Pyrolysis Of Polypropylene Research Articles

Pyrolysis of waste polypropylene plastics for energy recovery: Influence of heating rate and vacuum conditions on composition of fuel product

This study compared the pyrolysis of waste polypropylene (PP) into fuel products under atmospheric and vacuum pressure conditions at different temperatures and heating rates. Four different temperatures (450, 488, 525 and 600 °C) at slow (15 °C/min) and fast (about 180 °C/min) heating rates were examined on a bench scale reactor. Pyrolysis vapours were recovered as heavy and light fractions by fractional condensation and characterised using GC/MS. Among all temperatures, 488 and 525 °C generated promising yields of condensable products under both atmospheric and vacuum conditions, with total yields in the range of 81–93 wt%. Heating rate effects on product composition distribution were more pronounced under vacuum pyrolysis. Gasoline range compounds predominated in light condensable products recovered under both atmospheric and vacuum pyrolysis. Vacuum suction limited the condensation of gasoline range compounds in the heavy fraction, resulting in Diesel/Gasoline ratio higher than 30. Higher Heating Values (HHVs) of all condensable products recovered under both atmospheric and vacuum conditions ranged between 41 and 46 MJ/kg, with higher values being obtained under milder conditions. Increased production of aromatics explained the lower HHVs obtained at higher temperatures.

Activation of Zeolite from Malang as Catalyst for Plastic Waste Conversion to Fuel

Plastic pollution is an environmental problem that has not resolved until now. Pyrolysis is able to be a solution to reduce plastic waste. The use of catalysts will reduce heating temperatures, speed up processing time, and increase product yield. Natural zeolite has the potency as a catalyst in pyrolysis process due to its micropore structure, high acidity and thermal stability. The purpose of this research is to determine the effect of active zeolite catalyst on the polypropylene pyrolysis. The main process of this study is pyrolysis of polypropylene (PP) plastic waste without catalysts and with natural zeolite catalysts which were non-activated and activated. Natural zeolites were activated by HF, HCl and NH4Cl. The well result of this research is represented by the yield, viscosity, calorific value, FTIR and GC-MS analysis. Based on the results of diffractogram analysis, natural zeolites catalyst in this study is included in modernite minerals crystalline. The ratio of Si/Al in zeolite before activation was 7.07 and the acidity was 0.697 g/mmol. After the activation process, the ratio of Si/Al and zeolite acidity increased by 62.181% and 43.84%. The use of active natural zeolite catalysts in pyrolysis PP could reduce the total reaction time by 57.14%. Pyrolysis products with active zeolite catalyst compared to without catalysts had clearer color and higher heating value, compared to pirolysis without catalyst. Based on function group analysis with FTIR, the mixture of hydrolyzed compounds containing successive functional groups are-C-H (alkanes), double bond of C=C, hydroxyl-OH group which can be determined as phenol (ArOH), alcohol (ROH), and carboxylic acid (RCOOH). The GC-MS analysis showed that pyrolysis products are composed of a mixture of alkanes, cycloalkanes, alkenes, carboxylic acids with aromatic rings, and ketones. The pyrolysis products without catalysts consist of 5-11 (C5-C11) carbon atoms, whereas the range of carbon atoms of pyrolysis products with active zeolite catalysts was 6-24 (C6-C24).

Conversion Kinetics of the Gaseous Products of Pyrolysis of Polypropylene and Waste Tires

Numerical simulations are performed of reaction kinetics in the gaseous products of pyrolysis of polypropylene and waste tires at atmospheric pressure in the temperature range of 800 to 1300 K. The initial conditions are set by using the experimental data available in the literature. The reactions between gaseous pyrolysis products are found to result in a decrease in the mixture’s temperature of polypropylene and a temperature increase for waste tires. The increase in the initial temperature reduces the gaseous product’s conversion for both polypropylene and the waste tires. It is established that the conversion pathways for the C1–C4 alkenes and alkanes strongly depend on the initial temperature and their initial composition.

