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Scientific Reports volume 14, Article number: 28442 (2024 ) Cite this article tires recycling machine
This study aims to reach a sustainable solution for waste management of medical plastics through value-added product extraction. It uses the DOE technique to examine the effect of natural zeolite and synthetic Al2O3 and SiO2 as catalysts. A small lab-scale pyrolysis setup was used for medical plastic waste management treatment. Pyrolysis of medical plastics with temperature range (350–450 °C), three catalysts, and wt.% are examined. This process is designed for 3 factors and 3 levels, such as type of catalyst, catalyst wt.%, and temperature, to create an L9 orthogonal array. At the same time, the heating rate and residence time are maintained constant at 5 °C/min and 75 minutes, respectively. Furthermore, this study analyzed the input variables in catalytic pyrolysis using response surface methodology. As a result of the study, generating the regression equation for oil yield, F and P values assure the model is significant. Optimization result shows the type of catalyst, temperature, and catalyst concentration values are found as aluminum oxide, 376 °C, and 6.6 wt.%, respectively. HDPE and LDPE oil yield a value of 58.3648 and 61.2051 wt%, respectively, under the optimum variables condition. For oil yield prediction, HDPE and LDPE’s correlation coefficient (R2) were 0.9949 and 0.9943, respectively. Authentication of the model response using a regression equation validated with the experimental result shows good agreement. The produced medical plastic oil has a density, viscosity, flash & fire point, carbon residue, and cetane number 904 kg/m3, 2.3 cSt, 42 & 45 °C, 7.1 wt.% and 51 respectively. Finally, this study concludes that plastic oil extraction from medical waste through catalytic pyrolysis can be a potential source of alternative fuels in IC engines. Priority to optimization and low-cost catalysts highlights medical plastics waste management under the socio-economic model.
In the decade, catalytic pyrolysis has been given attention in the energy recovery and waste management sector1. Waste management is a significant challenge for every country, especially hazardous wastes like plastics, which require several years to decompose. Almost all industrial entities in the modern world depend on plastic materials as they are adapted to various design criteria and have led to technological advancements. Unfortunately, this has resulted in a substantial accumulation of waste plastics, which is rising at an alarming rate2. As of 2021, plastic production has reached 380 million tons per year, and the total production of plastic has reached 8 billion tons. This means that there is more than one ton of plastic for every person alive today. The absolute change in plastic production between 1950 and the past decade was estimated as 379 million tons per year, with a relative change of more than 18.59%. In India, more than 15 million pieces of plastic are produced yearly, yet proposed waste management and decomposition remains a significant challenge and requires a long-term and viable solution3.
Plastic has played a significant role in modernizing various industries, particularly healthcare4. Healthcare equipment uses significant plastics due to their durability, cost-effectiveness, etc5. However, plastic waste from medical equipment is a serious concern as it might contain public health risks. For example, 8 billion vaccine doses and 140 million test kits were generated for COVID-19, and most of them contained plastics. An overview of the Indian medical plastic market is shown in Fig. 1. Results show a steady increase in the use of plastics for medical purposes. Therefore, the WHO has requested the reform of medical plastics due to their abundant impact on the environment and on health. The current solution to hazardous medical plastics uses either landfills or incineration. However, incineration causes the production of toxic and greenhouse gases while landfills take up empty land, deeming it inhabitable due to the presence of waste6.
The production of plastics requires the use of crude oil and its derivatives. As most countries do not produce enough oil to sustain national plastic production, plastic production depends on imports and price fluctuations in the international market. To address this issue, many researchers have recommended using biodiesel from different feedstock as an alternative7. However, biodiesel utilization has some downsides, such as the availability of land, the oil’s stability, the extraction process’s complexity, and seasonal feedstock8.
