130 research outputs found
Contract on long-term biomass supply for energy generation
Proizvodnja energije iz obnovljivih izvora i poveÄanje koriÅ”Äenja obnovljivih izvora energije na 20% u ukupnoj bruto potroÅ”nji energije do 2020. godine, jedan je od ciljeva energetske strategije Evropske unije. Kroz proces Energetske zajednice i proces Stabilizacije i pridruživanja, Republika Srbija je preuzela obavezu implementacije odreÄenih propisa Evropske unije u svoj pravni okvir. Kao cilj Energetske politike Republike Srbije, utvrÄeno je stvaranje uslova za stimulisanje koriÅ”Äenja obnovljivih izvora u ukupnoj bruto potroÅ”nji energije, Å”to je preuzeto i u strateÅ”kim dokumentima u oblasti energetike. KoriÅ”Äenje biomase za proizvodnju toplotne i/ili elektriÄne energije je jedan od naÄina ostvarivanja ovog cilja. Ipak, da bi se ovaj cilj ostvario, potrebno je obezbediti neophodnu koliÄinu biomase, shodno moguÄnostima samog energetskog objekta i potrebama kupaca energije. U ovom radu se analizira ugovor o dugoroÄnom snabdevanju biomasom za proizvodnju toplotne i/ili elektriÄne energije, a izmeÄu ostalog i pojam, predmet, modaliteti ovog ugovora, obaveze i odgovornost ugovornih strana.One of the goals incorporated in the EU energy strategy is energy generation from renewable sources aimed at achieving a 20% increase in the share of overall gross energy consumption by 2020.Within the process related to the Energy Community and the process of Stabilization and Association, the Republic of Serbia committed itself to incorporate certain EU regulations into its own legal framework. Creating the conditions that encourage utilisation of renewable sources in overall gross consumption of energy is one of the goals of the energy policy of the Republic of Serbia incorporated in the strategic documents related to the energy sector. Utilization of biomass in production of heat and/or electrical energy is one of the ways of achieving such a goal. However, in order to achieve this goal, it is necessary to provide the necessary quantities of biomass according to the characteristics of the energy facility and the needs of energy consumers. The current paper presents an analysis of a contract on long-term supply of biomass to be used for heat and/or electrical energy generation including, among other topics, the subject and modalities of this type of a contract and duties and obligations of the contracting parties
Contract on long-term biomass supply for energy generation
Proizvodnja energije iz obnovljivih izvora i poveÄanje koriÅ”Äenja obnovljivih izvora energije na 20% u ukupnoj bruto potroÅ”nji energije do 2020. godine, jedan je od ciljeva energetske strategije Evropske unije. Kroz proces Energetske zajednice i proces Stabilizacije i pridruživanja, Republika Srbija je preuzela obavezu implementacije odreÄenih propisa Evropske unije u svoj pravni okvir. Kao cilj Energetske politike Republike Srbije, utvrÄeno je stvaranje uslova za stimulisanje koriÅ”Äenja obnovljivih izvora u ukupnoj bruto potroÅ”nji energije, Å”to je preuzeto i u strateÅ”kim dokumentima u oblasti energetike. KoriÅ”Äenje biomase za proizvodnju toplotne i/ili elektriÄne energije je jedan od naÄina ostvarivanja ovog cilja. Ipak, da bi se ovaj cilj ostvario, potrebno je obezbediti neophodnu koliÄinu biomase, shodno moguÄnostima samog energetskog objekta i potrebama kupaca energije. U ovom radu se analizira ugovor o dugoroÄnom snabdevanju biomasom za proizvodnju toplotne i/ili elektriÄne energije, a izmeÄu ostalog i pojam, predmet, modaliteti ovog ugovora, obaveze i odgovornost ugovornih strana.One of the goals incorporated in the EU energy strategy is energy generation from renewable sources aimed at achieving a 20% increase in the share of overall gross energy consumption by 2020.Within the process related to the Energy Community and the process of Stabilization and Association, the Republic of Serbia committed itself to incorporate certain EU regulations into its own legal framework. Creating the conditions that encourage utilisation of renewable sources in overall gross consumption of energy is one of the goals of the energy policy of the Republic of Serbia incorporated in the strategic documents related to the energy sector. Utilization of biomass in production of heat and/or electrical energy is one of the ways of achieving such a goal. However, in order to achieve this goal, it is necessary to provide the necessary quantities of biomass according to the characteristics of the energy facility and the needs of energy consumers. The current paper presents an analysis of a contract on long-term supply of biomass to be used for heat and/or electrical energy generation including, among other topics, the subject and modalities of this type of a contract and duties and obligations of the contracting parties
