts. When these substances possess odoriferous characteristics, the quality of the final dried product can be lowered due to aroma loss. Therefore, it is interesting to consider in the drying studies the evaporation of these volatile components other than water. The modification of atmosphere has been used only in storage, especially for vegetables, but can be extended to drying since it can influence the loss of volatile components responsible for the sensorial characteristics of the final product. In the present work, a drying equipment was developed, in which the drying atmosphere can be modified by the addition of gases or liquids. The equipment is composed of a drying tunnel with polycarbonate walls and a data acquisition and control system, allowing continuous monitoring of the sample weight and control of the drying gas temperature. Samples submitted to drying were a model-system and pineapple (Smooth Cayenne). The model-system was developed from the basic chemical composition of pineapple and the addition of other compounds, containing one of the main aroma components (ethyl hexanoate). The drying atmosphere was modified by the addition of ethanol (0,5% v/v) to air using a double-fluid atomizer, which is located in the upper part of the drying tunnel. In the experiments, the variation with time of water content and aroma components concentration, were monitored. The latter was measured by gas chromatography. An analytical methodology for determination of the aroma components in both systems was developed from the studies of aroma extraction and gas chromatography. The aroma present in the model-system was extracted with hexane and the volatile aroma components from the pineapple were extracted with ethylic ether. The modification of the atmosphere with ethanol in drying of the model-system promoted a less intense evaporation of both water and aroma component. In the experiments of pineapple drying, apparently the evaporation of aroma was more intense in modified atmosphere than in normal atmosphere
Doutorado
Engenharia de Processos
Doutor em Engenharia Química
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Pérez-Maciá, María Ángeles. "Liquid Phase Dehydration of 1-Butanol to Di-n-butyl ether Experimental Performance, Modeling and Simulation of Ion Exchange Resins as Catalysts." Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/336975.
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Di-n-butyl ether (DNBE) is considered a very attractive oxygenate compound to reformulate diesel fuel. The research work performed along this thesis has clearly proven that sulfonic P(S-DVB) ion exchange resins are suitable catalysts for the synthesis of DNBE from the liquid phase dehydration of 1-butanol at the temperature range of 140-190 °C. A catalyst screening of acidic P(S-DVB) ion exchange resins showed that resins activity is enhanced with high acid capacities and with polymer matrices that are able to swell moderately allowing 1-butanol ready access to the active sites but without resulting in very large distance between the active centers. The resin Amberlyst 36 (oversulfonated, medium values of %DVB) proved to be the most active catalysts tested. However, in an industrial process a high selectivity to DNBE is extremely desirable from an environmental and economic standpoint, and resins that present a more elastic polymer matrix and higher ability to swell (gel type resins and Amberlyst 70) are the ones that present higher selectivities. Among all the tested resins, Amberlyst 70 was selected as the most suitable catalyst for industrial use given its excellent property balance: satisfactory activity, high selectivity to DNBE and thermal stability up to 463 K.
The relatively large value found for the thermodynamic equilibrium constant of DNBE formation and the fact that the formation of the secondary product 1-butene was extremely slow assure high conversion levels in an industrial etherification process. DNBE formation proved to be a slightly exothermic reaction, almost athermic, whereas 1-butene formation was found to be an endothermic reaction.
A comprehensive kinetic analysis enlightened that the reaction rate to form DNBE on Amberlyst 70 is highly influenced by the temperature and the presence of water. Two kinetic models that are able to predict the reaction rates of DNBE formation were identified. One of them stems from a Langmuir-Hinshelwood-Hougen-Watson (LHHW) formalism in which two adsorbed molecules of 1-butanol react to yield ether and water, being the reversible surface reaction the rate limiting step. The other one stems from a mechanism in which the rate limiting step is the desorption of water and where the adsorption of DNBE is negligible. Both models present several characteristics in common: in both water inhibition effect is correctly represented by a correction factor derived from a Freundlich adsorption isotherm; the number of free active sites is found to be negligible compared to the occupied ones; both present similar values of apparent activation energies (122 ± 2 kJ/mol). The study of the influence of typical 1-butanol impurities (isobutanol or ethanol and acetone, depending on the production process) demonstrated that isobutanol enhances the formation of branched ethers whereas ethanol leads to the formation of ethyl butyl ether and di- ethyl ether and acetone hardly reacts. In the second part of this thesis, it was demonstrated the suitability of molecular dynamics simulations in the understanding of the microscopic structure of P(S-DVB) ion-exchange resins and the prediction of their properties. Atomistic simulations of the structure of sulfonated P(S-DVB) resins reveled the decisive role that internal loops (closed polymer chains) play in defining the properties (i.e. density, porosity and structures) of highly cross-linked resins. Thus, although crosslinks ensure the local backbone structure, internal loops confer rigidity and loop architecture. It was also demonstrated that the developed atomistic model is able to predict the swelling behavior of ion-exchange resins in 1-butanol. From the swelling study performed by means of molecular dynamic simulation it was possible to characterize and quantify the structure of the swollen polymeric network at molecular level and to conclude that alcohol molecules tend to interact with the sulfonic groups of the resin.
