Development in Renewable Energy Production in Serbia with the Emphasis on Bioethanol

Production and use of renewable energy sources has become an imperative for development around the world, including Serbia. The aim of this paper is to study the possibilities of production and use of renewable energy sources, especially bioethanol, as well as their place in the strategic objectives in the energy sector in Serbia. For this purpose, we will firstly frame the policies related to the production of renewable energy, and afterwards display the results of the cost-effectiveness of bioethanol production from the most important domestic biomass-based feedstock - corn. Our assumption is that, despite the existence of sufficient quantities of raw materials required for the production, knowledge, and the potential consumers of bioethanol in Serbia, its wider use will not be possible without the application of a systematic approach, especially without the development of adequate infrastructure in the production and use of energy resources

Investigation of various maize hybrids for bioethanol, starch and animal feed production

Bioetanol je biogorivo koje se širom sveta najviše koristi kao zamena za fosilna goriva. Trend proizvodnje ovog goriva je rastući, a kukuruz predstavlja jednu od najboljih obnovljivih sirovina za njegovu proizvodnju zahvaljujući visokom sadržaju skroba u zrnu. Suva džibra sa rastvorenim materijama (SDžSRM) je najznačajniji sporedni proizvod procesa proizvodnje bioetanola iz kukuruza. Zahvaljujući visokoj hranljivoj vrednosti, sadržaju proteina i drugih hranljivih materija, predstavlja kvalitetno hranivo koje može naći primenu kao komponenta u smešama koje se koriste za ishranu životinja. Procesom mokrog mlevenja zrna kukuruza se osim skroba, koji je osnovni proizvod od velikog značaja za prehrambenu i druge industrije, dobijaju vredni sporedni proizvodi koji takođe mogu naći primenu u ishrani ljudi i životinja. U teorijskom delu ove disertacije dat je sveobuhvatni prikaz svetskih trendova u proizvodnji bioetanola. Predstavljene su savremene tehnologije prerade kukuruza koje se koriste u proizvodnji ovog alternativnog goriva i skroba kao i inovacije koje se razvijaju u cilju poboljšanja efikasnosti i ekonomske isplativosti ovih postupaka. Hibridi kukuruza stvoreni u Institutu za kukuruz "Zemun Polje" predstavljaju jedinstven polazni materijal za istraživanja mogućnosti proizvodnje bioetanola, skroba i hrane za životinje. Cilj ovih istraživanja bio je da se polazeći od drugačijih fizičkih karakteristika i hemijskog sastava hibrida standardnog kvaliteta zrna i hibrida specifičnih svojstava različite genetičke osnove utvrdi na koji način i u kojoj meri ova svojstva zrna utiču na prinos i kvalitet finalnih proizvoda. Određena su fizička svojstva i hemijski sastav zrna ispitivanih hibrida kukuruza. Izvršena je optimizacija procesa enzimske hidrolize i alkoholne fermentacije brašna celog zrna odabranih hibrida kukuruza primenom enzima termostabilne α-amilaze Termamyl SC i glukoamilaze SAN Extra L, kao i proizvodnog mikroorganizma - kvasca Saccharomyces cerevisiae var. ellipsoideus. Pri optimalnim reakcionim uslovima (odnos kukuruznog brašna i vode 1:3; koncentracija α-amilaze Termamyl SC 0,02% (v/w), glukoamilaze SAN Extra L 0,12% (v/w) i koncentracija inokuluma kvasca Saccharomyces cerevisiae var. ellipsoideus 2% (v/v); temperatura fermentacije 30˚C) utvrđeno je adekvatno vreme trajanja fermentacije u cilju dobijanja što većeg prinosa etanola i uštede električne energije koji za modifikovani proces simultane saharifikacije i fermentacije iznosi 36h...Bioethanol is a biofuel that is mostly used as a replacement for fossil fuels worldwide. Trends of producing this alternative fuel are rising and maize is one of the best renewable raw materials for the production of fuel ethanol due to the high content of starch in the grain. Major by-product that arises from the fermentation process of corn is dried distillers’ grains with solubles (DDGS). Due to its high feeding value, high protein and other valuable nutrients it represents an excellent component for livestock feed mixtures. Corn grain wet milling process produces apart from corn starch, which is the main product of great importance to the food and other industries, valuable by-products, which may also find their applications in human and animal nutrition. In the theoretical part of this dissertation a comprehensive overview of global trends in the production of bioethanol was made. State of the art technologies of corn grain processing used in the production of this alternative fuel and starch, as well as innovations that are being developed in order to improve the efficiency and cost-effectiveness of these production processes were introduced. Hybrids created in the Maize Research Institute "Zemun Polje" represent unique starting material for research of the possibilities of bioethanol, starch and animal feed production. The aim of this study was to, starting from different physical properties and chemical composition of standard and specialty hybrids of different genetic background, determine how and in which level do the grain characteristics affect the yield and quality of the final products. The physical and chemical properties of grain corn hybrids were investigated. The optimization process of enzymatic hydrolysis and fermentation of whole grain flour obtained from the selected maize hybrids by using thermostable enzyme α-amylase Termamyl SC and glucoamylase SAN Extra L, as well as the production microorganism - yeast Saccharomyces cerevisiae var. ellipsoideus was conducted. Under optimal reaction conditions (ratio of corn flour and water 1:3, the concentration of α-amylase Termamyl SC 0.02% (v/w), glucoamylase SAN Extra L 0.12% (v/w) and inoculum concentration of Saccharomyces cerevisiae var. ellipsoideus 2% (v/v), fermentation temperature 30˚C) adequate fermentation time for the modified process of simultaneous saccharification and fermentation (SSF) was determined (36h) in order to obtain a higher yield of ethanol as well as electricity savings..

