Valorizacija ljuske suncokreta nakon konvekcijskog sušenja sjemenki za proizvodnju krutog goriva

Since the initial moisture content in sunflower seeds after the harvest is rather high, seeds must be processed by convection drying so that their quality can be maintained for as long as possible a period of time. Sunflower is an oilseed crop, which can be used as food and as a feedstock for solid fuels production. The aim of this paper is to determine the influence of the convection drying process (at 60 °C, 80 °C and 100 °C) on energy characteristics of seeds of four sunflower hybrids (Apolon, NK Brio, PR 63 A 90 and PR 63 D 82), which by their characteristics belong to early and medium-early hybrids. It will also be determined if the energy used in the drying process can be recovered through utilisation of energy from husk. On the basis of the obtained results, the changes in energy characteristics were identified, namely, the content of non-combustible matters (water, ash, coke, fixed carbon and nitrogen) and of combustible matters (carbon, sulphur, hydrogen, oxygen, volatile matter), as well as higher and lower heating values of sunflower seeds. The resulting data prove that convection drying of sunflower husk has a positive influence on its energy characteristics and that it can be used for solid fuel production.Zbog povišene početne vlažnost nakon žetve, sjemenke suncokreta moraju se doraditi konvekcijskim sušenjem kako bi im se očuvala kvaliteta kroz što dulje vrijeme. Suncokret je uljarica kojoj se osim za prehrambene svrhe može koristiti i u proizvodnji krutih goriva. Cilj ovog rada je utvrditi utjecaj termičkog procesa konvekcijskog sušenja (60 °C, 80 °C i 100 °C) na energetske karakteristike sjemenki 4 različita hibrida suncokreta (Apolon, NK Brio, PR 63 A 90 i PR 63 D 82) koji su po svojim svojstvima rani i srednje rani hibridi. Također će se utvrditi može li se utrošena energija u procesu sušenja vratiti kroz energetsku iskoristivost ljuske. Temeljem dobivenih rezultata određene su promjene energetskih karakteristika, odnosno sadržaj negorivih tvari (voda, pepeo, koks, fiksirani ugljik i dušik) te gorivih tvari (ugljik, sumpor, vodik, kisik, hlapiva tvar), kao i gornja i donja ogrjevna vrijednost sjemenki suncokreta. Dobiveni podaci dokazuju da konvekcijsko sušenje ljuske suncokreta pozitivno utječe na dobra energetske karakteristike ljuske te se može koristiti za proizvodnju krutog goriva

Experience in production and utilization of renewable energy sources in the European Union

Europska unija danas u proizvodnji bioenergije prelazi u drugu fazu proizvodnje obnovljivih izvora energije. To znači da je proces proizvodnje biogoriva, na temeljima Zelene i Bijele knjige, u potpunosti definiran. Dakle, utvrđen je udio biogoriva u potrošnji, način proizvodnje kao i kakvoća te je zakonski i legislativno utvrđen sustav njihove provedbe mogućnosti kontrole provedbe svake pojedine članice Europske unije. Europska unija je u drugu fazu proizvodnje biogoriva krenula izradom energetskih krugova i to uz još 7 vrsta biogoriva (EC 2003/30) na: - proizvodnju biodizela iz metilnih estera masnih kiselina koji se proizvode od biljnog ili životinjskog ulja te od otpadnog jestivog ulja, - proizvodnju bioetanola iz biomase i biorazgradivog dijela otpada, - proizvodnju bioplina iz biomase i biorazgradivog dijela otpada koji se može pročistiti do kakvoće prirodnog plina. Kako je biomasa jedini obnovljivi izvor energije iz kojeg je moguće proizvesti visokovrijedna tekuća i plinovita goriva, Europski parlament i Vijeće Europe izdali su gore navedenu Direktivu koju zemlje članice moraju postaviti kao nacionalni cilj te do 1. srpnja 2006. godine dati izvješće komisiji Europske unije o dosad učinjenom, kao i o mogućim potezima u sljedećih godinu dana. Druga faza je izrada projekta za 2020. godinu, gdje za Republiku Hrvatsku vrijedi da u području transporta mora potrošiti minimalno 260.000 t biogoriva. Međutim, uz navedeno će ostati i preko 500.000 t nusproizvoda, što agronomska, veterinarska i ostale struke trebaju shvatiti kao izazov i načiniti program, najbolji za Republiku Hrvatsku, kako bi u potpunosti mogli odgovoriti zahtjevima Europske unije.The European Union is entering the second phase of production of renewable energy sources. Namely, biofuel production is entirely defined due to EU\u27s Green and White paper. Hence, share of biofuels\u27 consumption, their production and quality as well as the system of application and monitoring by a single member state is determined. This second phase has begun with drafting energy cycles\u27 after defining 7 types of biofuels (EC/30/2003): - biodiesel production from fatty acid methyl esters from vegetable oil or animal fat and from edible waste oil, - bioethanol production from biomass and biodegradable waste, - biogas production from biomass and biodegradable fat which can be purified to natural gas quality. As biomass is the only renewable energy source from which it is possible to produce valuable liquid and gaseous fuels, the EU Parliament and the EU Commission have issued a Directive which has to be set as a national goal by its member states. Furthermore, they must submit their reports on previous activities together with the future plans. When speaking of the Republic of Croatia, the second phase plan for the year 2020 is that in transportation area it minimum 260,000 t of biofuels should be spent. However, this will lead to production of more than 500,000 t of by-products, which should be considered as a challenge for agricultural, veterinarian and related professions to prepare the best program for the Republic of Croatia in order to fulfil EU\u27s demands

