Waste Plastic Mixture Research Articles

PIROLISIS CAMPURAN BIOMASSA LIMBAH SEKAM PADI DAN LIMBAH PLASTIK LOW DENSITY POLYETHYLENE MENGGUNAKAN KOMPOR BIOMASSA

<p class="abstrak"><em>The demand for fuel oil is increasing day by day, resulting in the depletion of oil and gas reserves in Indonesia. Rice husk waste biomass and low-density polyethylene plastic are wastes that can be utilized as alternative fuel sources by pyrolysis method. Pyrolysis is the process of burning organic and synthetic materials in conditions of little or no oxygen by utilizing heat from high temperature combustion. Pyrolysis method processing requires a heater to burn the material during the process. Efforts that can be made are the use of biomass stoves as the right solution because of the availability of abundant and cheap raw materials, biomass stoves can also provide solutions to reduce the impact of environmental pollution smoke. The purpose of this study was to determine the temperature produced by the biomass stove and the effect of the comparison of the composition of the biomass mixture of rice husk waste and low density polyethylene plastic waste on the quantity of pyrolysis oil. This research uses experimental method with quantitative descriptive analysis technique. This research was conducted by pyrolyzing a mixture of rice husk biomass waste and low density polyethylene plastic waste with variations in composition ratio of 0%:100%, 25%:75%, 50%:50%, 75%:25%, and 100%:0%. The pyrolyzed oil was then filtered and tested for quantity. The test results show that the biomass stove can be used as a heater in a pyrolysis device with a capacity of 4 kg of coconut shell briquettes. The use of coconut shell briquettes as fuel has the advantage of being able to produce higher heat and last longer than charcoal. The biomass stove can produce the highest pyrolysis temperature reaching 665.5°C at the bottom, 541°C in the middle, and 430.3°C at the top. There is an effect of variation in the composition of the mixture of rice husk waste and low-density polyethylene plastic waste on the quantity of pyrolysis oil. The composition of more rice husk waste compared to low density polyethylene plastic waste produces less quantity of pyrolysis oil, while the comparison of the composition of more low density polyethylene plastic waste compared to rice husk waste produces pyrolysis oil with more quantity. This can be seen from the quantity of pyrolysis oil produced ranging from 265 ml to 853.3 ml. </em></p>

Reversible Crosslinking of Commodity Polymers via Photocontrolled Metal-Ligand Coordination for High-Performance and Recyclable Thermoset Plastics.

Thermoset plastics, highly desired for their stability, durability, and chemical resistance, are currently consumed in over 60 million tons annually across the globe, but they are difficult to recycle due to their crosslinked structures. The development of recyclable thermoset plastics is an important but challenging task. In this work, recyclable thermoset plastics are prepared by crosslinking a commodity polymer, polyacrylonitrile (PAN), with a small percentage of a Ru complex via nitrile-Ru coordination. PAN is obtained from industry and the Ru complex is synthesized in one step, which enables the production of recyclable thermoset plastics in an efficient way. In addition, the thermoset plastics exhibit impressive mechanical performance, boasting a Young's modulus of 6.3GPa and a tensile strength of 109.8MPa. Moreover, they can be de-crosslinked when exposed to both light and a solvent and can then be re-crosslinked upon heating. This reversible crosslinking mechanism enables the recycling of thermosets from a mixture of plastic waste. The preparation of recyclable thermosets from other commodity polymers such as poly(styrene-coacrylonitrile) (SAN) resins and polymer composites through reversible crosslinking is also demonstrated. This study shows that reversible crosslinking via metal-ligand coordination is a new strategy for designing recyclable thermosets using commodity polymers.