Recent trends in bioethanol production

Bioetanol je biogorivo koje se širom sveta koristi kao zamena za fosilna goriva. Upotrebom smeša bioetanola i benzina može se znatno smanjiti potreba za naftom kao i emisija gasova staklene bašte, odnosno zagađenje životne sredine. Iako se bioetanol već decenijama proizvodi iz skrobnih i šećernih sirovina, useva namenjenih prvenstveno ishrani, danas se smatra da korišćenje obradivih poljoprivrednih površina za proizvodnju ovog goriva nije opravdano pa se intenzivno razvijaju tehnologije za njegovo dobijanje iz lignoceluloznih izvora biomase kao što su šumski, poljoprivredni i komunalni otpad. Upotreba lignocelulozne biomase za proizvodnju biogoriva biće neizbežna u bližoj budućnosti kada se očekuje da će se tečna fosilna goriva morati zameniti obnovljivim održivim alternativama. Primena novih enzimskih sistema za hidrolizu celuloze, sinteza fermentativnih sojeva tolerantnih na inhibitore koji fermentišu pentozu, u kombinaciji sa optimizovanom integracijom procesa, obećavaju značajan napredak.The rapid depletion of the world petroleum supply and the increasing problem of greenhouse gas effects have strengthened the worldwide interest in alternative, nonpetroleum sources of energy. Bioethanol accounts for the majority of biofuel use worldwide, either as a fuel or a gasoline enhancer. Utilization of bioethanol can significantly reduce petroleum use and exhaust greenhouse gas emission. The production of this fuel has been increasing over the years, and has reached the level of 73.9 billion liters during the year 2009. Even though for decades ethanol production mainly depended on energy crops containing starch and sugar (corn, sugar cane etc.), new technologies for converting lignocellulosic biomass into ethanol are under development today. The use of lignocellulosic biomass, such as agricultural residues, forest and municipial waste, for the production of biofuels will be unavoidable if liquid fossil fuels are to be replaced by renewable and sustainable alternatives. For biological conversion of lignocellulosic biomass, pretreatment plays a central role affecting all unit operations in the process and is also an important cost deterrent to the comercial viability of the process. The key obstacles are: pretreatment selection and optimization; decreasing the cost of the enzymatic hydrolysis; maximizing the conversion of sugars (including pentoses) to ethanol; process scale-up and integration to minimize energy and water demand; characterization and evaluation of the lignin co-product; and lastly, the use of the representative and reliable data for cost estimation, and the determination of environmental and socio-economic impacts. Currently, not all pretreatments are capable of producing biomass that can be converted to sugars in high enough yield and concentration, while being economically viable. For the three main types of feedstocks, the developement of effective continuous fermentation technologies with near to 100% yields and elevated volumetric productivities is one of the main research subjects in the ethanol industry. The application of new, engineered enzyme systems for cellulose hydrolysis, the construction of inhibitor tolerant pentose fermenting strains, combined with optimized process integration promise significant improvements

