Efficiency assessment of two pyrolyzer models for converting waste plastics into fuels

This study aims to determine the effect of adding Bleaching Earth (BE) catalyst to the amount of liquid fraction by pyrolysis of Low Density Polyethylene (LDPE) and find out the concentration of gasoline and diesel fractions from plastic pyrolysis Low density polyethylene (LDPE). The method in this study is the pyrolysis method (heating without oxygen) and analysis of the liquid fraction resulting from pyrolysis using GCMS (Gas Chromatrographic Mass Spectrometry). In this study, the effect of adding Bleaching Earth (BE) catalyst on Low Densiry Polyethylene plastic pyrolysis is the more catalyst used, the lower the quantity of liquid fraction. Based on GCMS analysis on plastic pyrolysis of Low Density Polyethylene (LDPE) from various variations of Bleaching Earth (BE) catalysts used the optimum concentration was obtained by adding 2.5 g, 5 g, and 7.5 g Bleaching Earth (BE) catalysts to produce fractions higher diesel (C13-C20), 37.04%, 31.04% and 35.59% respectively

Two-fold advancement in LDPE Pyrolysis: Enhancing light oil output and substituting sand with kaolin in a fluidized bed system

Plastic waste accumulation, particularly polyethylene, poses a significant environmental burden due to its high consumption and resistance to degradation. In this study, a fixed-bed catalytic pyrolysis reactor was designed, fabricated and controlled to enable the environmentally sustainable conversion of polyethylene waste into liquid fuels. Linear low density polyethylene (LLDPE), low density polyethylene (LDPE), and high density polyethylene (HDPE) were converted into gasoline, jet-fuel, and diesel-range products using three different catalysts: Ru-MCM-41/ZrO2, ZrO2/ZSM 5/Fe3O4, and Co-Mo-Ni-MCM-41/Al2O3. The reactor was mechanically designed according to ASME pressure vessel standards using stainless steel (SS-304), and a closed-loop PID control system was implemented to ensure stable temperature and pressure operation. A modified catalyst configuration, in which the catalyst bed was positioned above the plastic feed, enhanced vapor–catalyst contact and promoted selective catalytic upgrading of pyrolysis vapors. Reactor operation was conducted at temperatures between 450 and 500 °C and a pressure of 0.22 MPa. The results demonstrated that catalytic pyrolysis achieved polyethylene conversion efficiencies of up to 90%, with product distribution strongly dependent on catalyst type and operating conditions. Ru-MCM-41/ZrO2 favored jet fuel-range hydrocarbons, ZrO2/ZSM-5/Fe3O4 enhanced gasoline-range fractions, and Co-Mo Ni-MCM-41/Al2O3 promoted diesel-range fuel formation. The implemented control strategy maintained process variables within narrow tolerances, improving operational stability and process reliability. Overall, this work presents an environmentally relevant and technically feasible approach for plastic waste valorization through catalytic pyrolysis, integrating reactor design, process control, and fuel selectivity. The proposed system offers a promising pathway for waste-to-energy applications and sustainable fuel production, particularly in regions facing challenges in plastic waste management.

Pyrolysis of waste low-density polyethylene (LDPE) is considered to be a highly efficient, promising treatment method. This work aims to investigate the kinetics of LDPE pyrolysis using three model-free methods (Friedman, Flynn-Wall-Qzawa (FWO), and Kissinger-Akahira-Sunose (KAS)), two model-fitting methods (Arrhenius and Coats-Redfern), as well as to develop, for the first time, a highly efficient artificial neural network (ANN) model to predict the kinetic parameters of LDPE pyrolysis. Thermogravimetric (TG) and derivative thermogravimetric (DTG) thermograms at 5, 10, 20 and 40 K min−1 showed only a single pyrolysis zone, implying a single reaction. The values of the kinetic parameters (E and A) of LDPE pyrolysis have been calculated at different conversions by three model-free methods and the average values of the obtained activation energies are in good agreement and ranging between 193 and 195 kJ mol−1. In addition, these kinetic parameters at different heating rates have been calculated using Arrhenius and Coats-Redfern methods. Moreover, a feed-forward ANN with backpropagation model, with 10 neurons in two hidden layers and logsig-logsig transfer functions, has been employed to predict the thermogravimetric analysis (TGA) kinetic data. Results showed good agreement between the ANN-predicted and experimental data (R > 0.9999). Then, the selected network topology was tested for extra new input data with a highly efficient performance.

12 - Emissions and Environmental Burdens Associated With Plastic Solid Waste Management

Pyrolysis of low density polyethylene (LDPE) waste from local waste separation company in subcritical water was conducted to investigate the effect of reaction time, temperature, as well as the mass ratio of water to polymer on the liquid yield. The data obtained from the study were used to optimize the liquid yield using response surface methodology. The range of reaction temperature used was 162–338°C, while the reaction time ranged from 37 min to 143 min, and the ratio of water to polymer ranged from 1.9 to 7.1. It was found that pyrolysis of LDPE waste in subcritical water produced hydrogen, methane, carbon monoxide and carbon dioxide, while the liquid product contained alkanes and alkenes with 10–50 carbons atoms, as well as heptadecanone, dichloroacetic acid and heptadecyl ester. The optimized conditions were 152.3°C, reaction time of 1.2 min and ratio of water solution to polymer of 32.7, with the optimum liquid yield of 13.6 wt% and gases yield of 2.6 wt%.