Clean Energy from Plastic: Production of Hydroprocessed Waste Polypropylene Pyrolysis Oil Utilizing a Ni–Mo/Laponite Catalyst

This research demonstrates a process to convert polypropylene pyrolysis oil (PPO) into diesel. The hydroprocessing of PPO (HPPO-B) utilizing a Ni–Mo/Lap bimetal catalyst has been attempted in this study. Hydroprocessing of plastic pyrolysis oil had been attempted earlier, but the hydroprocessing of PPO utilizing a bimetal catalyst and the corresponding validation suites consisting of physicochemical tests, composition comparison with diesel, and diesel engine trials have not yet been reported. The physicochemical properties of the produced HPPO-B matched EN590 standard (European diesel standards) requirements. The hydroprocess conditions (70 bar and 350 °C) and the synthesized Ni–Mo/modified Lap catalyst have been responsible for producing n-alkanes, isoalkanes, and aromatics in proportions that gave a 95% match with diesel. Diesel engine combustion and emissions of HPPO-B matched those of diesel. HPPO-B provides the opportunity to utilize plastic solid waste (PSW) as a transport fuel. The results of HPPO-B inspire and encourage pursuance of the hydroprocess path for protecting the environment from hazardous plastic solid waste (PSW).

Heavy crude oil viscosity reduction by dilution with hydrocarbons obtained via pyrolysis of polypropylene and polystyrene

Liquid hydrocarbons obtained from the pyrolysis of polypropylene and polystyrene were used as diluents to reduce the viscosity of a Mexican heavy crude oil of 10.6°API. Blends of oil and diluents were formulated with fractions of 5, 10 and 15 vol% of diluent. Viscosity results were plotted as a function of temperature and diluent volume fractions. The degree of viscosity reduction at room temperature was of 96 – 97% using 15 vol% of the proposed materials. Results show that viscosities lower than 400 cP, the classical maximum for pipeline transportation, are achieved at relatively low temperatures (45 – 65 °C).

Pyrolysis and in-line catalytic decomposition of polypropylene to carbon nanomaterials and hydrogen over Fe- and Ni-based catalysts

Thermo-chemical conversion of waste plastics into clean energy and valuable products can be a promising technology from both economic and environmental perspectives. In this work, pyrolysis and in-line catalytic decomposition of polypropylene was performed for production of hydrogen and carbon nanomaterials. A series of novel Fe/Ni catalysts were prepared, and the effects of catalyst active metal component (Fe, Ni, FeNi) and synthesis method (sol–gel and impregnation) were explored. Results show that the production of hydrogen and solid products was in a descending order as Fe-Ni, Fe and Ni loading, while sol–gel prepared catalysts were more catalytic effective than their impregnated counterparts. FeNi(SG) exhibited an optimal activity with productions of 25.14 mmol/gplastic of hydrogen and 360 mg/gplastic of high quality carbon nanomaterials, which was attributed to (i) uniform mesoporous structure with 212.30 m2/g specific surface area (ii) high dispersion degree (42.02%) of active metals and (iii) enhanced reducibility originated from the synergistic effect between Fe and Ni. Carbon nanomaterials which contained the majority of carbon nanotubes were comprehensively characterized in terms of structure complexity, morphology and graphitization degree, and the formation mechanism of bamboo-like multi-walled carbon nanotubes from pyrolysis and catalytic decomposition of polypropylene was also discussed.

Formation of non-oxygenated phase of bio-oil produced by copyrolysis of corn cobs and polypropylene plastic using zeolite catalysts at low heating rate

