PERSPECTIVE AND POTENTIAL USE OF MISCANTHUS X GIGANTEUS CULTURE IN CROATIA

Najosnovnije ljudske potrebe, kao i sve gospodarske i izvan gospodarske djelatnosti i aktivnosti, zahtijevaju potrošnju energije. Temeljem energetskih scenarija (smanjenje zaliha neodrživih izvora energije, konstantno povećanje cijena fosilnih goriva) i energetskih težnji (sigurna, održiva i kontinuirana opskrba energijom) u narednih desetak godina očekuje se povećani rast proizvodnje i potrošnje obnovljivih izvora energije na globalnoj razini. Obnovljivi izvori energije predstavljaju energetske resurse koji se koriste za proizvodnju električne i/ili toplinske energije, a čije rezerve se konstantno ili ciklički obnavljaju. Pod klasifikacijom obnovljivih izvora energije ubraja se i biomasa dobivena uzgojem kultura za proizvodnju energije. Cilj uzgoja kultura za proizvodnju energije je proizvodnja što veće količine biomase po jedinici površine s ciljem njene pretvorbe u energiju, a jedna od takvih kultura je vrsta Miscanthus x giganteus. Glavne karakteristike trave Miscanthus x giganteus su: izuzetna prilagodljivost uzgoju u različitim klimatsko-pedološkim uvjetima (od razine mora do 3000 m nadmorske visine), mogućnost uzgoja na tlima lošije kvalitete, prirodan je sterilni hibrid (ne postoji mogućnost nekontroliranog širenja), visoki prinosi suhe tvari po jedinici površine (prosjek 15-20 t/ha), izuzetna otpornost na bolesti i štetočinje (tretiranje pesticidima nije potrebno), mali zahtjevi za gojidbom te visoka energetska vrijednost (17,05 do 19,21 MJ/kg). Agronomski fakultet u Zagrebu započeo je 2011. godine istraživanja kulture Miscanthus x giganteus.The basic human needs, as well as all economic and non economic activities require energy consumption. Based on the energy scenarios (reduction of unsustainable energy reserve resources, constant increase of fossil fuel prices) and energy aspirations (safe, sustainable and continuous energy supply), the increased production and consumption of renewable energy on the global scale in the next ten years is expected. Renewable energy sources represent energy resources whose reserves are continuously or cyclically renewed and are used for the production of electrical and / or heat energy. Biomass that is obtained by cultivation of crops for energy production is also classified as renewable energy resources. The aim of cultivation of crops for energy production is production of highest quantity of biomass per unit of area and one of such crops is Miscanthus x giganteus. The main characteristics of grass Miscanthus x giganteus are: exceptional adaptability of cultivation to different climatic and soil conditions (from sea level up to 3000 m above sea level), the possibility of cultivation on low quality soils, it is natural sterile hybrid (there is no possibility of uncontrolled spread), high yields of dry matter per unit of area (average 15-20 t / ha), exceptional resistance to diseases and pests (pesticides treatment is not necessary), low fertilization demands and high energy value (17.05 to 19.21 MJ/kg). Faculty of Agriculture in Zagreb has started research on Miscanthus x giganteus in 2011

Ragweed (Ambrosia artemisiifolia L.) biomass as a source for energy production

Due to their rapid spread and reproduction, invasive plant species adversely affect agricultural production, the biodiversity of other species, as well as human health. They can be used as a potential raw material for energy production after mechanical removal to reduce their population without using herbicides. Ragweed belongs to the group of foreign invasive species, mainly as a weed, it can be found in crops, and its pollen causes allergies in humans. This paper aimed to investigate the energy properties of ragweed and the possibility of its use in thermal energy production. The results show that ragweed is a solid energy source for direct combustion, with a slightly higher proportion of ash, which negatively affects the energy properties.</p

