The Potential for Reindustrialization of the Republic of Serbia with the Use of Biomass as a Renewable Fuel

U kontekstu savremene geopolitičke situacije i energetske neizvesnosti, cilj rada je da jače afirmiše upotrebu biomase kao domaćeg energenta i da ukaže na smernice za njeno pravilno i efikasno iskorišćenje. Prema zvaničnim podacima Ministarstva rudarstva i energetike Republike Srbije, biomasa predstavlja ubedljivo najveći potencijal obnovljive energije u zemlji. Preko 60% procenjenog potencijala obnovljive energije u Republici Srbiji pripada biomasi (ne računajući velika hidroenergetska postrojenja). Mogućnost energetskog iskorišćenja biomase, pri tome, ne zavisi od vremenskih prilika, doba dana ili godišnjeg doba, za razliku od drugih izvora obnovljive energije poput energije vetra i sunca. Pored ove i drugih prednosti koje biomasa kao jedino ugljenično – CO2 – neutralno obnovljivo gorivo ima, potrebno je istaći i to da su postrojenja za konverziju energije iz biomase putem sagorevanja relativno jednostavna i u celosti se mogu proizvoditi u našoj zemlji. Ukoliko bi se ova postrojenja koristila u sistemima daljinskog grejanja uz mogućnost korišćenja toplotne energije i za tehnološke procese u uzgoju i preradi poljoprivrednih proizvoda i van grejne sezone, potencijali se šire. Postrojenja za preradu i doradu poljoprivrednih proizvoda (poput sušara) takođe se u velikoj meri mogu proizvoditi u Republici Srbiji. Prednosti i stepen iskorišćenja biomase kao obnovljivog energenta još više dolaze do izražaja pri njenoj upotrebi u kogenerativnim postrojenjima. Kad se sve navedeno uzme u obzir može se zaključiti da primena biomase može zauzeti značajno mesto u sveobuhvatnoj reindustrijalizaciji naše zemlje, o čemu će više reči biti u ovom radu. U radu je, takođe, ukazano na neke od prepreka za realizaciju ovih napora kao i primeri dobre prakse.In the context of the current geopolitical situation and energy uncertainty, the aim of the paper is to affirm the use of biomass as a domestic energy source and to point out guidelines for its proper and efficient use. According to the official data of the Ministry of Mining and Energy of the Republic of Serbia, biomass represents by far the greatest potential for renewable energy in the country. Over 60% of the estimated potential of renewable energy in the Republic of Serbia belongs to biomass (not counting large hydropower plants). The possibility of energy use of biomass, further, does not depend on weather conditions, time of day or season, unlike other renewable energy sources such as wind and solar energy. In addition to this and other advantages that biomass as the only carbon - CO2 - neutral renewable fuel has, it should be noted that facilities for the conversion of energy from biomass through combustion are relatively technologically simple and can be produced entirely in our country. If these facilities were used in district heating systems with the possibility of using thermal energy for technological processes in the cultivation and processing of agricultural products even out of the heating season, the potentials and effects of biomass utilization would increase. Facilities for processing and finishing agricultural products (such as dryers) can also be largely produced in the Republic of Serbia. Advantages and the degree of utilization of biomass as a renewable energy source are even more pronounced when used in cogeneration plants. When all the above is considered, it can be concluded that the use of biomass can take a significant place in the overall reindustrialization of our country, which will be discussed in more detail in this paper. The paper also points out some of the obstacles to the realization of these efforts as well as examples of good practice

Modeling of transport processes in the cigarette principle combustion furnace

This paper presents numerical and experimental investigations of complex and interrelated physical and chemical phenomena that occur during combustion of baled soybean residue in the furnace with the cigarette type of combustion. The result of comprehensive research is reactive flow model of biomass combustion inside furnace. Model is described by set of PDE which define momentum, heat and mass transfer processes in porous and fluid system. The main aim of developed CFD model is numerical simulation of combustion process inside the cigarette furnace. It is also used to provide deeper insight in complex processes occurring during biomass combustion. Verification of proposed numerical model was performed through comprehensive experimental tests on the experimental-industrial plant of 1.5 MW boiler for heating the greenhouses in the Agricultural Corporation in Belgrade. The tests included measurement of flow rate and air and flue gas temperature input and output values on the furnace that are taken as the boundary conditions of the developed model. Comparison of the experimental results shows satisfactory agreement with numerical results (the maximum relative deviation of calculation and measurement temperatures are 10-45%), therefore the developed mathematical model could be used to analyse the effects of structural and parametric (fuel composition, power rate, air excess etc.) changes of the facility, from the standpoint of energy efficiency and ecology

Development of the small scale boiler for combustion of baled biomass from agricultural production