Thermal co-pyrolysis of corn cobs and polypropylene (PP) at low heating rate (thermal slow co-pyrolysis) has succeeded in separating bio-oil produced between oxygenated and non-oxygenated phases spontaneously. In co-pyrolysis, PP can sequester oxygen from bio-oil to convert part of bio-oil to non-oxygenated phase and can contribute partly non-oxygenated phase by PP carbon chain cracking. Catalytic fast co-pyrolysis has been commonly used to improve bio-oil yield and to improve non-oxygenated fraction of bio-oil. However, the catalytic fast co-pyrolysis is unable to obtain separate non-oxygenated fraction of bio-oil. In present work, zeolite catalyst was introduced in co-pyrolysis of corn cobs and PP at low heating rate to undertake catalytic slow co-pyrolysis in order to obtain synergistic effect of non-oxygenated fraction of bio-oil while obtaining separate non-oxygenated fraction of bio-oil. The present co-pyrolysis work was carried out in a stirred tank reactor at heating rate of 5 °C/min and maximum temperature of 500 °C. The composition of feed was varied at 0, 50 and 100%PP in the mixture of corn cob particles and PP granules. The experiment involved 3 catalytic configurations, i.e., no catalyst, ZSM5-38 and ZSM5-70, in which 38 and 70 represents the mole ratio of SI/Al in the catalysts. The results show that in slow co-pyrolysis of biomass-PP, the use of zeolite catalyst with high acidity suppressed the pyrolysis of PP to form wax and reduced bio-oil yield, and the synergistic effect was obtained as the co-pyrolysis used no catalyst and zeolite catalyst of ZSM5-70, while that using zeolite catalyst of ZSM5-38 reached negative synergistic effect. Utilization of catalyst generated high amount of aliphatic moieties, i.e. methyl, methine and methylene. With ZSM5 catalyst utilization, production of allyl decreased. Most of non-polar bio-oil fractions have similar or slightly higher heating values (HHVs) compared to those of commercial fuels. Branching index (BI) values of non-polar phase of bio-oil generated straight carbon chain with higher branches compared to those commercial fuels.

Correction to: Pyrolysis of polypropylene over a LZ-Y52 molecular sieve: kinetics and the product distribution

The original version of this article unfortunately contained a mistake. The affiliation of the Afzal Shah was incorrect.

Synergistic Effect on the Non-Oxygenated Fraction of Bio-Oil in Thermal Co-Pyrolysis of Biomass and Polypropylene at Low Heating Rate

Biomass pyrolysis and polypropylene (PP) pyrolysis in a stirred tank reactor exhibited different heat transfer phenomena whereby heat transfer in biomass pyrolysis was driven predominantly by heat radiation and PP pyrolysis by heat convection. Therefore, co-pyrolysis could exhibit be expected to display various heat transfer phenomena depending on the feed composition. The objective of the present work was to determine how heat transfer, which was affected by feed composition, affected the yield and composition of the non-polar fraction. Analysis of heat transfer phenomena was based on the existence of two regimes in the previous research in which in regime 1 (the range of PP composition in the feeds is 0–40%), mass ejection from biomass particles occurred without biomass particle swelling, while in regime 2 (the range of PP composition in the feeds is 40–100%), mass ejection was preceded by biomass particle swelling. The co-pyrolysis was carried out in a stirred tank reactor with heating rate of 5 °C/min until 500 °C and using N2 gas as carrier gas. Temperature measurement was applied to pyrolysis fluid at the lower part of the reactor and small biomass spheres of 6 mm diameter to simulate heat transfer to biomass particles. The results indicate that in regime 1 convective and radiative heat transfers sparingly occurred and synergistic effect on the yield of non-oxygenated phase increased with increasing convective heat transfer at increasing %PP in feed. On the other hand, in regime 2, convective heat transfer was predominant with decreasing synergistic effect at increasing %PP in feed. The optimum PP composition in feed to reach maximum synergistic effect was 50%. Non-oxygenated phase portion in the reactor leading to the wax formation acted as donor of methyl and hydrogen radicals in the removal of oxygen to improve synergistic effect. Non-oxygenated fraction of bio-oil contained mostly methyl comprising about 53% by mole fraction, while commercial diesel contained mostly methylene comprising about 59% by mole fraction

In-situ production of valuable aromatics via pyrolysis of waste polypropylene using commercial catalyst ZSM-5

