Investigation in PO blending and compression ratio on engine performance and gas emissions including environmental health risk assessment and economic analysis.

Waste management and mitigation is the primary necessity across the globe. The daily use of plastic materials in different forms emergence the plastic pollutions, and it has been significantly increased during the COVID-19 pandemic. Thus, mitigation of waste plastics generation is one of the major challenges in the present situation. The present study addressed the conversion of waste plastics into value-added products such as liquid hydrocarbon fuels and their application in reducing greenhouse gas emissions. A comprehensive investigation has been performed on engine performance and combustion characteristics at various compression ratios and PO blending. The effect of liquid fuel blending with commercial diesel was investigated at three different compression ratios (15.1, 16.2, and 16.7) under various BMEP conditions. The results revealed that blending of liquid fuel produced from waste plastic can improve the BTE significantly, and the highest 35.77% of BTE was observed for 10% blending at 15.1 CR. While the lowest BSFC of 5.77 × 10-5 kg/kW-s was estimated for 20% PO blending at 16.7 CR under optimum BMEP (4.0 bar) conditions. The investigation of combustion parameters such as cylinder pressure, net heat release rate, rate of pressure rise, and cumulative heat release showed that it increases with the compression ratio from 15.1 to 16.7. At the same time, the emissions of CO, CO2, and unburnt hydrocarbon was decreased significantly. The economic analysis for the present lab-scale study estimated that approximately ₹12.17 ($0.15) profit per liter is possible in the 1st year, while the significant profit starts from the 2nd year onward, which is in the range of ₹59.78-₹84.48 ($0.75-$1.07) when the PO is blended with CD within the permissible limits as per the norms.

Use of COVID-19 single-use face masks to improve the rutting resistance of asphalt pavement.

Today, the world faces an enormous increase in plastic waste pollution caused by the emergence of the COVID-19 pandemic. Plastic pollution has been already one of the greatest threats to our planet before the Coronavirus outbreak. The disposal of millions of personal protective equipment (PPE) in the form of face masks has significantly contributed to the generation of plastic waste and has exacerbated plastic pollution. In an attempt to mitigate pollution caused by the excess PPE waste, an innovative way was developed in this research to reduce pandemic-generated wastes by using the shredded face mask (SFM) fibers as an additive to hot mix asphalt (HMA) to enhance rutting resistance. Rutting or permanent deformation is one of the major distresses of asphalt pavement. Since the SFM behaves as a semi-liquid between 115.5 and 160 °C, which is in the range of HMA mixing and paving temperature, it can function as a binding agent to glue the aggregates. When the pavement is cooled down to ambient temperature, the hardened SFM can provide stability and stiffness to HMA. Based on the results of this study, the modified mixes exhibited excellent resistance to permanent deformation under the Asphalt Pavement Analyzer (APA), as rutting depth values were reduced from 3.0 mm to 0.93 mm by increasing the SFM content from 0% to 1.5%. From the rutting test results and premature distress mechanism study, the appropriate addition of SFM modifiers could improve the high-temperature properties of HMA that can be used to strengthen high-compression and shearing zones in the pavement structure.

Imprints of COVID-19 lockdowns on total petroleum hydrocarbon levels in Asia's largest brackish water lagoon.

India successfully executed one of the strictest lockdowns in the world during the height of the COVID-19 pandemic in early 2020, which provided unique opportunities to analyze the second-largest populous country's anthropogenic footprint on its natural systems. India's first Ramsar site and the world's second-largest brackish water system Chilika lagoon experienced a substantial decline (64%) in the total petroleum hydrocarbon (TPHC) level in water, which was attributed to the massive declines or, at times, an abrupt complete halt of motorized boat operations for fishing and tourism. Using the TPHC values during the lockdown period, our study recommends a TPHC baseline threshold of 2.02 µg L-1 and 0.91 µg g-1 for Chilika waters and sediment, respectively. These baseline values can be used to quantify oil pollution and to formulate policy and management action plans for Chilika lagoon as well as for other similar ecosystems by local environmental agencies.

Self-Perpetuating Carbon Foam Microwave Plasma Conversion of Hydrocarbon Wastes into Useful Fuels and Chemicals.

White wastes (unseparated plastics, face masks, textiles, etc.) pose a serious challenge to sustainable human development and the ecosystem and have recently been exacerbated due to the surge in plastic usage and medical wastes from COVID-19. Current recycling methods such as chemical recycling, mechanical recycling, and incineration require either pre-sorting and washing or releasing CO2. In this work, a carbon foam microwave plasma process is developed, utilizing plasma discharge to generate surface temperatures exceeding ∼3000 K in a N2 atmosphere, to convert unsorted white wastes into gases (H2, CO, C2H4, C3H6, CH4, etc.) and small amounts of inorganic minerals and solid carbon, which can be buried as artificial "coal". This process is self-perpetuating, as the new solid carbon asperities grafted onto the foam's surface actually increase the plasma discharge efficiency over time. This process has been characterized by in situ optical probes and infrared sensors and optimized to handle most of the forms of white waste without the need for pre-sorting or washing. Thermal measurement and modeling show that in a flowing reactor, the device can achieve locally extremely high temperatures, but the container wall will still be cold and can be made with cheap materials, and thus, a miniaturized waste incinerator is possible that also takes advantage of intermittent renewable electricity.