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Volatile compounds of capers and sea fennel : master thesis
No full textU ovom radu proučavani su hlapljivi spojevi dviju samoniklih biljaka rasprostranjenih u mediteranskom dijelu Hrvatske, kapara (Capparis orientalis Veill.) i motara (Crithmum maritimum L.). Hlapljivi spojevi izolirani su dvjema metodama, vodenom destilacijom i mikroekstrakcijom vršnih para na krutoj fazi (HS-SPME). Dobiveni uzorci hlapljivih spojeva, eterična ulja i vršne pare, analizirani su vezanim sustavom plinska kromatografija-spektrometrija masa (GC-MS). Glavni sastojci eteričnog ulja listova i cvjetnih pupova kapara su diterpenski alkohol fitol (62,9 %, odnosno 24,3 %) i ciklooktasumpor, S 8 (14,7 %, odnosno 24,0 %), dok su glavni sastojci eteričnog ulja plodova kapara masne kiseline, dodekanska ili laurinska kiselina (38,7 %) i tetradekanska ili miristinska kiselina (24,7 %). Glavni sastojak vršnih para listova, cvjetnih pupova i plodova kapara je metil-izotiocijanat (87,3 %, 96,2 % i 96,4 %), razgradni produkt glukozinolata trivijalnog imena glukokaparin. Metil-izotiocijanat nije identificiran u eteričnim uljima kapara. Za razliku od eteričnog ulja i vršnih para kapara u kojima su identificirani spojevi iz različitih skupina prirodnih organskih spojeva, sastojci eteričnog ulja i vršnih para motara su gotovo isključivo terpeni. Glavni sastojak eteričnog ulja i vršnih para listova motara je monoterpenski ugljikovodik limonen (50,0 %, odnosno 56,5 %). Ostali kvantitativno značajni sastojci identificirani u eteričnom ulju su germakren B (10,4 %) sabinen (7,2 %) i cis-ocimen (5,9 %), a u vršnim parama sabinen (26,4 %) i cis-ocimen (8,1 %). Glavni sastojci eteričnog ulja i vršnih para cvjetova motara su monoterpenski ugljikovodici. U eteričnom ulju cvjetova to su limonen (47,4%), sabinen (17,3 %), α-pinen (8,8 %), a u vršnim parama također limonen (62,8 %), sabinen (17,1 %) i α-pinen (5,3 %).In this study, volatile compounds from two wild-growing plants widespread in the Mediterranean part of Croatia, caper plants (Capparis orientalis Veill.) and sea fennel (Crithmum maritimum L.), were investigated. Volatile compounds were isolated by two methods, hydrodistillation and headspace solid-phase microextraction (HS-SPME). Analysis of all samples, essential oils and headspaces, was carried out by gas chromatography with a mass spectrometry detector (GC/MS). The main constituents in essential oils of caper leaves and flower buds were diterpene alcohol phytol (62,9 % and 24,3 %, respectively) and cyclic octaatomic sulfur, S 8 (14,7 % and 24,0 %, respectively), while the main constituents of caper fruits essential oil were fatty acids, namely dodecanoic or lauric acid (38,7 %) and tetradecanoic or myristic acid (24,7 %). The predominant compound in headspaces of caper leaves, flower buds and fruits was methyl-isothiocyanate (87,3 %, 96,2 % and 96,4 %, respectively), degradation product of glucosinolate with trivial name glucocapparin. Methyl-isothiocyanate was not identified in all studied caper essential oils. In contrast to the essential oils and headspaces of capers, in which compounds from different groups of natural organic compounds have been identified, the constituents of the essential oils and headspaces of sea fennel were almost exclusively terpenes. The major constituent in essential oil and headspace of sea fennel leaves was monoterpene hydrocarbon limonene (50,0 % and 56,5 %, respectively). Other quantitatively important constituents identified in essential oil were germacrene B (10,4 %), sabinene (7,2 %) and cis-ocimene (5,9 %), and in headspace sabinene (26,4 %) and cis-ocimene (8,1 %). Monoterpene hydrocarbons were qualitatively and quantitatively the most important ingredients of essential oil and headspace of sea fennel flowers. The main constituents of essential oil were limonene (47,4%), sabinene (17,3 %), α-pinene (8,8 %). The main constituents of headspace were also limonene (62,8 %), sabinene (17,1 %) and α-pinene (5,3 %)
