Composition Of Pyrolysis Oil Research Articles

Study on biomass and polymer catalytic co-pyrolysis product characteristics using machine learning and shapley additive explanations (SHAP)

Biomass and polymer catalytic co-pyrolysis can convert waste into higher-quality fuels, thereby reducing the use of fossil fuels to some extent. However, this process is an extremely complex thermochemical conversion, influenced by numerous factors such as feedstock properties, operational variables, and catalyst. Currently, experimental methods require substantial time and resource investment. Machine learning (ML) can fit and match input and output features based on existing data, achieving extremely high accuracy in the co-pyrolysis process. This study applies advanced ML models to study the biomass and polymer catalytic co-pyrolysis process, with a focus on the yield of pyrolysis products and the variations of the oxygen-containing components in the pyrolysis oil. The best-performing model is used for feature analysis of the correlation between inputs and outputs, based on game theory SHAP analysis. The results indicate a significant negative correlation between the polymer addition ratio and the generation of oxygen-containing components during the co-pyrolysis process. The addition of catalysts promotes the generation of pyrolysis gas during co-pyrolysis but suppresses the yield of pyrolysis oil. Additionally, catalysts significantly inhibit the formation of oxygenates in the pyrolysis oil. The XGBR model shows the highest performance in predicting pyrolysis oil yield, achieving R2 values of 0.98 during training phase and 0.91 during testing phase. The GBR model performs well in predicting the oxygenate composition of pyrolysis oil from small datasets.

Production of cycloalkane-rich fuel by vacuum pyrolysis of mixed waste plastics using combined titanium and aluminum oxide: a preliminary investigation

The mitigation of plastic pollution constitutes one of the major challenges worldwide. Innovative research approaches have been solicited to improve the properties of fuel derived from plastic pyrolysis. The present study looks at the effect on the chemical composition of pyrolysis oil of the application in situ of a mixed metal oxide of titanium and aluminum in vacuum pyrolysis of mixed waste polyethylene, polypropylene, and polyethylene terephthalate. The experiment was performed at process parameters of 250 °C temperature, 79.9 Kpa vacuum pressure, and 1:10 catalyst-to-feedstock ratio, first without the mixed metal oxide (parent reaction) and then with the mixed metal oxide (modified reaction). The results showed that the presence of combined titanium and aluminum oxides in the reaction medium accounted for the presence of alkyl-substituted cycloalkanes at an area% of 33.97% in the liquid product, and a calorific value of 11,950 cal/gm was reported for the modified reaction. The parent reaction produced higher liquid and gaseous yields of 28.3% and 43.1% respectively while the modified reaction produced a greater percentage of char (23.8%) and residual wax(36.0%). The fuel properties of the liquid products obtained were equally determined.

Co-pyrolysis characteristics and pyrolysis oil analysis of Chlorella vulgaris and marine waste plastics with multi-metal MOFs-derived additive

In this study, MOFs-derived additives with microwave absorption and catalytic characteristics were employed in the microwave co-pyrolysis of Chlorella vulgaris (CV) and marine waste plastics (MW) to produce high-quality pyrolysis oil. The effects of additives (Ni-Cu@C, Ni-Co@C, Cu-Co@C and Ni-Cu-Co@C) under different addition amounts (10%, 20%, 30%) on co-pyrolysis characteristics, product yield and pyrolysis oil composition were investigated. Furthermore, the pyrolysis mechanism was analyzed. The results showed that the MOFs-derived additives improved the co-pyrolysis characteristics, especially at 30% addition amount. The maximum average weight loss rate (0.0273 wt.%/s) and pyrolysis oil yield (14.33%) obtained at 30% Ni-Cu-Co@C group. Moreover, the aromatic content (30.07%), deoxygenation efficiency (27.70%) and denitrogenation efficiency (80.03%) in pyrolysis oil were maximum at adding 30% Ni-Cu-Co@C. Ni-Cu-Co@C promoted the nitrogen transformation into gaseous products, while reduced the nitrogen contents in char and pyrolysis oil. Meanwhile, the nitrogen in char was dominated by pyridine-N and quaternary-N. Importantly, the activity of the Ni-Cu-Co@C remained 0.66 times of the initial activity after 5 cycles, demonstrating the excellent regenerative usability.

