Ocena emisije gasova s efektom staklene bašte lanca snabdevanja kukuruzovine

Within this investigation, different scenarios for supply chains of corn stover intended for biogas production were evaluated in terms of emissions of the greenhouse gasses and their impact to global warming. A primary difference between the scenarios was due to application of different stover collection techniques i.e. forage harvester, baling of big rectangular and round bales. It was found that the supply chain, which includes the application of forage harvester for stover collection is characterized by the highest value of impact, approximately 70 and 85 kg CO2 eq MgDM–1, respectively for the usual and reduced corn stover yield. For the supply chain which includes baling of big rectangular bales, these values are around 62 and 68 kg CO2 eq MgDM–1, and for the baling of round bales, values are 61 and 67 kg CO2 eq MgDM–1. Among the analyzed greenhouse gases emissions, the dominant impact is due to the emissions of carbon dioxide. The reduction of the corn stover yield, caused by extreme drought, is followed by higher GHG emissions, first of all due to longer distances during harvest and transportation.U okviru istraživanja su, za različite scenarije lanca snabdevanja kukuruzovinom namenjene za proizvodnju biogasa, određene vrednosti emisija gasova s efektom staklene bašte i ocenjen njihov uticaj na doprinos globalnom zagrevanju. Osnovna razlika između scenarija proizilazi iz načina ubiranja kukuruzovine i to silažnim kombajnom i formiranjem velikih četvrtastih i valjkastih bala. Ustanovljeno je da se lanac snabdevanja sa primenom silažnog kombajna rezultuje najvišom vrednošću uticaja, koja iznosi 70 i 85 kg CO2 ekv MgSM–1, za visok i nizak prinos kukuruzovine respektivno. Za lanac sa ubiranjem u formi četvrtastih bala, te vrednosti iznose 62 i 68 kg CO2 ekv MgSM–1, a za valjkaste bale 61 i 67 kg CO2 ekv MgSM–1. Od analiziranih gasova s efektom staklene bašte, dominantan uticaj ima ugljen-dioksid. Smanjenje prinosa kukuruzovine, usled suše, nepovoljno se odražava na lanac snabdevanja, pre svega zbog dužine puta pri ubiranju i transportu

Potencijal žetvenih ostataka uljane repice u Srbiji

Rapeseed straw is potential source of renewable energy, but important source of soil organic matter as well. The amount of crop residues, available for energy use, per hectare, is not well known. Excessive offtake of crop residues can be followed by reduction of soil fertility, removal of nutrients, organic carbon and wind erosion. The objective of the investigation was to define total and harvestable amount of crop residues – straw, and amount that remain on the field, which can be background for the calculation of soil fertility preservation. In 2013 (climatic conditions characterized as moderate dry) samples of aboveground mass of eight varieties were collected from three locations, and in 2014 (characterized as moderate to extreme humid) six varieties for one location. The samples were divided into: grain, stalks and hulls. It has been defined yield of fractions and calculated harvest index. The stalks were split along their lengths, parts measured and created cumulative mass distribution. For common harvest procedures have been defined harvestable mass, potential, for two selected cutting heights. Average harvest index was in 2013 0.34, and in 2014 lower, 0.29. Percentage of harvestable mass was between 35 and 51 % of total aboveground residual mass. Harvestable yield was in 2013 about 46 %, due to less favorable climatic conditions. This should be considered by the planning of any use of this material as energy source. It was assessed that the energy potential of rapeseed straw, including measures for preservation of soil fertility, is 1.1 to 2.0 Mg ha–1, in average. On field remained residual mass can ensure, if proper tillage is applied, protection of wind erosion and increase of soil organic matter and soil organic carbon. It is concluded that rapeseed straw can be used for soil amelioration if adequate crop rotation is applied, and can compensate offtake of residues of other crops, e.g. wheat straw and corn stover. Future investigation should be oriented toward this utilization of rapeseed straw.Slama uljane repice potencijalni je izvor obnovljive energije, ali i značajan izvor organske mase u zemljištu. Količina žetvenih ostataka, slame, koja je na raspolaganju, po hektaru, nije dovoljno poznata. Prekomerno skidanje žetvenih ostataka može da izazove negativne posledice u pogledu plodnosti zemljišta, uklanjanje nutrijenata, organskog ugljenika u zemljištu i erozije vetra. Cilj istraživanja bio je da se utvrdi ukupna količina žetvenih ostataka uljane repice, količine, koje mogu da se uberu i količine nadzemnih žetvenih ostataka, kao podloge za donošenje mera za očuvanje plodnosti zemljišta. Prikupljeni su uzorci nadzemne mase osam reprezentativnih sorti sa tri lokacije, 2013. godine (koja je bila sa umerenom sušom) i šest sorti sa jedne lokacije 2014. godine (u toku koje je bila umerena do ekstremna vlažnost). Uzorci biljaka su podeljeni na delove: zrno, stabljika i mahune. Utvrđen je žetveni indeks, prinos i relativni prinos žetvenih ostataka. Stabljike su podeljene u sekcije po visini, izmerene mase i kreiran dijagram kumulativne mase po visini. Za uobičajeni postupak ubiranja slame, presovanjem, ocenjena je količina žetvenih ostataka, koja može da se ubere za dve odabrane visine rezanja. Prosečan žetveni indeks u sezoni 2013. bio je 0,34, dok je u 2014. bio niži i iznosio je 0,29. Procenat žetvenih ostataka, koji može da se ubere bio je između 35 i 51 % od ukupne biljne mase nadzemnih žetvenih ostataka. Tehnički prinos pri lošim klimatskim uslovima bio je za oko 46 % niži, što bi trebalo da se uzme u obzir u slučaju planiranja raspoložive količine. Procenjeno je da bi energetski potencijal, uzimajući u obzir i očuvanje plodnosti zemljišta, uljane repice mogao da bude 1,1 do 2,0 Mg ha–1. Nadzemna masa žetvenih ostataka može, uz primenu obrade zemljišta bez prevrtanja, da osigura zaštitu zemljišta od erozije vetra i doprinese očuvanju plodnosti zemljišta, organske mase i organskog ugljenika. Žetveni ostaci uljane repice mogu da budu dobra podloga za sprovođenje upravljanja organskom materijom, primenom odgovarajućeg plodoreda, te da se koriste za kompenzovanje organske materije koja se iznosi ubiranjem žetvenih ostataka drugih biljnih vrsta, na primer, pšenice, soje i kukuruza. Buduća istraživanja trebalo bi da budu usmerena ka oceni primenljivosti žetvenih ostataka repice za očuvanje plodnosti zemljišta

