Search results for "METHANE"
showing 10 items of 1763 documents
Direct Measurement of Methane Emission Rates: Multiyear Application to a Municipal Landfill in Southern Italy
2012
Municipal Solid Waste (MSW) landfills have been identified as one of the most important sources of methane (CH4) emission. MSW contains a certain amount of biodegradable organic matter which undergoes anaerobic degradation resulting in the production of the landfill gas (LFG), which main component is tipically represented by CH4. In order to minimise its negative effects on the envi-ronment, LFG recovery is a suitable tool to control CH4 emissions from a landfill site and the measurement of CH4 emissions represents a good way to evaluate the effectiveness of LFG recover-ing system in reducing biogas emission to the atmosphere. However, up to now few measurements of landfill CH4 emissions ha…
Estimation of methane emission by a municipal landfill: the case of Palermo
2010
CH4 diffuse emissions from municipal solid waste landfills represent one of the most important anthropogenic source of greenhouse-gas. CH4 is produced by anaerobic biodegradation of organic matter in land-filled MSW and it constitutes the major component of landfill gas. Gas recovery is a suitable tool to effectively control CH4 emissions from landfill sites and the quantification of CH4 emissions represents a good tool to evaluate the effectiveness of biogas recovering system in reducing biogas emission. In particular, LFG emissions can be indirectly evaluated from mass balance equations between formation, recovery and oxidation of biogas in the landfill, as well as on a direct approach ba…
La produzione ed il trasporto di energia rinnovabile. L'impianto di biometano di Caltanissetta e l'allacciamento alla rete del gas naturale
2022
Le centrali di energia elettrica alimentate da fonti rinnovabili sono spesso oggetto di contestazione da parte di amministrazioni e comunità locali nel cui territorio sono ospitate. La disciplina del biometano, da questo punto di vista, è emblematica. Il legislatore prevede una serie di incentivi alla produzione di energia attraverso tale fonte, e, coerentemente, stabilisce una serie di procedure semplificate per la realizzazione dei necessari impianti. La costruzione di questi ultimi, tuttavia, si scontra in concreto con numerosi intoppi e ritardi natura amministrativa o burocratica. The power plants using renewable sources are often subject of dispute by local administrations and communit…
Chemical characterisation of the gases released at Gyali Island, Dodecanese, Greece and preliminary estimation of the CO2 output
2021
Greece belongs to the most geodynamically active regions of the world and as such, it has to be considered an area of intense geogenic degassing. In terms of carbon, the territory is characterized by the high hydrothermal and volcanic activity of the South Aegean Active Volcanic Arc (SAAVA), and by widespread geological seeps of buried carbon dioxide and methane. In the present work, we investigate the island of Gyali located in the volcanic system Kos-Gyali-Nisyros. Nine gas samples have been collected on the island of Gyali in areas found both on land, in a small lake (∼2000 m2) along its beach, and in the sea close to the shore at shallow depths (<20 m). Results show that CO2 is the p…
Effect of micro-aeration and leachate replacement on COD solubilization and VFA production during mono-digestion of grass-silage in one-stage leach-b…
2010
The effect of micro-aeration and leachate replacement with fresh water on chemical oxygen demand (COD) solubilization and volatile fatty acid (VFA) production during the mono-digestion of grass-silage in one-stage leach-bed reactors (LBRs) was investigated in four LBRs, L0 (control), L1, L2 and L3 in batch mode at 35 + or - 1 degrees Celsius for 57 days. Results showed that leachate replacement without pH adjustment (L3) resulted in 2.7 and 1.3 times more SCOD in the leachate compared to control (L0) or leachate replacement with initial pH adjustment (L1), respectively. Micro-aeration at flow rate of 1 L min(-1) (2.5 L of air) in L2 resulted in 4-fold increase in VFA production (from 2.2 to…
Co-digestion of grass silage and cow manure in a CSTR by re-circulation of alkali treated solids of the digestate.
2008
Three laboratory, continuously stirred tank reactors (CSTRs) co-digesting grass silage and cow manure (forming 30% and 70% of substrate volatile solids (VS), respectively) were operated to evaluate the effects of re-circulating an alkali-treated and untreated solid fraction of the digestate back to the reactors. The CSTRs were operated at an organic loading rate (OLR) of 2 kg VS m(-3) day(-1) and hydraulic retention time (HRT) of 20 days with a semi-continuous mode of feeding. The feasibility of co-digestion with substrate VS containing 30% VS of crop was reinforced, resulting in average specific methane yield of about 180-185 1 CH4 kg(-1) VS. Re-circulation of the solid fraction of digesta…
Effect of macro and micro nutrients addition during anaerobic mono-digestion of grass silage in leach-bed reactors
2019
The effect of macro- (NH4Cl) (set I) and micro-nutrients (Fe, Ni, Co and Mo) (set II) addition on chemical oxygen demand (COD) solubilisation during anaerobic mono-digestion of grass silage was investigated in two sets of leach bed reactor experiments at 35°C. Results showed that addition of NH4Cl and micro-nutrients improved COD solubilisation by 18% (0.56 g SCOD g−1 volatile solids) and 7% (0.45 g SCOD g−1 VS), respectively than control. About 20–50% of the added micro-nutrients were bioavailable in the produced leachates, while the rest (50–80%) were adsorbed onto the grass silage. Results of biological methane potential assays showed that, specific methane yields of grass silage were im…
Silver ion oxidative coupling of diene and triene-diolates of unsaturated carboxylic acids. A facile synthesis of octa- and dodeca-dienedioic acids
1988
Abstract Polyunsaterated dicarboxylic acids 3 and 5 are very easily prepared by oxidative coupling of lithium diene- and triene-diolates 1 and 2 with silver nitrate.
Synthesis of Dienedioic and Tetraenedioic Acids by Oxidative Coupling of Unsaturated Carboxylic Acid Dienediolates by 1,2-Diiodoethane
1993
Abstract Acyclic and cyclic unsaturated carboxylic acids 1 to 4 are most easily converted to unsaturated dicarboxylic acids 5 to 8 by oxidative coupling of their diene- or triene-diolates by 1,2-diiodoethane. This procedure improves formerly reported oxidations by iodine or silver salts.
ChemInform Abstract: Synthesis of Dienedioic and Tetraenedioic Acids by Oxidative Coupling of Unsaturated Carboxylic Acid Dienediolates by 1,2-Diiodo…
2010
Abstract Acyclic and cyclic unsaturated carboxylic acids 1 to 4 are most easily converted to unsaturated dicarboxylic acids 5 to 8 by oxidative coupling of their diene- or triene-diolates by 1,2-diiodoethane. This procedure improves formerly reported oxidations by iodine or silver salts.