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Cholerton, Mary. "Dehydration of alcohols using solid acid catalysts." Thesis, University of Southampton, 2014. https://eprints.soton.ac.uk/362638/.
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Solid acid catalysts were prepared through silicon substitution into aluminophosphate frameworks. Silicon incorporation was confirmed using solid state nuclear magnetic resonance spectroscopy. The nature of the acid sites generated was determined using Fourier Transform infrared spectroscopy. These materials were tested as catalysts for the dehydration of ethanol to ethylene at low operating temperatures. The materials were active for dehydration of ethanol to ethylene with significant differences observed between aluminophosphate frameworks both in terms of selectivity to the desired product but also in terms of the nature of the silicon substitution and the active sites. Links have been made between these properties and the observed catalytic behaviour. The effect of the catalytic framework is further explored though the testing of cobalt substituted aluminophosphates for ethanol dehydration. Silicon substituted aluminophosphates have been tested for the dehydration of 1-phenylethanol to styrene as an example of catalysis in the liquid phase. Here the influence of framework was particularly significant due to the large substrate. The effect of redox metals in the aluminophosphate framework has been investigated through the use of calcined and pre-reduced cobalt substituted aluminophosphates for the dehydration of ethanol to ethylene. Analysis of the catalytic product stream was combined with UV-Visible measurements to investigate potential redox processes occurring during the reaction time on stream and the influence of the oxidation state of the redox metal on the catalytic products of the reaction.
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Hintermeier, Peter Heinrich [Verfasser], Johannes A. [Akademischer Betreuer] Lercher, Johannes A. [Gutachter] Lercher, and Klaus [Gutachter] Köhler. "Zeolite catalyzed dehydration of substituted cyclic alcohols in aqueous phase / Peter Heinrich Hintermeier ; Gutachter: Johannes A. Lercher, Klaus Köhler ; Betreuer: Johannes A. Lercher." München : Universitätsbibliothek der TU München, 2017. http://d-nb.info/1151638560/34.
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Hintermeier, Peter Heinrich Verfasser], Johannes [Akademischer Betreuer] [Lercher, Johannes A. [Gutachter] Lercher, and Klaus [Gutachter] Köhler. "Zeolite catalyzed dehydration of substituted cyclic alcohols in aqueous phase / Peter Heinrich Hintermeier ; Gutachter: Johannes A. Lercher, Klaus Köhler ; Betreuer: Johannes A. Lercher." München : Universitätsbibliothek der TU München, 2017. http://d-nb.info/1151638560/34.
Full textBooks on the topic "Alcohol dehydration"
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Cohen, Jeffrey A., Justin J. Mowchun, Victoria H. Lawson, and Nathaniel M. Robbins. A 19-Year-Old Male with Stiffness and Weakness After Waking. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780190491901.003.0026.
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The distinctive, but somewhat odd, development of intermittent “attacks” of weakness/stiffness define this disorder. Interview of the patient to determine the impact of diet (including timing, content and relationship of attack to fasting), activity, emotional stress, alcohol intake, cold exposure, time of day and physiologic perturbations (eg – electrolytes, infection, dehydration, etc) help to confirm and categorize the periodic paralysis. Periodic paralyses are most often associated with a genetic channelopathy. However, they can also occur as a result of a secondary causes including thyroid disturbance or distal renal tubular acidosis. The clinical picture, laboratory investigation, and treatment of this condition are presented.
Book chapters on the topic "Alcohol dehydration"
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Klemm, W. R., and L. Yurttaş. "The Dehydration Theory of Alcohol Intoxication." In Alcohol Abuse Treatment, 169–85. Totowa, NJ: Humana Press, 1992. http://dx.doi.org/10.1007/978-1-4612-0363-6_7.
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TAKETANI, YUTAKA, and HIROYOSHI MINEMATSU. "Dehydration of Alcohol-Water Mixtures Through Composite Membranes by Pervaporation." In ACS Symposium Series, 479–90. Washington, D.C.: American Chemical Society, 1985. http://dx.doi.org/10.1021/bk-1985-0281.ch035.
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Moulik, Siddhartha, Siddhartha Moulik, D. Vaishnavi, S. Sridhar, and S. Sridhar. "Dehydration of Acetonitrile Solvent by Pervaporation through Graphene Oxide/Poly(Vinyl Alcohol) Mixed Matrix Membranes." In Membrane Processes, 123–40. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2018. http://dx.doi.org/10.1002/9781119418399.ch4.
