http___fulir.irb.hr_3455_.xml
http___fulir.irb.hr_1739__1.xml
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Nikolov, Jovana; Krajcar Bronić, Ines; Stojković, Ivana; Todorović, Nataša; Barešić, Jadranka; Krmpotić, Matea; Tomić, Milan (2017) Comparison of two different methods for determination of biogenic fraction in liquid fuels. In: Radolić, Vanja; Poje Sovilj, Marina; Krajcar Bronić, Ines, (eds.) Zbornik radova Jedanaestog simpozija Hrvatskog društva za zaštitu od zračenja. Zagreb, HDZZ, pp. 206-211 . Abstract European Union’s promotion of the use of sustainable and renewable resources requires use of at least 10 % of synthesized biodiesel in liquid fuels by the year 2020. This legislation has stimulated various types of petrodiesel and bio-based component blends production, and development of methods for exact, effective and reliable quantification of biodiesel content. The method for determination of the biogenic fraction in liquid fuels by direct measurement of the 14C activity concentration via liquid scintillation counting (LSC) technique was developed in few laboratories worldwide. It is based on different 14C signatures of the two components: the biogenic component reflects the modern atmospheric 14C activity, while no 14C is present in fossil fuels. The quantity of 14C in the fuel is the criterion for bio-fuel presence. A great variety of biogenic matrices in fuels results in a wide range of quenching properties of different fuel mixtures. The laboratories participating in this intercomparison study developed two different calibration techniques. The Ruđer Bošković Institute data evaluation method is based on calibration curves for purely biogenic and purely fossil liquids, and does not depend on the exact chemical composition of the organic liquid. The limits of the method are defined by the SQP of app. 690 below which the count rate of biogenic and fossil liquids become indistinguishable from one another. The University of Novi Sad data evaluation method is very dependent on the composition of the examined fuels, so the obtained results in this case were relatively good. Future investigation should also test whether this calibration method is suitable for some other fuel matrices, for example for various types of domestic oil used in everyday life. Testing advantages and limitations of the two methods will continue in the future.
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Krajcar Bronić, Ines; Barešić, Jadranka; Horvatinčić, Nada; Krištof, Romana; Kožar-Logar, Jasmina (2015) New technique of determination of biogenic fraction in liquid fuels by the 14C method. In: Petrinec, Branko; Bituh, Tomislav; Milić, Mirta; Kopjar, Nevenka, (eds.) Zbornik radova Desetog simpozija Hrvatskog društva za zaštitu od zračenja. Zagreb, Hrvatsko društvo za zaštitu od zračenja, pp. 360-365 . Abstract Povišenje koncentracije CO2 u atmosferi tijekom 20. stoljeća posljedica je intenzivnog korištenja fosilnih goriva. Smanjenje emisije CO2 nastalog izgaranjem fosilnih goriva proizvodnjom energije iz biogenih materijala (biogoriva) danas se stimulira i poreznom politikom pa se javlja potreba kontrole proizvođača i distributera goriva primjenom pouzdane metode određivanja udjela biogene komponente u gorivima. Jedna od metoda za određivanje udjela biogene komponente u smjesi fosilnog i biogoriva je 14C metoda, koja se zasniva na različitoj koncentraciji izotopa 14C u pojedinim komponentama smjese: biogoriva odražavaju 14C aktivnost suvremene atmosfere, dok fosilna goriva ne sadrže 14C. Za tekuća goriva moguće je primijeniti tehniku direktnog mjerenja u tekućinskom scintilacijskom brojaču (LSC) uz dodatak odgovarajućeg scintilatora. U ovom radu ćemo prikazati novu tehniku direktnog mjerenja koja koristi karakteristike gašenja zbog boje za kalibraciju brojača. Određivanje udjela biogene komponente u tekućim gorivima moguće je direktnim mjerenjem sadržaja 14C tekućinskim scintilacijskim brojačem. Tehnika obrade rezultata razvijena na IRB daje rezultate usporedive s drugačijom tehnikom korištenom na IJS. Donja granica detekcije je oko 0, 5 % biogene komponente, a tehnika se može primijeniti na sve vrste goriva bez obzira na fosilnu matricu i vrstu biogenog aditiva.