Improving aerobic stability and biogas production of maize silage using silage additives

The effects of air stress during storage, exposure to air at feed-out, and treatment with silage additives to enhance aerobic stability on methane production from maize silage were investigated at laboratory scale. Up to 17% of the methane potential of maize without additive was lost during seven days exposure to air on feed-out. Air stress during storage reduced aerobic stability and further increased methane losses. A chemical additive containing salts of benzoate and propionate, and inoculants containing heterofermentative lactic acid bacteria were effective to increase aerobic stability and resulted in up to 29% higher methane yields after exposure to air. Exclusion of air to the best possible extent and high aerobic stabilities should be primary objectives when ensiling biogas feedstocks

Improving aerobic stability and biogas production of maize silage using silage additives

The effects of air stress during storage, exposure to air at feed-out, and treatment with silage additives to enhance aerobic stability on methane production from maize silage were investigated at laboratory scale. Up to 17% of the methane potential of maize without additive was lost during seven days exposure to air on feed-out. Air stress during storage reduced aerobic stability and further increased methane losses. A chemical additive containing salts of benzoate and propionate, and inoculants containing heterofermentative lactic acid bacteria were effective to increase aerobic stability and resulted in up to 29% higher methane yields after exposure to air. Exclusion of air to the best possible extent and high aerobic stabilities should be primary objectives when ensiling biogas feedstocks

Biogas crops grown in energy crop rotations: Linking chemical composition and methane production characteristics

Methane production characteristics and chemical composition of 405 silages from 43 different crop species were examined using uniform laboratory methods, with the aim to characterise a wide range of crop feedstocks from energy crop rotations and to identify main parameters that influence biomass quality for biogas production. Methane formation was analysed from chopped and over 90 days ensiled crop biomass in batch anaerobic digestion tests without further pre-treatment. Lignin content of crop biomass was found to be the most significant explanatory variable for specific methane yields while the methane content and methane production rates were mainly affected by the content of nitrogen-free extracts and neutral detergent fibre, respectively. The accumulation of butyric acid and alcohols during the ensiling process had significant impact on specific methane yields and methane contents of crop silages. It is proposed that products of silage fermentation should be considered when evaluating crop silages for biogas production

Effect of short-term storage on quality of wheat stored in large polyethylene bags

Abstract: The aim of this study was to compare the short-term storage of food grains in large polyethylene bag silos with the conventional bulk storage of grain regarding quality parameters.  This storage option provides the chance to get along fluctuations in prices without investment in building operations.75 t newly harvested wheat with a dry matter content of 89.1% was stored during a period of six months in two polyethylene bags and as control in a granary on the same farm.  After two weeks, one month, three and six months samples were collected off the first bag below the polyethylene film and in 1.20 m depth and at the same time samples were taken in the granary.  The second bag was kept closed over the six month. Results demonstrated that there are no differences between the measuring points within a bag, between the two bags and no differences between the storage systems regarding the parameters dry matter, pH, starch, crude protein, content of mesophilic microorganisms (bacteria, yeast, mould) and germination.  The temperature in the polyethylene bag silos resembled rapidly to the ambient temperature.  There was no local overheating due to microbiological activity.  The results demonstrate that the temporary grain storage in polyethylene bags does not lead to any grain quality loss compared to the conventional storage.  Because of the very low cost, the flexible bagging system represents an alternative to high investment in permanent storage structures for grain. Key words: wheat, storage, polyethylene bags, quality, costs

Storage Problems of Poplar Chips from Short Rotation Plantations with Special Emphasis on Fungal Development = Rövid vágásfordulójú nyár apríték tárolási problémái, különös tekintettel a kifejlődő gombákra