U radu je prikazan razvoj kotla za sagorevanje balirane biomase iz poljoprivredne proizvodnje, gde je organizacija sagorevanja izvedena po principu sagorevanja cigarete. U tu svrhu razmatrana je pogodnost sagorevanja biomase iz poljoprivredne proizvodnje, zatim je prikazan energetski potencijal biomase u našoj zemlji, a dat je i pregled dosadašnjih tehnologija koje se koriste kako u svetu tako i kod nas za sagorevanje biomase iz poljoprivredne proizvodnje. Eksperimentalno postrojenje za sagorevanje balirane biomase iz poljoprivredne proizvodnje izgrađeno je kod odabranog korisnika u mestu Stapar, blizu Sombora. Kao gorivo u ovim eksperimentima korišćena je balirana sojina slama. Da bi postrojenje radilo na određenoj nominalnoj ili ustaljenoj snazi napravljen je i ugrađen odgovarajući akumulator toplote. Merenja su urađena za više različitih režima rada kotla, sa povremenim uključivanjem u rad i akumulatora toplote. Merene su temperature dimnog gasa u ložištu, u zoni dogorevanja i iza izmenjivača toplote, kao i temperature razvodne i povratne vode. Pri svim režimima rada kotla meren je i sastav izlaznih dimnih gasova. Rad kotla tokom eksperimenta je regulisan pomoću upravljačkog sistema koji je koncipiran za ovu vrstu kotlova, a koji je baziran na kontroli temperature dimnog gasa na izlazu iz kotla i temperature tople vode na izlazu iz izmenjivača toplote. Prikazani su rezultati merenja u dugotrajnom radu, kao i analiza rezultata merenja, a na osnovu toga dati su i predlozi za poboljšanje budućih konstrukcija ovakvih kotlova.Development of boiler for combustion of baled bio mass from agricultural production, where combustion process is organized like cigarette combustion, has been presented in this paper. In that intention first of all was done suitability of agricultural biomass combustion, after that analysis of the energy potential of the biomass in our country, and a review of the previous technologies used for combustion of the biomass from the agricultural production. Experimental plant for combustion of the baled biomass from agricultural production has been developed at chosen user in Stapar, near Sombor, Serbia. As a fuel in these experiments has been used baled soya straw. To ensure power stability of the plant suitable heat storage has been developed. Measurements were done for different regimes, with periodically getting into the function the heat storage. After that results of the measuring in the long time period, and analyze of the measured results has been presented, and recommendations for the improving future designs of boilers like this has been given

Development of the small scale boiler for combustion of baled biomass from agricultural production

U radu je prikazan razvoj kotla za sagorevanje balirane biomase iz poljoprivredne proizvodnje, gde je organizacija sagorevanja izvedena po principu sagorevanja cigarete. U tu svrhu razmatrana je pogodnost sagorevanja biomase iz poljoprivredne proizvodnje, zatim je prikazan energetski potencijal biomase u našoj zemlji, a dat je i pregled dosadašnjih tehnologija koje se koriste kako u svetu tako i kod nas za sagorevanje biomase iz poljoprivredne proizvodnje. Eksperimentalno postrojenje za sagorevanje balirane biomase iz poljoprivredne proizvodnje izgrađeno je kod odabranog korisnika u mestu Stapar, blizu Sombora. Kao gorivo u ovim eksperimentima korišćena je balirana sojina slama. Da bi postrojenje radilo na određenoj nominalnoj ili ustaljenoj snazi napravljen je i ugrađen odgovarajući akumulator toplote. Merenja su urađena za više različitih režima rada kotla, sa povremenim uključivanjem u rad i akumulatora toplote. Merene su temperature dimnog gasa u ložištu, u zoni dogorevanja i iza izmenjivača toplote, kao i temperature razvodne i povratne vode. Pri svim režimima rada kotla meren je i sastav izlaznih dimnih gasova. Rad kotla tokom eksperimenta je regulisan pomoću upravljačkog sistema koji je koncipiran za ovu vrstu kotlova, a koji je baziran na kontroli temperature dimnog gasa na izlazu iz kotla i temperature tople vode na izlazu iz izmenjivača toplote. Prikazani su rezultati merenja u dugotrajnom radu, kao i analiza rezultata merenja, a na osnovu toga dati su i predlozi za poboljšanje budućih konstrukcija ovakvih kotlova.Development of boiler for combustion of baled bio mass from agricultural production, where combustion process is organized like cigarette combustion, has been presented in this paper. In that intention first of all was done suitability of agricultural biomass combustion, after that analysis of the energy potential of the biomass in our country, and a review of the previous technologies used for combustion of the biomass from the agricultural production. Experimental plant for combustion of the baled biomass from agricultural production has been developed at chosen user in Stapar, near Sombor, Serbia. As a fuel in these experiments has been used baled soya straw. To ensure power stability of the plant suitable heat storage has been developed. Measurements were done for different regimes, with periodically getting into the function the heat storage. After that results of the measuring in the long time period, and analyze of the measured results has been presented, and recommendations for the improving future designs of boilers like this has been given