Quantification of the composition of pyrolysis oils of complex plastic waste by gas chromatography coupled with mass spectrometer detector.

Waste valorisation through pyrolysis generates solid, liquid and gaseous fractions that need to be deeply characterised in order to try to recover secondary raw materials or chemicals. Depending on the waste and the process conditions, the liquid fraction obtained (so-called pyrolysis oil) can be very complex. This work proposes a method to quantitatively measure the composition of pyrolysis oils coming from three types of polymeric waste: (1) plastic packaging from sorting plants of municipal solid waste, (2) plastic rich fractions rejected from sorting plants of waste of electrical and electronic equipment and (3) end-of-life carbon/glass fibre reinforced thermoset polymers. The proposed methodology uses a gas chromatography (GC) coupled with mass spectrometer detector (MS) analytical technique, a certified saturated alkanes' mix, an internal standard and fourteen model compounds. Validation of the methodology concluded that the average relative error was between -59 wt% and +62 wt% (with standard deviations between 0 wt% and 13 wt%). Considering that the state-of-the-art scenario to quantify complex plastic pyrolysis oils as a whole is almost none and that they are usually evaluated only qualitatively based on the area percentage of the GC-MS chromatograms, the presented quantification methodology implies a clear step forward towards complex pyrolysis oil compositional quantification in a cost-effective way. Besides, this quantification methodology enables determining what proportion is being detected by GC-MS with respect to the total oil. Finally, the presented work includes all the Kováts RI for complex temperature-program gas chromatography of all the signals identified in the analysed pyrolysis oils, to be readily available to other researchers towards the identification of chemical compounds in their studies.

The characterization of pyrolysis oil from plastic waste using FTIR and GC-MS techniques

This research aims to investigate the characterization of pyrolysis oil products derived from plastic waste using FTIR (Fourier Transform Infrared) and GC-MS (Gas Chromatography-Mass Spectrometry) techniques. Plastic waste samples were subjected to pyrolysis, and the resulting pyrolysis oils were analyzed using FTIR to identify the functional groups present in the oil product. Additionally, GC-MS analysis was performed to obtain detailed information about the composition of the pyrolysis oils. The FTIR spectra revealed the presence of various functional groups, indicating the complexity of the pyrolysis oil composition. The functional groups identified in the pyrolysis oil included methyl C-H stretch and C-C stretch. The GC-MS analysis provided insights into the specific compounds present in the pyrolysis oils. The results demonstrate the potential of pyrolysis as a method for converting plastic waste into valuable oil products. The characterization of these products using FTIR and GC-MS techniques provides valuable information for further optimization and utilization of pyrolysis oil derived from plastic waste.

Chemical elucidation of recycled plastic pyrolysis oils by means of GC×GC-PI-TOF-MS and GC-VUV

Detailed chemical characterization of the composition of pyrolysis oils produced from plastics is a mandatory step in understanding the recycling process. Even though the chemical composition of pyrolysis plastic waste oils shows similarities with fossil-based oils, e.g. PIONA related compounds, the relative proportions of the chemical classes are significantly different, resulting in important changes in the global properties of these fluids. In this context, an analytical method based on comprehensive two-dimensional gas chromatography (GC×GC), coupled with photoionization (PI) – time-of-flight mass spectrometry (TOF MS) was developed to obtain a detailed chemical characterization of plastic pyrolysis-oil. A group-type analysis was achieved thanks to the detection of molecular ions by soft ionization PI-TOF MS. Moreover, olefins were successfully distinguished from naphthenes by in-depth consideration of MS spectra, even though such compounds elute very close in the 2D chromatographic separation space. A part of the olefins identified by PI was further confirmed by GC coupled to vacuum ultraviolet detection (VUV) since olefins VUV spectra differ from other compounds. The overall combination of the entire set of data of this multi-modal approach was valuable in studying the pyrolyzed plastic oil composition. It was furthermore applied to monitor the efficiency of upgrading processes that were applied to the oils to remove specific contaminants such as the diolefins. This approach has the potential to support the production of plastic pyrolysis oils that could efficiently be reintroduced in the market to sustain economic circularity needs.