Problems of mechanical harvesting of lavender

S obzirom na intenzivnije podizanje plantaža lavande zadnjih godina, ne samo u priobalnom, nego i u kontinentalnom području, nužno je procese kod sadnje, održavanje plantaže te ubiranje cvjetova u potpunosti mehanizirati. Samo tako možemo određene radnje obaviti na vrijeme i kvalitetno i što je najvažnije, biti konkurentan cijenom ubranog cvijeta, a kasnije i lavandinog ulja. U radu je istaknuta problematika strojnog ubiranje cvijeta lavande, ovisno o veličine plantaže lavande. Primjena suvremenih strojeva za ubiranje cvijeta lavande omogućuje velike učinke u berbi na većim plantažama, minimalne gubitke i hlapljenje eteričnih ulja do trenutka prerade cvjetova u destilerijama, što izravno utječe na kvalitetu i količinu dobivenog ulja.Considering the fact that lavender plantations have been set up more frequently in the last years, not only in coastal areas, but in continental areas as well, it is necessary to mechanize completely planting processes, plantation maintaining and flower picking. It is the only way to do some actions in time and in terms of quality, and what is the most important – to be competitive in price of the picked flowers and later of the lavender oil as well. This paper points out problems of mechanical harvesting of lavender, depending on the plantation size. Applying modern machines for picking lavender flowers largely affects picking on bigger plantations, minimum losses and evaporation of essential oils until the time of processing flowers in distilleries, which directly affects the quantity and quality of obtained oil

Convective Drying of Rapeseed Hybrids’ Seeds

The aim of this study was to investigate the water release from seeds of three rape hybrids, (‘Artus’, ‘Baldur’ and ‘Titan’), during the convection drying of the seeds at three different drying temperature (40, 60 and 80 °C). The drying was conducted in laboratory scale drier which can simulate the conditions of large drier. The air velocity in the drier was maintained at 1.0 m/s. Activation energy needed for starting the process of water release during the convective drying of oil seed rape seeds was also studied. According to the obtained values, the mathematical models (equations and curves) of kinematic drying were determined. By comparing the exponential equations and the constants of water release from seeds it was observed that drying of hybrid Artus was the slowest and the one of hybrid Titan the fastest. Results showed that there was a significant difference between all investigated hybrids in water release rate and that within the same drying conditions, hybrids showed different behaviour. Moreover, air temperature increase caused significant increase in water release from the seeds. The highest activation energy needed for starting the process of water release from the seeds had the hybrid Artus and the lowest one hybrid Titan. Due to this, it can be concluded that the activation energy was reversely proportional to the water release rate from the seeds

Problems of mechanical harvesting of lavender

S obzirom na intenzivnije podizanje plantaža lavande zadnjih godina, ne samo u priobalnom, nego i u kontinentalnom području, nužno je procese kod sadnje, održavanje plantaže te ubiranje cvjetova u potpunosti mehanizirati. Samo tako možemo određene radnje obaviti na vrijeme i kvalitetno i što je najvažnije, biti konkurentan cijenom ubranog cvijeta, a kasnije i lavandinog ulja. U radu je istaknuta problematika strojnog ubiranje cvijeta lavande, ovisno o veličine plantaže lavande. Primjena suvremenih strojeva za ubiranje cvijeta lavande omogućuje velike učinke u berbi na većim plantažama, minimalne gubitke i hlapljenje eteričnih ulja do trenutka prerade cvjetova u destilerijama, što izravno utječe na kvalitetu i količinu dobivenog ulja.Considering the fact that lavender plantations have been set up more frequently in the last years, not only in coastal areas, but in continental areas as well, it is necessary to mechanize completely planting processes, plantation maintaining and flower picking. It is the only way to do some actions in time and in terms of quality, and what is the most important – to be competitive in price of the picked flowers and later of the lavender oil as well. This paper points out problems of mechanical harvesting of lavender, depending on the plantation size. Applying modern machines for picking lavender flowers largely affects picking on bigger plantations, minimum losses and evaporation of essential oils until the time of processing flowers in distilleries, which directly affects the quantity and quality of obtained oil

Positive Impact of European Directives on the Implementation of Biofuels in Croatia

The first Directive on the promotion of renewable fuels was adopted in 2003 - Directive 2003/30/ EC of the European Parliament and of the Council of 8 May 2003 on the promotion of biofuels or other renewable fuels for transport. In 2009, a new (so called RED Directive, 2009/28/ EC) was adopted, which creates a legal framework to promote the use of energy from renewable sources. First generation biofuels require an increased share of arable land on which crops are grown for biofuel production. The Directive RED II limits the share of conventional biofuels to 7% and requires a minimum share of advanced biofuels from lignocellulosic feedstocks and waste in final energy consumption in the transport sector of at least 0.2% in 2022, 1% in 2025 and 3.5% in 2030