EXPERIMENTAL RESEARCH OF THERMAL PROCESSES IN THE THERMAL STORAGE TANK WITH A PHASE CHANGE MEDIUM

Introduction of thermal storage tanks (TST) in facilities that use renewable energy resources represents a good way to increase their energy efficiency. This paper surveys a part of the activities (performed during the realization of the second year of project III 42011 financed by the Ministry of education and science of the Republic of Serbia) on the development of TST whose storage medium melts at the atmospheric pressure, enabling on that way the use of the energy of phase change for energy storage. TST of this type enable more thermal energy storage per volume unit, but also (depending of the working medium) enable higher temperatures of the working medium, which is necessary in the co-generated facilities. For the purpose of the experimental research of thermal and flow processes in TST in the Laboratory for thermal engineering and energy of the Vinča Institute a prototype of TST was designed and made. It has a cylindrical shape, with the working volume of 77 dm3. The working material is heated by 2.4 kW electric heater positioned along the TST axes, and is cooled by the air which circulates around the tank. The measurement of temperature inside the tank was performed by 16 thermocouples, 4 along the tanks height and 4 along the tanks radius. For the purpose of this work paraffin as a working medium was used. Measurements were performed for non-stationary as well as for stationary working regimes. As a result, an extensive set of experimental data was obtained, which, in the later work on the project, will serve in the numerical study, as a basis for the developing a numerical model, to verify its results and, if necessary, to correct the model

Technical and economic feasibilityof replacing the existing heavy fuel boilers with new biomass boiler within the heating system of the institute Vinča

Institut „Vinča“ se greje iz centralne kotlarnice toplom vodom u primarnom krugu. U kotlarnici su instalisana četiri mazutna vrelovodna blok kotla ukupne snage od 9,65 MW. To je veoma zastareo sistem grejanja koji ima niz nedostataka. Međutim, promena tog sistema i eventualno prelazak na dvostepeni (primarni i sekundarni vrelovodni/toplovodni krugovi sa ugradnjom podstanica) je veoma skup poduhvat i u ovom trenutku se ne razmatra. U radu je sagledana mogućnost supstitucije postojećeg goriva (mazut) biomasom. Za tu svrhu bi se morao izgraditi novi kotao koji će sagorevati biomasu. Analiza sprovedena u ovom radu je pokazala da li je i u kojoj meri to isplativo, ekološki prihvatlјivo, energetski efikasnije, kao i koliko je naučno istraživački korisno. U radu je prikazana i analiza angažovane snage kotlarnice za dve izabrane grejne sezone, što može pomoći u određivanju potrebne instalisane snage novog kotla na biomasu. Takođe, u radu je prikazana i kompletna logistika neophodna za realizaciju korišćenja biomase kao goriva u sistemu centralnog grejanja instituta Vinča."Vinca" Institute is heated from a central boiler station using a hot water in the primary circuit. In the boiler room a four heavy fuel oil hot water block boilers were installed with total capacity of 9.65 MW. It is very outdated heating system which has a number of disadvantages. However, the change of the system and eventually change to a two-stage (primary and secondary hot water/hot water circuits with installation of substations) is a very expensive proposition and at this time is not considered. In the paper is investigated the possibilities of substitution of the existing fuel (heavy fuel oil) with biomass. For this purposes a new boiler which will burn biomass would be built.The analysis conducted in this paper has shown whether and to what extent is cost-effective, environmentally friendly, energy efficient, and how is useful from scientific and research point of view. In the paper has been presented the analysis for two selected heating season, which may help in determining the installed capacity of the new biomass boiler. Also, in the paper are presented a complete logistics system required for implementation of biomass usage as a fuel in heating system of the Vinca Institute.28. Međunarodni kongres o procesnoj industriji - PROCESING ′15 : zbornik radova ; 4-5. jun, Inđij

Results of balled biomass combustion investigation in boiler with thermal power of 70 kW