Motor oil effects on characteristics of engine
Over the last decades there has been more and more severe requirements set to producers of motor vehicles and lubricants. Beside the fact they should provide functional, reliable and permanent operation, a vehicle as a whole is expected to give an adequate answer to wider and various market requirements in terms of environmental protection, improvement of vehicle performance, reduction of fuel consumption and increased traffic safety. When it comes to requirements related to lubricant characteristics, ways of use and intervals in which their replacement should take place, they are becoming more severe, since the motor vehicles' constructors keep making new and harder conditions in reference with performance improvement and lubricant efficiency. This paper describes the results of motor oil quality measurements in relation with exterior speed characteristics of engine as well as the testing programme for oil in the engine on motor brake. The evaluation of motor oil quality is monitored by measuring sediments in vital parts of engine on one hand, and on the other, by measuring output characteristics of engine
Impact of pellet raw material on the energy and environmental characteristic of low power domestic stoves
U radu su prikazani rezultati eksperimentalnih ispitivanja energetskih i ekoloÅ”kih karakteristika peÄi male snage (8,5 kW) za sagorevanje drvenih peleta koja se koristi za zagrevanje domaÄinstava. Celokupni postupak ispitivanja kao i projektovanje i izrada ispitne instalacije izvrÅ”ena su u skladu sa zahtevima važeÄeg Evropskog propisa EN 14785 za ovu vrstu peÄi. Eksperimentalna instalacija je projektovana i izvedena u Laboratoriji za goriva i sagorevanje MaÅ”inskog fakulteta Univerziteta u Beogradu. Ispitivanja su obavljena za tri toplotna optereÄenja peÄi (minimalno, srednje i maksimalno) i sa tri vrste ispitnog goriva. Kao ispitna goriva koriÅ”Äeni su peleti proizvedeni od bukovog drveta, Äamovine i njihove meÅ”avine, Äime je omoguÄeno odreÄivanje uticaja sirovine za proizvodnju peleta na proces sagorevanja. Obradom rezultata ispitivanja u skladu sa zahtevima standarda omoguÄeno je odreÄivanje energetskih i ekoloÅ”kih karakteristika ispitivane peÄi i njena klasifikacija prema kriterijumima definisanim standardom EN 14758.The results of experimental tests for determine thermal and environmental characteristics of low power pellet stove (8.5 kW) for combustion of wood pellets used for house hold heating are presented in this paper. Test procedure as well as design and manufacturing of test installation were carried out in accordance with the requirements of the applicable European regulation EN 14785 for ovens of this type. Test installation was de signed and assembled in the Laboratory for Fuel and Combustion at the University of Belgrade, Faculty of Mechanical Engineering. Tests were conducted for three thermal loads of the stove (minimum, medium and maximum) and three types of test fuel. Used test fuels were produced from beech wood, fir wood and their mixture, which allowed determining impact of pellet raw material on combustion process. Recalculation of test results in accordance with the requirements of a standard provided determination of energy and environmental characteristics of the tested stove and its classification according to the criteria defined by standard EN 14785
Impact of pellet raw material on the energy and environmental characteristic of low power domestic stoves
U radu su prikazani rezultati eksperimentalnih ispitivanja energetskih i ekoloÅ”kih karakteristika peÄi male snage (8,5 kW) za sagorevanje drvenih peleta koja se koristi za zagrevanje domaÄinstava. Celokupni postupak ispitivanja kao i projektovanje i izrada ispitne instalacije izvrÅ”ena su u skladu sa zahtevima važeÄeg Evropskog propisa EN 14785 za ovu vrstu peÄi. Eksperimentalna instalacija je projektovana i izvedena u Laboratoriji za goriva i sagorevanje MaÅ”inskog fakulteta Univerziteta u Beogradu. Ispitivanja su obavljena za tri toplotna optereÄenja peÄi (minimalno, srednje i maksimalno) i sa tri vrste ispitnog goriva. Kao ispitna goriva koriÅ”Äeni su peleti proizvedeni od bukovog drveta, Äamovine i njihove meÅ”avine, Äime je omoguÄeno odreÄivanje uticaja sirovine za proizvodnju peleta na proces sagorevanja. Obradom rezultata ispitivanja u skladu sa zahtevima standarda omoguÄeno je odreÄivanje energetskih i ekoloÅ”kih karakteristika ispitivane peÄi i njena klasifikacija prema kriterijumima definisanim standardom EN 14758.The results of experimental tests for determine thermal and environmental characteristics of low power pellet stove (8.5 kW) for combustion of wood pellets used for house hold heating are presented in this paper. Test procedure as well as design and manufacturing of test installation