Pyrolysis of plastic waste into diesel engine-grade oil

The pyrolysis of plastic waste to fuel will lead to greener waste management, ensure sustainability and serve as an alternative energy source. This study seeks to convert plastic waste into diesel engine-grade oil as an alternative energy source for various applications. A mixture of plastic waste of 58% PET, 20% HDPE, 12% LDPE, 7% PP, and 3% PS were used for the study. Catalytic and thermal pyrolysis was conducted in a batch reactor at a temperature of 450 °C for 2 h using Nitrogen gas. The plastic fuel produced was then analyzed using the Fourier Transform Infrared (FT-IR) spectroscopy and Gas Chromatography-Mass Spectrometry (GC–MS). The various characteristics of the oil, such as the kinematic viscosity, calorific value, density, and pour point, were determined. The results indicated that thermal pyrolysis produced 13% liquid, 59% gas and 27% solid residue, and on the other hand, catalytic pyrolysis yielded 15.16% liquid, 69.16% of gas, and 14.8% of solid residue. The FT-IR also showed the presence of aliphatic and aromatic compounds with a predominance of the aliphatic group. From the GC–MS analysis, the plastic fuel contains 30 compounds in the C8- C40 range. The calorific value of plastic fuel after analysis was 43.175 MJ/kg in catalytic pyrolysis and 34.132 MJ/kg in thermal pyrolysis. Also, the kinematic viscosity was 4.344 cSt in catalytic pyrolysis and 2.750 cSt in thermal pyrolysis, while the density and pour point were 0.856 g/cm3 and −17 °C respectively. These results show that catalytic pyrolysis yielded more gas and liquid with high calorific value than the thermal pyrolysis. This is an indication of the use of catalysts to improve the conversion of plastic into energy. The conversion of plastic waste into diesel oil will not only address environmental challenges but help achieve the SDGs 7 & 13 as well as Goal 7 of Agenda 2063.

Thermochemical and Kinetic Analysis of Combustion of Plastic Wastes and Their Blends with Lignite

The management of plastic waste is considered to be among the major environmental problems that must be urgently addressed. For various reasons, recycling of plastic waste is not always feasible. In this study, a comprehensive evaluation of a mixture of plastic wastes (of the municipal solid wastes, MSW) as potential fuel is performed. Precisely, the combustion of plastic waste and the co-combustion of plastic waste-lignite blends are studied. Thermochemical characteristics, chemical composition, and kinetic parameters are measured/estimated. The environmental impact of these samples is also evaluated in terms of CO2 maximum potential emissions and ash production. In addition, the ash quality and its risk for slagging problems are explored. The random mixture of plastic waste revealed extremely high energy content (34 MJ/kg), which is higher than some well-established liquid fuels, e.g., ethanol and lower ash content (~5 wt.%), with lower activation energy and a higher maximum rate of mass loss (~9%/min) than lignite. Besides the much lower amount of produced ash, plastic waste, despite its higher carbon content, exhibits lower CO2 maximum potential emissions (~75 g CO2/MJ). The composition of the ash produced by plastic waste and lignite is different quantitatively but qualitatively is of the same type (similar medium risk ash). The superior characteristics of plastic waste are also evident in the blends. Provided that toxic emissions are captured, the utilization of plastic waste through combustion seems to be an attractive approach for simultaneous waste management and energy production, especially for plastic waste of limited recycling potential.

Towards fuels production by a catalytic pyrolysis of a real mixture of post-consumer plastic waste

The contribution provides a valorization alternative for rejected plastic wastes from mechanical-biological treatment (non-recyclable material) via an in-situ catalytic pyrolysis process focused on the production of a liquid fraction with similar properties to traditional fuels (i.e., gasoline, kerosine, and diesel). According to the ASTM recommendations, on small samples without prior physical separation, fuel fraction identification was carried out by Simulated Distillation along with a hydrocarbon types analysis and complemented with CHNS-O analysis and Fourier Transform Infrared Spectroscopy. Two catalytic structures were employed named Sepiolite and Montmorillonites, both K10 and K30, which after simple heat treatment to stabilize the structure, were characterized to analyze the main properties affecting the catalytic activity and product yields (i.e., morphological and acidity properties). A whole screaming of the products by analogy with hydrocarbon of the petroleum industry is presented. Such an approach allows a real evaluation of the studied technology in the current energy scenario.

