Search results for "METHANE"

Methane in Titan's atmosphere: from fundamental spectroscopy to planetology

2009

The methane molecule (CH4) is relatively abundant in the Universe and in particular in our Solar System. On Earth, it is the main compound of natural gas and is also the second greenhouse gas of anthropic origin. On Saturn's satellite Titan it plays a role similar to water on Earth and leads to a complex chemistry.

Oxidative Coupling Reactions of 1,3-Diarylpropene Derivatives to Dibenzo[a,c]cycloheptenes by PIFA

2011

The oxidative cyclization reactions of a variety of α-benzyl-cinnamates can be selectively performed with hypervalent iodine as an oxidant. The dibenzo[a,c]cycloheptenes were isolated in up to 55 % yield. When an oxo substrate is applied, the yield was significantly increased. With this synthetic approach, a central intermediate for the synthesis of metasequirin-B was obtained in three steps from very simple starting materials. For this transformation, both aryl moieties have to be activated.

Cover Picture: Oxidative Cyclization Reaction of 2-Aryl-Substituted Cinnamates To Form Phenanthrene Carboxylates by Using MoCl5 (Chem. Eur. J. 39/201…

2014

Life Cycle Impact Assessment applied to cactus pear crop production for generating bioenergy and biofertiliser

2020

Among the potential uses of cactus pear, the generation of bioenergy (biogas) and biofertiliser (digestate), from the Anaerobic Digestion (AD) of cladodes and fruits, is surveyed in this paper. Data for Life Cycle Impact Assessment (LCIA) was drawn from a farm located in Roccapalumba (Palermo, Sicily, Italy), where three cultivars were cultivated: 1) yellow pulp cultivar; 2) red pulp cultivar; 3) white pulp cultivar. LCIA was applied to six scenarios: 1) current dry crop; 2) current irrigated crop; 3) dry crop for fruit and bioenergy production; 4) irrigated crop for fruit and bioenergy production; 5) dry crop for bioenergy production; 6) irrigated crop for bioenergy production. According t…

On the determination of intramolecular potential functions : Application to hydrogen sulphide and methane

2008

Determination of intramolecular potential functions : Application to hydrogen sulphide and methane

2008

Thermophilic anaerobic digestion of pulp and paper mill primary sludge and co-digestion of primary and secondary sludge

2012

Anaerobic digestion of pulp and paper mill primary sludge and co-digestion of primary and secondary sludge were studied for the first time in semi-continuously fed continuously stirred tank reactors (CSTR) in thermophilic conditions. Additionally, in batch experiments, methane potentials of 210 and 230 m³CH₄/t volatile solids (VS)(added) were obtained for primary, and 50 and 100 m³CH₄/tVS(added) for secondary sludge at 35 °C and 55 °C, respectively. Anaerobic digestion of primary sludge was shown to be feasible with organic loading rates (OLR) of 1-1.4 kgVS/m³d and hydraulic retention times (HRT) of 16-32 d resulting in methane yields of 190-240 m³CH₄/tVS(fed). Also the highest tested OLR o…

PDMS membranes for feasible recovery of dissolved methane from AnMBR effluents

2020

[EN] This study aimed to evaluate the feasibility of degassing membrane (DM) technology for recovering dissolved methane from AnMBR effluents. For that purpose, a PDMS membrane module was operated for treating the effluent from an AnMBR prototype-plant, which treated urban wastewater (UWW) at ambient temperature. Different transmembrane pressures and liquid flow rates were applied for evaluating methane recovery efficiency. Maximum methane recoveries were achieved when increasing the vacuum pressure and reducing the liquid flow rate, reaching a maximum methane recovery efficiency of around 80% at a transmembrane pressure (TMP) of 0.8 bars and a treatment flow rate (Q(L)) of 50 L h(-1). The …

Effect of catchment characteristics on aquatic carbon export from a boreal catchment and its importance in regional carbon cycling

2013

Inland waters transport and emit into the atmosphere large amounts of carbon (C), which originates from terrestrial ecosystems. The effect of land cover and land-use practises on C export from terrestrial ecosystems to inland waters is not fully understood, especially in heterogeneous landscapes under human influence. We sampled for dissolved C species in five tributaries with well-determined subcatchments (total size 174.5 km(2)), as well as in various points of two of the subcatchments draining to a boreal lake in southern Finland over a full year. Our aim was to find out how land cover and land-use affect C export from the catchments, as well as CH4 and CO2 concentrations of the streams,…

The role ofSphagnummosses in the methane cycling of a boreal mire

2010

Peatlands are a major natural source of atmospheric methane (CH4). Emissions from Sphagnum-dominated mires are lower than those measured from other mire types. This observation may partly be due to methanotrophic (i.e., methane-consuming) bacteria associated with Sphagnum. Twenty-three of the 41 Sphagnum species in Finland can be found in the peatland at Lakkasuo. To better understand the Sphagnum-methanotroph system, we tested the following hypotheses: (1) all these Sphagnum species support methanotrophic bacteria; (2) water level is the key environmental determinant for differences in methanotrophy across habitats; (3) under dry conditions, Sphagnum species will not host methanotrophic ba…