High quality liquid fuel production from waste plastics via two-step cracking route in a bottom-up approach using bi-functional Fe/HZSM-5 catalyst

A feasible approach for the treatment of waste computer casing plastic using subcritical to supercritical acetone: Statistical modelling and optimization

Electronic waste (e-waste) usage has increased tremendously with the rapid evolution of technologies. The accumulated e-waste has now emerged as one of the crucial concerns regarding environmental pollution and human health. Recycling e-waste is commonly focused on metal recovery; nevertheless, a significant fraction of plastics (20-30%) are in e-waste. There is an indispensable need to focus on e-waste plastic recycling in an effective way, which has been mostly overlooked to date. An environmentally safe and efficient study is conducted using subcritical to supercritical acetone (SCA) to degrade the real waste computer casing plastics (WCCP) in the central composite design (CCD) of response surface methodology (RSM) to achieve the maximum oil yield of the product. The experiment parameters were varied in the temperature span of 150-300 °C, residence time between 30 and 120 min, solid/liquid ratio between 0.02 and 0.05 (g/ml), and NaOH amount from 0 to 0.5 g. Adding NaOH into the acetone helps to achieve efficient degradation and debromination efficiency. The study emphasized the attributes of oils and solid products recovered from the SCA-treated WCCP. The characterization of feed and formed products is performed with different characterization techniques such as TGA, CHNS, ICP-MS, FTIR, GC-MS, Bomb calorimeter, XRF, and FESEM. The highest oil yield achieved is 87.89% from the SCA process at 300 °C, in 120min, 0.05 S/L ratio, and 0.5 g of NaOH. GC-MS results disclose that the liquid product (oil) comprises single- and duplicate-ringed aromatic and oxygen-containing compounds. Isophorone is the significant component of the liquid product obtained. Furthermore, SCA's possible polymer degradation mechanistic route, bromine distribution, economic feasibility, and environmental aspect were also explored. This present work represents an environmentally friendly and promising approach for recycling the plastic fraction of e-waste and recovering valuable chemicals from WCCP.

Experimental investigation on slow thermal pyrolysis of real-world plastic wastes in a fixed bed reactor to obtain aromatic rich fuel grade liquid oil

Plastic wastes have become one of the biggest global environmental issues and thus recycling such massive quantities is targeted. Thermal pyrolysis has been the most suitable approach to convert the waste plastic into a source of energy. This study aims to compare the thermal pyrolysis of waste plastic with that of the modal plastic compounds in a fixed bed reactor. The liquid oil, obtained from the thermal pyrolysis of HDPE, LDPE, PP and PS wastes were characterized using FT-IR, GC-MS and 1H NMR. Also, their fuel properties such as viscosity and calorific values were characterized using parallel plate rheometer and bomb calorimeter respectively. C10-C44 paraffins and C10-C22 olefins were obtained along with aromatics and alcohols in different type of plastic waste pyrolysis oil. The viscosity of the plastic oil is within kerosene and diesel range. The calorific values of the oils are at par with the Petro fuels.

The Design of Sulfated Ce/HZSM-5 for Catalytic Decomposition of CF4

CF₄ has a global warming potential of 6500 and possesses a lifetime of 50,000 years. In this study, we modified the HZSM-5 catalyst with Ce and sulfuric acid treatment. The S/Ce/HZSM-5 catalyst achieves 41% of CF₄ conversion at 500 °C, which is four times higher than that over Ce/HZSM-5, while the HZSM-5 exhibits no catalytic activity. The effects of modification were studied by using NH₃-TPD, FT-IR of pyridine adsorption, and XPS methods. The results indicated that the modification, especially the sulfuric acid treatment, strongly increased the Lewis acidic sites, strong acidic sites, and moderate acidic sites on catalysts, which are the main active centers for CF₄ decomposition. The mechanism of acidic sites increases by modification and CF₄ decomposition is clarified. The results of this work will help the development of more effective catalysts for CF₄ decomposition.

Potential Routes to the Sustainability of the Food Packaging Industry

Plastic packaging of food products has a significant impact on the sustainability of the food industry and trade. The article presents selected problems surrounding the production of plastic packaging for food storage and distribution that might cause disruptions in the implementation of sustainable production. An important question regards the extent to which the industry that produces this packaging complies with the sustainability requirements. The present work consists in an investigation of the problems observed in a plastic packaging manufacturing company located in Poland, which is part of a global corporation. Plastic waste management was analyzed and compared with the requirements of a closed loop economy. The quantities of raw material processed and the quantities of waste in the defined period were analyzed. During the analyzed period, 0.05% of the monthly production was non-recyclable waste. The quality of raw material seems to be responsible for the majority of wastes. Therefore, the important role of SAP (Systems Applications and Products) in the use of lower quality batches of raw material is indicated. On the other hand, a possibility of converting the wastes into liquid or gaseous fuels is suggested. In addition, the paper investigates the efficiency of machine use in a film bag production line in a three-shift system. Process losses were analyzed and reliability indicators such as overall equipment efficiency (OEE) and its components, mean time between failures (MTBF), and mean failure repair time (MTTR) were determined. The monthly OEE values for each change individually exceeded 80%.

Conversion of plastic waste into fuels: A critical review

Plastic wastes have posed serious threats to the environment, including decrease of soil nutrient effectiveness and agricultural production as well as emerge of ecological instability. Fuel conversion from plastic waste is regarded as a promising strategy for its disposal and energy utilization. Plastic wastes can be converted into target fuels by adjusting cracking of chemical bonds. Currently, numerous technologies regarding fuel conversion from plastic wastes have been reported, including conventional pyrolysis, novel heat treatment and advanced oxidation. However, systematic summary and comparative analysis of different technologies are still scarcely reported. In this review, fuel conversion from plastic wastes was summarized comprehensively, highlighting novel heat treatment and advanced oxidation technologies reported in recent years. Furthermore, the superiority and drawbacks of each technology were analyzed, and future prospects of technology application were proposed. With lower reaction temperature and higher-value fuel, novel heat treatment of plastics is more popular than traditional one. Advanced oxidation can be controlled to convert plastics into fuels under room temperature and pressure, guiding the new normal in energy utilization of plastic wastes. This review aims to provide inspiration for energy utilization of solid waste, addressing the issues of white pollution and energy shortage.