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Elyassini, J., Q. T. Nguyen, and J. Néel. "PREPARATION AND STUDY OF POLYVINYL ALCOHOL)-POLY(ETHYLENE GLYCOL) BLEND FILMS IN DEHYDRATION OF ETHANOL BY PERVAPORATION." In Synthetic Polymeric Membranes, edited by Blahoslav Sedláček and Jaroslav Kahovec, 507–14. Berlin, Boston: De Gruyter, 1987. http://dx.doi.org/10.1515/9783110867374-050.
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"Section 12 Alcohol Dehydration by Pervaporation." In The Membrane Alternative: Energy Implications for Industry, 109–14. CRC Press, 2004. http://dx.doi.org/10.1201/9781482296570-15.
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Tejero, J., A. Zywert, R. Bringué, S. Kowalak, E. Janiszewska, and M. Iborra. "Zeolite catalysed dehydration of alcohol to linear ether." In Zeolites and related materials: Trends, targets and challenges, Proceedings of the 4th International FEZA Conference, 1115–18. Elsevier, 2008. http://dx.doi.org/10.1016/s0167-2991(08)80081-x.
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Kakodkar, Sachin B., Sajo P. Naik, Krishnaswamy Narasimhan, and Julio B. Fernandes. "Catalytic activity of copper Y zeolite towards dehydration of tertiary butyl alcohol." In Recent Advances In Basic and Applied Aspects of Industrial Catalysis, Proceedings of 13th National Symposium and Silver Jubilee Symposium of Catalysis of India, 729–35. Elsevier, 1998. http://dx.doi.org/10.1016/s0167-2991(98)80352-2.
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Banerjee, A. K., A. R. K. Sarma, P. K. Mukherjee, Dina Nath, N. Singh, H. Mahapatra, and D. S. Majumdar. "Selective dehydration of ethyl alcohol to ethylene by vapour phase catalytic process." In Recent Advances In Basic and Applied Aspects of Industrial Catalysis, Proceedings of 13th National Symposium and Silver Jubilee Symposium of Catalysis of India, 241–45. Elsevier, 1998. http://dx.doi.org/10.1016/s0167-2991(98)80291-7.
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Knight, Charles, and Saidi A. Mohiddin. "Alcohol septal ablation for obstructive hypertrophic cardiomyopathy." In Oxford Textbook of Interventional Cardiology, 683–98. Oxford University Press, 2010. http://dx.doi.org/10.1093/med/9780199569083.003.041.
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Hypertrophic cardiomyopathy (HCM) is a genetic disease occurring in approximately one in 500–1000 of the general population. HCM is often undiagnosed or misdiagnosed, and asymptomatic cases are often unrecognized. Asymmetric left ventricular (LV) hypertrophy (LVH) most often develops during the period of rapid body growth of adolescence, but it may be present in childhood or, rarely, before birth. Progressive LVH after age 20 is uncommon, but initial diagnosis even in old age is not. The hypertrophy predominantly involves the LV, and is often more marked than in any other cardiac disease. Hypertrophy may involve the right ventricle (RV), and an atrial myopathy may be progressive (left atrial enlargement [LA) and increased risks of atrial fibrillation [AF]). RV and LA involvement may be secondary to the LV disease, and/or a primary consequence of the basic molecular defect. The LVH represents hypertrophy and hyperplasia of several cell types, including cardiac myocytes, fibroblasts, and smooth muscle cells, along with excessive collagen and matrix deposition, and abnormalities of the microvasculature. The normal parallel arrangement of myocytes is often disturbed (fibre disarray). Clinical practice addresses three needs: 1) assessing and treating the symptomatic patient; 2) assessing and addressing prognostic risks; and 3) genetic counselling, family screening, and mutation detection (genetic testing). Symptoms due to HCM will often have a striking variation in severity when patients may describe good and bad days, exacerbation of symptoms following large meals and an intolerance of dehydration or a hot climate. Chest pain, with a quality similar to angina pectoris but often developing at rest, dyspnoea, palpitations, dizziness, pre/syncope, and fatigue are the common complaints. Although the relief of LV outflow obstruction (LVOTO) by alcohol septal ablation (ASA) for the management of symptomatic HCM is the focus of this chapter, we will first describe some of the more important features of HCM in order that this procedure can be placed in the context of a complex cardiac condition.
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Larsen, Gustavo, Edgar Lotero, Mark Nabity, Lucía Petkovic, and Carlos A. Querini. "Alcohol dehydration reactions as chemical precursors for coke formation and acidity probes in tungstated zirconia catalysts." In Catalyst Deactivation, Proceedings of the 7th International Symposium, 147–52. Elsevier, 1997. http://dx.doi.org/10.1016/s0167-2991(97)80149-8.