To address the issue of crude oil imports and plastic waste management, it is important to realize that plastic waste contains hydrocarbons. Any attempt to extract the hydrocarbons from waste plastics would solve the issue of waste management and reliance on oil imports. A source of energy recovery from plastic through pyrolysis is a sustainable solution to plastic waste management. Pyrolysis is a thermo-chemical process that occurs in a closed environment. Compared to other pyrolysis processes, incineration pyrolysis is an environment-friendly waste management approach. Czajczyńska et al.9 studied the potential of energy recovery from pyrolysis using organic and inorganic materials. Qureshi et al.10 also studied the possibilities and challenges of plastic waste management by pyrolysis. Due to socioeconomic benefits, they concluded that pyrolysis provides a great alternative to incineration and landfilling. Pyrolysis has also been successfully used for waste management of medical applications. Velghe et al.11 experimented with oil production from municipal solid waste and identified the distillation temperature as the most critical parameter. Ding et al.12 studied the pyrolysis dynamics of syringes and medical bottles as feedstock. They were able to produce aromatic compounds up to C24 and C41. The present study selects high-density and low-density polyethylene feedstock for investigation.
Indian plastic market size (by application) - 2014–20254.
Distribution of plastic-type and their demand in the Indian market - 2019 onwards.
The operational behavior of pyrolysis and its end product depend on various parameters. Hence, effective tuning of this parameter is essential to attain higher production. Like catalysts, process optimization can also be used to improve the process efficiency of pyrolysis. This makes it possible to find a way to improve oil yield productivity, effective resource utilization, and energy consumption. Process parameters such as temperature, pressure, residence time, reactor type, bed material, heating rate, and quantity of the feedstock affect the pyrolysis process23. Furthermore, the end product requires specific agendas, particularly for oil yield, which is crucial to tune parameters. Which was fall to tune, gas products are increasing. Response surface methodology (RSM) is an emerging trend in various process optimization. More information is needed from a minimum number of experiments. RSM, generate models, fit detail summary, and main effects of input variables and their correlation on the response. Jha et al.24 used DOE to find the optimal catalyst ratio, temperature, and residence time. Results from consistent literature show the importance of DOE in optimizing process parameters to extract the maximum yield from the pyrolysis process. However, more work is needed to maximize the use of statistical approaches for optimizing the pyrolysis process. Therefore, based on the previous consistent literature, predicting the optimal region is crucial to oil extraction among gas and char yield. Moreover, the interaction effect of zeolite-based catalysts and their concentration relative to temperature is rarely validated. In the present study, considering the disposal of plastic medical waste is a significant concern, pyrolysis can be used as a viable solution. This work uses synthetic and natural zeolite catalysts to perform pyrolysis on medical waste. In addition, a DOE approach is also used to optimize the process based on the type of catalyst, temperature, and concentration of the catalyst. The objective of the optimization performed in this work was to reduce the energy input and increase the process yield to enable the adoption of catalytic pyrolysis as a large-scale industrial process.
The medical plastic waste, such as full-sleeve gloves, masks, syringes, and shoe covers, was collected from the nearest healthcare hospitals with proper safety precautions. The collected plastic waste was preheated by sterilizing it to a higher temperature of 121 °C. In this work, high-density polyethylene (HDPE) and low-density polyethylene (LDPE) plastics were used after being shredded, washed, and dried A small lab-scale bench-type pyrolysis reactor with a 2kW electric heater was used in this work (Fig. 3). Waste plastics were treated at a temperature of 350, 400, and 450 °C with a heating rate of 5 °C/min and a starting capacity of 2000 ml with maximum weight of 1500 g. The gases were condensed to liquid oil using a water-cooled double-column boron tube condenser at 27–30 °C. Three catalysts, namely aluminum oxide, silicon oxide, and natural zeolite, with different concentrations of 4 wt.%, 5.3 wt.%, and 6.6 wt.%, respectively, were used for experimentation. A total of 18 experiments are carried out, which means 9 experiments are conducted (3+3+3) on each plastic, for example, alumina catalyst with a temperature range of 350, 400, 450 °C and catalyst concentration (4, 5.3, 6.6 wt%). Simultaneously, silica and natural zeolite were used on each plastic.