CHEMICAL COMPOSITION AND BIOLOGICAL POTENTIAL OF SEA FENNEL : diplom athesis
No full textCilj ovog rada bio je istražiti utjecaj okolišnih faktora na kemijski sastav i biološki potencijal samonikle biljke motar (Crithmum maritimum L.) te mogućnosti njene primjene u prehrambenoj industriji. Analizirani su metanolni ekstrakti lista motra prikupljeni duž Jadranske obale na 7 različitih lokacija. U eksperimentalnom dijelu rada spektrofotometrijski je u uzorcima određen udio ukupnih fenola i flavonoida, te je korištenjem tekućinske kromatografije visoke djelotvornosti (HPLC; engl. High-performance liquid chromatography) identificirana i kvantificirana klorogenska kiselina i njeni derivati. Antioksidacijska aktivnost određena je pomoću 3 različite metode: metodom određivanja snage redukcije željeza (engl. Ferric Reducing Antioxidant Power, FRAP), ispitivanjem kapaciteta apsorpcije kisikovih radikala (engl. Oxygen Radical Absorbance Capacity, ORAC) te metodom redukcije 2,2-difenil-1-pikrilhidrazil radikala (engl. 2,2 diphenyl-1-pycrilhydrazyl, DPPH). Dobiveni rezultati ukazuju na utjecaj mjesta uzorkovanja na njihov kemijski sastav i biološki potencijal. Pjeskovito stanište, koje biljci uskraćuje hranjive tvari i izlaže je stresu, pokazalo se kao potencijalno važni uzročnik bogatog fenolnog sastava i izuzetnog biološkog potencijala uzoraka. Sukladno tome, najviši udio fenolnih komponenti (ukupni fenoli, flavonoidi, klorogenska kiselina) i najbolja redukcijska snaga i antioksidacijski potencijal zabilježen je u uzorku lista motra uzorkovanom na lokaciji Neretva, dok su uzorci prikupljeni na srednjem Jadranu (Lokacije Split i Drašnice) imali najniži udio navedenih spojeva i slabu antioksidacijsku aktivnost.The aim of this work was to investigate the influence of environmental factors on the chemical composition and biological potential of the wild sea fennel (Crithmum maritimum L.) and the possibilities of its application in the food industry. Methanolic extracts of sea fennel leaves collected along the Adriatic coast at 7 different locations were analyzed. In the experimental part of the work, the content of total phenols and flavonoids was determined spectrophotometrically, while the concentration of chlorogenic acid and its derivatives was identified and quantified using high-performance liquid chromatography (HPLC). Antioxidant activity was determined using 3 different methods: the Ferric Reducing Antioxidant Power (FRAP) method, the Oxygen Radical Absorbance Capacity (ORAC) test, and the method of reducing 2,2-diphenyl- 1-picrylhydrazyl radical (DPPH). The obtained results indicate the influence of the sampling site on the chemical composition and biological potential of the samples. The sandy habitat, which deprives the plant of nutrients and exposes it to stress, can potentially be a reason for the rich phenolic composition and exceptional biological potential of the samples. Accordingly, the highest proportion of phenolic components (total phenols, flavonoids, chlorogenic acid) and the best reducing power and antioxidant potential was recorded for the sea fennel leaves sampled at the Neretva location, while the samples collected in the central Adriatic (Split and Drašnice locations) had the lowest content of the mentioned compounds and weak antioxidant activity
TOCOPHEROL CONTENT IN SEA FENNEL (CRITHMUM MARITIMUM L.) : bachelor thesis