Institut za nuklearne nauke „Vinča“, Laboratorija za termotehniku i energetiku, poslednjih nekoliko godina ulaže velike napore u promovisanje korišćenja nusproizvoda iz poljoprivredne proizvodnje. Radi se o tehnologiji cigaretnog sagorevanja balirane biomase koja je i od strane Evropske unije označena kao najpogodnija za tu namenu. Prednost ovog načina sagorevanja su minimalan utrošak električne energije za pripremu goriva, zadovoljavanje ekoloških kriterijuma sagorevanja, niski eksploatacioni i investicioni troškovi i mogućnost automatizacije rada. U tom cilju razvijen je kotao toplotne snage 70 kW za sagorevanje malih bala poljoprivredne biomase koje proizvode praktično svi ratari. Kotao je predviđen za rad sa malim četvrtastim balama dimenzija 40 cm × 50 cm × 80 cm. U radu su izloženi rezultati ispitivanja sagorevanja balirane biomase na pomenutom kotlu. Ispitivanja su izvršena sa više uvodnika bala (skraćeni, kosi i horizontalni). Sva ispitivanja su bila praćena odgovarajućim temperaturskim merenjima, kao i merenjima sastava produkata sagorevanjaAt the Vinca Institute of Nuclear Sciences, the Laboratory for Thermal Engineering and Energy has for the last few year made a lot of efforts in promoting the usage of residues of agricultural production. The method concerned is cigarette burning biomass combustion technology, which was evaluated by the European Union as very suitable for that purpose. The advantages of this type of combustion are minimal electricity consumption for fuel preparation, the meeting of ecological criteria, lower exploitation and investment costs and possibilities of operation process automation. For that purpose, a boiler of 70 kW heat power for small bale biomass combustion was developed. The producers of small bales are practically all agricultural workers. The boiler was designed for using small square bales with dimensions 40x50x70 cm. The results of the baled biomass combustion investigation in the above-mentioned boiler are presented in the paper. The investigations were performed with several types of baled feeders (shortened, inclined and horizontal). All the investigations were followed with adequate temperature and flue gas composition measurements.23. Međunarodni kongres o procesnoj industriji - PROCESING ′10: 26. savetovanje sa međunarodnim učešćem ZAVARIVANJE 2010 : 26. savetovanje sa međunarodnim učešćem IBR 2010 zbornik radova; 2-4. jun, Tar

Boiler combusting large soya straw bales for heating the greenhouses complex

U jednoj od najvećih kompanija koje se bave poljoprivrednom proizvodnjom u Srbiji pod zasadom soje se nalazi preko 2000 ha, i svake godine se proizvede oko 4000 t balirane sojine slame. Planirano je da se sojina slama koristi za grejanje plastenika, ukupne površine 5 ha. Zbog toga, u Laboratoriji za termotehniku i energetiku Instituta za nuklearne nauke 'Vinča' je učinjen napor da se razvije tehnologija za korišćenje krupne balirane biomase za proizvodnju energije. U prvoj fazi, razvijeno je demonstraciono eksperimentalno postrojenje - ložište za sagorevanje bala sojine slame. Ložište je izgrađeno i termotehnički ispitano, da bi se utvrdio kvalitet sagorevanja. Kako su rezultati ispitivanja bili veoma zadovoljavajući, u drugoj fazi razvoja, vrelovodni kotao sličnih karakteristika (koji sagoreva bale sojine slame dimenzija 0,7 x 1,2 x 2,7 m) je projektovan, i trenutno je u fazi izgradnje.In one of the largest agricultural companies in Serbia with over 2000 ha of soya plantations there is 4000 t/year of baled soya straw production. Soya straw biomass is planned to be used as renewable energy source for heating the greenhouses, with 5 ha in area. Therefore, efforts have been made to develop a technology for utilizing large bales of soya straw for energy production. In the first phase, a demo energy production facility - furnace was developed and built. The facility was tested in order to examine the quality of combustion of large soya straw bales. Since the experimental results obtained by testing of this facility proved to be very satisfactory in the second phase of development, the hot water boiler of similar characteristics (burning soya straw bales, with dimensions 0.7 x 1.2 x 2.7 m) was designed

EXPERIMENTAL RESEARCH OF THERMAL PROCESSES IN THE THERMAL STORAGE TANK WITH A PHASE CHANGE MEDIUM

Introduction of thermal storage tanks (TST) in facilities that use renewable energy resources represents a good way to increase their energy efficiency. This paper surveys a part of the activities (performed during the realization of the second year of project III 42011 financed by the Ministry of education and science of the Republic of Serbia) on the development of TST whose storage medium melts at the atmospheric pressure, enabling on that way the use of the energy of phase change for energy storage. TST of this type enable more thermal energy storage per volume unit, but also (depending of the working medium) enable higher temperatures of the working medium, which is necessary in the co-generated facilities. For the purpose of the experimental research of thermal and flow processes in TST in the Laboratory for thermal engineering and energy of the Vinča Institute a prototype of TST was designed and made. It has a cylindrical shape, with the working volume of 77 dm3. The working material is heated by 2.4 kW electric heater positioned along the TST axes, and is cooled by the air which circulates around the tank. The measurement of temperature inside the tank was performed by 16 thermocouples, 4 along the tanks height and 4 along the tanks radius. For the purpose of this work paraffin as a working medium was used. Measurements were performed for non-stationary as well as for stationary working regimes. As a result, an extensive set of experimental data was obtained, which, in the later work on the project, will serve in the numerical study, as a basis for the developing a numerical model, to verify its results and, if necessary, to correct the model