Low temperature pyrolysis of polylactic acid (PLA) and its products

The fact that polylactic acid (PLA) is not biodegradable makes it necessary to find the methods of effective treatment of its waste. A significant method of processing waste PLA can be slow low-temperature pyrolysis, providing mostly oil and energy gas. The PLA pyrolysis provides almost 50 wt.% oil and 21–23 wt.% energy gas with a high carbon monoxide content above 90 vol.% at temperatures up to 420 °C. The temperatures above 420 °C do not give acceptable yields of oil anymore, and at the same time there are higher losses due to the release of low boiling aldehydes and ketones. The obtained oil and gas showed an acceptable calorific value as a basis for their use as substitute fuels. Due to its composition, oil can also be considered as a source of valuable chemicals (tetrahydrofuran, paraldehyde, cyclopentanone and ether) and gas as a source of carbon monoxide for industrial applications and, more recently, for biomedical use. Even plastic waste mixtures with a high proportion of PLA in a 1:1 ratio can be efficiently processed by slow low-temperature pyrolysis. The pyrolyzed mixture showed very similar yields of solid carbonaceous residue and oil (38 wt.% and 35 wt.%). The composition of the solid phase was only minimally different from the low-temperature pyrolysis of PLA. Although the ratio of PLA:LPO components was 1:1, the CO content decreased by ca. 20 vol.% at the expense of CO2 and lighter C2-C5.

Conversion of municipals waste into syngas and methanol via steam gasification using CaO as sorbent: An Aspen Plus modelling

The conversion of wastes specially (plastic and food waste) for energy and value-added products through gasification is under investigation. This investigation configures an integrated simulation process model for steam gasification, syngas treatment, methanol production and purification for plastic waste ((Polyethylene(PE) + polyethylene terephthalate (PET)), food waste (vegetable and fruits) and their blend using a simulation tool Aspen Plus®. The impact of three process parameters such as temperature (650–900 °C), steam/feedstock ratio (1.0–2.0) and CaO/feedstock ratio (0.5–2.0), on syngas composition and downstream product methanol. H2 and methanol yield increases with the increase of temperature in all cases. In the case of plastic, H2 and methanol yield were increased from 75.68 to 92.77 kmol/h and 709.60 to 960.13 kg/h respectively with the injection of steam flowrate. A similar H2 and methanol yield trend was obtained for food and mixture of plastic and food waste with a little variation. In the case of food waste, methanol has ascending order and maximum final methanol production 476.56 kg/h at 1800 kg/h steam flowrate. The gas composition profile which define the H2-CO/CO + CO2 ratio increase from 1.27 to 1.88 governing methanol production for plastic. CaO is added to capture the CO2 to get the augmented syngas composition for methanol production. The general trend of H2 production was ascending, whereas methanol is descending with an increase of temperature and CaO flowrate for most cases. Maximum 978 kg/h MeOH noticed at temperature of 700 °C, steam flowrate of 1000 kg/h and CaO flowrate of 500 kg/h for plastic. Although, its flowrate extensively affected the CO and CO2 flowrates that need to be optimized for a desired composition to maintain a good H2-CO/CO + CO2 ratio for methanol production.

Bifunctional metal-loaded micro-mesoporous zeolites for waste plastics conversion to high quality liquid product

A series of micro-mesoporous zeolitic catalysts synthesized using recrystallization of two different zeolites (HZSM-5 and beta) were impregnated with Pt and other notable metals. The resulting bifunctional catalysts were characterized and tested for the hydrocracking of a model municipal waste plastic mixture. Actual waste plastic mixture of the same composition was also employed for the comparison. The hydrocracking experiments were carried out in a Parr stirred batch reactor at 325, 350, and 375 °C. The other reaction conditions were fixed at the initial cold H2 pressure of 20 bar, reaction time of 60 min, and plastic to catalyst ratio of 20:1 by wt. The inclusion of the Pt metal has shown to increase the hydrocracking activity of the micro-mesoporous supports. The Pt micro-mesoporous ZSM-5 catalysts have shown the better activity while Pt micro-mesoporous beta catalysts have shown better selectivity towards liquid. The presence of Pt metal has also produced a better quality liquid product with fewer unsaturated hydrocarbons and results in lower coke formation as determined by the TGA analysis of the spent catalysts.

