Production of biodiesel from waste oil and biobutanol by using guanidine catalysts

Veliki zahtjevi na ograničene svjetske sirovine potakli su razvoj kružne ekonomije. To je koncept prema kojem bi se proizvodi osmišljavali tako da budu dio vrijednosne mreže unutar koje bi ponovna uporaba i prenamjena proizvoda i materijala zajamčila trajnu reciklažu resursa. Europska unija potiče takav pametan i održiv razvoj, a recikliranje otpadnih jestivih ulja odlično se uklapa cijeli koncept. Za sintezu biodizela korišteno je otpadno restoransko ulje za koje je pokazano da ima iznimnu kvalitetu s obzirom na ključne parametre, n-butanol i N,N',N''-tris(3-dimetilamino)propil gvanidin (GV3) kao katalizator. Prednost novih gvanidinskih katalizatora je visoka aktivnost i izbjegavanje nepoželjnih procesa saponifikacije koji postoje kod konvencionalnih baznih katalizatora. Provedena su preliminarna ispitivanja u kojima je odabran n-butanol nad izo-butanolom. Također, određeni su značajni reakcijski parametri čije utjecaje na reakciju treba istražiti. Značajni parametri su temperatura, vrijeme reakcije, molarni omjer butanola i ulja i maseni udio katalizatora. Odziv procesa je konverzija otpadnog biljnog ulja u produkte. Određeno je i radno područje unutar kojeg će se ispitivanja vršiti i s tim je radnim područjem, pomoću programskog paketa Design Expert, izrađen Box-Behnken plan pokusa s četiri parametra koji se variraju na tri razine. Pokusi su izvršeni prema planu pokusa i rezultati su analizirani metodom 1H NMR. Na temelju rezultata pokusa, metodom odzivnih površina (RMS), dobiven je empirijski model unutar kojeg je za bilo koju kombinaciju ulaznih faktora (T, t, wkat i molarni omjer A/U) moguće predvidjeti odziv procesa, konverziju Xm. Valjanost modela provjerena je kroz različite funkcije cilja u kojima je zahtijevana visoka konverzija uz uštedu katalizatora i/ili butanola. Dobiveni optimalni parametri za jednu od funkcija cilja su: temperatura 40,5 °C, vrijeme 30 min, molarni omjer reaktanata od 9,82 mol/mol i maseni udio katalizatora 1,38 % uz predviđenu konverziju od 92,4 %. U tom je pokusu ostvarena konverzija 84,9 %.Great demands on worlds limited supplies of raw materials have induced the development of circular economy. It is a concept by which products would be made to be a part of a network in which reuse and redevelopment of products and materials would guarantee permanent recycling of resources. European Union encourages that sort of smart and sustainable development, and recycling of waste vegetable oils fits perfectly in that concept. Waste restaurant oil, that has exceptional quality in terms of key parameters, n-butanol and N,N',N''-tris(3-dimethylamino)propyl guanidine (GV3) as a catalyst have been used for biodiesel production. Advantage of novel guanidine catalysts is their high activity and avoiding undesirable saponification that happens when using conventional base catalysts. In preliminary tests n-butanol was chosen over iso-butanol. Also, important reaction parameters, whose influence should be estimated, were determined. Important parameters are reaction temperature, reaction time, butanol to oil ratio and mass share of catalyst. Response of the process is the conversion of waste vegetable oil into products. Operating range has been determined, and with that operating range, using program package Design Expert, a Box-Behnken design of experiments has been made with four parameters varied on three levels. Experiments were executed according to the design of experiments and results have been analyzed with 1H NMR method. Using the results, with response surface methodology (RMS), an empirical model has been made and with it, it is possible to predict the process response (conversion Xm) for any combination of input parameters (T, t, wkat and molar ratio A/U). Validation of the model has been made with different objective functions where a high conversion rate has been demanded with minimizing the catalyst mass share and/or minimizing butanol to oil ratio. Optimal parameters for one of objective functions are: temperature 40.5 °C, time 30 min, butanol to oil ratio 9.82 mol/mol and mass share of catalyst 1.38 % with predicted conversion rate of 92.4 %. Conversion for that experiment was determined to be 84.9 %