No full textMotar (Crithmum maritimum L.) je jedna od najpoznatijih halofitnih vrsta jadranske obale koji zbog svog bogatog kemijskog profila i mogućnosti prilagodbe ima bitnu ulogu u prehrambenoj i kemijskoj industriji te medicini. Značajni spojevi motra su hlapljivi spojevi eteričnog ulja, masne kiseline, fenoli, minerali, vitamini, karotenoidi i drugi. Cilj ovog istraživanja je bio identificirati i kvantificirati tokoferole (α-, β- i γ-) prisutne u uzorcima motra pri čemu su korištene metode direktne acetonske ekstrakcije i saponifikacije te tekućinska kromatografija (HPLC). Istraživanje se provodilo na 13 različitih uzoraka (10 uzoraka lista i 3 uzorka cvijeta) sa 10 lokaliteta duž jadranske obale. Nakon analize rezultata, utvrđeno je da je najviša koncentracija ukupnih tokoferola zabilježena u listovima ubranim na Pelješcu te u cvjetovima ubranim na Pagu. U svim uzorcima je dominirao α-tokoferol s koncentracijama koje su se kretale od 3,87 µg/mL u uzorku iz Šibenika do 21,57 µg/mL u uzorku s Pelješca. Uzorak motra sa Pelješca je imao najviši udio i β-tokoferola, dok je najviša koncentracija γ-tokoferola pronađena u uzorku ubranom u Šibeniku.Sea fennel (Crithmum maritimum L.) is one of the best known halophytic species of the Adriatic coast, which plays an important role in the food, chemical industry and medicine due to its rich chemical profile and adaptability. The most important constituents of sea fennel include volatile components of essential oils, fatty acids, phenolics, minerals, vitamins, carotenoids, and others. The aim of this study was to identify and quantify tocopherols (α-, β- and γ-) present in sea fennel samples using direct acetone extraction and saponification methods followed by high performance liquid chromatography (HPLC). The study was conducted on 13 different samples (10 leaf samples and 3 flower samples) from 10 locations along the Adriatic coast. After analyzing the results, it was found that the highest concentration of total tocopherols was obtained from the leaves harvested on Pelješac and the flowers harvested on Pag. α-tocopherol was the dominating chemical species in all samples with concentrations ranging from 3.87 µg/mL in the sample from Šibenik to 21.57 µg/mL in the sample from Pelješac. The sea fennel sample from Pelješac had the highest content of β-tocopherol, while the highest content of γ-tocopherol was found in the sample collected in Šibenik
MOCIFICATION OF POLY (ETHYLENE OXIDE) / MONTMORILLONITE COMPOSITES FOR THE PURPOSE OF IMPROVING IONIC CONDUCTIVITY : bachelor thesis
No full textU ovom radu ispitivan je utjecaj dodatka soli litijevog bis(oksalato)borata (LiBOB) i litijevog montmorilonita (LiMMT) na staklište, talište i kristalnu strukturu poli(etilen-oksida) (PEO10). Tijekom ispitivanja primijenjene su metode diferencijalne pretražna kalorimetrije (DSC) i infracrvene spektroskopije s Fourierovom trnasformacijom (FTIR). LiMMT pripremljen je metodom ionske izmjene iz prirodnog montmorilonita, a polimerni nanokompoziti PEO/LiMMT/LiBOB s molnim omjerima PEO/LiBOB 1/7, 1/9, 1/16, 1/32, 1/40 pripremljeni su metodom interkalacije iz taljevine. Molni udjeli uzoraka predstavljaju omjer litijevog kationa iz LiBOB i kisika iz PEO s ciljem ostvarivanja dovoljne koncentracije litijevih kationa u elektrolitu. U pripremljenim uzorcima maseni udio polimera i punila odnosno PEO i LiMMT je u omjeru 60/40. Metodom diferencijalne pretražne kalorimetrije utvrđeno je da dodatak LiBOB u potpunosti narušava kristalnost uzorka PEO/LiMMT/LiBOB 1/7 i 1/9, a uzorci PEO/LiMMT/LiBOB 1/16, 1/32, 1/40 pokazuju toplinske prijelaze kristalizacije s talištem nižim od tališta čistog PEO. Metodom infracrvene spektroskopije s Fourierovom transformacijom potvrđeno je da dodatak LiMMT-a narušava kristalnost PEO.In this work the influence of the addition of lithium bis(oxalate)borate (LiBOB) salt and lithium montmorillonite (LiMMT) on the glass transition temperature, melting temperature and crystal structure of poly(ethylene oxide) (PEO10) was examined. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were used to study the material properties. LiMMT was prepared by ion exchange method from natural montmorillonite and polymer nanocomposites PEO/LiMMT/LiBOB, with mole ratios PEO LiBOB 1/7, 1/9, 1/16, 1/32, 1/40, were prepared by intercalation method from the melt. Molar ratios represent the ratio of lithium cation from LiBOB to oxygen from PEO in order to achieve sufficient concentration of lithium cations in the electrolyte. In the prepared samples, the mass ratio of PEO and LiMMT was 60/40. Differential scanning calorimetry show that the addition of LiBOB completely impairs the crystallinity of PEO/LiMMT/LiBOB 1/7 and 1/9 sample, while PEO/LiMMT/LiBOB 1/16, 1/32, 1/40 samples exhibit thermal crystallization transitions with melting temperatuare lower than pure PEO. The Fourier transform infrared spectroscopy confirm that the addition of LiMMT corroborate the crystallinity of PE
Research optimization possibilities of technological process of production of plant-based biostimulators : diploma thesis
No full textU ovom diplomskom radu ispitana je mogućnost optimizacije tehnološkog procesa proizvodnje biostimulatora na biljnoj bazi s ciljem povećanja brzine procesa i prinosa bioaktivnih tvari. Biostimulatori su pripremljeni dodavanjem mješavine odabranog osušenog biljnog materijala (korijen gaveza, list koprive, poljska preslica te list sljeza) i vodovodne vode kao otapala u šaržni reaktor. Optimizacija je provedena jednovarijantnom tehnikom „jedna varijabla u vremenu“ pri čemu se ispitivao utjecaj temperature, miješanja, omjera sirovina/otapalo i režima aeracije na brzinu procesa i količinu prinosa u vremenu od 7 dana. Za temperaturu su odabrane vrijednosti 20, 25, 35 i 45 °C, za miješanje broj okretaja 250, 500 i 750 o min -1 , za omjer sirovina/otapalo 15, 20, 25, 30 i 35 g L -1 , a za aeraciju protok zraka od 0,1; 0,3 i 0,5 L min -1 . Nakon provedenog niza eksperimenata utvrdilo se da su za ovaj tip procesa optimalne vrijednosti parametara sljedeće: temperatura smjese od 35 °C, brzina miješanja od 250 o min -1 , omjer sirovina/otapalo od 30 g L -1 te aeracijski režim od 0,3 L min -1 . Također, ispitana je i mogućnost optimizacije izvedbe reaktora za provedbu procesa ekstrakcije gdje se pokazalo da izvedba reaktora sa ugrađenim dvjema perforiranim pliticama postavljenim na 20% i 80% visine reaktora povećavaju učinkovitost procesa u odnosu na referentni proces. Kao referentni proces koristio se proces proizvodnje biostimulatora na biljnoj bazi na OPG Vedran Pezelj u Trilju čiji se biostimulatori nalaze na tržištu od 2018. godine.In this diploma thesis, the possibility of optimizing the technological process of plant-based biostimulator production with the aim of increasing the process kinetic and yield of bioactive substances was investigated. Biostimulators were prepared by adding a mixture of selected dried plant material (comfrey root, nettle leaf, horsetail and marshmallow leaf) and tap water as solvent into the batch reactor. The optimization was performed using a single-variant "one time variable" technique, investigating the influence of the temperature, mixing, raw material/solvent ratio and aeration regime on the process kinetic and yield over time of 7 days. Values of 20, 25, 35 and 45 ° C were selected for the temperature, 250, 500 and 750 rpm for mixing, 15, 20, 25, 30 and 35 g L -1 for the raw material/solvent ratio, and for aeration the flow of air at 0.1; 0.3 and 0.5 L min -1 . After a set of experiments, it was determined that for this type of process the optimal parameter values are as follows: mixture temperature of 35 ° C, mixing speed of 250 rpm, raw material/solvent ratio of 30 g L -1 and aeration regime of 0.3 L min -1 . Also, the possibility of optimizing the reactor design for the extraction process was investigated, where it was shown that the design of the reactor with two perforated trays installed at 20% and 80% of the reactor height increases the process efficiency compared to the reference process. The process of plant-based biostimulator production at the Vedran Pezelj family farm in Trilj was used as a reference process, whose biostimulators have been on the market since 2018