Waste polypropylene has been subjected to pyrolysis followed by in-situ aromatization in a specially designed semi batch reactor at the temperature ranging from 500 - 800°C. The molecules of interest are valuable aromatics benzene, toluene, ethyl benzene and xylene (BTEX) which appeared highest amount in the liquid mixture. The catalyst used is commercial ZSM-5 (30:1). The catalytic pyrolysis of PP is studied in a semi batch reactor in two different phases, keeping the catalyst in the liquid phase (L-type) and liquid and vapor phase/multiphase (M-type), respectively. The BTEX yield is enhanced significantly using multiphase catalytic pyrolysis of polypropylene. The catalytic performance of ZSM-5 catalyst for PP pyrolysis is evaluated with respect to target aromatics BTEX. The thermal pyrolysis of PP produced maximum liquid yield of 80.56 wt. % at a temperature of 700°C. The commercial catalysts ZSM-5 produced highest liquid yield of 86.3 wt. % for liquid phase (L-type) pyrolysis. The BTEX yield is significantly increased from 30.9 wt.% for thermal pyrolysis to 53.09 wt. % for catalytic multiphase/M-type pyrolysis. Almost 72 % increase in BTEX yield is recorded for catalytic multiphase/M-type pyrolysis in comparison to thermal process. The pyrolysis oil is analyzed using GC-FID, carbon residue test and other fuel testing methods to examine the suitability of its end use and aromatic content.

Behaviour of waste polypropylene pyrolysis char-based epoxy composite materials.

In this study, polypropylene (PP) plastic wastes were pyrolysed. Solid pyrolysis product (char) was used as filler material for the preparation of epoxy composite. 300, 400, 500, 600 and 700°C were selected as final pyrolysis temperatures. Solid pyrolysis product (char) was analysed by elemental, FTIR, SEM, BET and TGA analysis. The epoxy composite samples were prepared with char obtained from pyrolysis. Mechanical properties of composites were analysed by hardness, tensile strength, elongation at break, electrical conductivity tests to explain the effects of pyrolysis temperature and char doses over composite properties. Thermogravimetric properties of composites were determined by TGA analyses. The water absorption behaviour of composite samples was determined by water adsorption test. Epoxy composite produced from PP char obtained under 300°C showed the most ideal behaviour.

Gas and tar generation behavior during flash pyrolysis of wood pellet and plastic

Fluidized bed gasifiers (FBGs) and gas engines (GEs) could be available as waste-to-energy technology, because most small- and medium-scale municipal solid waste treatment plants have low electricity generation efficiencies. As feedstock composition vary widely based on regional characteristics, clarifying the relationship between gas and tar generation behaviors and feedstock is useful for the design of the GE generation process to predict gas and tar yields and compositions. To understand the synergistic effect of feedstock characteristics in fluidized bed gasification, flash pyrolysis of wood pellet, polyethylene, and polypropylene at 900 °C was conducted. Yields and compositions of gasses and tar from single and co-pyrolysis were investigated. The results reveal that co-pyrolysis increases the gas yield because of oxygenates and moisture present in the wood pellet. Tar yields found to decrease while polycyclic aromatic hydrocarbons (PAHs) are not reduced even during co-pyrolysis. That is because most chain hydrocarbons of tar are converted to CmHn gases and PAHs.

Experimental investigation to identify the type of waste plastic pyrolysis oil suitable for conversion to diesel engine fuel