Thermogravimetric analysis (TGA) analysis is used to predict the optimal conversion temperature range. This helps in finding the thermal stability of the feedstock medical plastics and the material behavior in an anti-oxidizing environment (Fig. 4). The TGA technique determines the highest conversion region of HDPE and LDPE plastics to execute the process. At 400 °C, solid was present up to 33.05%, but at a short period, the amount is reduced to 0.54% within 500 °C. The maximum conversion is obtained from HDPE at 420 °C. The predominantly liquid yield produced from the conversion is 80.88 wt.%. In another sample, LDPE normally has weaker intermolecular force, tensile strength, and hardness compared to HDPE, whereas the ductility of the LDPE is better than HDPE. Conversation of these medical plastics highly occurs between 420 °C with more form of liquid 85.68%. Maximum liquid conversions occur between 380 and 500 °C in both cases. It is found that 420 °C is the optimized process temperature for executing the pyrolysis process for the feedstock LDPE and HDPE medical plastics used in this work by TGA. However, it is possible to reduce the temperature using a catalyst. This study found the optimal temperature by experimenting with a catalyst and using RSM relative to maximum oil yield.
RSM plots in Figs. 5, 6 and 7 show the corresponding results from the statistical analysis of the proposed Taguchi design. In general, results show that temperature plays an important role in the yield of the pyrolysis process. A high liquid yield of 95 wt.% is obtained with low gas yield and negligible char at 420 °C. On the other hand, the temperature range above 420 °C increases the gas yield from both HDPE and LDPE. In addition, both plastic samples produced better yields with all three catalysts, and an increase in catalyst ratio increased the yield and reduced the energy consumption.
Contour Plots of HDPE and LDPE Plastic Oil Yield wt.% (a, b) Catalyst concentration, (c, d) catalyst type, and (e, f) reaction temperature.
The effect of catalyst concentration on oil yield (4.5 wt% to 6.6 wt%) concerning various temperatures and catalysts, as shown in Fig. 5a, b, e, and f, typically, an increase in catalyst concentration increases more active contact between feedstock. Multitudinous researchers have reported up to 3 to 12 wt% catalyst concentration as the suitability of oil yield. Gas yield increases with the increase of catalyst28. Maximum oil yields are obtained at a catalyst concentration of 6.6 wt.% to all temperature ranges and both plastics. Based on hefty diversity consistent with previous literature, feedstock and catalyst ratios up to 12 wt.% catalysts support oil yield better. More augmented catalysts in the feedstock ratio lead to more gas products29. Figure 5a&b displays the oil yield based on the type of catalyst and catalyst concentration. All catalysts attained optimized yield at 6.6 wt.% concentration. Further concentration increases enhanced the gas yield and reduced the oil yield by 5.3 wt.% concentration of NZ, alumina, and silica extracted 62.2, 60.2, and 50.8 wt% oil yields, respectively, from HDPE and 63.9, 63.6, and 52.6 wt.% from LDPE, respectively. The results clearly show the importance of catalyst concentration as it influences the oil yield.
Typically, an increase in temperature increases the rate of cracking. In pyrolysis, consistent with literature from previous studies, an increase in temperature increases oil yield up to critical temperature; the critical temperature varies by feedstock and operational behavior. High temperatures quickly break the chains of molecules in the feedstock so that volatile compounds rapidly evaporate sequentially to augment non-condensable gas’s end product30. The pyrolysis process and end products are radically different by the reaction temperature. An increase in temperature increases thermal degradation, mainly above 500 °C, and more light olefins are formed, indicating the augmentation of the gas product31. The oil yield rate is high at the range of 350 to 450 °C. The present study restricted the temperature range to 450 °C. The temperature and catalyst concentration correlation for HDPE and LDPE plastic oil yield was exhibited in 2D plots in Fig. 5e&f. It is well known that temperature and catalyst concentration are directly proportional to oil extraction because an increase in temperature and the presence of a catalyst accelerates thermal degradation32. Results show that increased temperature and catalyst concentration increase the oil yield. However, after 420 °C, the rate of oil yield extraction decreased as gas formation increased. This is due to higher temperatures giving kinetic energy to the feedstock particles, and the key to moving based on Charles’s law was already proven.