The phytoremediation potential of heavy metals from soil using Poaceae energy crops: A review

Fitoremedijacija je metoda koja koristi biljke u uklanjanju ili stabiliziranju onečišćujuće tvari u okolišu. Cilj sanacije onečišćenih područja uslijed ljudske aktivnosti je vraćanje takvih ekosustava u prvobitno stanje. Zbog primjene na veliki broj onečišćujućih tvari, kao i mogućnosti provedbe na raznim površinama te zbog manjeg utjecaja na okoliš i nižih troškova, fitoremedijacija se smatra zelenom tehnologijom. Kulture za proizvodnju energije su relativno nove u tom području te nedovoljno istražene. Ipak, dosadašnji rezultati ukazuju na njihovu sposobnost uklanjanja ili stabiliziranja metala u tlu. Cilj ovoga istraživanja bio je proučiti dostupnu literaturu na temu i utvrditi potencijal fitoremedijacije kadmija, kroma, bakra, žive, olova, nikla i cinka iz tla koristeći Arundo donax, Miscanthus x giganteus, Panicum virgatum, Pennisetum purpureum, Sida hermaphrodita i Sorghum x drummondii. Ovisno o uvjetima istraživanja istraživane kulture svrstane su u potencijalne fitoekstraktore, rizofiltratore, stabilizatore i akumulatore teških metala. Ipak, većina ovih biljnih vrsta akumulira veće koncentracije teških metala u korijenu, što ih čini ekskluderima budući da se metali ne translociraju u nadzemne dijelove, te povoljnima u provođenju rizofiltracije.Phytoremediation is a method that use plants which can remove or stabilize pollutants in the environment. The aim of the polluted area remediation is to return ecosystems into original condition. Phytoremediation is a green technology used for a wide range of pollutants as well as on various lands, low costs and reduced environment impacts. Energy crops are relatively new in this field of researches and insufficiently explored. However, the results so far show their potential in heavy metal removal. The aim of this research was to examine the available literature and determine the phytoremediation potential of cadmium, chromium, copper, lead, mercury, nickel and zinc from the soil using Arundo donax, Miscanthus x giganteus, Panicum virgatum, Pennisetum purpureum, Sida hermaphrodita and Sorghum x drummondii. According to the researches conditions, studied energy crops are reccomended in heavy metals phytoextraction, rhizofiltration, stabilization and accumulation. Still, those plants accumulate higher concentrations of heavy metals in the rhizosphere which makes them heavy metals excluders since heavy metals are not translocated into the plants\u27 shoot system and favorable in the implementation of rhizofiltration as well

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

Machines for cane shoots disposal in vineyards

U radu su prikazani suvremeni strojevi i alati (škare) za kontinuiranu i diskontinuiranu rezidbu rozgve u vinogradu. Sve do nedavna zbrinjavanje orezane rozgve predstavljao je mukotrpan fizički posao koji je na velikim površinama trajao mjesecima, te se sakupljena masa spaljivala neposredno uz vinograde. Prema tome, pored strojeva za rezidbu, ukazana je mogućnost iskorištenja orezane i usitnjene mase za izradu briketa kao vrlo vrijednog energetskog goriva namijenjenog za grijanje stambenih i proizvodnih objekata (staklenika, plastenika i dr.). Istraživanjem je potvrđeno da oko 2.5 kg briketa energetski može zamjeniti jednu litru značajno skupljeg loživog ulja.The paper presents modern machines and tools (shears) for continuous and discontinuous cane pruning in a vineyard. Disposal of pruned cane represented a hard work which used to take months up to recently and the collected mass was burned nearby the vineyards. Therefore, except for pruning machines, a possibility has appeared to use pruned and chopped mass to make briquettes as highly valuable energy fuel for heating housing and production- buildings (hothouses and polythene greenhouses). The research has confirmed that about 2.5 kg of briquettes can replace 1 l of significantly more expensive heating oil in terms of energy