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- Aad, G, et al.
(författare)
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- 2015
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swepub:Mat__t
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| 2. |
- Van Der Veen, A. M. H., et al.
(författare)
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International comparison CCQM-K112 biogas
- 2020
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Ingår i: Metrologia. - : Institute of Physics Publishing. - 0026-1394 .- 1681-7575. ; 57:1 A
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Tidskriftsartikel (refereegranskat)abstract
- At the highest metrological level, biogas standards are commonly prepared gravimetrically as PSMs (primary standard mixtures). This international key comparison addresses the composition of biogas, to support calibration and measurement services for this renewable energy gas. The mixtures contain nitrogen, carbon dioxide, methane, ethane, propane, hydrogen and oxygen and represent the composition of biogas from landfills. The results in this Track C key comparison on the composition of biogas are generally good. Some of the datasets, especially that of oxygen, showed substantial extra dispersion, that could not be explained by the stated uncertainties. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
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| 7. |
- Arrhenius, Karine, et al.
(författare)
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Suitability of vessels and adsorbents for the short-term storage of biogas/biomethane for the determination of impurities – Siloxanes, sulfur compounds, halogenated hydrocarbons, BTEX
- 2017
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 0961-9534 .- 1873-2909. ; 105, s. 127-135
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Tidskriftsartikel (refereegranskat)abstract
- Biogas is a renewable energy source with many different production pathways and various excellent opportunities to use, for example as vehicle fuel (biomethane). Reliable analytical methodologies for assessing the quality of the gas are critical to ensure that the gas can technically and safely be used. An essential part of any procedure aiming to determine the quality is the sampling and the transfer to the laboratory. One of the greatest challenges is then to ensure that the composition of the sample collected does not change between the time of sampling and the analysis. The choice of the sampling vessel to be used must be made only after fully assessing its short-term stability. In this paper, the results from short-term stability studies in different vessels (cylinders, bags and sorbents) are presented for siloxanes, BTEX, halogenated hydrocarbons and sulfur compounds. Storage of dry gas at high pressure (> 6 MPa) appears to be a good alternative however it is currently challenging to find an optimal treatment of the cylinders for all species to be assessed in biogas/biomethane. At lower pressure, adsorption effects on the inner surface of the cylinders have been observed. The use of bags and sorbent tubes also shows limitation. No existing sorbent tubes are sufficiently universal as to trap all possible impurities and high boiling compounds may adsorbed on the inner surface of the bags walls. Moreover, the presence of water when storing biogas most certainly impacts the storage stability of compounds in most vessels. Using at least two sampling methods for a given compound and comparing results will allow taking into account the eventual effects of water vapour, and adsorption on the inner surface of the vessels.
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| 8. |
- Beranek, Luke P., et al.
(författare)
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Detrital zircon U-Pb-Hf isotope signatures of Old Red Sandstone strata constrain the Silurian to Devonian paleogeography, tectonics, and crustal evolution of the Svalbard Caledonides
- 2020
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Ingår i: Geological Society of America Bulletin. - : Geological Society of America. - 0016-7606 .- 1943-2674. ; 132:9-10, s. 1987-2003
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Tidskriftsartikel (refereegranskat)abstract
- Detrital zircon provenance studies of Mesoproterozoic basement and overlying Old Red Sandstone strata in northwestern Svalbard, Arctic Norway, were conducted to test competing models for Caledonian paleogeography and tectonics and constrain the magnitude of orogen-parallel, Silurian to Devonian strike-slip faulting following the Laurentia-Baltica collision. Mesoproterozoic basement strata, cut by earliest Tonian orthogneiss units, mostly yielded 1640-1050 Ma detrital zircon populations that are consistent with pre-Caledonian locations near northeast Greenland. Basal Old Red Sandstone deposits that filled pull-apart basins showed basement-derived signatures but also contained 530-450 Ma and 670-570 Ma populations with slightly subchondritic (epsilon(Hf[t]) = -4 to -2) Hf isotope compositions. These results are consistent with late Silurian-Early Devonian proximity to the northeast Greenland Caledonides and Pearya, which indicates limited (<200 km) strike-slip displacement of Svalbard's Caledonian allochthons after the Laurentia-Baltica collision. Previously interpreted connections between the Svalbard Old Red Sandstone and British Caledonides are incompatible with these detrital zircon results. Lochkovian Old Red Sandstone strata were deposited after a second episode of strike-slip faulting and show recycled basement signatures. The lack of 530-450 Ma and 670-570 Ma populations suggests that the second deformation episode reorganized local drainages. Pragian-Givetian strata have provenance from local Old Red Sandstone sources that were uplifted during a third and final episode of strike-slip deformation. The results indicate that northern Caledonian (Svalbard, Pearya) crustal evolution was characterized by the reworking of Mesoproterozoic-Paleoproterozoic sources and mostly <600 m.y. crustal residence times, whereas the southern Caledonides (UK, Ireland) show evidence for the reworking of older basement and mostly >600 m.y. crustal residence times.
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