The phenomenon can be elucidated as HDPE and LDPE are from the same family, PE. However, they have some unique features. Notably, HDPE is tightly packed together against LDPE due to crystallization differences. HDPE is an opaque linear structure, and LDPE is a transparent branched version of PE. HDPE’s melting point is 20 °C higher than LDPE. LDPE melting point was 115 °C33. Meticulously found, this was the reason for HDPE and LDPE oil yield contrast. In TGA analysis, HDPE and LDPE exhibit a similar thermograph with a single mass-loss zone with a difference of around 10–20 °C. The contours and surface plots for the effect of catalyst concentration and catalyst type on HDPE and LDPE plastic oil yield are shown in Fig. 5a and b, respectively. Results showed that the LDPE plastic type obtained a higher oil yield at all stages of process conditions. For both HDPE and LDPE feedstock, an increase in temperature and catalyst concentration enhances the oil yield. Up to 380 °C, the oil yield difference between LDPE and HDPE was observed to be around 10 wt.%. Figure 5e,f Further increase of temperature and catalyst concentration improve the HDPE plastic oil yield substantially; consequently, at a maximum region and above 400 °C, both HDPE and LDPE plastic oil extraction contrast are shrinkage to 2-5 wt%. HDPE’s bulky molecular size, when compared to LDPE, is thought to be a significant contributing factor to this behavior34. It should be noted that catalyst cracking ability depends mainly on the molecular size of the feedstock and catalyst and their relative quantity. This phenomenon is key for plastic oil extraction energy conservation by minimizing the process temperature. It is well known that catalyst usage minimizes the activation energy and improves the oil quality due to a higher level of the fraction35. In both cases (HDPE and LDPE), the aluminum oxide catalyst provides maximum oil yield over the other two catalysts, NZ and silica oxide. More than 90 wt.% of oil yield was obtained at 380 °C–420 °C and 6.6% \(\hbox {Al}_2\hbox {O}_3\) concentration. Natural zeolite catalyst with 5.3% catalyst concentration and 400 °Cprocess reaction temperature extracted 62.2% and 63.9% oil yield from HDPE and LDPE respectively. At the same condition, oil yield through aluminum oxide extraction was 3 wt.% less because the higher crystallinity of natural zeolite contributed to effective cracking. But above the reaction temperature of 400 °C, natural zeolite catalyst enhanced the gas yield while reducing the oil production. Lastly, silica catalysts with both raw materials showed the least yield in this work. Based on these results, the \(\hbox {Al}_2\hbox {O}_3\) catalyst yielded should be used for maximum yield while a natural zeolite catalyst can be used for a low-energy consumption process with catalyst modification for maximum oil yield based on the investigation input factors selection is crucial to oil yield; therefore, these results show the importance of catalyst modification and making a hybrid catalyst, optimization of concentration, and temperature. This increase in the oil yield, followed by a reduction in the oil yield, was used to find the optimum input factor for oil extraction to achieve maximum yield. This remaining paper tries to predict the optimum parameter within the experimental scheme.