There are several problems in storing wood chips freshly harvested from short rotation plantations, which result in quality losses as well as in dry matter and energy losses. The factors influencing the degradation of raw material are examined in this paper with special focus on fungal development. An excessive growth of fungi is connected to dry matter losses and also to an increased health risk during raw material handling. The following factors were measured during 6 months storage of poplar wood chips depending on particle size: box temperature, moisture content, pH-value, appearance of fungi in the storage and the concentration of fungal particles in the air. The results show a close connection between particle size, temperature and attack of fungi. During the storage mesophilic and termophilic species of the genera Alternaria, Aspergillus, Cladosporium, Mucor and Penicillium appeared. The concentration of fungal particles is the highest for fine chips and decreases in bigger particles. There was a special focus on the investigation of the properties of coarse chips (G 50), which represent a good compromise between handling, storage losses and health risk due to fungal development. | Frissen kitermelt rövid vágásfordulójú fafajokból előállított apríték tárolása során számos probléma merül fel, melyek eredménye minőség-, szárazanyag- és energiaveszteség. Ebben a tanulmányban a nyersanyag-degradációt befolyásoló tényezők kerültek vizsgálatra, különös tekintettel a kifejlődő gombákra. Ezek rendkívüli elszaporodásának köszönhető a szárazanyag-veszteség mellett a nyersanyag kezelése során fellépő, megnövekedett egészségügyi kockázat is. Nyár faapríték hat hónapos tárolása folyamán az aprítékméret függvényében a következő tényezők mérése zajlott: a tárolón belüli hőmérséklet, nedvességtartalom, pH, a tárolóban megjelenő gombák és azok száma a levegőben. Az eredmények szoros összefüggést mutatnak, különösen az aprítékméret, a hőmérséklet és a gombák száma közt. A tárolás során mezofil és termofil gombák fejlődtek. A következő nemzetségekhez tartozó fajok voltak megfigyelhetők: Alternaria, Aspergillus, Cladosporium, Mucor, Penicillium. A gombák száma a finom aprítéknál volt a legmagasabb, ami az aprítékméret növekedésével csökkent. A kutatás folyamán különös szerepet kapott a középfinom apríték tulajdonságainak vizsgálata (G 50), mely kompromisszumos megoldást jelent a kezelés, tárolási veszteségek és a kifejlődő gombáknak köszönhető egészségügyi kockázatok között

Storage problems of poplar chips from short rotation plantations with special emphasis on fungal development

There are several problems in storing wood chips freshly harvested from short rotation plantations, which result in quality losses as well as in dry matter and energy losses. The factors influencing the degradation of raw material are examined in this paper with special focus on fungal development. An excessive growth of fungi is connected to dry matter losses and also to an increased health risk during raw material handling. The following factors were measured during 6 months storage of poplar wood chips depending on particle size: box temperature, moisture content, pH-value, appearance of fungi in the storage and the concentration of fungal particles in the air. The results show a close connection between particle size, temperature and attack of fungi. During the storage mesophilic and termophilic species of the genera Alternaria, Aspergillus, Cladosporium, Mucor and Penicillium appeared. The concentration of fungal particles is the highest for fine chips and decreases in bigger particles. There was a special focus on the investigation of the properties of coarse chips (G 50), which represent a good compromise between handling, storage losses and health risk due to fungal development.Rövid vágásfordulójú nyár apríték tárolási problémái, különös tekintettel a kifejlődő gombákra. Frissen kitermelt rövid vágásfordulójú fafajokból előállított apríték tárolása során számos probléma merül fel, melyek eredménye minőség-, szárazanyag- és energiaveszteség. Ebben a tanulmányban a nyersanyag-degradációt befolyásoló tényezők kerültek vizsgálatra, különös tekintettel a kifejlődő gombákra. Ezek rendkívüli elszaporodásának köszönhető a szárazanyag-veszteség mellett a nyersanyag kezelése során fellépő, megnövekedett egészségügyi kockázat is. Nyár faapríték hat hónapos tárolása folyamán az aprítékméret függvényében a következő tényezők mérése zajlott: a tárolón belüli hőmérséklet, nedvességtartalom, pH, a tárolóban megjelenő gombák és azok száma a levegőben. Az eredmények szoros összefüggést mutatnak, különösen az aprítékméret, a hőmérséklet és a gombák száma közt. A tárolás során mezofil és termofil gombák fejlődtek. A következő nemzetségekhez tartozó fajok voltak megfigyelhetők: Alternaria, Aspergillus, Cladosporium, Mucor, Penicillium. A gombák száma a finom aprítéknál volt a legmagasabb, ami az aprítékméret növekedésével csökkent. A kutatás folyamán különös szerepet kapott a középfinom apríték tulajdonságainak vizsgálata (G 50), mely kompromisszumos megoldást jelent a kezelés, tárolási veszteségek és a kifejlődő gombáknak köszönhető egészségügyi kockázatok között