Adsorptionof nickel on egg shells (T = 308 K) : diploma thesis
No full textU ovom je diplomskom radu ispitana adsorpcija niklovih iona na ljuskama jaja u ovisnosti o različitim početnim koncentracijama otopina niklovih iona (3,922; 9,885; 13,139; 20,411 30,327 mmol dm-3) pri stalnoj temperaturi od 308 K, brzini miješanja od 200 okr min-1, u trajanju od 96 h. Na temelju dobivenih rezultata može se zaključiti kako količina adsorbiranih niklovih iona (qe) raste s porastom početne koncentracije niklovih iona u otopini (c0) postižući maksimalnu vrijednost pri najvišoj odabranoj koncentraciji te iznosi qe = 0,337 mmol g-1. Učinkovitost adsorpcije niklovih iona dostiže svoju maksimalnu vrijednost pri početnoj koncentraciji od 13,139 mmol dm-3 te iznosi 6,911%. Uzimajući u obzir izračunate vrijednosti za koeficijent korelacije R2 može se zaključiti kako se adsorpcija niklovih iona na ljuskama jaja najbolje može opisati Langmuirovim adsorpcijskim modelom.In this diploma thesis the adsorption of nickel ions on egg shells was studied depending on the different initial concentrations of nickel ions solutions (3.922, 9.885, 13.139, 20.411 and 30.327 mmol dm-3) at a constant temperature of 308 K, stirring speed of 200 rpm for 96 h. Based on the results obtained, it can be concluded that the amount of adsorbed nickel ions (qe) increases with the increase of the initial concentration of nickel ions in solution (c0) reaching its maximum value of qe = 0.337 mmol g-1 at the highest selected concentration. The adsorption efficiency of nickel ions reaches its maximum value of 6.911% at initial concentration of 13.139 mmol dm-3. Taking into account the calculated values of the correlation coefficient R2 it can be concluded that the adsorption of nickel ions on egg shells can best be described by the Langmuir adsorption model
PROFILE OF VOLATILE COMPOUNDS OF CHEESE WITH THE ADDITION OF AROMATIC HERBS : diploma thesis
No full textU ovom diplomskom radu analiziran je sastav i sadržaj hlapljivih spojeva punomasnog tvrdog sira (od miješanog kravljeg i ovčjeg mlijeka) i istih sireva kojimu je dodano aromatično bilje (lavanda, kadulja i bosiljak) u različitim udjelima. Izolacija hlapljivih spojeva izvršena je mikroekstrakcijom vršnih para na krutoj fazi korištenjem vlakna sastava divinilbenzen/karboksen/polidimetilsiloksan (DVB/CAR/PDMS) pri temperaturi od 60 ℃. Svi uzorci analizirani su vezanim sustavom plinska kromatografija-spektrometrija masa na nepolarnoj koloni, a dobiveni rezultati su uspoređeni. U svim uzorcima najzastupljenije su karboksilne kiseline, posebno masne kiseline butanska, heksanska i oktanska kiselina te octena i propanska kiselina. U svim ispitanim sirevima identificirani su i terpeni. U aromatiziranim sirevima identificiran je veći broj terpena nego u siru bez dodatka. Za sve aromatizirane sireve vrijedi isto: što je udio pojedine aromatične biljke u siru veći, veći je i broj i udio terpena, a ističu se terpeni specifični za pojedinu biljku.In this thesis, the composition and content of volatile compounds of full-fat hard cheese (from mixed cow's and sheep's milk) and the same cheese to which aromatic herbs (lavender, sage, basil) were added in different proportions were analyzed. Isolation of volatile compounds was performed by solid phase microextraction (HS- SPME) using divinylbenzene/carboxen/polydimethylsiloxane fiber (DVB/CAR/PDMS) at a temperature of 60 ℃. All samples were analyzed by chromatography-mass spectrometry using nonpolar column, and the results were compared. In all samples, the most abundant compounds are carboxylic acids, especially the fatty acids butanoic, hexanoic and octanoic acid as well as propanoic and acetic acid. Terpenes were also identified in all the cheeses studied. A higher number of terpenes was identified in the flavored cheeses than in the cheese without additives. For all flavored cheeses: the higher the proportion of a particular aromatic plant in the cheese, the higher the number and proportion of terpenes, with the terpenes specific to a particular plant standing out