Full textConference papers on the topic "Alcohol dehydration"
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Sousa, Gustavo Gomes de, and José Roberto dos Santos Politi. "ASPECTOS ENERGÉTICOS E ELETRÔNICOS DA ZEÓLITA H-ZSM-5 NA AÇÃO CATALÍTICA DA REAÇÃO DE DESIDRATAÇÃO DE ÁLCOOIS." In VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol202087.
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Due to the growth of ecological concerns and the need to reduce dependence on fossil fuels, the dehydration of alcohols by acid catalysis has been used for the production of various hydrocarbons. Inside this theme, the H-ZSM-5 zeolite has been widely used as a catalyst for this reaction because its high efficiency. Thus, in order to understand the catalyzed reaction mechanism of the alcohol dehydration reaction, this work used the computational methodology ONIOM to study the catalytic behavior of the H-ZSM-5. It was modeled the dehydration reaction process for several alcohols (ethanol, propanol, isopropanol, butanol and 2-butanol) by modeling these alcohols within the zeolite cavity. The study was divided into 3 stages: the adsorption and protonation of alcohols by zeolite, the description of the hydroxyl outlet, and the formation of the double bond. The analysis of the results indicates that the first stage of the reaction occurs with the contact of alcohol with the zeolite cavity, where acid hydrogen promotes the protonation of alcohols, occurring differently for each alcohol. The dehydration process occurs, preferably, via E2 type elimination mechanisms. However, the profile of the energy curves indicates that for larger alcohols, the mechanism is intermediate between the elimination mechanisms E2 with some features of E1 (E2[E1]). Therefore, the zeolite converts alcohols to hydrocarbons in a specific way. Primary, lower-chain alcohols follow E2 mechanism, while secondary and longer-chain alcohols react by a slightly different mechanism, namely E2[E1].
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Chen, Hung-Hsing, Meng-Kai Chen, and I.-Lung Chien. "Using [EMIM][OAC] as entrainer for isopropyl alcohol dehydration via extractive distillation." In 2017 6th International Symposium on Advanced Control of Industrial Processes (AdCONIP). IEEE, 2017. http://dx.doi.org/10.1109/adconip.2017.7983790.
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Martinez-Pastor, Juan, Patricio Franco, and Domingo Moratilla. "Experimental Analysis of NC Fibers Sedimentation After Dehydration Process in Propellant Production." In ASME 2014 12th Biennial Conference on Engineering Systems Design and Analysis. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/esda2014-20399.
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During the manufacture of energetic materials, the dehydration process of nitrocellulose doughs provides a residual liquid mixture consisting of water, alcohol and nitrocellulose (NC) fibers. The separation of such fibers is required for distillation of alcohol, in order to make possible its reutilization in subsequent processes. In this work, an experimental analysis of sedimentation mechanisms of NC fibers contained in the fluid mixtures from nitrocellulose plants, is presented. The goal of the work is to obtain the time periods needed for complete sedimentation of these solid fractions (NC fibers). Cylindrical tanks with vertical or horizontal orientation are considered in this study, and the results obtained for both tank configurations are compared. From the experimental observations about sedimentation mechanisms of solid fraction in these fluid mixtures, recommendations about optimum times for NC fibers removal are proposed. These optimum times should be assumed as basic guidelines for scheduling and execution of the distillation process, due to its high influence on minimization of the overall operational costs for this process. Great discrepancies were registered between sedimentation times of NC fibers in vertical or horizontal tanks, with reductions in sedimentation rate of until 40% for recipients located in vertical orientation.
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Laksmono, J. A., I. M. Pratiwi, M. Sudibandriyo, A. Haryono, and A. H. Saputra. "Kinetic studies of adsorption in the bioethanol dehydration using polyvinyl alcohol, zeolite and activated carbon as adsorbent." In PROCEEDINGS OF THE 3RD INTERNATIONAL SYMPOSIUM ON APPLIED CHEMISTRY 2017. Author(s), 2017. http://dx.doi.org/10.1063/1.5011933.
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Valevakhin, G. N., A. A. Kontar, E. R. Galeev, and A. I. Dokhov. "Intensification of the process of dehydrating alcohol by microwave electromagnetic energy." In 2015 International Conference on Antenna Theory and Techniques (ICATT). IEEE, 2015. http://dx.doi.org/10.1109/icatt.2015.7136893.
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Thiemann, Thies, Goreti Morais, and Cristina das Neves Oliveira. "Application of the Thermal Dehydration of Benzylic Alcohols in the Preparation of Estra-1,3,5(10),6-tetraen-3,17-diol Derivatives." In The 9th International Electronic Conference on Synthetic Organic Chemistry. Basel, Switzerland: MDPI, 2005. http://dx.doi.org/10.3390/ecsoc-9-01491.
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