In the analysis performed in this work, three input and one output factor were used for the statistical analysis. The three factors are (a) the type of catalyst (\(\hbox {Al}_2\hbox {O}_3\) , \(\hbox {SiO}_2\) , and NZ), (b) catalyst wt.% (4–6.6 wt.%), and (c) temperature (350–450 °C). The experimental design using the RSM is used to identify the effect of each parameter so that the output can be optimized. Parameter optimization was performed after the experimental design and analysis. 68 iterations were performed. A multi-objective optimization yielded maximum oil yield at the lowest temperature. A low temperature was set as an optimization objective to lower the production costs of pyrolysis. Weight and importance were given equally to all parameters to avoid bias. Optimization results show aluminum oxide with 6.6 wt.% at 376 °C to yield the maximum 5% and 61% yield for HDPE and LDPE, respectively. Tables. 2 and 3 illustrate the fit summary of the designed model. Equality of means (F value) is above 4, and a very minimum lack of fit (P value) assures the model can exhibit the result 95% confidence level at any time and under the same condition. The null hypothesis is discredited.
The regression equation from the model for HDPE and LDPE is given Eqs. 2 and 3.
Full interaction plot for HDPE oil yield (wt.%).
Full interaction plot for LDPE oil yield (wt.%).
Figures 6 and 7 visualize the effect of interaction between three factors concerning HDPE and LDPE oil yield, respectively. All lines concerning each factor are not horizontal, indicating three factors mutually affect oil yield. There was a strong three-way interaction between the main effect of temperature, catalyst concentration, and type of catalyst, as evident from the nonparallel nature of the effect lines for the interaction on HDPE and LDPE oil yield. When catalyst concentration is at its low level, temperature strongly affects the oil yield of both LDPE and HDPE oil yield. The interaction of each factor line mentioned the greater strength of the interaction between all factors. The graph also shows that temperature does not interact much with the type of catalyst factor. Catalyst concentration slightly interacts with the type of catalyst factor. All the interactions \(\hbox {Al}_2\hbox {O}_3\) catalyst at a higher level than natural zeolite and \(\hbox {SiO}_2\) . Compared to the HDPE and LDPE, interaction plot slope formation is higher in LDPE because HDPE has a longer hydrocarbon chain; hence, the sustainable amount of intermolecular force is required to break the bonds, hence requiring a higher temperature for initial cracking compared to LDPE. By examining the full interaction, the effect of both HDPE and LDPE oil yield depends on the temperature range. The LDPE interaction line has a higher delta value than the corresponding plot line in the HDPE interaction. Figure 8 shows the overlay Plot proposed by the design expert V13 Software, showing design space in yellow relative to optimized formulations with the responses. Optimal response relative to their DoE is pinned and exhibits the response values of 58.355 wt% and 61.1957 wt.% LDPE and HDPE respectively for \(\hbox {Al}_2\hbox {O}_3\) , concentration of 6.6 wt% at 376 °C. Results show an improvement in yield with \(\hbox {Al}_2\hbox {O}_3\) , a higher catalyst%, and at an optimum temperature. For both HDPE and LDPE oil yield responses, selected factors play a vital role in deciding the oil yield response is almost the same.
Overlay Plot (a) Catalyst type vs catalyst concentration, (b) Catalyst type vs temperature, and (c) Catalyst concentration vs temperature.
The experimentally observed response versus the response predicted by the model is graphically presented in Fig. 9a and b for HDPE and LDPE oil yield, respectively. A reference dotted line is drawn to show a 100% accurate model. For both HDPE and LDPE, the regression coefficient R2 value was found to be 0.9949 and 0.9945, respectively. This high \(\hbox {R}^2\) value shows a near-perfect prediction model, as shown in Fig. 9a and b. Finally, the predicted optimum values are authenticated by the linear regression equation. RSM has the potential to forecast the pyrolysis yield. The prediction of optimization and various interaction investigations are useful for waste plastic catalytic pyrolysis upcycling, especially for oil extraction at optimal process conditions. Extracted oil fuel properties are measured and compared in conventional diesel.