Plastics for various applications is increasing every year due to outstanding advantages, but after use recycling and disposal have remained a challenge. In this paper, through experiments, we compare properties of pyrolysis oil derived from after use HDPE (High-density polyethylene), LDPE (Low-density polyethylene), PP (Polypropylene)and styrene for their suitability as diesel engine fuel. This experimental study is to identify which type of plastic is suitable for blending with diesel. The physicochemical properties of pyrolysis oil of HDPE, LDPE, PP, and styrene were tested, tabulated and compared with diesel. The physicochemical properties of polypropylene pyrolysis oil (PPO) were found to be superior to the produced pyrolysis oil of HDPE, LDPE, and styrene. The GC-MS(Gas chromatography-mass spectrometry)and FT-IR (Fourier transform-infrared spectroscopy) were taken for pyrolysis oil of HDPE, LDPE, PP, and styrene and compared with diesel. PPO showed lower carbon number chain compounds compared to the other three waste plastics. We selected PPO for diesel engine performance and emission trials based on the results of the above tests. PPO was blended in the ratios of 5%, 10% and 15% with diesel. Combustion analysis showed a increase in cylinder pressure in comparison to diesel values. The heat release rates (HRR) were sharply higher than diesel. Both cylinder pressure and HRRvalues for PPO increased as the blend ratios increased. The emission results showed an increase in carbon monoxide (CO), hydrocarbon (HC)and oxides of Nitrogen (NO x )emissions. The multiple times increase in emissions is due to the presence of unsaturated hydrocarbons and higher carbon number of saturated compounds in PPO. GC-MS tests confirmed the presence of such compounds in PPO. To reduce the unsaturation to negligible levels, we will take up future experiments in hydrogenating PPO with various catalysts and test the performance and emissions in diesel engines. The experiment and analysis plan for conversion of solid waste plastics to diesel fuel. • Four types of plastics selected to determine which plastic has a diesel like quality. • Physicochemical properties, FTIR, GCMS results showed Polypropylene had diesel like qualities. • Diesel Engine trials done with polypropylene pyrolysis oil blended with diesel as fuel. • Engine trial results showed delayed combustion, high heat release rate and higher emission.

Combustion and emission analysis of hydrogenated waste polypropylene pyrolysis oil blended with diesel

Petroleum-based plastic pyrolysis oil contains unsaturated compounds, and the presence of these compounds makes the produced fuel unsuitable for combustion in diesel engines. Hydrogenation of pyrolysis oil is performed to convert unsaturated compounds to saturated compounds. Past studies have shown that hydrogenation of petroleum-based plastic pyrolysis oil is viable; however, its combustion and emissions analysis in diesel engines has not yet been reported. In this study, we investigated the combustion, performance, and emissions of hydrogenated polypropylene pyrolysis oil (HPPO) blended with diesel. Polypropylene (PP) was converted to pyrolysis oil using ZSM-5 as the catalyst. The hydrogenation of polypropylene pyrolysis oil (PPO) was conducted at pressure of 70 bar, and the reaction temperature was maintained at 350 °C. Ni metal impregnated on the ZSM-5 base support was used as the catalyst of choice. The produced HPPO possessed physicochemical properties that match the EN590 standards(European diesel fuel standards). Gas chromatography-mass spectrometry (GC–MS) studies of PPO and HPPO showed the effectiveness of hydrogenation for the complete conversion of alkenes to alkanes, and hydrocracking resulted in cracking higher carbon number alkanes to lower values. HPPO was blended with diesel in ratios of 10 wt.%, 20 wt.%, 30 wt.%, and 40 wt.%. The diesel engine performance results for the blended fuel showed combustion, performance, and emissions on par with pure diesel fuel for blending ratios up to 20 wt.%. As is known, plastic solid waste (PSW) materials pose serious hazards to the environment. Our HPPO physicochemical properties matched the EN590 standards for diesel fuel. The combustion of HPPO in diesel engines can provide an option for environmentally cleaner disposal of PSW.

Deflagration-to-detonation transition in air mixtures of polypropylene pyrolysis products

A new method for determining the detonability of fuel is proposed based on the measured values ​​of the detonation run-up distance and time in the standard pulsed detonation tube (PDT). Granulated polypropylene (GP) was used as a fuel. A test bench with the PDT and a gas generator was designed and manufactured for the preparation of the GP pyrolysis products at a decomposition temperature of up to 800 °C. Experiments on deflagration-to-detonation transition in air mixtures of pyrolysis products of the GP showed that such mixtures exhibit detonability close to that of liquefied hydrocarbon gas (LPG) of the propane-butane automobile brand in a stoichiometric mixture with air under normal conditions.