TESTING MEMBRANE RESPONSE BASED ON NiS: Ag2S:PTFE = 1:1:2 WITH THE ADDITION OF NANOPARTICLES AKAGANEITE AND ALUMINUM : bachelor thesis
No full textIspitan je odziv ionsko-selektivnih membrana na niklove(II) ione pri pH = 4 i pH = 5, te utjecaj dodatka različitih postotaka nanočestica željezovih i aluminijevih oksida na odziv membrana. Membrane su sastavljene od niklovog(II) sulfida, srebrovog sulfida i teflona koji osigurava čvrstoću membrane, dok su nanočestice magnetita, hematita, akaganeita te aluminijeva oksida dodavane u postotcima od 1, 0,5 i 0,25 %. Ukupno je testirano 13 membrana uključujući referentnu membranu te su grafički prikazani rezultati koji su pokazali najbolji odziv. Svako mjerenje je ponovljeno minimalno tri puta. Ispitivanje odziva izvršeno je potenciometrijski zbog jednostavnosti i praktičnosti metode. Membrane su se ispitivale u elektrokemijskoj ćeliji koristeći otopinu niklovog(II) sulfata, pripremljenu u otopini perklorne kiseline pH=1 i u 0,1M otopini klorovodične kiseline pH=2, metodom slijednog razrjeđivanja. Za svako mjerenje zabilježena je vrijednost elektrodnog potencijala.The response of ion-selective membranes to nickel(II) ions at pH = 4 and pH = 5 was tested, as well as the influence of the addition of different percentages of nanoparticles of iron and aluminum oxides on the response of the membranes. The membranes are composed of nickel(II) sulfide, silver sulfide, and teflon, which ensures the strength of the membrane, while nanoparticles of magnetite, hematite, akaganeite, and aluminum oxide were added in percentages of 1, 0.5, and 0.25%. A total of 13 membranes were tested, including the reference membrane, and the results that showed the best response are shown graphically. The response test was performed potentiometrically. The membranes were tested in an electrochemical cell using a nickel(II) sulfate solution, prepared in perchloric acid solution pH=1 and in 0.1M hydrochloric acid solution pH=2, using a similar dilution method
Chemical composition and cytotoxic activity of Helichrisyum italicum essential oil: research of pure compounds and synergic combinations : bachelor thesis
No full textEterična ulja su smjese velikog broja različitih kemijskih spojeva, koja nastaju kao sekundarni metaboliti aromatičnih biljaka. Helichrysum italicum (Roth) G. Don., smilje, višegodišnja je biljna vrsta koja se koristi u etnomedicini i prehrambenoj industriji kao dodatak hrani, pićima i pekarskim proizvodima. Poznata su njegova različita biološka djelovanja, poput antioksidativne i antibakterijske aktivnosti. U ovom radu izvršena je izolacija eteričnog ulja smilja pomoću hidrodestilacije korištenjem aparature po Clevengeru, a kemijski sastav je određen primjenom vezanog sustava plinske kromatografije i spektrometrije masa (GC-MS). Ispitivanja citotoksične aktivnosti eteričnog ulja provedena su in vitro na dvije stanične linije: humanog dermalnog fibroblasta (HDF) i staničnoj liniji karcinoma dojke (MDA-MB- 231) primjenom MTT testa. Sinergistički i antagonistički citotoksični učinci odabranih komponenti iz eteričnog ulja smilja simulirani su testiranjem čistih spojeva (linalol, nerol, nerolidol, terpinen-4-ol, α- terpineol) i njihovih smjesa na zdrave stanice fibroblasta i stanice raka dojke. Rezultati potvrđuju veću biološku aktivnost eteričnog ulja u odnosu na ukupni učinak njegovih komponenti.Essential oils are mixtures of numerous different chemical compounds that occur as secondary metabolites in aromatic plants. Helichrysum italicum (Roth) G. Don, also known as immortelle, is a perennial plant species used in ethnobotanical medicine and the food industry as