[1] Firn-air and ambient air measurements of CHF3 (HFC23) from three excursions to Antarctica between 2001 and 2009 are used to construct a consistent Southern Hemisphere (SH) atmospheric history. The results show atmospheric mixing ratios of HFC-23 continuing to increase through 2008. Mean global emissions derived from this data for 2006–2008 are 13.5 ± 2 Gg/yr (200 ± 30 10 gCO2equivalent/yr, ...

The attenuation of methane and four chlorofluorocarbons was investigated in a dynamic methane and oxygen counter-gradient system simulating a landfill soil cover. Soil was sampled at Skellingsted Landfill, Denmark. The soil columns showed a high capacity of methane oxidation with oxidation rates of 210 g m(-2) d(-1) corresponding to a removal efficiency of 81%. CFC-11 and to a lesser extent als...

Introduction: The air-conditioning and refrigeration industry is well on its way towards the design and commercialization of systems using R134a as the preferred environmentally acceptable replacement for CFC-12 in many applications. The industry is now turning some of its attention to replacements for HCFC-22. The US Clean Air act and its subsequent amendment calls for phaseout of CFCs by the ...

Detection of atmospheric trace gases by optical remote sensing techniques relies on the availability of molecular absorption spectra over a range of relevant temperatures. Absorption cross-sections of a pure vapour of the hydrochlorofluorocarbon HCFC-141b are reported at a resolution of 0.02 cm 1 for a range of temperatures between 223 and 283 K and a spectral range of 570–3100 cm . The integra...

Natural technologies for sustainability: accelerating implementation The Life-C4R project is an international marketing that, thanks to Epta’s Full Transcritical Efficiency (FTE) and Extreme Temperature (ETE) systems, will substantially contribute replacing HCFC HFC greenhouse refrigerants with CO2 in commercial refrigeration a very simple, efficient reliable way any country, external temperatu...

The refrigeration and air conditioning industry shows much interest in environmentally-friendly natural refrigerants. One such refrigerant is R744, carbon dioxide. It is attractive because it is not toxic, not flammable, and is widely available as a byproduct of industrial processes. However, carbon dioxide (CO2) systems operate at much higher pressures than systems using HCFC, HFC, or HFC-blen...

As the phase-out of chlorofluorocarbons (CFC's) approaches, there is a current need for the development of new vapor compression chillers which can operate with non-CFC refrigerants while still maintaining high operating efficiencies. Redesign of the traditional flooded evaporator used in refrigeration chillers so as to incorporate a spray evaporation capability offers both a potential for incr...