Fuel Gas Production from the Co-Gasification of Coal, Plastic Waste, and Wood in a Fluidized Bed Reactor: Effect of Gasifying Agent and Bed Material

In this study, the effect of gasifying agent and bed material on the performance of the co-gasification of a mixture of coal, plastic waste, and wood was investigated. The experimental runs were carried out in a lab-scale bubbling fluidized bed reactor utilizing air, oxygen-enriched air, a mixture of air and steam, and a mixture of oxygen and carbon dioxide as reactant gases, while silica sand, olivine, and a mixture of olivine and dolomite as bed materials were used. The results indicated that both gasifying agent and bed material strongly affect the gas composition and, as a consequence, the process performance. In particular, the test with oxygen-enriched air and silica sand provided a producer gas with the highest heating value (9.32 MJ/Nm3), while the best performance in terms of gas yield (2.98 Nm3/kg) and tar reduction (−94.5%) was obtained by utilizing the air/steam mixture and olivine. As regards tar composition, it was observed that the most abundant and recalcitrant tar substance groups are naphthalenes and PAHs. On the other hand, phenols and furans appear to be the most sensitive groups to the effect of gasifying agent and bed material.

Kinetic Analysis of Thermal Degradation of Recycled Polypropylene and Polystyrene Mixtures Using Regenerated Catalyst from Fluidized Catalytic Cracking Process (FCC).

The pyrolysis process is a thermochemical recycling process that in recent years has gained importance due to its application in plastic waste, which is one of the biggest environmental problems today. Thus, it is essential to carry out kinetic and thermodynamic analyses to understand the thermocatalytic degradation processes involved in plastic waste mixtures. In this sense, the main objective of this study is to analyze the degradation kinetics of the specific mixture of polypropylene (25%) and polystyrene (75%) with 10% mass of regenerated FCC catalyst which was recovered from conventional refining processes using 3 heating rates at 5, 10 and 15 K min-1 by thermogravimetric analysis (TGA). The obtained TGA data were compared with the isoconversional models used in this work that include Friedman (FR), Kissinger Akahira Sunose (KAS), Flynn-Wall-Ozawa (FWO), Starink (ST) and Miura-Maki (MM) in order to determine the one that best fits the experimental data and to analyze the activation energy and the pre-exponential factor; the model is optimized by means of the difference of minimum squares. Activation energy values between 148 and 308 kJ/mol were obtained where the catalytic action has been notorious, decreasing the activation energy values with respect to thermal processes.

Pengaruh Campuran Limbah Anorganik (Plastik) Sebagai Pengganti Semen Terhadap Kuat Tekan Paving Block

The increased production of waste that is hard to degrade is inorganic waste, so it takes effort to reduce it into a useful product. One of the alternatives, inorganic waste recycling is becoming one of the mixture ingredients of paving blocks. This research aimed to determine the best composition of mixture ingredients towards the compressive strength of paving blocks with plastic waste as a substitute for cement. Research methods with experimental testing in the laboratory using paving blocks mixed with plastic waste as a substitute for cement. Plastic waste used is cleaned first and dried, chopped into smaller pieces afterward, and heated inside a cauldron until melted and ready to be mixed with sand. The composition used is 80% plastic: 20% sand, 70% plastic: 30% sand, 60% plastic: 40% sand, and 50% plastic: 50% sand. The result of the compressive strength test of paving block composition affected by a proper mixture of plastic waste as a substitute of cement towards compressive strength of paving block is type LDPE with a variation of 50%: 50%, with average compressive strength of 8,5 MPa with category D of paving block quality that good to be used for park and another usage. For the absorption capacity test of the paving blocks that absorb most of the water is located in the ratio of 50% plastic: 50% sand with 1,30% satisfy SNI requirement 03-0691-1996 entering grade A with average water absorption of 3%.