Agricultural model of biodiesel fuel production

Kako Republika Hrvatska općenito nema modele korištenja biogoriva, u ovom radu istraživali su se tehničko – tehnološko – troškovni agrarni modeli iskorištenja jednog od najzanimljivijih poljoprivrednih biogoriva – biodizelskoga goriva. Na temelju dobivenih modela i ocjenom rentabilnosti strukture troškova, odredio se najučinkovitiji te najpovoljniji model proizvodnje biodizelskoga goriva u Republici Hrvatskoj, odnosno neposredno povećanje proizvodnje u poljoprivredi. Iz dobivenih rezultata vidi se da model proizvodnje bio-dizelskoga goriva s nositeljem proizvodnje, poljoprivrednom tvrtkom s pogonom za rafinaciju sirovoga ulja ima najbolju ocjenu rentabilnosti uz najbržu amortizaciju uloženih sredstava. Međutim, zbog trenutnih neriješenih vlasničkih odnosa i loše financijske situacije poljoprivrednih tvrtki, model proizvodnje biodizelskoga goriva s nositeljem proizvodnje, poljoprivrednom zadrugom prihvaćen je kao najpovoljniji model proizvodnje biodizelskoga goriva u ovom trenutku za Republiku Hrvatsku.Since the Republic of Croatia does not have the biofuel utilization models, in this paper technical, technological, cost and agrarian models of utilization of one of the most interesting agricultural biofuels – biodiesel were investigated. Based on the obtained models and the cost-effectiveness evaluation of the costs, the most efficient and the most convenient model of biodiesel fuel production in the Republic of Croatia was determined. In the obtained results, it was observed that the biodiesel production model with producer an agricultural company with the machinery for raw oil refining, had the best cost-effectiveness evaluation together with a high amortization of invested capital. However, because of the current unresolved proprietary conditions and unsatisfactory financial situation of agricultural companies, the biodiesel fuel production model with the producer an agricultural cooperative society was accepted as currently the most prosperous biodiesel fuel production model in the Republic of Croatia

Otpuštanje vode konvekcijskim sušenjem različitim temperaturama iz sjemenki uljane repice

Rapeseed is one of the most important oil plants in the world. The objective of this research was to analyse the influence of thermal treatment temperature on rapeseed quality, i.e. to investigate the content of oil and free fatty acids in chosen rapeseed hybrids: Turan, Traviata, NK Toccata, NK Petrol, PR 46 W 14 and PR 46 W 15. By their characteristics, these varieties are early, medium-early and medium-late hybrids. The initial moisture content of the investigated hybrids ranged from 11.28% to 11.69%. The hybrids were subjected to thermal process of thin-layer convective drying, at temperatures of 40°, 60° and 80°C and air velocity of 1.0 m/s. During the investigation, decomposition of oil due to drying at 80°C and increase of free fatty acids concentration above permitted 2% were observed. Furthermore, based on the obtained results, velocity of water release from seed have been determined, and the drying process was mathematically modelled, whereby determination coefficient (R2) and activation energy were also determined.Uljana repica pripada najznačajnijim svjetskim uljaricama. Cilj istraživanja bio je istražiti utjecaj termičke dorade na kvalitetu uljane repice, odnosno analizirati sadržaj ulja i slobodnih masnih kiselina u izabranim hibridima uljane repice: Turan, Traviata, NK Toccata, NK Petrol, PR 46 W 14 i PR 46 W 15. Po svojim karakteristikama, nabrojeni su hibridi rani, srednje rani i srednje kasni hibridi. Početna vlaga istraživanih hibrida kretala se od 11,28 do 11,69%. Hibridi su podvrgnuti termičkoj doradi konvekcijskim sušenjem u tankome sloju, pri temperaturama 40, 60 i 80°C i brzini strujanja zraka 1,0 m/s. Tijekom istraživanja, uočeno je raspadanje ulja tijekom sušenja na 80°C te povećanje slobodnih masnih kiselina preko dopuštenih 2%. Nadalje, temeljem dobivenih rezultata, određena je brzina otpuštanja vode te je postupak sušenja matematički modeliran, gdje su određeni koeficijent determinacije (R2) i energija aktivacije vode