In general, pyro oil has more hydrocarbons, and waste plastic pyro oil is similar to fossil fuels like diesel36. Plastic oil is recommended as a blending fuel with diesel without any internal combustion engine modifications. Non-condensable gases collected from pyrolysis can also be used as fuels like LPG. Lastly, solid residue in the bottom of the flasks (char) after the pyrolysis reaction can be used as an absorbing material for filtering applications, composite material, and road construction37.
Density is an important property in fuels because fuel consumption, efficiency, and engine operation depend on density38. Diesel fuel has a density of 830 kg/\(\hbox {m}^3\) (Table 4). A higher density results in piston sticking and ignition delay, reducing efficiency. Medical waste plastic oil density was measured as 904 kg/\(\hbox {m}^3\) . Viscosity also plays an important role in fuel performance. The viscosity of diesel fuel is commonly around 1.2 cSt, while the viscosity of plastic oil was 2.35 cSt. Flash and fire points are important parameters to gauge fuel performance. Flash and fire points for diesel are around 52 and 56 °C, while the flash and fire points of the medical plastic oil were 42 and 45 °C, respectively. The smoke point is linked with the hydrocarbon composition of the MPO. A high smoke point is favorable for good fuel, and it has a low smoke-producing tendency. The radiant heat transfer of the fuel is more related to the smoke point. The value of the smoke point is 20 mm for medical plastic oil. In engines, fuel injectors, plugs, and small passages are clogged by increasing the fuel’s cloud point. The cold operating condition of fuel in the engine fuel injector could lead to wax formation due to low temperature. The cloud point of the MPO is 2 °C. Carbon residue is another problem in fuel, and it raises more problems in engines, such as the absence of ignition, reduced heat transfer rate, and piston sticking, which leads to a reduction in engine operation. The lower the carbon residue, the more valuable the fuel, and it indicates an oil tendency toward coke formation. The carbon residue of the MPO sample is found to be 7.1 wt.%. Cetane number is another important thermos physical property of the fuel, and this number measures the fuel’s ignition quality. The cetane number of the MPO is 48, which is quite lower than conventional diesel (52)39. As a result of medical plastic oil characterization, it is strongly recommended that it be considered an alternative fuel for IC engines. By-products, such as char and gases, have the potential to be used as absorbent and energy carriers; therefore, the business model of plastic pyrolysis is strengthened and will be key to commercialization soon. Pyrolysis energy consumption and quality can be compromised by the presence of plastic waste pollutants. Table 5 summarizes relevant previous studies and their findings on various aspects of plastic oil production, including the type of feedstock used, the catalysts applied, the processes employed, the resulting yields, and the key inferences drawn regarding plastic oil yield optimization. Also, this highlights the importance of catalyst choice and process conditions in optimizing the yield and quality of the final products, such as oil and gas. For instance, using a zeolite-based catalyst with specific acidity characteristics in a thermocatalytic reactor greatly influences the hydrocarbon fraction, favoring tar elimination and yielding diesel-grade oil. In contrast, when no catalyst is used, the type of plastic heavily dictates the end product composition, with a notable increase in solid residues as the proportion of PET in the feedstock rises. Advanced catalysts, such as MFI-type HZSM-5 zeolite and FCC catalysts, significantly enhance the degree of polymer cracking, leading to higher gas and liquid yields, which are substantially more than yields obtained without catalysts. Moreover, different catalysts and reactor types (e.g., fixed bed, fluidized bed, microwave-assisted) offer varying degrees of effectiveness in breaking down complex polymers, as evidenced by differing yields and product compositions. Overall, the table underscores that the choice of catalyst and pyrolysis method is critical for optimizing outputs, reducing energy requirements, and tailoring the chemical makeup of the resulting pyrolysis products to meet specific industrial needs.
Linear agreement between experimental yield and predicted yield of (a) HDPE and (b) LDPE.