Simulation of Simple Linear Regression

Cilj rada je računalno simuliranje uvjeta koji su pretpostavka modela jednostavne linearne regresije i računalno potvrđivanje temeljnih formula. Za tu svrhu opisan je model jednostavne linearne regresije i diskutirane su matematičke osnove na kojima se model zasniva. Navedene su formule za procjenu koeficijenata regresijskog pravca i intervala povjerenja (relacije (1.4), (3.5.1), (3.5.2), (3.8) i (3.9)) te za procjenu varijance pogreške (relacije (3.4), (3.6), (3.11) i (3.12)). U programskom paketu Matlab generirano je 10 000 nizova po sedam podataka kojima je simulirano ponavljanje 10 000 pokusa pri istim uvjetima u inženjerskoj praksi. Svaki od tih nizova simulira mjerenje vrijednosti zavisne veličine za sedam fiksiranih vrijednosti nezavisne veličine u okolnostima pri kojima su zadovoljene pretpostavke modela linearne regresije. Za slučajno odabrani niz od sedam podataka primijećeno je znatno odstupanje procjena parametara modela od stvarnih vrijednosti (tablica 1), što upućuje na to da relativno mali broj mjerenja u praksi može voditi do nepouzdanih procjena. S druge strane, pokazalo se da je aritmetička sredina pripadnih 10 000 izračunatih parametara gotovo identična stvarnoj vrijednosti parametara. Drugim riječima, potvrđeno je da su procjene dobivene uzastopnim ponavljanjem mjerenja pri istim uvjetima u prosjeku točne. Simulacija sa svih 10 000 generiranih nizova potvrdila je i druge spomenute formule. Tako računalna simulacija može poslužiti za bolje razumijevanje linearne regresije i uspješno zamijeniti zahtjevno dokazivanje matematičkih činjenica na kojima se ona zasniva. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna.The purpose of this paper is a computer simulation of conditions relevant for simple a linear regression model and computer confirmation of its basic equations. To that end, a simple linear regression model is described and mathematical foundations of the model are discussed. Listed are the equations for the objective function (Equation 1.3), regression line parameters (Equation 1.4), estimation of regression line parameters (Equation (3.2)), and confidence interval (Equations (3.8) and (3.9)). Estimation of variance (Equation (3.4)) is based on Equations (3.6) and (3.11), while (3.11) is based on (3.12). The conditions of the simple linear regression were simulated in Matlab. The model parameters were selected with Equations (4.1) and (4.2), and 10 000 series of 7 data were generated as a simulation of 10 000 experiments under the same conditions in engineering practice. Each series represented a measurement of a dependent variable for seven fixed independent variable values in circumstances in which the linear regression model assumptions had been satisfied. For a randomly chosen series of 7 data, the estimates of parameters can significantly deviate from true parameter values (Table 1), indicating that a relatively small number of measurements in practice can lead to unreliable estimates. The estimate can deviate from true value even if the number of measurements is relatively large (Table 2). On the other hand, it is shown that the arithmetic mean of 10 000 calculated parameters is almost identical to true parameter values. In other words, it is confirmed that the estimates from consecutive measurements under the same conditions are, in average, correct. Simulation of 10 000 series also confirmed other mentioned equations: distribution from Equation (3.12) (Table 3 and Fig. 2), t-distribution from (3.5.1) and (3.5.2) (Table 4 and Fig. 3), and confidence intervals for regression line parameters from Equations (3.8) and (3.9). The computer simulation can serve for the better understanding of the simple linear regression model and successfully replace proving the mathematical facts on which linear regression is based. This work is licensed under a Creative Commons Attribution 4.0 International License

Ružička days : International conference 16th Ružička Days “Today Science – Tomorrow Industry” : Proceedings

Proceedings contains articles presented at Conference divided into sections: open lecture (1), chemical analysis and synthesis (3), chemical and biochemical engineering (8), food technology and biotechnology (8), medical chemistry and pharmacy (3), environmental protection (11) and meeting of young chemists (2)

Le Conservateur : Journal politique de l'arrondissement de Marennes...

22 décembre 18951895/12/22 (A18,N969)

Terpolymerization kinetics and properties of (tert-butylamino)ethyl methacrylate, alkyl methacralyte and styrene terpolymers