Učinak mikronizacije na sastav i svojstvo brašna dobivenog od bijelog, žutog i crvenog zrnja kukuruza

The process of micronisation, a short time high temperature process that utilizes electromagnetic radiation in the infrared region to rapidly heat materials, is often used to improve storage stability of whole grain flour. In this work the consequences of such temperature treatment on the quality and solubility of proteins, viscosity, content of total phenolics, tocopherols, ß-carotene, as well as the antioxidant properties of maize (Zea mays L.) flour are presented. For these studies three maize hybrids were used: the semi-flint hybrid ZP 633 with pronounced yellow kernels, ZP Rumenka with dark red pericarp and yellow endosperm, and ZP 551b hybrid which is characterized by white kernels. The process of micronisation did not change the content of crude protein, the amount of albumin, globulin and zein were decreased, while glutelin remained the same or increased after micronisation. As a consequence of thermal effect on maize protein, tryptophan content was significantly decreased. Micronisation had a significant effect on the pasting properties of the selected maize flour. Viscosity of all micronised flour samples increased constantly, but without reaching a peak during heating of the slurry to 95 °C. At 95 °C it was slightly higher, but final viscosity at 50 °C was significantly lower. The micronisation treatment decreased the content of bioactive compounds (tocopherols, ß-carotene) naturally present in the raw grains. The whole grain flour from micronised grain, with modified nutritional and technological characteristics, represents a good raw material for production of gluten-free products.Mikronizacija, tj. postupak kratkotrajnog izlaganja materijala visokoj temperaturi pomoću elektromagnetskoga zračenja u infracrvenom području, često se primjenjuje za poboljšanje stabilnosti pri skladištenju cjelovitoga brašna žitarica. U radu je ispitan utjecaj takva postupka na kakvoću i topljivost proteina, viskoznost, udio ukupnih fenola, tokoferola i β-karotena, te na antioksidativna svojstva kukuruznoga brašna. Upotrijebljena su tri hibrida kukuruza (Zea mays L.): ZP 633, polutvrdunac izrazito žutih zrna; ZP Rumenka, tamnocrvenoga perikarpa i endosperma žute boje, te ZP 551b bijelih zrna. Mikronizacija nije utjecala na udio sirovih proteina, ali je smanjila udio albumina, globulina i zeina, dok je udio glutelina ostao nepromijenjen ili se neznatno povećao. Nakon toplinske obrade udio se triptofana znatno smanjio. Mikronizacija je također uvelike utjecala na vezivna svojstva brašna. Povećana je viskoznost svih uzoraka brašna, ali nije dosegla vrhunac zagrijavanjem suspenzije do 95 ºC. Na 95 ºC viskoznost je bila nešto veća, dok je pri završetku mikronizacije na temperaturi od 55 °C bila kudikamo manja. Mikronizacijom se smanjio udio bioaktivnih spojeva (fenola, tokoferola i β-karotena) prisutnih u sirovom zrnju. Cjelovito brašno dobiveno mikronizacijom zrnja žitarica zbog svojih je hranjivih i tehnoloških svojstava dobra sirovina za dobivanje bezglutenskih proizvoda

Učinak mikronizacije na sastav i svojstvo brašna dobivenog od bijelog, žutog i crvenog zrnja kukuruza