Medical plastic is converted into value-added products using pyrolysis technology, and it is experimentally investigated in a small lab-scale pyrolysis reactor using three different catalysts. Pyrolysis technology is utilized well to reduce the carbon footprint value chain through medical plastic treatment in a close environment. Production of value-added products from waste plastic by catalyst pyrolysis creates awareness about medical plastic waste management. These results conclude catalyst performance depends on the process parameters. Pyrolysis based on the design of the experiment is very useful in identifying the optimized solution to a particular operating condition. Performance optimization of the work is carried out by using DOE software. From the results, the following conclusions have arrived:
The aluminium oxide catalyst gives more liquid yield than the other two catalysts. The natural zeolite catalyst extracts low liquid yield, but there is a quick start-up during the thermal cracking period, even at low temperatures. On average, natural zeolite produced a 10% higher oil yield than silica oxide catalysts.
An increase in the reaction temperature using NZ produced a low oil yield compared to \(\hbox {Al}_2\hbox {O}_3\) as a catalyst. This might be due to the higher internal crystal structure of NZ. This is because a high internal crystal structure increases the gas yield at high-temperature regions, consequently reducing the liquid yield.
The process optimization of DoE is found to be \(\hbox {Al}_2\hbox {O}_3\) , temperature 376.6 °C, and Catalyst concentration of 6.5999 is the optimal solution. In this optimum solution, HDPE and LDPE oil extraction are 58.3646% and 61.2051%, respectively.
The model evaluation results are significant, and the input variables are desirable. The experimental results are authenticated by RSM, along with the R-value above 0.9.
Medical plastic oil characteristics are tested and compared with commercial fuel. The test results showed that the produced plastic oil exhibits similar properties to commercial fuel and can be used in a diesel engine without any modification.
By-products char and gases have the potential to be used as absorbents and energy carriers; therefore, the business model of plastic pyrolysis is strengthened and key to commercialization soon. Plastic waste pollutants can compromise pyrolysis energy consumption and quality.
Overall, this study supports medical plastic waste management in a greener way along with value-added end products and supports the circular economy of plastics.
The datasets used and/or analyzed during the current study are available within the article.
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The authors would like to thank the Deanship of Research Oversight and Coordination (D-ROC), Mechanical Engineering Department and IRC Sustainable Energy Systems, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia, for their continuous support. The corresponding author would like to thank Mrs. Abarna Ravishankar and Mrs. Santharani Sathyamurthy for their moral support. Pitchaiah Sudalaimuthu would like to thank SRM TRP Engineering College, Tamil Nadu, Indiafor their financial support, vide number SRM/TRP/RI/005.
Department of Mechanical Engineering, SRM TRP Engineering College, Tiruchirapalli, Tamil Nadu, 621105, India
Department of Mechanical Engineering, King Fahd University of Petroleum and Minerals, 31621, Dhahran, Saudi Arabia
Usman Ali & Ravishankar Sathyamurthy
IRC Sustainable Energy Systems (IRC-SES), King Fahd University of Petroleum and Minerals, 31261, Dhahran, Saudi Arabia
IRC for Advanced Materials, King Fahd University of Petroleum and Minerals, 31261, Dhahran, Saudi Arabia
Center for Research, SRM Institute of Science and Technology, 621105, Tiruchirapalli, India
Interdisciplinary Research Center for Industrial Nuclear Energy (IRC-INE), King Fahd University of Petroleum and Minerals, 31261, Dhahran, Saudi Arabia
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P.S. R.S. conceived the experiment(s) and conducted the experiment(s), and P.S., U.A., and R.S. analyzed the results. All authors reviewed the manuscript.
The authors declare no competing interests.
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Sudalaimuthu, P., Ali, U. & Sathyamurthy, R. Optimization of process parameters of catalytic pyrolysis using natural zeolite and synthetic zeolites on yield of plastic oil through response surface methodology. Sci Rep 14, 28442 (2024). https://doi.org/10.1038/s41598-024-78180-1
DOI: https://doi.org/10.1038/s41598-024-78180-1
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