were carried out in accordance with the requirements of the applicable European regulation EN 14785 for ovens of this type. Test installation was de signed and assembled in the Laboratory for Fuel and Combustion at the University of Belgrade, Faculty of Mechanical Engineering. Tests were conducted for three thermal loads of the stove (minimum, medium and maximum) and three types of test fuel. Used test fuels were produced from beech wood, fir wood and their mixture, which allowed determining impact of pellet raw material on combustion process. Recalculation of test results in accordance with the requirements of a standard provided determination of energy and environmental characteristics of the tested stove and its classification according to the criteria defined by standard EN 14785
Motor oil effects on characteristics of engine
Over the last decades there has been more and more severe requirements set to producers of motor vehicles and lubricants. Beside the fact they should provide functional, reliable and permanent operation, a vehicle as a whole is expected to give an adequate answer to wider and various market requirements in terms of environmental protection, improvement of vehicle performance, reduction of fuel consumption and increased traffic safety. When it comes to requirements related to lubricant characteristics, ways of use and intervals in which their replacement should take place, they are becoming more severe, since the motor vehicles' constructors keep making new and harder conditions in reference with performance improvement and lubricant efficiency. This paper describes the results of motor oil quality measurements in relation with exterior speed characteristics of engine as well as the testing programme for oil in the engine on motor brake. The evaluation of motor oil quality is monitored by measuring sediments in vital parts of engine on one hand, and on the other, by measuring output characteristics of engine
Fitoremedijacijski potencijal divljih biljnih vrsta koje rastu na zemljiŔtu kontaminiranom teŔkim metalima
Phytoremediation is an emerging technology that employs higher plants to cleanup contaminated environments, including metal-polluted soils. Because it produces a biomass rich in extracted toxic metals, further treatment of this biomass is necessary. The aim of our study was to assess the five-year potential of the following native wild plants to produce biomass and remove heavy metals from a polluted site: poplar (Populus ssp.), ailanthus (Ailanthus glandulosa L.), false acacia (Robinia pseudoacacia L.), ragweed (Artemisia artemisiifolia L.), and mullein (Verbascum thapsus L). Average soil contamination with Pb, Cd, Zn, Cu, Ni, Cr, and As in the root zone was 22,948.6 mg kg-1, 865.4 mg kg-1, 85,301.7 mg kg-1, 3,193.3 mg kg-1, 50.7 mg kg-1, 41.7 mg kg-1,and 617.9 mg kg-1, respectively. We measured moisture and ash content, concentrations of Pb, Cd, Zn, Cu, Ni, Cr, and As in the above-ground parts of the plants and in ash produced by combustion of the plants, plus gross calorific values. The plants\u27 phytoextraction and phytostabilisation potential was evaluated based on their bioconcentration factor (BCF) and translocation factor (TF). Mullein was identified as a hyperaccumulator for Cd. It also showed a higher gross calorific value (19,735 kJ kg-1) than ragweed (16,469 kJ kg-1).The results of this study suggest that mullein has a great potential for phytoextraction and for biomass generation, and that ragweed could be an effective tool of phytostabilisation.Fitoremedijacija je tehnologija kojom se pomoÄu biljaka zemljiÅ”ta Äiste od zagaÄivala, ukljuÄujuÄi metale. S obzirom na to da se stvara biomasa bogata ekstrahiranim toksiÄnim metalima, potrebno ju je dodatno obraditi. Cilj ovoga petogodiÅ”njeg istraživanja bio je procijeniti potencijal sljedeÄih divljih biljnih vrsta za proizvodnju biomase i za uklanjanje teÅ”kih metala iz zagaÄenog zemljiÅ”ta: topole (Populus ssp.), pajasena (Ailanthus glandulosa L.), bagrema (Robinia pseudoacacia L.), ambrozije (Artemisia artemisiifolia L.) i divizme (Verbascum thapsus L.). ProsjeÄno oneÄiÅ”Äenje zemljiÅ”ta olovom, kadmijem, cinkom, bakrom, niklom i kromom te arsenom u zoni korijena bilo je 22.948,6 mg kg-1, 865,4 mg kg-1, 85.301,7 mg kg-1, 3.193,3 mg kg-1, 50,7 mg kg-1 i 41,7 mg kg-1 te 617,9 mg kg-1. TakoÄer su izmjereni sadržaj vlage i pepela nastalog paljenjem biljaka, sadržaj Pb, Cd, Zn, Cu, Ni, Cr i As u nadzemnim dijelovima biljaka i njihovu pepelu te bruto toplotna vrijednost. Fitoekstrakcijski i fitostabilizacijski potencijal utvrÄen je za divizmu i ambroziju na temelju faktora biokoncentracije (BCF) i faktora translokacije (TF). Divizma se je pokazala kao hiperakumulator kadmija, a pokazala je i veÄu gornju toplotnu moÄ (19.735 kJ kg-1) u odnosu na ambroziju (16.469 kJ kg-1). Rezultati ovog istraživanja upuÄuju na to da divizma ima potencijala za fitoekstrakciju i za proizvodnju biomase, a da ambrozija može biti djelotvorna u remedijaciji zemljiÅ”ta fitostabilizacijom