UTILIZATION OF PLASTIC WASTE AS A SUBSTITUTIONAL MATERIAL FOR PAVING BLOCK MANUFACTURING

Besides reducing environmental pollution, the use of garbage or plastic waste can also be used as an alternative to building materials. The potential for utilizing plastic waste still needs to be developed, by conducting research on plastic waste to be substituted into paving block making materials, by replacing some of the sand material in normal paving blocks. The research used is an experimental method. In this test the test object was made by adding additives/mixture of plastic waste as a filler/mixture in the paving block mix with a percentage of plastic mixture of 2.56%, 5.26%, 8.11%, 10.11%. Then the paving block is tested for compressive strength at the age of 28 days which is possible to have reached the maximum compressive strength value. The results of the paving block compressive strength test will increase according to the increase in the percentage of plastic mixture. The compressive strength of paving blocks with a plastic mixture of 0%, 2.56%, 5.26%, 8.11% and 10.11% obtained compressive strengths of 10.44 MPa, 10.64 MPa, 10.95 respectively MPa, 11.15 MPa and 11.33 MPa. The increase in compressive strength of normal paving blocks (0% mixture of plastic waste) was 1.83%, 4.6%, 6.35% and 7.86%. The highest compressive strength occurs in paving blocks with a mixture percentage of 10.11% plastic waste, according to the SNI-03-0691-1996 standard the compressive strength is included in the quality level D which can be used for parks and other uses.

Low-cost activated carbon from the pyrolysis of post-consumer plastic waste and the application in CO2 capture

Chemical recycling by pyrolysis of plastic waste has been considered a potential approach. However, little attention has been paid to the reuse of the char residue generated. The preparation of materials from char residue obtained from the pyrolysis process has become an essential task. The purpose of this work is the preparation of activated carbons from the resulting char from the pyrolysis of a dirty and wet mixture of post-consumer plastic waste. The porous materials have been applied to the adsorption of CO2. Both physical and chemical activation methods were investigated to modify the surface texture properties. The properties of the developed activated carbons were characterized by diverse techniques such as elemental and proximate analysis, Fourier Transform Infrared Spectroscopy (FTIR), adsorption-desorption isotherms with N2, and Scanning Electron Microscopy (SEM). Among all synthesized samples, the activated samples prepared by chemical activation with KOH (char: KOH ratio 2:1; surface area, 487.0 m2·g−1) exhibited the highest CO2 adsorption uptake (∼49 mg·g−1). The activation temperature was explored within 680–840 ºC. For physical activation, an increase in the activation temperature decreases the adsorption uptake of the samples. For chemical activation, the adsorption increased as activating temperature rise to a maximum value, subsequently decreasing with further temperature rise. Increasing the amount of the chemical activating agent significantly decreases the adsorption capacities. The best-activated carbon was chosen, and several parameters were investigated on CO2 adsorption, C: KOH mass ratio (6:1–1:4), and adsorption temperature (15–60 °C). The highest adsorption of CO2 achieved was 62.0 mg·g−1 for activated carbon operating at the lower adsorption temperature (15 ºC).

Pyrolysis-plasma/catalytic reforming of post-consumer waste plastics for hydrogen production

Different types of single waste plastics and a range of real-world mixed waste plastics from several different industrial and commercial sources have been processed in a pyrolysis-plasma/catalytic experimental reactor system for the production of hydrogen. The hydrocarbons produced from the pyrolysis stage were catalytically (Ni/MCM-41) steam reformed in a low temperature, non-thermal plasma/catalytic reactor. The polyolefin plastics, high density polyethylene, low density polyethylene and polypropylene produced the highest yield of hydrogen at 18.0, 17.3 and 16.3 mmol g−1plastics respectively. The aromatic structured polystyrene produced a lower hydrogen yield of 11.9 mmol g−1plastics and polyethylene terephthalate with an aromatic and oxygenated structure produced only 10.2 mmol g−1plastics and a high yield of carbon oxide gases. The real-world mixed plastic waste produced yields of hydrogen in the range of 13.4–16.9 mmol g−1plastics. The lowest hydrogen yield of 13.4 mmol g−1plastics was produced from the mineral water bottle packaging waste due to the high content of polyethylene terephthalate in the plastic waste mixture.