The process of micronisation, a short time high temperature process that utilizes electromagnetic radiation in the infrared region to rapidly heat materials, is often used to improve storage stability of whole grain flour. In this work the consequences of such temperature treatment on the quality and solubility of proteins, viscosity, content of total phenolics, tocopherols, ß-carotene, as well as the antioxidant properties of maize (Zea mays L.) flour are presented. For these studies three maize hybrids were used: the semi-flint hybrid ZP 633 with pronounced yellow kernels, ZP Rumenka with dark red pericarp and yellow endosperm, and ZP 551b hybrid which is characterized by white kernels. The process of micronisation did not change the content of crude protein, the amount of albumin, globulin and zein were decreased, while glutelin remained the same or increased after micronisation. As a consequence of thermal effect on maize protein, tryptophan content was significantly decreased. Micronisation had a significant effect on the pasting properties of the selected maize flour. Viscosity of all micronised flour samples increased constantly, but without reaching a peak during heating of the slurry to 95 °C. At 95 °C it was slightly higher, but final viscosity at 50 °C was significantly lower. The micronisation treatment decreased the content of bioactive compounds (tocopherols, ß-carotene) naturally present in the raw grains. The whole grain flour from micronised grain, with modified nutritional and technological characteristics, represents a good raw material for production of gluten-free products.Mikronizacija, tj. postupak kratkotrajnog izlaganja materijala visokoj temperaturi pomoću elektromagnetskoga zračenja u infracrvenom području, često se primjenjuje za poboljšanje stabilnosti pri skladištenju cjelovitoga brašna žitarica. U radu je ispitan utjecaj takva postupka na kakvoću i topljivost proteina, viskoznost, udio ukupnih fenola, tokoferola i β-karotena, te na antioksidativna svojstva kukuruznoga brašna. Upotrijebljena su tri hibrida kukuruza (Zea mays L.): ZP 633, polutvrdunac izrazito žutih zrna; ZP Rumenka, tamnocrvenoga perikarpa i endosperma žute boje, te ZP 551b bijelih zrna. Mikronizacija nije utjecala na udio sirovih proteina, ali je smanjila udio albumina, globulina i zeina, dok je udio glutelina ostao nepromijenjen ili se neznatno povećao. Nakon toplinske obrade udio se triptofana znatno smanjio. Mikronizacija je također uvelike utjecala na vezivna svojstva brašna. Povećana je viskoznost svih uzoraka brašna, ali nije dosegla vrhunac zagrijavanjem suspenzije do 95 ºC. Na 95 ºC viskoznost je bila nešto veća, dok je pri završetku mikronizacije na temperaturi od 55 °C bila kudikamo manja. Mikronizacijom se smanjio udio bioaktivnih spojeva (fenola, tokoferola i β-karotena) prisutnih u sirovom zrnju. Cjelovito brašno dobiveno mikronizacijom zrnja žitarica zbog svojih je hranjivih i tehnoloških svojstava dobra sirovina za dobivanje bezglutenskih proizvoda

Ispitivanje kvaliteta džibre nakon mlečno-kiselinske fermentacije kao hrane za životinje

Lactic acid is a significant chemical for the food industry. Fermentative lactic acid production on wastes could significantly improve the economy and sustainability of the process. In this study, lactic acid production was performed by L. rhamnosus ATCC 7469 on a stillage from bioethanol production on waste bread. Under optimal conditions, in fed-batch fermentation lactic acid productivity of 1.80 g L-1 h-1 has been achieved with a cell number of above 109 CFU mL-1. L. rhamnosus has shown high survival rate of over 85% in the presence of beef bile and at low pH value of MRS broth. The residuals after the fermentation were chemically analyzed and their composition corresponded well with the values recommended for the feed. The digestible energy was 17452.25 kJ kg-1, while metabolisable energy was 17360.83 kJ kg-1. The high values of energy parameters indicated that an integrated process for lactic acid and feedstuff production could be a good strategy.Mlečna kiselina je važna supstanca za prehrambenu industriju. Proizvodnja mlečne kiseline fermentacijom na otpadnim sirovinama može značajno da poveća ekonomičnost i održivost procesa. U ovom radu je ispitivana proizvodnja mlečne kiseline pomoću L. rhamnosus ATCC 7469 na džibri iz proizvodnje bioetanola na otpadnom hlebu. Pod optimalnim uslovima, u dolivnom postupku je postignuta produktivnost mlečne kiseline od 1.80 g L-1 h-1 sa više od 109 CFU mL-1 bakterija. L. rhamnosus je pokazao visok stepen preživljavanja od preko 85% u prisustvu žučnih soli i pri niskoj pH vrednosti MRS bujona. Ostatak nakon mlečno-kiselinske fermentacije džibre je hemijski analiziran i pokazano je da dobijene vrednosti odgovaraju preporučenim. Svarljiva energija je iznosila 17452,25 kJ kg-1, dok je metabolička energija bila 17360,83 kJ kg-1. Visoke vrednosti energetskih parametara hraniva ukazuju da integrisani proces proizvodnje mlečne kiseline i stočne hrane na džibri predstavlja povoljnu strategiju