Engine and road tests of blends of biodiesel and diesel fuel
KoriÅ”Äenje alternativnih goriva u saobraÄaju je veoma važno zbog zavisnosti od nafte, velikog porasta broja vozila i kao posledica toga, visoke emisije CO2. Istraživanja biodizela kao alternativnog goriva obuhvataju sirovine, proizvodnju, kvalitet (Äisto ili u meÅ”avini sa dizelom), motorska i vozilska ispitivanja i odreÄivanje usklaÄenosti sa kriterijumima održivosti. U ovom radu su prikazani rezultati istraživanja obavljenih sa biodizelom pripremljenim od oÅ”teÄenih semenki suncokreta i otpadnog ulja za kuvanje koriÅ”Äenjem najnovije tehnologije za preÄiÅ”Äavanje biodizela od metanola zasnovane na principu jonske razmene. Glavni cilj je bio da se ispita moguÄnost koriÅ”Äenja razliÄitih meÅ”avina biodizela i dizela u dizel motorima i njihov uticaj na snagu motora, obrtni moment, potroÅ”nju goriva i izduvnu emisiju. Prikazani su rezultati standardnih i nestandardnih motorskih i vozilskih ispitivanja meÅ”avina biodizela i dizela.The utilization of alternative fuels in transport is very important due to dependence on petroleum, increaseasing in number of vehicles and as consequence high CO2 emission. The investigations of biodiesel as an alternative fuels include raw materials, production, quality (pure or in mixture with diesel), engine and vehicle tests and determining compliance with sustainability criteria. In this paper, the investigations were performed with the biodiesel prepared from damaged sunflower seed and used cooking oils using the latest technology for the purification of biodiesel from methanol based on ion exchange principle. The main target was to examine the possibility of utilisation of different biodiesel and diesel blends in Compression Ignition (CI) engines and their influence on engine power, torque, fuel consumption and exhaust emission. The results of standard and non-standard investigations and engine and vehicle tests of biodiesel and diesel blends are presented
Impact of fuel quality and burner capacity on the performance of wood pellet stove
Pellet stoves may play an important role in Serbia in the future when fossil fuel fired conventional heating appliances are replaced by more efficient and environmentally friendly devices. Experimental investigation was conducted in order to examine the influence of wood pellet quality, as well as burner capacity (6, 8, and 10 kW), used in the same stove configuration, on the performance of pellet stove with declared nameplate capacity of 8 kW. The results obtained showed that in case of nominal load and combustion of pellets recommended by the stove manufacturer, stove efficiency of 80.03% was achieved The use of lower quality pellet caused additional 1.13 kW reduction in heat output in case of nominal load and 0.63 kW in case of reduced load This was attributed to less favourable properties and lower bulk and particle density of lower quality pellet. The use of different burner capacity has shown to have little effect on heat output and efficiency of the stove when pre-set values in the control system of the stove were not altered It is concluded that replacement of the burner only is not sufficient to increase/decrease the declared capacity of the same stove configuration, meaning that additional measures are necessaly. These measures include a new set-up of the stove control system, which needy to be properly adjusted for each alteration in stove configuration. Without the adjustment mentioned, declared capacity of the stove cannot be altered, while its CO emission shall be considerably increase
Mixtures of bioethanol and gasoline as a fuel for SI engines
The importance of alternative fuels, especially bioethanol and biodiesel, rises due to the limited oil sources, secure supply, prices changes, and environment pollution. Bioethanol is an alternative fuel which will be important in future, as a fuel produced from different crops and lignocelluloses materials. The quality of bioethanol has significant influence on the characteristics of mixtures with gasoline and engine performance. The investigations were performed with the bioethanol obtained as by-product from sugar industry, which is not denaturated and produced according the requests prescribed by standards for ethanol used in mixtures with gasoline. Main target was to examine the possibility of utilisation of bioethanol obtained as by-product and without additional technologies for purification and additional costs. The results of standard and non-standard investigations and engine tests of bioethanol and gasoline mixtures are presented
- ā¦