Webbasierte Schwachstellenanalyse an landwirtschaftlichen Biogasanlagen

Eine suboptimale Dimensionierung oder ein ineffizienter Betrieb landwirtschaftlicher Biogasanlagen haben negative Umweltwirkungen und eine mangelhafte Wirtschaftlichkeit zur Folge. Wir stellen hier eine Bewertungsmethode vor, mit der eine betriebsindividuelle Schwachstellenanalyse und eine vergleichende Bewertung von Biogasanlagen möglich werden. Die Methode kombiniert Elemente aus Fuzzy-Sets und Expertensystemen, um Biogasanlagen hinsichtlich verschiedener Kriterien zu bewerten. Die Bewertungsergebnisse für einzelne Anlagen und die Rangfolge in einem Anlagenvergleich sind hierbei unabhängig von der jeweiligen Stichprobe, da die einzelnen Kriterien auf Basis des Standes von Wissenschaft und Technik bewertet werden. Um den Bewertungsalgorithmus einem breiteren Nutzerkreis verfügbar zu machen, wurde die Web-Anwendung „Biogas Doc“ entwickelt, mit welcher die erforderlichen Informationen zur Anlagenkonfiguration sowie die Daten zum Betriebsergebnis der Biogasanlage strukturiert erfasst und dargestellt werden können. Mit der Anwendung kann der Nutzer prinzipiell auch die Auswirkungen von Repowering-Maßnahmen oder Änderungen bei den Einsatzstoffen auf wichtige Leistungskennwerte der Biogasanlage simulieren und damit zuverlässiger planen

Assessing sustainable biogas potentials—case study for Serbia

Biogas is efficient renewable energy source concerning greenhouse gases emission (GHG) reduction and waste disposal. The most abundant biogas substrates are originating from agriculture, i.e., energy plants and wastes such as manure, and respective production and utilization can be used to support rural development. Defining sustainable potentials, i.e., realistic value under defined conditions, of biogas production in some geographical region is important, as a background for policy development on a national, regional, and even local level. The objective of the study was defying method for its assessment. The characteristics of the proposed method are as follows: (1) biogas potential is expressed in electric power of cogeneration units that can operate with biogas produced from available feedstock. Available thermal energy, or biomethane production, can be calculated based on biogas potential; (2) the determined sustainable potential is based on environmental, technological, and socio-economic criteria; (3) the assessment is related to the actual substrates’ availability, whereby expected technological advancements are considered. Developed method has been tested in the form of a case study for Serbia and obtained outcomes compared with studies previously done by other authors. The potential is lower than previously assessed. The forecasted technology advancements and reduction of specific investment costs in the future can contribute to the increase of potential, higher share of wastes and by-products in substrates. New, smaller biogas plants would be constructed in undeveloped regions, what could contribute to rural development.JRC.C.2-Energy Efficiency and Renewable

Investigation on Possibilities for Sustainable Provision of Corn Stover as an Energy Source: Case Study for Vojvodina

Corn stover, among other crop residues, is becoming important an energy source, as non food/feed feedstock, especially for biofuels. A problem is to ensure a secure supply, which is influenced by drought. The further requirement is to eliminate or minimize biomass removal impact on soil fertility and erosion. The objective of the investigation was to assess possibilities for sustainable provision of corn stover as an energy source, considering these issues. The investigation is conducted in the province Vojvodina, an agricultural part of Serbia, for seasons 2011 and 2012. Weather in 2011 was dry and in 2012 extremely dry. Stover samples were divided in the following fractions: the lowest 0.2 m, stalk + leaves, cobs and husks. Yields and relative yields of these fractions were calculated and thereafter used to determine the total and usable mass of stover, considering three stover harvest procedures. The on-field remaining mass of stover was used to determine if the prerequisites for conservation soil tillage, i.e. erosion protection, can be achieved. Relative harvestable yields (related to grain yield) for three harvest procedures, and both seasons, were 53, 43, 19% (2011) and 16% (2012). The harvestable mass, i.e. stover yield, in 2012 was, compared with 2011, reduced due to unfavorable weather by 31% for two harvest procedures and even 42% if only cobs are harvested. The on-field remaining mass of stover was sufficient to achieve conservation tillage and protection from soil erosion. Determination of nutrient removal costs can represent significant problem, and results from this investigation may contribute. The potential of corn stover harvestable yield depends on harvest procedure. When developing novel harvest solutions, it is recommendable that they should minimize the reduction of grain harvest productivity and stover contact with soil. This needs further R&D activities.JRC.C.2-Energy Efficiency and Renewable