A review of gas chromatographic techniques for identification of aqueous amine degradation products in carbonated environments

Amine response smartphone-based portable and intelligent polyvinyl alcohol films for real-time detection of shrimp freshness

Food freshness monitoring is an important component in ensuring food safety for consumers and the food industry. Therefore, there is an urgent need for a portable, low-cost, and efficient detection method to determine the freshness. In this study, polyvinyl alcohol (PVA) was used as polymer carrier to prepare electrospinning film containing curcumin (Cur) and gardenia blue (GB) as intelligent indicator label on food packaging for real-time nondestructive detection of freshness of shrimp. The detection limit of ammonia response is less than or equal to 20 ppm, and the detection time is about 1 min, indicating that it has a sensitive response effect. At the same time, a smartphone application that can identify amines in response to color changes has been developed, and consumers can understand freshness by scanning the label. This study demonstrates the huge potential of smart indicator labels for food freshness monitoring.

Amine Adsorbents Stability for Post-Combustion CO2 Capture: Determination and Validation of Laboratory Degradation Rates in a Multi-staged Fluidized Bed Pilot Plant

Alternative to current liquid amine technologies for post-combustion CO2 capture, new technologies such as adsorbent-based processes are developed, wherein material lifetime and degradation is important. Herein a robust method to determine degradation rates in a laboratory setup is developed, which was validated with a continuous multi-staged fluidized bed pilot plant designed to capture 1 ton CO2 per day. An amine functionalized polystyrene adsorbent showed very good agreement between the experimental 1000-hour laboratory degradation rates and 2200 hours of degradation in a pilot plant. This validates how laboratory experiments can be extrapolated for sorbent screening and for scale-up. Resulting, the oxidative degradation in the desorber at high temperatures (120 °C) and low O2 concentrations (150 ppmv) is 3 times higher compared to the adsorber at low temperatures and high O2 (56 °C, 7 vol %). Laboratory degradation experiments can hence be used to further optimize process operations to limit degradation or screen for potential new adsorbents.

Deodorization of post-consumer plastic waste fractions: A comparison of different washing media

An important impediment to the acceptance of recyclates into a broader market is their unwanted odor after reprocessing. Different types of washing procedures are already in place, but fundamental insights into the deodorization efficiencies of different washing media are still relatively scarce. Therefore, in this study, the deodorization efficiencies of different types of plastics after washing with different media were determined via gas chromatography and mass spectrometry analysis. A total of 169 compounds subdivided into various chemical classes, such as alkanes, terpenes, and oxygenated compounds, were detected across all packaging types. Around 60 compounds were detected on plastic bottles, and around 40 were detected on trays and films. Owing to the differences in physicochemical properties of odor compounds, different deodorization efficiencies were obtained with different washing media. Water and caustic soda were significantly more efficient for poly(ethylene terephthalate) bottles with deodorization efficiencies up to 80%, whereas for polyethylene (PE) and polypropylene bottles, the washing media were relatively inefficient (around 30-40%). Adding a detergent or an organic solvent could increase deodorization efficiencies by up to 70-90% for these packaging types. A similar trend was observed for PE films having deodorization efficiencies in the range of 40-50% when washing with water or caustic soda and around 70-80% when a detergent was added. Polystyrene trays were most effectively deodorized with a detergent, achieving efficiencies up to 67%. Hence, this study shows that optimal washing processes should be tailored to specific packaging types to further improve deodorization and to eventually be able to meet ambitious European recycling targets.