Studying Properties of Hydroconversion Products of Thermolysis Oil Produced from Waste of Mixed Plastics

The results of the study of liquid products of hydrogenation processing of thermolysis oil obtained from a mixture of plastic waste are presented. It is established that as a result of hydrogenation processing of thermolysis oil in the conditions of the process of preparation of fuel for catalytic cracking and in the presence of catalysts of this process, hydrogenates with a high content of paraffins and low content of sulfur, nitrogen, condensed aromatic compounds and unsaturated hydrocarbons were obtained. Methods of processing these hydrogenates into motor fuels and feedstock for petrochemicals are proposed.

Thermo-catalytic co-pyrolysis of palm kernel shell and plastic waste mixtures using bifunctional HZSM-5/limestone catalyst: Kinetic and thermodynamic insights

Kinetic and thermodynamic parameters of catalytic co-pyrolysis of palm kernel shell (PKS) and high-density polyethylene (HDPE) with three different catalysts (zeolite HZSM-5, limestone (LS) and bifunctional HZSM-5/LS) using thermogravimetric analyser via nitrogen environment were studied. The experiments were carried out at different heating rates ranging from 10 to 100 K/min within temperature range of 50–900 °C. Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS) and modified Distributed Activation Energy Model (DAEM) methods were employed in this current study. The average Ea for PKS, HDPE, PKS/HDPE (2:8) – HZSM-5, PKS/HDPE (2:8) – LS, PKS/HDPE (2:8) – HZSM-5/LS, PKS/HDPE (5:5) – HZSM-5/LS, PKS/HDPE (8:2) – HZSM-5/LS are 137.26–145.49, 247.73–250.45, 168.97–172.50, 149.74–152.79, 115.30–120.39, 124.36–129.41, 151.03–154.47 and 152.67–157.31 kJ mol−1, respectively. Among the different catalysts used, LS demonstrated the lowest average Ea (151.30–120.39 kJ mol−1) and ΔH (109.65–114.74 kJ mol−1). Positive values for ΔH and ΔG were found for the catalytic co-pyrolysis of PKS/HDPE mixtures which indicates the process is in endothermic reaction and possess non-spontaneous nature. The kinetic and thermodynamic analyses revealed the potential of PKS and HDPE as a potential feedstock for clean bioenergy production.

Enhanced Liquid Fuel Production from Pyrolysis of Plastic Waste Mixtures Using a Natural Mineral Catalyst

Since plastic wastes are commonly found and accumulate in numerous types and forms, the pyrolysis of plastic waste mixtures seems more feasible to be selected for large-scale production. However, the process typically produces less liquid than individual plastic pyrolysis. This study proposed a viable approach for catalytic pyrolysis by using natural mineral catalysts without modification. Bentonite was selected as a natural mineral catalyst while HZSM-5 was used for performance comparison. The process was evaluated in situ using a fixed-bed reactor at temperatures between 400 °C and 500 °C. The mixture of plastic waste composition was designed based on the non-recycled plastics data. The results showed that 42.55 wt% of liquid yield was obtained from thermal pyrolysis using Malaysia’s non-recycled plastics data. It was then found that using HZSM-5 and bentonite catalysts significantly boosted liquid products to about 56 and 60%, respectively. The presence of catalysts also positively minimized tar formation and eliminated wax formation in the liquid product. Furthermore, the catalytic process showed remarkable improvements in aromatics and alkane compounds in the liquid while only alkenes were found to be high when bentonite was used.

Thermal and catalytic pyrolysis of a real mixture of post-consumer plastic waste: An analysis of the gasoline-range product

In this work, the thermal and catalytic pyrolysis of different types of plastic waste and a real mixture were investigated in a fixed-bed reactor over different catalysts (CaO, MgO, HY, HZSM-5). Important differences in gas, liquid, and solid yields were found as a function of polymer type. The highest gas yield was obtained with expanded polystyrene (52.3%), and the maximum oil production with high-impact polystyrene (55.5%), while polypropylene film led to the highest char release (17.5%). Regarding the composition of the liquid oil, high-impact polystyrene showed the highest yield of gasoline-range product (426 g per kg of pyrolyzed plastic), mainly composed of aromatics compounds (90%). The addition of catalysts increased the gas yield to the detriment of the oil produced. The effect was more evident for zeolite-type catalysts, i.e., the gas yield raised from 43.3 (non-catalytic) to 51.5% (HZSM-5). Low influence on the oil composition, i.e., gasoline-range product, was detected. This can be explained by the fast deactivation of catalysts because of coke deposition. Only an increase in the fraction of gasoline in liquid oil was observed when low-cost catalysts (CaO and MgO) were used, without significant changes in the composition of this product.

