Title (srp)

Katalizovana i nekatalizovana metanoliza triglicerida : kinetika reakcije i simulacija procesa : Doktorska disertacija

Author

Glišić, Sandra B.

Contributor

Skala, Dejan
Šerbanović, Slobodan
Veljković, Vlada

Description (srp)

Glavni problem za širu primenu metil estara masnih kiselina (biodizela) je njihova visoka cena proizvodnje. Proizvodna cena biodizela bi mogla da se smanji kako smanjenjem cene sirovina (biljnih ulja, životinjskih masti, korišćenih ulja) tako i primenom efikasnijih tehnologija za njegovu proizvodnju. Da bi se tehnologija sinteze biodizela, koja se danas najviše primenjuje u industrijskim uslovima, poboljšala ili eventualno predložila nova, neophodno je da se sam reakcioni sistem jasno definiše. U ovom radu je analizirana sinteza u natkritičnim uslovima, definisana fazna ravnoteža sistema triglicerida i metanola, kao i njihovih proizvoda, metil estara, diglicerida, monoglicerida i glicerola. Metodom doprinosa grupa izračunati su kritični parametri i na osnovu eksperimentalnih podataka rastvorljivosti triglicerida u metanolu u natkritičnim uslovima i njihovom regresijom na više temperature i pritiske, definisan je termodinamički model, koji najbolje opisuje ponašanje analiziranog sistema. Simulacijom u programskom paketu ASPENplus analizirano je ponašanje ovako kompleksnog sistema, ravnoteža i broj faza tokom reakcije metanolize. U zavisnosti od reakcionih uslova, pritiska i temperature, kao i molskog odnosa metanol – ulje, predloženi su kinetički modeli i određeni kinetički parametri reakcije metanolize triglicerida u subkritičnim i natkritičnim uslovima. Ovako definisani kinetički modeli su potvrdili postojanje promene faza, odnosno broja faza u reakcionom sistemu u zavisnosti od temperature i pritiska. Sa definisanim termodinamičkim parametrima i kinetičkim modelom, izvršena je simulacija procesa natkritične proizvodnje biodizela i ovaj postupak sinteze upoređen sa homogeno katalizovanom metanolizom triglicerida. Dobijeni rezultati ukazuju da je proizvodnja biodizela u natkritičnim uslovima konkurentna i realno primenljiva u industrijskim uslovima. Na osnovu detaljne analize i simulacije procesa ukazani su nedostaci postojeće klasične tehnologije zasnovane na primeni alkalnog katalizatora. Takođe, ukazano je da če se buduća industrijska proizvodnja biodizela zasnivati na primeni heterogenog katalizatora.

Description (srp)

Hemija i hemijska tehnologija - Hemijsko inženjerstvo / Chemistry and chemical technology - Chemical engineering Datum odbrane: 12.06.2009.

Description (eng)

The main obstacle for wider application of biodiesel is its relatively high cost. This is still the truth, although the price gap between petroleum based diesel fuel and biodiesel is narrowing due to the recent increase of crude oil prices. The overall cost of biodiesel fuel could be reduced either by the reduction of raw material cost (vegetable oil, animal fat, used vegetable oil) or by the application of more efficient processing technology. For the further development of biodiesel production technology or application of some advance and new technology, it is necessary clearly defined the reaction system. In this study it was detailed defined the phase equilibria for the system triglycerides and methanol as well as for their products (methyl esters, diglycerides, monoglycerides and glycerol). It was calculated the new value for the critical parameters based on group contribution method. Regression of experimental data for solubility of triglycerides in methanol in subcritical conditions and simulation to higher temperature and pressure, it was define the thermodynamic model which truly describe such system (RK-Aspen equation of state). Simulation with ASPENplus software it was defined the behavior of such complex system during the reaction of methanolysis of triglycerides. The phase content and phase transition was clearly described, also. Kinetic model and kinetic parameters of methanolysis reaction in subcritical and supercritical conditions are proposed in dependenc of temperature and pressure and methanol to oil molar ratio. Such defined the kinetic model was matched and have explanation with the phase equilibria of analyzed system (the number of phases for subcritical and supercritical conditions for reaction). Furthermore, with defined therodinamic and kinetic data, it was performed the process design for the supercritical production of biodiesel. The obtained results are comperd with design’s data for the clasicaly production of biodiesel (alkali homgenious catalysed reaction). There are compared by process parameter and process unit as well as by energy consumption. The obtained result of such analyses showed that biodiesel production at supercritical methanol represents the competitive technology for biodiesel production, and not only competitive with classical one (homogeneous alkali catalysed alcoholysis) but even less energetic required, what have influence on biodiesel price. Based on this design it was pointed the unsufficiences of classic biodiesel technologu as well as their solutions. The end of this study is focused on determination the best route for reducing the energy consumption in biodiesel production at supercritical condition. It was shown that future technology must be mainly based on use of heterogeneous catalyst at moderate pressure and temperature as well as at optimal molar ratio of methanol and oil.

Object languages

Serbian

Date

2009

Rights

Creative Commons License
This work is licensed under a
CC BY-NC-ND 2.0 AT - Creative Commons Attribution - Non-Commercial - No Derivative Works 2.0 Austria License.

http://creativecommons.org/licenses/by-nc-nd/2.0/at/legalcode