Konzerviranje zrna strnih žita drobljenjem i hermetičkim skladištenjem

Grinding and airtight storing of maize grains is well known technology in region of Pannonia plane, European Corn Belt. The energy needs for this kind of preservation is considerably lower than energy used for preservation by drying, especially for high-moisture late hybrids. The same preservation of cereals grains is practiced in the regions where, due to climatic conditions, grains couldn’t reach phase of full ripeness, or they have in harvesting time high moisture content. Due to very low prices of cereals grains they are more and more used as fodder. In that case they cereals grains can be earlier harvested, with the moisture content 16-24%, grained and airtight stored. This can extend harvesting season and reduce costs of storage. The paper presents results of investigation of cereal grains grinding and making silage. It has been measured process of grinding with hammer mill and press rollers. The capacity, energy input and particle fineness of cereal grains has been measured. The microbiology tests of processed and stored grain have been provided. It has bin found out that grinding with press rollers results with bigger particles but much less energy is needed in comparison with hammer mill grinding. In all cases tests of silage hygienic were positive. The prices of this fodder processing procedure have been compared with drying and grinding. It was find out that, depending on weather conditions in harvest period, the costs for grinding and airtight storing of cereal grains are 5 to 50% lower than for its drying and dry grinding. The profitability of moist grinding and airtight storing of cereal grains processing procedure should be considered concerning individual conditions, e.g. using of same grinding equipment for maize corn processing, weather conditions, own and neighboring farms structure et cetera,Mlevenje vlažnog zrna kukuruza i hermetičko skladištenje je tehnologija poznata u regionu Panonske nizije, kukuruznog pojasa Evrope. Energija potrebna za ovaj način konzerviranja je niža nego za sušenje, posebno visokovlažnih kasnostasnih hibrida. Isti postupak koristi se za konzerviranje zrna strnih žita u područjima u kojima, zbog klimatskih uslova, potpuno dozrevanje nije moguće, ili je vlažnost zrna u vreme žetve visoka. Niske cene zrna strnih žita uzrokovale su da se ono sve više koristi kao stočna hrana. Žetva žitarica mogla bi da otpočne ranije, kada je vlažnost zrna 16-24%, te da se ono samelje i hermetički skladišti, sa ili bez dodavanja sredstava za konzervaciju. Ovakvim postupkom moglo bi da se produži trajanje žetve, te da se kombajn duže koristi, i da se uštedi na troškovima skladištenja zrna. U radu su prikazani rezultati ispitivanja opisanog postupka konzerviranja zrna pšenice i raži. Za mlevenje je korišćen uređaj sa dva para narebrenih valjaka. Mereni su učinak, potrebna energija i ostvareno usitnjavanje zrna, a dobijeni rezultati upoređeni sa onima drugih autora i sa rezultatima dobijenim mlevenjem čekićarem. Takođe su obavljeni mikrobiološki testovi obrađenog materijala. Utvrđeno je da se mlevenjem uređajem sa narebrenim valjcima ostvaruje veća krupnoća usitnjenog materijala, ali je potrebno manje energije. Udeo bakterija i kvasaca, konzerviranog materijala veće krupnoće, je ispod granica dozvoljenog, te su higijenski zahtevi zadovoljeni. U radu je dato poređenje troškova prerade zrna ovim postupkom i upoređene sa cenom sušenja i naknadnog drobljenja, za uslove u Nemačkoj. U zavisnosti od vremenskih uslova u vreme žetve postupkom mlevenja vlažnog zrna i konzervacije hermetičkim skladištenjem cena je za 5 do 50% niža nego ukoliko se zrno suši i kasnije melje. Na osnovu cene žitarica, potrebnih ulaganja, i mogućnosti kombinovanja sa preradom zrna kukuruza, svaki proizvođač treba da izračuna da li je ovakav postupak prerade zrna strnih žita u konkretnim uslovima isplativ

Establishment of a Laboratory Scale Set-Up with Controlled Temperature and High Humidity to Investigate Dry Matter Losses of Wood Chips from Poplar during Storage