Effect of Micronisation on the Composition and Properties of the Flour from White, Yellow and Red Maize

The process of micronisation, a short time high temperature process that utilizes electromagnetic radiation in the infrared region to rapidly heat materials, is often used to improve storage stability of whole grain flour. In this work the consequences of such temperature treatment on the quality and solubility of proteins, viscosity, content of total phenolics, tocopherols, beta-carotene, as well as the antioxidant properties of maize (Zen mays L.) flour are presented. For these studies three maize hybrids were used: the semi-flint hybrid ZP 633 with pronounced yellow kernels, ZP Rumenka with dark red pericarp and yellow endosperm, and ZP 551b hybrid which is characterized by white kernels. The process of micronisation did not change the content of crude protein, the amount of albumin, globulin and zein were decreased, while glutelin remained the same or increased after micronisation. As a consequence of thermal effect on maize protein, tryptophan content was significantly decreased. Micronisation had a significant effect on the pasting properties of the selected maize flour. Viscosity of all micronised flour samples increased constantly, but without reaching a peak during heating of the slurry to 95 degrees C. At 95 degrees C it was slightly higher, but final viscosity at 50 degrees C was significantly lower. The micronisation treatment decreased the content of bioactive compounds (tocopherols, beta-carotene) naturally present in the raw grains. The whole grain flour from micronised grain, with modified nutritional and technological characteristics, represents a good raw material for production of gluten-free products

Uporedni prikaz odabranih hibrida kukuruza za proizvodnju hrane za životinje

The objectives of this study were to investigate chemical composition and in   vitro dry matter digestibility (IVDMD) as well as to determine correlations   between some important quality parameters of the maize hybrids developed for   silage preparation in order to evaluate their suitability for feed   production. The IVDMD coefficients of the whole plant ranged from 0.5667 to   0.6734 with the neutral detergent fibers digestibility (NDFD) varying from   166 to 322 g/kg. Regarding IVDMD, the hybrids ZP 427, ZP 648 and ZP 666 were   superior to other investigated hybrids. Very significant positive   correlation was found between IVDMD of the whole maize plant and NDFD   (r=0.79); very significant negative correlation was determined between L/NDF   of the whole maize plant and NDFD and IVDMD (r=-0.73, r=-0.91). Obtained   results are of an exceptional importance for the breeding programs and   selection of potentially most suitable hybrids for silage production.Osnovni cilj istraživanja prikazanog u ovom radu bio je da se ispitaju   hemijski sastav i in vitro svarljivost suve materije odabranih domaćih   hibrida kukuruza različitog genetičkog porekla i grupa zrenja. Pored toga,   cilj je bio i da se odrede korelacije između pojedinih značajnih parametara   kvaliteta hibrida kukuruza selekcionisanih za pripremanje silaže, kako bi se   odredila njihova podobnost za proizvodnju hrane za životinje. Svi ispitivani   hibridi su komercijalni i njihova detaljna karakterizacija je neophodna za   proširenje njihove upotrebe u proizvodnji hrane za životinje. In vitro   svarljivost suve materije određivana je enzimskom metodom prema Aufréré.   Koeficijenti svarljivosti cele biljke kretali su se od 0,5667 do 0,6734, dok   se svarljivost NDF-a (NDFD) kretala od 166 do 322 g/kg. Odnos ligninske   frakcije i NDF-a cele biljke ispitivanih hibrida varirao je u rasponu od 30   do 39 g/kg. Na osnovu svarljivosti suve materije hibridi ZP 427, ZP 648 i ZP   666 su ocenjeni kao veoma pogodni za proizvodnju hrane za životinje.   Utvrđene su značajne razlike u hemijskom sastavu i svarljivosti suve   materije ispitivanih hibrida. Veoma značajna pozitivna korelacija određena   je između svarljivosti suve materije cele biljke i NDFD (r=0,79); veoma   značajna negativna korelacija između L/NDF cele biljke kukuruza i NDFD,   odnosno svarljivosti suve materije (r=- 0,73, r=-0,91). Rezultati ovog   istraživanja imaju veliki značaj za selekciju potencijalno najpogodnijih   hibrida za proizvodnju silaže. PR This research was supported by the Serbian Ministry of Education, Science and Technology of the Republic of Serbia, Project TR 31068

