Examinando por Autor "Gavioso, Roberto Maria"

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An investigation of the comparative performance of diverse humidity sensing techniques in natural gas
(Elsevier, 2015-02-21) García Gallegos, Jaime; Benyon Puig, Robert; Ávila, Sara; Benito, Angel M.; Gavioso, Roberto Maria; Mitter, Helmut; Bell, Stephanie; Stevens, Mark; Böse, Norbert; Ebert, Volker; Heinonen, M.; Peruzzi, Andrea; Bosma, Rien; Val´ková, Miroslava
Moisture content is a key factor regardless of the activity carried out inside the natural gas industry (production, processing, transmission, etc.). Not only does the efficiency of the final product, known as heating value, decrease when the water content is high, but it can also trigger potentially dangerous conditions due to the formation of hydrates, that can block pipelines and damage pumping devices and produce other negative effects. For these reasons, accurate measurement and control of humidity is absolutely essential. However, current practice for such moisture measurements is for the devices to be calibrated at atmospheric pressure and in nitrogen or air as the matrix gas, conditions that vary significantly from those present in the actual industrial process. For that, eleven hygrometers based on different measurement principles (chilled-mirror, electrolytic sensor, a spectroscopic analyzer, polymeric and metal oxide humidity sensors) have been compared at facilities of the main carrier of natural gas in Spain, using natural gas at absolute pressures between 0.1 MPa and 6 MPa, and for a range of water content from 13 ppmv to 250 ppmv. Their relative performance is described in terms of the response times, long term stability, hysteresis and behaviour under large pressure changes. Most instruments, exceptions are detailed in the article, show good behaviour regarding response time, hysteresis and under sudden pressure changes. In contrast, drift can be identified in most of the aluminium oxide probes tested.
Restringido
Measuring Humidity in Methane and Natural Gas with a Microwave Technique
(Springer Nature Link, 2014-04-01) Gavioso, Roberto Maria; Madonna Ripa, D.; Benyon Puig, Robert; García Gallegos, Jaime; Perez Sanz, Fernando; Corbellini, S.; Ávila, Susana; Benito, Angel M.
The results of microwave measurements with a quasi-spherical resonator in humid methane samples realized under laboratory conditions at the Istituto Nazionale di Ricerca Metrologica (INRiM) and under industrial conditions in a natural gas sample made available at the facilities of the Technical Manager of the Spanish Gas System and main supplier of natural gas in Spain (ENAGAS) are reported. Measurements at INRiM included vapor phase and condensation tests on methane samples prepared with amount fractions of water between 600 ppm and 5000 ppm at temperatures between 273 K and 295 K and pressures between 150 kPa and 1 MPa. ENAGAS measurements were performed at ambient temperature, 750 kPa on natural gas sampled from the pipeline and successively humidified at amount fractions of water between 140 ppm and 250 ppm for completeness of the comparison with several humidity sensors and instrumentation based on different technologies. To enhance the sensitivity of the microwave method at low humidity, an experimental procedure based on the relative comparison of the dielectric permittivity of the humid gas sample before and after being subject to a chemical drying process was conceived and implemented. The uncertainty budget and the final sensitivity of this procedure are discussed.