Search results for "Light hydrocarbons"
showing 5 items of 5 documents
Tuning the selectivity of light hydrocarbons in natural gas in a family of isoreticular MOFs
2017
Purification of methane from other light hydrocarbons in natural gas is a topic of intense research due to its fundamental importance in the utilization of natural gas fields. Porous materials have emerged as excellent alternative platforms to conventional cryogenic methodologies to perform this task in a cost- and energy-efficient manner. Here we report a new family of isoreticular chiral MOFs, prepared from oxamidato ligands derived from natural amino acids L-alanine, L-valine and L-leucine, where, by increasing the length of the alkyl residue of the amino acid, the charge density of the MOF's channels can be tuned (1 > 2 > 3), decreasing the adsorption preference towards methane over lig…
Light hydrocarbons as a proxy to identify the origin of the gas manifestations in Greece
2017
The geologic emissions of greenhouse gases (CO2 and CH4) have an important natural contribution in the global carbon budget. Tectonics, through faults in geothermal and oil producing areas, play a significant role in the release of C-gases in many non-volcanic regions of the Earth. Methane, the most abundant organic compound in Earth’s atmosphere, has a potential global warming that is 28 times higher than that of CO2 on a 100-year time horizon. In this study, δ13C-CH4, δ2H-CH4 and light hydrocarbon (alkane: CH4, C2H6, C3H8, C3H6, i-C4H10, n-C4H10; alkene C3H6, iC4H8; and aromatic C6H6) gas concentration data of 119 gas samples (103 unpublished data and 16 literature data) from volcanic-hyd…
Mineralogy of the soils altered by fumarolic activity at Nisyros volcano, Greece
2017
Nisyros is the easternmost island of the South Aegean Active Volcanic arc in Greece. It is an active stratovolcano known for its intense hydrothermal activity. In this study we present the results of the mineralogical analyses of 20 soil samples collected in the caldera area. Samples were analysed through X-ray diffraction and the results allow us to divide them in two groups: Lakki Plain and Stefanos Crater. In their majority the soils of Lakki Plain have a main mineralogical assemblage that consists of quartz, feldspar and gismondine (Ca2Al4Si4O16·9H2O). Gismondine as well as stellerite (CaAl2Si7O18·7H2O), which is appearing in some samples, derive from hydrothermal alteration, whilst wol…
Origin of methane and light hydrocarbons in natural fluids emissions: A study from Greece.
2018
Abstract Greece, a country characterised by intense seismic and volcanic activity, has a complex geodynamic and geological setting that favours the occurrence of many gas manifestations. In this study, we address the origin of CH 4 and light hydrocarbons in cold and thermal emissions discharging along the Hellenic territory. Also, we investigate their possible relationship with the main geochemical composition of the gases and the different geological settings of the sampling sites. For this purpose we collected 101 new samples that were analysed for their chemical (O 2 , N 2 , CH 4 , CO 2 , He, Ne, Ar, H 2 , H 2 S and C 2 -C 6 hydrocarbons) and isotopic (R/R A , δ 13 C-CO 2 , δ 13 C-CH 4 a…
GEOCHEMISTRY OF THE GAS MANIFESTATIONS OF GREECE: METHANE AND LIGHT HYDROCARBONS
2017
Το σύνθετο γεωδυναμικό καθεστώς της Ελλάδας πηγάζει από την πολύπλοκη γεωλογική της ιστορία, η οποία χαρακτηρίζεται από έντονη σεισμική δραστηριότητα και ενισχυμένη γεωθερμική βαθμίδα. Αυτή η δραστηριότητα σε συνδυασμό με το ενεργό ηφαιστειακό τόξο, ευνοεί την ύπαρξη πολλών εκπομπών αερίων, με αποτέλεσμα την κατηγοριοποίηση σε CO2-, N2- και CH4-αέρια, ανάλογα με το επικρατών είδος. Η παρούσα εργασία επικεντρώνεται στο μεθάνιο και τους ελαφρούς υδρογονάνθρακες (C2-C6) με σκοπό τον προσδιορισμό της προέλευσή τους. Οι συγκεντρώσεις του CH4 (<2 έως 915,200 μmol/mol) και η ισοτοπική του αναλογία (δ13C -79.8 έως +16.9 ‰, δD -298 έως +264‰) καλύπτουν ένα ευρύ φάσμα τιμών, που υποδεικνύει διαφορ…