Sa svrhom ispitivanja kopolimerizacijskih reaktivnosti provedene su terpolimerizacije tert-butilaminoetil-metakrilata (TBAEMA), oktadecil-metakrilata (ODMA) i metil-metakrilata (MMA) te TBAEMA, ODMA i stirena (St). Navedeni materijali potencijalno su primjenjivi kao reološki modifikatori u industriji maziva. Reakcije su provedene do niskih konverzija (< 10 mas. %) uz peroksidni inicijator pri temperaturi od 70 °C u dilatometru volumena oko 20 mL i uz ukupnu koncentraciju monomera u toluenu od 2 mol dm^-3. Na oba ternarna sustava ispitan je dizajn optimalnih eksperimenata prema kojemu je za potpuni opis terpolimerizacijskog sustava (međuovisnosti sastava smjese monomera i sastava terpolimera) dovoljno provesti samo tri eksperimenta pri čemu se udjeli monomera u pojedinoj reakcijskoj smjesi mijenjaju tako da jedan monomer ima udio 80 mol. %, a druga dva po 10 mol. %. Za predviđanje sastava polimera korišteni su omjeri kopolimerizacijskih reaktivnosti pripadajućih binarnih smjesa određeni u prijašnjim istraživanjima na Zavodu za tehnologiju nafte i petrokemiju Fakulteta kemijskog inženjerstva i tehnologije. Stvarni sastav sintetiziranih terpolimera određen je nuklearnom magnetskom rezonancijom (NMR). Toplinska stabilnost dobivenih terpolimera ispitana je termogravimetrijskom analizom.With the purpose of determining copolymerization reactivity ratios, terpolymerizations of 2-(tert-butylamino)ethyl methacrylate (TBAEMA), octadecyl methacrylate (ODMA), and methyl methacrylate (MMA) as well as that of TBAEMA, ODMA and styrene (St) have been conducted. The reactions were carried out with a peroxide initiator at 70 °C in a 20 mL dilatometer with total monomer concentration of 2 mol dm^-3 in toluene and terminated at low conversions (< 10 wt %). For both ternary systems the optimal experiment design was studied, according to which for a complete description of the terpolymer system (the interdependence of the composition of the monomer mixture and the composition of the terpolymer) only three experiments need to be performed, with alternating the monomer concentrations in each reaction mixture so that one monomer has a portion of 80 mol %, with the other two having 10 mol %. Copolymerization reactivity ratios of the corresponding binary mixtures were obtained from past research on Petroleum and Petrochemical Department, Faculty of Chemical Engineering and Technology, University of Zagreb, and used to predict the composition of terpolymers. Actual composition of synthesized terpolymers was determined from nuclear magnetic resonance (NMR) spectrums. Thermal stability of terpolymers was examined using thermogravimetric analysis (TGA)

Terpolymerization kinetics and properties of (tert-butylamino)ethyl methacrylate, alkyl methacralyte and styrene terpolymers

Sa svrhom ispitivanja kopolimerizacijskih reaktivnosti provedene su terpolimerizacije tert-butilaminoetil-metakrilata (TBAEMA), oktadecil-metakrilata (ODMA) i metil-metakrilata (MMA) te TBAEMA, ODMA i stirena (St). Navedeni materijali potencijalno su primjenjivi kao reološki modifikatori u industriji maziva. Reakcije su provedene do niskih konverzija (< 10 mas. %) uz peroksidni inicijator pri temperaturi od 70 °C u dilatometru volumena oko 20 mL i uz ukupnu koncentraciju monomera u toluenu od 2 mol dm^-3. Na oba ternarna sustava ispitan je dizajn optimalnih eksperimenata prema kojemu je za potpuni opis terpolimerizacijskog sustava (međuovisnosti sastava smjese monomera i sastava terpolimera) dovoljno provesti samo tri eksperimenta pri čemu se udjeli monomera u pojedinoj reakcijskoj smjesi mijenjaju tako da jedan monomer ima udio 80 mol. %, a druga dva po 10 mol. %. Za predviđanje sastava polimera korišteni su omjeri kopolimerizacijskih reaktivnosti pripadajućih binarnih smjesa određeni u prijašnjim istraživanjima na Zavodu za tehnologiju nafte i petrokemiju Fakulteta kemijskog inženjerstva i tehnologije. Stvarni sastav sintetiziranih terpolimera određen je nuklearnom magnetskom rezonancijom (NMR). Toplinska stabilnost dobivenih terpolimera ispitana je termogravimetrijskom analizom.With the purpose of determining copolymerization reactivity ratios, terpolymerizations of 2-(tert-butylamino)ethyl methacrylate (TBAEMA), octadecyl methacrylate (ODMA), and methyl methacrylate (MMA) as well as that of TBAEMA, ODMA and styrene (St) have been conducted. The reactions were carried out with a peroxide initiator at 70 °C in a 20 mL dilatometer with total monomer concentration of 2 mol dm^-3 in toluene and terminated at low conversions (< 10 wt %). For both ternary systems the optimal experiment design was studied, according to which for a complete description of the terpolymer system (the interdependence of the composition of the monomer mixture and the composition of the terpolymer) only three experiments need to be performed, with alternating the monomer concentrations in each reaction mixture so that one monomer has a portion of 80 mol %, with the other two having 10 mol %. Copolymerization reactivity ratios of the corresponding binary mixtures were obtained from past research on Petroleum and Petrochemical Department, Faculty of Chemical Engineering and Technology, University of Zagreb, and used to predict the composition of terpolymers. Actual composition of synthesized terpolymers was determined from nuclear magnetic resonance (NMR) spectrums. Thermal stability of terpolymers was examined using thermogravimetric analysis (TGA)