Title (eng)

Thermodynamic characterization of multicomponent mixtures of esters and alcohols at atmospheric and elevated temperatures and pressures: doctoral dissertation

Author

Aissa, Mohamed Ahmed M., 1980-, 54716169

Contributor

Kijevčanin, Mirjana, 1970-, 12801895
Radović, Ivona, 1974-, 8393319
Ivaniš, Gorica, 1986-, 55044361
Živković, Nikola, 1970-, 55066633

Description (srp)

Biogoriva su privukla značajnu paţnju, kako za trenutnu, tako i za buduću upotrebu zahvaljujući svojim prednostima kao obećavajućim alternativnim, ekološkim i ekonomičnim gorivima, a posebno se ističu biodizel i bioalkoholi. Da bi se biodizel koristio u dizel motorima moraju mu se poboljšati volumetrijska i transportna svojstva (tj. gustina i viskoznost), jer utiču na raspršivanje, atomizaciju i sagorevanje goriva. Pored toga, izvedene termodinamičke veličine, kao što su izotermska stišljivost i izobarni koeficijent termičkog širenja, značajno utiču na proces atomizacije, a samim tim i na potrošnju goriva u dizel motorima. Stoga je poznavanje ovih svojstava pod različitim pritiscima i temperaturama vaţno kako bi se predvideo i poboljšao rad dizel motora. Gustine, viskoznosti, brzine zvuka i indeksi refrakcije čistih komponenti: 1-butanola, 1-propanola, n-heksadekana, etil oleaat, etil linoleata, etil laurata, etil miristata i metil laurata su mereni na temperaturama T = (293,15 do 343,15 ) K pri atmosferskom pritisku. Izmerena vrednosti su poreĎene sa nekoliko dostupnih literaturnih podataka, I primećeno je dobro slaganje, ukupno prosečno pocentualno odstupanje (AAD) je bilo oko 0,04%, 0,07%, 3% i 0,1%, redom za gustine, brzine zvuka, viskoznosti i indekse refrakcije. Pored toga, merene su i gustine, viskoznosti, brzine zvuka i indeksi refrakcije ternerne smeše etil oleat + n-heksadekan + 1-butanol , i odgovarajućih binarnih smeša etil oleat + 1-butanol, etil oleat + 1-propanol, etil oleat + n-heksadekan, etil laure + 1-propanol, n-heksadekan + 1-butanol i nheksadekan + 1-propanol u temperaturnom opsegu T = (293,15 do 343,15) K sna atmosferskom pritisku. Merenja su izvršena na Anton Paar DSA 5000 M ureĎaju za merenje gustine i brzine zvuka, Anton Paar SVM 3000 digitalnom viskozimetru i Anton Paar RKSA 156 refraktometru. Iz eksperimentalnih podataka su, takoĎe, izračunai I brojni termodinamički paramtetri, kao na pr. Dopunska molarna zapremina (VE), odstupanje viskoznosti (∆), odstupanje indeksa refrakcije (∆nD), dopunska molarna Gibsova energija aktivacije viskoznog toka (∆G*E) i višak izentropske kompresibilnosti (∆κs). Binarna i ternarna svojstva su nakon toga korelisana u zavisnosti od molekulskih sastava primenom Redlih-Kister i Nagata i Tamura jednačina, redom, a potom su korištena za analizu molekulskih interakcija unutar smeša...

Description (eng)

Biofuels have attracted considerable attention for current and future utilization because of their benefits as promising alternative, ecological and economical viable fuels, with particular reference to biodiesel and alcohols. In order to use biodiesel in diesel engines, the volumetric and transport properties of the fuel (i.e. density and viscosity) must be improved since they affect spray properties, atomization and combustion processes of a fuel. In addition, the derived thermodynamic magnitudes, such as isothermal coefficient and isobaric thermal expansion coefficient, greatly influence the atomization process and, consequently, the fuel consumption of diesel engines. Therefore, knowledge of these properties at different pressures and temperatures is important in order to predict and improve the performance of diesel engines. Densities, viscosities, sound velocities and refractive indices of pure components: 1-butanol, 1-propanol, ethyl laurate, ethyl linoleate, ethyl myristate, ethyl oleate, methyl laurate and n-hexadecane were measured at temperatures T= (293.15 to 343.15) K and atmospheric pressure. The measured values were compared to several available literature data, and good agreement was noticed: an overall absolute average percentage deviation (AAD) of 0.04%, 0.07%, 3 % and 0.1% for density, speed of sound, viscosity and refractive index data, respectively. Besides that, densities, viscosities, speeds of sound and refractive indices of ternary mixture ethyl oleate + n-hexadecane + 1-butanol (3), and for the corresponding binary mixtures: ethyl laurate + 1- propanol, ethyl oleate + 1-butanol, ethyl oleate + 1-propanol, ethyl oleate + n-hexadecane, nhexadecane + 1-butanol and n-hexadecane + 1-propanol were measured in the temperature range T= (293.15 to 343.15) K at atmospheric pressure. The measurements were performed on an Anton Paar DSA 5000 M density and sound velocity meter, Anton Paar SVM 3000 digital viscometer, and Anton Paar RXA 156 refractometer. From the experimental data, a number of thermodynamic parameters were also calculated, namely, excess molar volumes (VE), viscosity deviation functions (∆), deviations in refractive index (∆nD), excess molar Gibbs energy of activation of viscous flow (∆G*E) and deviation in isentropic compressibility (∆κs). The binary and ternary properties are then correlated as a function of the mole fraction by using the Redlich–Kister and Nagata and Tamura equations, respectively, and then used to analyze molecular interactions present in the mixtures...

Description (eng)

Chemical engineering / Hemijsko inženjerstvo Datum odbrane: 09.06.2020.

Object languages

English

Date

2019

Rights

Creative Commons License
This work is licensed under a
CC BY 2.0 AT - Creative Commons Attribution 2.0 Austria License.

CC BY 2.0 AT

http://creativecommons.org/licenses/by/2.0/at/

Subject

experimental measurements, viscosity, density, refractive index, ester, alcohol, excessthermodynamic properties, molecular interactions, viscosity modeling

OSNO - Opšta sistematizacija nau?nih oblasti -- Inženjerstvo. Tehnika uopšte (34) -- Tehnologija (3409) -- Hemijsko inženjerstvo (340905)

Identifiers