The Effect of Sanitizing Treatments on Respirator Filtration Performance

The potential for alcoholic vapors emitted by common sanitizing treatments to deteriorate the (electrostatic) filtration performance of disposable respirator masks has been investigated. Reports in the literature and some standard test methods provide a confusing and ambiguous picture concerning the relevance of this effect. Four different types of exposure were investigated in this study to clarify the effect of alcoholic vapor emissions on respirator masks. These included exposure to saturated vapors, use of hand sanitizers, cleaning of table surfaces and sanitization of masks by spraying them with alcohol-containing solutions. Methods employed were designed to be as real-world oriented as possible while remaining reproducible. Filtration performance and deterioration effects on exposure to the different treatments were determined on three different types of certified commercial respirator masks—a P2 and two KN95 masks. This study provides substantial evidence that disposable respirator masks with an accepted performance rating are seriously compromised from an exposure to saturated alcoholic vapors, can tolerate a one-off spray treatment with an alcoholic solution and retain their attested protection under the influence of alcoholic vapors from the use of hand sanitizer or spray sanitizer. Considering the range of vastly different outcomes obtained from the four treatments investigated, it seems prudent to assess in each case the specific effects of alcoholic solution treatments and vapors on respirator masks before use.

Influence of Sustainable Aviation Fuels on the Formation of Contrails and Their Properties

Condensation trails and contrail cirrus are currently responsible for the largest contribution to radiative forcing in the aviation sector, yet they have lifetimes of only a few hours. Their much shorter lifetimes when compared to long-lived greenhouse gases makes them ideal for the implementation of short-term mitigation measures. The use of Sustainable Aviation Fuel (SAF) instead of regular jet fuel has been associated to a reduction in soot particle emissions, leading to a decrease in initial ice crystal numbers in contrails, but also to a possible increase in contrail frequency and contrail ice mass due to higher water vapor emissions. A computational model was used to explore the influence of the variations of soot and water vapor emissions when using SAF and SAF blends in the formation of contrails, their ensuing optical depth, and their lifespan. An increase in frequency of contrails was found in cases where regular jet fuel emissions were close to threshold conditions. Reductions in contrail lifetime of up to 76% were found for contrails with lifetimes of over 30 min, while decreases in optical depth of up to 37% were found for contrails formed in air with a relative humidity of 42% or above. This work provides a better understanding of the potential of SAF as a mitigation measure against the impact of contrails on global warming.

Progress in Life Cycle Impact Assessment: Water Vapor Emissions and Respiratory Inorganics

Life cycle assessment (LCA) is being included formally in EcoDesign regulations. Especially product carbon footprint will be mandatory in Europe. However, life cycle impact assessment, including global warming potential (GWP) in LCA, is hampered by several challenges. One of these is a lack of water vapor characterization indexes for GWP. A life cycle inventory profile for air transport fuel, including water vapor emissions, is evaluated with state-of-the-art practice, i.e., Environmental Footprint (EF) Method and International Life Cycle Data (ILCD) 2011 Mid-point+, neglecting water vapor’s high altitude GWP compared to carbon dioxide. Then, the characterization factor in GWP over 100 years (GWP100) for water vapor and alternate normalization for particulates are introduced. The results are compared. The main findings are that the previous EF method and ILCD both generate rather realistic results for Particulate Matter and Respiratory Inorganics mid-point indicators, respectively, but the number of premature deaths should be better allocated to different specific emissions, and that water vapor may dominate the GWP100 result over the usual carbon dioxide. Respiratory inorganics may need one impact category, each starting with particles smaller than 2.5 µm. LCIA mid-points need measurable and understandable bases. The common knowledge of water vapor’s GWP100 should not be neglected in LCIA for air transport and beyond where relevant.

Employing Space-Based Hyperspectral Imagery for Pipeline Leak Prevention, Detection and Compliance

We are now living in what has been described as the Experience Era, where lines between the digital and physical are increasingly blurred. As such, we are just beginning to see how customized access to space will improve asset stewardship in ways that are still evolving, as customization of on-orbit technology pushes the bounds of how we receive and process information. Specific to oil and gas operators, one technology being launched by microsatellite, hyperspectral imagery (HSI), is poised to enable unparalleled daily global pipeline leak prevention, detection and speciation, intrusion and change detection capabilities. This will replace conventional DOT pipeline patrol for compliance while contributing to our understanding of vapor emissions as regulated by the Environmental Protection Agency. This paper discusses both the evolving space marketplace and the state of the art for HSI, including current examples of hyperspectral findings regarding pipeline and terminal leaks. Successful deployment of HSI will drive a decrease in the number and magnitude of pipeline leaks using persistent, global, high-resolution data collection, rapid and reliable analysis, and immediate reporting of actionable information. For decades, satellite HSI technology has offered a promise of remote hydrocarbon detection and other features of interest. It is only now becoming scalable, accessible to, and cost-effective for the pipeline industry, and thus a reality for cost-effective pipeline stewardship.

Evaporative Emissions From Automotive Gasoline Fuel Tank Refueling: Experimental Activity and Numerical Simulation

Vehicle evaporative emission is one of the most important sources of pollution from a gasoline-fueled vehicle. Since international regulations on Volatile Organic Compounds (VOC) emission are becoming increasingly stringent every year, the study of the VOC generation has become of fundamental importance. It is known that VOC generation is particularly high during the refueling phase: fresh fuel coming from the refueling nozzle impacts on the filling pipe wall and it is a source for sloshing in the fuel tank. Fuel vapor generated can be collected by a vapor recovery nozzle and stored in the gas station tank (Stage II vapor recovery system, European normative) or trapped by the vehicle carbon canister (On-board Refueling Vapor Recovery system, U.S. normative). In this activity, an automotive gasoline fuel tank for U.S. applications has been used for both experimental and numerical analyses, provided by FCA. Experiments were performed in FCA laboratories, in a sealed and thermal controlled environment (mini-SHED): vapor flow exiting the fuel tank during refueling has been measured, and fuel vapor mass has been evaluated by dynamically measuring the weight variation of a carbon canister filter connected to the fuel tank vent system. A CFD model was built based on CAD geometries provided by FCA, and numerical analysis of the refueling process has then been executed by using a commercial 3D CFD software. Results were then compared with experimental data. This activity is a part of a collaboration between University of Naples Federico II and FCA Italy about fuel vapor emissions control and prediction.