an additive in food, beverages, and bakery products. It is well-known for its various biological effects, such as antioxidant and antibacterial activities. In this study, the isolation of immortelle essential oil was carried out using hydrodistillation with Clevenger-type apparatus, and the chemical composition was determined using a coupled gas chromatography-mass spectrometry (GC-MS) system. Cytotoxicity studies of the essential oil were conducted in vitro on two cell lines: human dermal fibroblasts (HDF) and breast cancer cell line (MDA-MB-231) using the MTT assay. Synergistic and antagonistic cytotoxic effects of selected components from immortelle essential oil were simulated by testing pure compounds (linalool, α-terpineol, terpinene-4-ol, nerol, and nerolidol), and their mixtures on healthy fibroblast cells and breast cancer cells. The results confirm higher biological activity of immortelle essential oil compared to the cumulative effect of its components
Processes of ethylene production from nonrenewable and renewable resources : bachelor thesis
No full textEtilen je jedan od najvažnijih proizvoda kemijske industrije. Zbog njegove velike primjene u industriji polimera, proizvodnja etilena raste iz godine u godinu. Najznačajniji način dobivanja etilena je parno krekiranje ugljikovodika. To je proces koji koristi sirovine iz fosilnih izvora. Sirovina se izlaže visokim temperaturama i vodenoj pari pri čemu dolazi do cijepanja ugljikovodičnih lanaca i nastajanja molekula ugljikovodika manjih molekulskih masa. Nakon procesa krekiranja slijedi složeni postupak odvajanja različitih ugljikovodika kako bi se dobili čisti proizvodi za upotrebu u drugim industrijama. Uz etilen, kao značajni proizvodi dobivaju se propilen i pirolitički benzin (bogat aromatima). Parno krekiranje je usavršen proces te mu ostali procesi dobivanja etilen ne mogu parirati. Zbog povećane ekološke osviještenosti i smanjenja zaliha fosilnih goriva, počinju se razvijati nove metode dobivanja etilena koje imaju manju emisiju CO₂ i koriste sirovine iz obnovljivih izvora. Većina procesa je još u fazi razvoja, ali pokazuju obećavajuće rezultate. Procesi koji se najviše istražuju za proizvodnju etilena su dobivanje iz metanola (metanol se dobiva iz otpadnog CO₂), oksidacijom metana, elektrolitičkom redukcijom CO₂ i dobivanje pomoću biljaka. Ovi procesi će biti neophodni u daljoj budućnosti, no za sada parno krekiranje ostaje primaran način proizvodnje etilena.Ethylene is one of the most important products of chemical industry. Production of ethylene increases by year due to its extensive usage in polymer industry. The most important way of producing ethylene is steam cracking of hydrocarbons. It uses raw materials such as fossil fuels and exposes it to high temperatures and steam which leads to cracking of hydrocarbon chains and formation of hydrocarbons with lower molecular mass. The cracking process is followed by complex process of separation of all hydrocarbons in order to get clean products for subsequent usage in other industries. Beside ethylene, propylene and pyrolysis gasoline (rich with aromatics) are significant products from stean cracking. Steam cracking is a very developed process and other processes of ethylene production can't even come close to it. New ethylene production methods that have lowered emission of CO₂ and use renewable resources are being developed because of increased enviromental awareness and lower stock of fossil fuels. Most of processes are still in the phase of development but they show promising results. Some of the processes that are being developed include production from methanol (which is produced from waste CO₂), oxidative coupling of methane, electrochemical reduction of CO₂ and production through plants. These processes will be necessary in the further future but for now steam cracking remains the main way of ethylene production