Suva džibra različitih hibrida kukuruza kao hranivo za životinje

This paper presents results of studies on qualities of maize dried distillers' grains with solubles (DDGS), as animal feed, which is a by-product from the process of maize grain-based bioethanol production. Twenty maize hybrids, developed at the Maize Research Institute, Zemun Polje, were used in this study. The moisture content in all DDGS samples was below 13% - the maximum value according to the Serbian Regulation. Furthermore, obtained results show that all observed DDGS samples had a high content of protein (29.58 - 36.08%), i.e. three-fold higher than in the initial raw material - maize grain. The digestibility of dry matter in samples of DDGS ranged from 74.09 (ZP Rumenka) to 82.41% (ZP 505). Based on obtained results, samples of DDGS were of high quality and therefore can be used as feed for the preparation of complete and concentrated feed.Proizvodnjom bioetanola od zrna kukuruza dobija se sporedni proizvod poznat kao kukuruzna džibra. Na svaki litar bioetanola proizvedenog od zrna kukuruza nastaje oko 0,89 kg suve kukuruzne džibre. Ovaj sporedni proizvod industrije bioetanola predstavlja odličan izvor proteina i energije pa se zbog toga najčešće koristi kao komponenta smeša za ishranu domaćih životinja. Prihod od prodaje suve kukuruzne džibre mogao bi da ima pozitivan uticaj na ekonomsku isplativost proizvodnje bioetanola postupkom suvog mlevenja s obzirom da se ovim procesom jedna trećina kukuruznog zrna prevodi u suvu džibru. U ovom radu prikazani su rezultati ispitivanja kvaliteta suve kukuruzne džibre, kao hraniva za životinje. U istraživanju je korišćeno 20 hibrida kukuruza Instituta za kukuruz 'Zemun Polje '. Sadržaj suve materije kretao se od 90,47 (ZP Rumenka) do 91,87% (ZP 362), što ukazuje da je sadržaj vlage u svim uzorcima bio manji od 13%, maksimalne vrednosti prema Pravilniku o kvalitetu hrane za životinje. Rezultati su pokazali da su svi ispitani uzorci imali visok sadržaj proteina, između 29,58 (ZP 505) i 36,08% (ZP 611k). Pored toga uočeno je da je sadržaj proteina u suvoj džibri skoro utrostručen u odnosu na zrno kukuruza kao polaznu sirovinu. Svarljivost suve materije uzoraka suve kukuruzne džibre kretala se u rasponu od 74,09 (ZPRumenka) do 82,41% (ZP 505). Na osnovu dobijenih rezultata ustanovljeno je da su uzorci suve džibre svih ispitivanih hibrida dobrog kvaliteta i mogu se koristiti kao hranivo za pripremu potpunih i koncentrovanih smeša za ishranu životinja

Characterisation of different maize hybrids for bioethanol and starch production

The suitability of selected ZP maize hybrids for bioethanol and starch production was studied. The composition, physical and chemical traits, and the alcoholic fermentation of the maize hybrids hydrolysates were studied using Saccharomyces cerevisiae var. ellipsoideus yeast. The hybrid ZP 434 achieved the highest ethanol yield of 90.2% of the theoretical yield after 34 hr of fermentation, the maximum yield of 65.16%, and starch recovery of 93.14%. The hybrid ZP 544 obtained the lowest ethanol yield of 69.32%. The similar ethanol yield (approximately 79%) was also detected in Hybrids ZP 704wx and ZP 341 obtained similar ethanol yield of ≈ 79%, but differed very much on their starch content. The highest (74.13%) and the lowest (69%) starch contents were determined in hybrids ZP 704wx and ZP 341, respectively. This is an abstract of a paper presented at the 19th International Congress of Chemical and Process Engineering and 7th European Congress of Chemical Engineering (Prague, Czech Republic 8/28/2010-9/1/2010)