GASIFICATION OF HIMMETOĞLU AND SEYITOMER OIL SHALES WITH PLASTIC CITY WASTES IN A BUBBLING FLUIDIZED BED REACTOR

Artan plastik kullanımı ve kullanılan plastiklerin bir süre sonra atık olarak birikmesi günümüzün başlıca sorunlarındandır. Atık plastiklerin yeniden değerlendirilmesi için termokimyasal dönüşüm prosesleri oldukça verimlidir. Atık plastiklerin tek başına ve çeşitli yerli kömürler ile birlikte gazlaştırılması sayesinde yakıt olarak kullanıma uygun CO, CH4 ve bir enerji taşıyıcısı olan H2 içeren sentez gazı üretimi mümkündür. Bu amaçla yapılan çalışmada, Himmetoğlu ve Seyitömer bitümlü şeylleri ile plastik atık karışımı (%56 polietilen, %28 polipropilen ve %16 polistiren) gazlaştırılmıştır. Deneysel çalışmalar, 4 cm iç çapında ve 110 cm boyundaki kuvars camdan imal edilen laboratuvar ölçekli akışkan yataklı sistemde gerçekleştirilmiş olup akışkanlaştırıcı gaz olarak hava ve gazlaştırıcı akışkan olarak da su buharı kullanılmıştır. Sıcaklığın (750◦C, 800◦C, 850◦C), su buharı akış hızının (5-10-15 g/dak) ve beslemedeki plastik oranının (%40 ve %70) sentez gazındaki H2 ve CH4 konsantrasyonuna etkileri incelenmiştir. 5-10 g/dak akış hızındaki su buharı kullanımı Himmetoğlu bitümlü şeylinin ve karışımlarının gazlaştırılması için uygundur. Seyitömer bitümlü şeyli ve karışımlarının gazlaştırılmasında ise 10-15 g/dak olacak şekilde daha yüksek akış hızlarının uygun olduğu görülmüştür. Himmetoğlu ve Seyitömer bitümlü şeyllerine %40 ve %70 oranında plastik atık karıştırıldığında üretilen sentez gazındaki H2 konsantrasyonu azalırken CH4 konsantrasyonu artmıştır. Çalışma sonucunda, en yüksek H2 konsantrasyonu %21,33 (750◦C - 10 g/dak- %60 Himmetoğlu bitümlü şeyli ve %40 plastik beslemesi) ve en yüksek CH4 konsantrasyonu ise %74,71 (850◦C - 10 g/dak- %30 Himmetoğlu bitümlü şeyli-%70 plastik atık) olarak elde edilmiştir. Üretilmesi planlanan sentez gazının kullanım alanına göre sıcaklık, su buharı akış hızı ve besleme karışım oranı değiştirilerek uygun çalışma koşulları belirlenebilir.

2-step process recycles mixed plastics

A two-stage process that combines the power of chemistry and biology can convert mixtures of common waste plastics into single products, potentially overcoming a major obstacle in recycling ( Science 2022, DOI: 10.1126/science.abo4626 ). Plastic waste contains a mélange of materials , so it typically goes through a laborious sorting process to separate certain types of plastic for mechanical recycling. For example, polyethylene terephthalate (PET) and high-density polyethylene (HDPE) can be chopped up and used to make new products. But most other plastics cannot be recycled in this way, including composite materials that are difficult to tease apart. Overall, the US recycles less than 10% of its plastic waste, with the remainder landfilled, incinerated, or dumped, according to the US Government Accountability Office. Although a growing number of chemical processes are able to break down polymers into their constituent monomers, which can then be turned into fresh plastics, very few