Effect of Storage Temperature on Rapeseed Quality

The objective of this paper was to determine the influence of storage conditions on the quality of seeds in rapeseed cultivar Bristol and hybrid Triangl, namely on the oil and free fatty acids content, which are the two most important rapeseed quality parameters. The rapeseed seeds were stored in two conditions: in storage facility with controlled atmosphere (with temperature of 10 ｰC and relative air moisture approximately 70%) and in storage facility without atmosphere control (where the air temperature and moisture varied). During a nine-month storing period, the samples’ mass was monitored monthly while oil content, free fatty acids (FFA) content and seed moisture were determined before and after storing. Storing in conditions without atmosphere control showed that the samples’ mass was increasing during the first four months, in the following three months it was decreasing, and then stagnated until the end of the storing period. Samples stored in controlled atmosphere showed variations in mass, with minor oscillations during the whole storing period, which resulted in lower FFA content in comparison with the samples stored in facilities without atmosphere control. The oil content after storing in both facilities decreased, and FFA content rose in all samples. In conclusion; storing in controlled atmosphere gave better results in terms of rapeseed quality

Potato processing and storage

Krumpir (Solanum tuberosum L.) je kroz povijest bio važan izvor hrane u svijetu. Kako bi se krumpir mogao koristiti kroz cijelu godinu potrebno je očuvati njegova fizikalna i kemijska svojstva doradom. U doradu krumpira pripada sušenje, čišćenje, sortiranje i preradu u gotove proizvode. Nakon berbe krumpira gomolji se čiste od zemlje i primjesa, dok zdravi i kvalitetno očišćeni gomolji odlaze na skladištenje. Krumpir se čuva u privremenim i stalnim skladištima na optimalnoj temperaturi skladištenja. Održavanjem optimalnih uvjeta u skladištima koji obuhvaćaju praćenje temperature, vlažnosti i sastava zraka smanjuju se gubici na najmanju moguću mjeru (oko 3,7 %), a gomolji održavaju i zadovoljavajuću kvalitetu. Slijedom navedenog, cilj ovog rada je utvrditi i dati pregled za najpovoljniji način dorade i skladištenja krumpiraPotato (Solanum tuberosum L.) historically has been an important source of food in the world. In order for potatoes to be used throughout the year, it is necessary to preserve their physical and chemical properties by processing them. Potato processing includes drying, cleaning, sorting and processing into finished products. After the potato harvest, they are cleaned of soil and impurities, healthy and well-cleaned potato goes to the storage. Potatoes are stored in temporary and permanent warehouses at the optimal storage temperature. By maintaining optimal consditions in the warehouses, which include monitoring of temperature, humidity and air composition, losses are reduced to the smallest possible extent (about 3.7%), and the potato maintain a satisfactory quality. Accordingly, the aim of this paper is to determine and provide an overview of the most favorable way of processing and storing potatoes

Possibilities of olive cake utilization in energy production

U radu su istražene mogućnosti dobivanja energije iz komine masline u odabranoj otočnoj mikroregiji. Godišnja proizvodnja komine masline u odabranoj mikroregiji iznosi 2.065 tona. Od te količine moguće je dobiti 530 MWh/godišnje električne energije koja se može iskoristi na različite načine, od iskorištavanja u kućanstvima do iskorištavanja u manjim pogonima kao što su npr. pogoni za desalinizaciju morske vode. Korištenjem komine kao energenta rješava se problem njenog neadekvatnog odlaganja. Ona više ne bi završavala na divljim odlagalištima te tako ugrožavala okoliš, a ovisnosti o varijanti korištenja komine kao energenta moglo bi se zaposliti i dio lokalnog stanovništva.The aim of this paper was to investigate the potential energy production from olive cake in a specific region of islands in the Adriatic sea, which has a yearly olive cake production of 2,065 tons. Energy production potential from this quantity of olive cake is approx. 530 MWh of electric power per year, which can be differently utilised on behalf of great manig of energy consumers such as households or small-capacity plants for production of drinking water. Utilization of olive cake in energy production could contribute to waste management because it would not be deposited as waste, thus causing pollutions. Moreover, utilization of olive cake in energy producton could contribute to providing work for the local community