The paper aims to highlight the importance of renewable energy in the contemporary world facing a range of environmental challenges. It brings out the conceptual, theoretical and methodological use of alternative fuel through an experimentation conducted in our research institute. The present work involves the energy and exergy analysis of a 5.9 kW diesel engine fuelled with diesel and WPE10 [10% of low-density polyethylene (LDPE) oil blended with 90% diesel by volume]. The LDPE oil was obtained at optimum condition of kaolin catalysed pyrolysis method. The analysis was conducted on per mole of fuel and on stoichiometric basis. The energy and exergy analysis was carried out by using 1st law and 2nd law of thermodynamics, respectively. The energetic and exergetic performance of WPE10 resembles with the diesel fuel which can be a substitute as an alternative fuel. The use of plastic waste for creating fuel is a step towards plastic waste management. The attempt of this paper is for a larger contribution to sustainable development.

Synthesis and characterization of Argania spinosa (Argan oil) biodiesel by sodium hydroxide catalyzed transesterification reaction as alternative for petro-diesel in direct injection, compression ignition engines

Plastic waste has emerged as a formidable environmental challenge globally, prompting nations to reassess and enhance their waste management strategies. This study encapsulates a comprehensive review focusing on the effectiveness of plastic waste management in the United States. The review explores the multifaceted dimensions of plastic waste management, encompassing legislative frameworks, recycling initiatives, public awareness campaigns, and the impact of technological advancements. It delves into the intricate web of challenges posed by plastic pollution and evaluates the strategies employed by the USA to mitigate these environmental threats. Key facets of the review include an analysis of federal and state-level regulations governing plastic waste, with a keen eye on the evolution of policies over time. The effectiveness of recycling programs and infrastructure, their scope, and the challenges hindering optimal performance are scrutinized. Additionally, the review assesses the role of extended producer responsibility (EPR) programs and the integration of innovative technologies in enhancing plastic waste management practices. Beyond regulatory measures, the review delves into the public's role in plastic waste management, considering the efficacy of awareness campaigns and community engagement initiatives. The societal shift toward sustainable practices and the influence of consumer behavior on plastic consumption and disposal are also examined. Furthermore, the review scrutinizes the challenges associated with plastic waste exports and the potential global implications of the USA's plastic waste management practices. It considers the broader environmental and health impacts of plastic pollution, emphasizing the need for holistic and sustainable solutions. In synthesizing these diverse aspects, the review aims to provide a nuanced understanding of the strengths and weaknesses in the USA's approach to plastic waste management. By identifying areas of improvement and acknowledging successful interventions, the review contributes valuable insights to the ongoing global discourse on mitigating the environmental impact of plastic waste.

Characterization of post-consumer plastic film waste from mixed MSW in Spain: A key point for the successful implementation of sustainable plastic waste management strategies

This study is designed to examine sustainable plastic waste management in the Urban district of Zanzibar. A survey study employed a sampled population of 696 respondents through purposive and random sampling. Descriptive analysis was used to analyze. The findings revealed that there is a counterbalance in the households' awareness of the impact of improper management of plastic waste due to the level of their knowledge on understanding the environmental consequences of plastic pollution. However, increased education campaigns for the community and commitment to sustainable handling, collection, storage, and disposal of plastic waste in Stone Town and outside Stone Town are highly needed to improve the health of all citizens and the sustainability and beauty of the environment. The householders had awareness of the importance of keeping containers for waste storage; waste is stored in different types of containers, plastic sacks, plastic buckets and plastic containers and then transferred to the collection point. The municipal council uses trucks to collect all wastes from the collection point and dispose of them at the Kibele landfill site. The study recommends that the government increase plastic waste management awareness from the elementary level with the cooperation of education institutions and take steps to promote recycling to manufacturers of plastic products, waste managers and consumers who can all exert a significant influence on the development of the recycling sector and lastly, promote behavioral changes among plastic importers and industries by introducing Extended Producer Responsibility (EPR) to hold manufacturers accountable.

The advances in additive manufacturing (AM) help the recycling, redesign, and reuse of waste plastics, enabling circular economy supply chains and business ecosystems. Distributed Recycling through Additive Manufacturing (DRAM) is a technique for recycling waste plastics using mechanical processes for AM. Even though these integrated concepts enable a new path to recycle waste plastics, there are numerous barriers to their implementation, especially in developing economies. The ten barriers to implementing DRAM for waste plastic recycling were finalized through the use of a literature review and the Delphi technique. To determine the contextual relationship between the barriers, the Interpretative Structural Modeling (ISM) technique was used. A case study was carried out to investigate the barriers to implementing AM in plastic waste management in a developing economy. The interrelationship among barriers was investigated and barrier prioritization was performed. The findings from the case study reveal that the lack of flexibility to implement circular economy (CE) goals is one of the main barriers to implementing AM in plastic waste management. Findings from this study provide insights for industry practitioners and policymakers in developing a strategy to implement AM in plastic waste management.

Quantitative assessment of plastic waste in rubber plantations through modelling approach

The problem of plastic bottle waste is still a big challenge for Riau Province, including the Sedinginan, which is one of the villages traversed by the Rokan river. Plastic bottle waste from households along the Rokan river is disposed of in the river, so that the volume of waste in the river is increasing. Reprocessing plastic bottle waste is an effort to avoid environmental pollution by plastic waste. Through creativity, plastic bottle waste can be recycled into a minimalist sofa that has economic value. This Community Service was carried out by means of training on processing plastic bottle waste into minimalist sofas for PKK Sedinginan. The purpose the activity is to provide them with knowledge and skills on how to process plastic bottle waste into minimalist sofas. The implementation method is by conducting counseling and training to PKK mothers. The result of the activity was an increase in the knowledge and skills of PKK women on how to process plastic bottle waste into goods of economic value. Based on the activities that have been carried out, it can be concluded that there must be ongoing training in plastic waste management, not only in the form of plastic bottles but also other plastics produced from household waste so that people have skills in managing waste.

Pyrolysis of polyolefins for increasing the yield of monomers’ recovery