Sökning: "methane emission"

Visar resultat 1 - 5 av 95 avhandlingar innehållade orden methane emission.

1. 1. Abiotic and biotic methane dynamics in relation to the origin of life

   Författare :Nguyen Thanh Duc; David Bastviken; Patrick Crill; Nils Holm; Edward Hornibrook; Stockholms universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; methane; methanogens; methane formation; methane oxidation; lake sediment; olivine; origin of life; geokemi; Geochemistry;

   Sammanfattning : Methane (CH4) plays an important role in regulating Earth’s climate. Its atmospheric concentrations are related to both biotic and abiotic processes. The biotic one can be formed either by chemoautotrophic or heterotrophic pathways by methanogens. LÄS MER

3. 2. Emission of methane from northern lakes and ponds

   Författare :Martin Wik; Patrick Crill; Isabelle Laurion; Stockholms universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; lakes; ponds; water bodies; methane; fluxes; ebullition; stable isotopes; arctic; subarctic; carbon cycling; climate change; geokemi; Geochemistry;

   Sammanfattning : Northern lakes and ponds are abundant and emit large amounts of the potent climate forcer methane to the atmosphere at rates prone to change with amplified Arctic warming. In spite of being important, fluxes from surface waters are not well understood. LÄS MER

4. 3. Palladium Catalyzed Methane Oxidation for Emission Control

   Författare :Ida Friberg; Chalmers University of Technology; []
   Nyckelord :NATURVETENSKAP; TEKNIK OCH TEKNOLOGIER; NATURAL SCIENCES; ENGINEERING AND TECHNOLOGY; water deactivation; methane oxidation; regeneration; Pd beta; Pd Al2O3; Si Al ratio; Ba; sulfur poisoning; Pd SSZ-13;

   Sammanfattning : The use of methane based fuels, such as natural gas and biogas, benefits from lower emissions of CO2, CO, NOx, non-methane HC, SOx and particulate matters compared to traditionally used liquid fossil fuels. However, the exhaust gases contain significant levels of unburnt CH4 residuals, which are desirable to minimize since CH4 is a strong greenhouse gas with high global warming potential. LÄS MER

5. 4. Greenhouse gas emission from tropical reservoirs : Spatial and temporal dynamics

   Författare :Annika Linkhorst; Sebastian Sobek; Frédéric Guérin; Uppsala universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; methane; carbon dioxide; climate; carbon cycle; lake; limnology; inland water;

   Sammanfattning : The emission of methane (CH4) and carbon dioxide (CO2) from reservoirs has been estimated to make up for about 1.3% of the global anthropogenic greenhouse gas emission. The impoundment of a river leads to the accumulation of sediment that is brought in from inflowing rivers, and the sediment organic matter is degraded to CH4 and CO2. LÄS MER

7. 5. Gas Exchange over Aquatic Interfaces and its Importance for Greenhouse Gas Emission

   Författare :Jovana Kokic; Sebastian Sobek; Erik Sahlée; Marcus B. Wallin; Anne Ojala; Uppsala universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; gas exchange; lake; stream; lake sediment; headwaters; carbon dioxide; methane; greenhouse gas emission; carbon; turbulence; Biology with specialization in Limnology; Biologi med inriktning mot limnologi;

   Sammanfattning : Aquatic ecosystems play a substantial role in global cycling of carbon (C), despite covering only about 4% of the earth surface. They emit large amounts of greenhouse gases (GHG) to the atmosphere, comparable to the amount of C stored annually in terrestrial ecosystems. In addition, C can be buried in lake sediments. LÄS MER