The aim of this work was to improve the understanding of dry matter losses (DML) that occur in wood chips during the initial phase of storage in outdoor piles. For this purpose, a laboratory scale storage chamber was developed and investigated regarding its ability to recreate the conditions that chips undergo during the initial phase of outdoor storage. Three trials with poplar Max-4 (Populus maximowiczii Henry  Populus nigra L.) chips were performed for 6–10 weeks in the storage chamber under controlled temperature and assisted humidity. Two different setups were investigated to maintain a high relative humidity (RH) inside the storage chamber; one using water containers, and one assisted with a humidifier. Moisture content (MC) and DML of the chips were measured at different storage times to evaluate their storage behaviour in the chamber. Additionally, microbiological analyses of the culturable fraction of saproxylic microbiota were performed, with a focus on mesophilic fungi, but discriminating also xerophilic fungi, and mesophilic bacteria, with focus on actinobacteria, in two trials, to gain a view on the poplar wood chip-inhabiting microorganisms as a function of storage conditions (moisture, temperature) and time. Results show that DML up to 8.8–13.7% occurred in the chips within 6–10 storage weeks. The maximum DML were reached in the trial using the humidifier, which seemed a suitable technique to keep a high RH in the testing chamber, and thus, to analyse the wood chips in conditions comparable to those in outdoor piles during the initial storage phase

Methanbildungspotenziale verschiedener Pflanzenarten aus Energiefruchtfolgen

Das Methanbildungspotenzial ist ein entscheidendes Qualitätsmerkmal von Biomassen bei ihrer Nutzung als Einsatzstoff für die Biogasproduktion. Von 769 unter einheitlichen Bedingungen silierten Erntegütern aus Energiefruchtfolgen wurden mittels Batch-Gärtests in zwei verschiedenen Versuchsanlagen spezifische Methanausbeuten ermittelt. Daraus konnten Richtwerte für mittlere Methanausbeuten je Fruchtart und Fruchtfolgestellung, Schnitt bzw. Trockenmassebereich oder Entwicklungsstadium zur Ernte für 93 verschiedene pflanzliche Biomassen abgeleitet werden. Die Ergebnisse stellen eine umfassende Datengrundlage dar, die in Verbindung mit Biomasseerträgen für die Abschätzung von Methanhektarerträgen zur ökonomischen und ökologischen Bewertung von Energiefruchtfolgen, zur Planung und Auslegung von Biogasanlagen sowie zur Entscheidung hinsichtlich des Anbaus alternativer pflanzlicher Kosubstrate und der Konzeption nachhaltiger Biogasfruchtfolgen genutzt werden können.The methane production potential represents an essential quality parameter of biomass if used as feedstock for biogas production. 769 harvested crop materials from crop rotations were ensiled at standardized conditions and were analyzed regarding their specific methane yields by applying two different experimental setups of batch anaerobic digestion tests. Based on this analysis, reference values for average methane yields per crop species and position within the crop rotation, cutting regime, range of dry matter content, or stage of growth at harvest have been deduced for 93 different crop biomasses. Results provide a comprehensive dataset that can be used in combination with biomass yields for the estimation of methane hectare yields, for economic and ecological evaluation of energy crop rotations, for planning and structural design of biogas plants as well as for decisions regarding the cultivation of alternative co-substrates and the design of sustainable biogas crop rotations

“Damp in bathroom. Damp in back room. It's very depressing!” exploring the relationship between perceived housing problems, energy affordability concerns, and health and well-being in UK social housing

Social housing residents often struggle with achieving adequate levels of warmth in their home on a limited household budget. Additionally, other housing problems such as damp are common. Previous research has found a link between housing problems and poor health and reduced well-being, but this relationship is complex and poorly understood. A survey among UK social housing residents (N=536) investigated the association between cold and damp housing, as well as the role of energy affordability concerns in the relationship between housing problems and health. The findings indicated that struggles with keeping warm related to a cluster of damp and mould issues rather than any one specific issue. In describing these problems householders expressed a sense of frustration and helplessness. Support was found for an indirect effect on health whereby households experiencing cold, damp or mould issues reported more difficulty with affording their energy bills, these affordability concerns in turn related to poor health and well-being. The effects were found to be more consistent and stronger for men compared to women. Policies aimed at reducing housing problems should consider the important role of affordability concerns and the need for households to regain control of their energy bills