SPANISH BROOM (SPARTIUM JUNCEUM L.) – FEEDSTOCK FOR BIOPLASTIC AND BIOENERGY INDUSTRY

Spanish Broom (Spartium junceum L.) is a Mediterranean plant of various usage possibilities. Its fibres were known since ancient time but in some point of last century, more accurately in 1950s, their production was abandoned due to the negative economic effect. Another drawback was large time consumption, especially during the old tradition method – Spanish Broom maceration in salt water. Nowadays, due to technology development and ecological awareness, it is much easier to produce Spanish Broom fibres of enhanced quality. One of the fibre extraction methods is the one assisted with microwave oven. Demerit of such fibre production is in large residue content after obtaining fibres - approx. 90 % of initial Spanish Broom weight. Due to the need for finding sustainable solutions in the development of new materials, the usage of Spanish Broom fibres in the service of reinforcement for biopolymer poly (lactic acid) (PLA) matrix was investigated. Obtained results target our further research into the direction of Spanish Broom fibres and PLA application in the production of green composites. The aim of this research was to prove that developed product can be categorized under the biodegradable group by investigating its degradation properties using serine endopeptidase enzyme. The results show positive degradation effect while using 50 wt.% (on weight of material) enzyme concentration during a 5-day treatment. Stem residues of Spanish Broom plant derived from salty water and microwave maceration were further investigated for their potential as raw material for second-generation biofuel production. Examination of its energy properties consisted of determination of proximate and ultimate properties of the biomass. The results show low moisture content (6.5 % - 7.5 %), ash content below 5 % and higher values of fixed carbon and volatile matter content of 13.2 % and 75 %, respectively. Higher heating values that were determined (17.2 - 18.8 MJ/kg) indicate a high quality biomass that can be used most effectively in solid biofuel production

Fuel Properties’ Comparison of Allochthonous Miscanthus x giganteus and Autochthonous Arundo donax L.: a Study Case in Croatia

Increased energy demands, EU intentions for energy independence, together with decreasing fossil fuel reserves, have initiated the interest for new technology development. This would enable more intensive use of new renewable energy sources and contribute to increase among appliances based on biomass and energy crops. Miscanthus x giganteus is a perennial crop which has been received particular attention during the last decade as an energy crop. In the Republic of Croatia, it has been under investigation for the last two years, and the yields obtained by far are very promising. However, due to its potential and autochthonicity, there is a need for investigating the potential of another perennial, Arundo donax L. as energy crop. Among numerous tested energy crops, both species seem to be especially promising feedstocks due to their high production potential. Cultivation of these plants may be a sufficient alternative to wood from short-rotation forestry. Therefore, the objective of this study was to determine fuel properties of the two-abovementioned species, relevant for combustion of biomass to be used as solid fuel, and to compare them. Since biomass is characterized by a series of parameters that determine their most suitable process of conversion, properties such as biomass type, particles size, chemical and physical composition, way of fixation of the moisture, ash content, and higher heating value (HHV). Accordingly, proximate, and ultimate analyses, together with fuel properties determination were conducted on both, M. giganteus and A. donax Results indicated that both species could be proposed as biomass energy crops in the Republic of Croatia, with a significant and environmentally compatible contribution to energy needs

Influence of Treatment and Storage of Rapeseed on its Properties as a Raw Material for Biodiesel Production

In order to reach targets set by the EU in the 2003/30/EC Directive, in Republic of Croatia in the last years the emphasis was put on cultivation and treatment of rapeseed hybrids as the crucial raw material for biodiesel fuel production. Since in the Republic of Croatia such researches are in the very onset, the aim of this paper was to determine the yield of three rapeseed hybrids, ‘Artus’, ‘Baldur’ and ‘Titan’, as well as to establish their properties after drying and storage, which are critical for biodiesel production. In this research, drying curves of three investigated hybrids’ seed were determined. The impact of drying temperature on oil content and on free fatty acids content was determined as well. It was found that Baldur hybrid had the highest oil content, followed by ‘Titan’, and ‘Artus’ with somewhat lower oil content. Moreover, hybrid Artus had the lowest free fatty acid content, irrespective of the drying air temperature, while the free fatty acid content in hybrids ‘Baldur’ and ‘Titan’ was 30% higher. It was evident that the oil content and free fatty acid content are hybrid property of particular hybrids. Furthermore, the impact of storage conditions, hybrid type and temperature on rapeseed’s oil content and free fatty acid content was determined. It was found that controlled storage conditions provided better quality of rapeseeds. The conclusion of this research is that the characteristics of rapeseed hybrids corroborate viability of sowing this crop and its usability as raw material for oil production, and thus, for biodiesel production