Effect of Vapor Carbon Coating on the Surface Structure and Sodium Storage Performance of Hard Carbon Spheres

Hard carbons have received considerable attention as anode materials for sodium‐ion batteries (SIBs). However, it is still a challenge to improve the plateau capacity and initial coulombic efficiency (ICE) of hard carbons. Herein, a facile vapor carbon‐coating method is used to modify the surface structure of carbon spheres (CS) via the pyrolysis of polypropylene (PP), aiming to seal the exposed pores through a high‐quality carbon layer. CS@2%PP exhibits highly improved sodium storage performance compared to that of the pristine CS, which delivers a plateau capacity of 220 m Ah g−1 and an ICE of 81%. Further investigations show that the improved sodium storage performance of CS@2%PP can be mainly attributed to the reduced structural defects on the surface, lower specific surface area (11.5 m2 g−1), and increased closed pores (12.5%) via carbon coating. The results prove that the surface vapor carbon coating is a facile route to improve the plateau capacity and ICE of hard carbon anodes in SIBs.

Pyrolysis of polypropylene over a LZ-Y52 molecular sieve: kinetics and the product distribution

The present work demonstrates the decomposition kinetics of polypropylene in the presence of LZ-Y52 molecular sieve. The pyrolysis was performed at different heating rates in the temperature range 30–600 °C in an inert atmosphere. The kinetics parameters were calculated by applying Ozawa–Flynn–Waal, Tang–Wanjun, and Coats–Redfern (modified) methods. The activation energy (Ea) and frequency factor (A) were found in the range of 52.44–74.50 kJ mol−1 and 1.5 × 10−2 to 9.05 × 108 min−1, respectively. Based on the activation energy data, all three methods agreed well. Moreover, pyrolysis was performed at 350–390 °C in a pyrolysis chamber and the conditions were optimized for maximum oil production. A 10% catalyst amount, at 370 °C, nitrogen flow rate 16 mL/min, and reaction time 60 min were the optimum conditions during experimental work. The products collected were analyzed by gas chromatography/mass spectrometry. In the case of thermal degradation, no oil was obtained; however, thermo-catalytic degradation resulted in more than 40% oil at 370 °C for 1 h. Fuel properties of the oil obtained were determined. These properties were in good agreement with standard values and therefore it has potential applications for replacing fuel oil.

Feasibility of Using Polypropylene for Metal Oxide Reduction

In this study, NiO reduction behavior was investigated in the gas atmosphere generated by polypropylene (PP) pyrolysis to reveal the feasibility of using polypropylene as a reducing agent precursor for metal oxides. Chemical equilibrium calculations were performed to guide the experimental studies and to better understand the processes. PP fibers and NiO powder were simultaneously heated to 600–900 K in a tubular reactor. During heating, the PP was pyrolyzed into the gaseous species as indicated by the mass measurements. NiO was reduced to Ni by the pyrolytic gas carried by Ar flow. The thermodynamic calculations predicted that the pyrolytic gas consisted of mainly H2, CH4, and C6H6. The degree of NiO reduction increased with temperature and with the pyrolyzed the PP mass. The oxide reduction was complete at 800–900 K, provided that the sufficient amount of PP was pyrolyzed. The results show that NiO reduction via PP pyrolysis route is feasible.

Deflagration-to-Detonation Transition in Air Mixtures of Polypropylene Pyrolysis Products

Deflagration-to-Detonation Transition in Air Mixtures of Polypropylene Pyrolysis Products

Pyrolysis of polypropylene over zeolite mordenite ammonium: kinetics and products distribution

Abstract The present work reveals pyrolysis kinetics of polypropylene (PP) over zeolite modernite using thermogravimetry. The activation energy (E a) and frequency factor (A) were calculated applying Ozawa Flynn Wall, Coats-Redfern, and Tang Wanjun methods. The E a calculated by all the methods were found in accord with each other. The pyrolysis was also performed in a salt bath in the temperature range 350°C–390°C. It was observed that a temperature of 370°C is the optimum temperature for maximum liquid fuel production. Moreover, the amount of solid residue decreases with the rise in temperature. Similarly, gas fraction also shows linear relationship with temperature. The condensable and noncondensable fractions were collected and analyzed by gas chromatography-mass spectrometry. The fuel properties of the oil produced were assessed and compared with commercial fuel. These properties agree well with fossil fuel and therefore have potential applications as fuel.