Experimental investigation of emission parameters of diesel engine fueled with various plastic pyrolysis oils

Plastic has various advantages and is becoming more ubiquitous by the year, yet recycling and disposal remain challenges for the world. We conduct tests in this study to evaluate the appropriateness of various Plastic Pyrolysis Oils (PPOs) made from Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE), and Polypropylene (PP) for diesel engine fuel. Determine which type of plastic pyrolysis oil would function best as an alternative fuel in an experimental investigation. The elemental composition of pyrolysis oil generated from LDPE, HDPE, and PP to diesel was assessed, tabulated, and compared in this study. This study examines emission characteristics (Nitrogen Oxide (NOX), Hydro Carbon (HC), and Carbon Monoxide (CO)) for Diesel, LDPE, HDPE and PP in CI engines using different injection pressure, compression ratio, and load in a specific configuration. In the result of experimental work the CO emission range for diesel and LDPE is exceeded only during overload situations or when the engine load is 100%. The average NOX emission is lowest when PP is used in comparison to other fuels, and the highest NOX emission occurs when LDPE is utilised as a fuel. Increased fumigation rates may be to blame for the rising hydrocarbon content of plastic oil. Unburned hydrocarbon levels are lower at lighter loads due to increased oxygen availability. The use of this whole pyrolysis oil results in a significant decrease in Nitrogen Oxide (NOX), Hydro Carbon (HC), and Carbon Monoxide (CO) exhaust emissions. With the help of this current study. one can solve plastic waste disposal problem and also find any unknown fuel (PPOs) that can be used as an alternative fuel for CI engine or not.

In-situ catalytic pyrolysis of pine powder by ZnCl2 to bio-oil under mild conditions and application of biochar

Fast pyrolysis of biomass is an effective way for biomass conversion and utilization. However, the pyrolysis temperature is usually high because it is a non-catalytic process, resulting in the complicated composition of bio-oil and difficulty to control. Aiming to explore in-situ catalysis in this paper, the fast pyrolysis of lignin, cellulose, corncob and pine wood powder was studied using ZnCl2 as the catalyst. The activation energies of non-catalytic pyrolysis and catalytic pyrolysis were obtained based on kinetic fitting of their thermal gravimetric curves. The variation in pyrolysis oil composition was analyzed. It was found that ZnCl2in situ catalysis could not only significantly reduce the pyrolysis temperature, but also simplify the resultant bio-oil composition. Even under pyrolysis temperature as low as 350 °C, fast pyrolysis of pine wood powder could achieve a yield of 47% of bio-oil, which was predominantly composed of the derivatives of cellulose and hemicellulose. ZnCl2in situ catalysis could significantly decrease the activation energy of cellulose cracking from 304.78 to 112.46 kJ/mol, but has little effect on that of lignin. The carbon residue from ZnCl2-catalyzed pyrolysis was further carbonized at 600 °C, affording activated carbon with adsorption capacity of phenol up to 165 mg/g. The research work provides guidance and reference for the development of in-situ catalytic pyrolysis technology with high efficiency.

Investigation of pyrolytic characteristics of three oily sludges with focus on properties of oil product

Pyrolysis is an important thermochemical conversion technology to recover the oily sludge resources and reduce the harmfulness of waste. This work aims to investigate the pyrolysis behaviors of three different oil sludges by using a thermogravimetric analyzer and two fixed-bed reactors. An attempt was made to determine a wide range of properties of liquid products. Three oily sludges included a tank bottom sediment (OS-1), an oil-water separator scum (OS-2), and a wastewater sediment concentrate (OS-3). OS-1 had a high content of oil, whereas OS-2 and OS-3 were characteristic of high contents of water and oxygen. The pyrolysis of as-received oily sludge in a vertical tubular reactor at 700 °C attained the oil yield up to 69.2 % for OS-1, against the oil yields ranged in 34.4–35.5 % for OS-2 and OS-3. These yields of pyrolysis oil were higher than or close to those of extraction oil. Through characterizing the molecular composition of pyrolysis oil and extraction oil, it was revealed that the pyrolysis promoted the cracking of long-chain alkanes and O/N-containing functional groups accompanied by the conjugation, cyclization and aromatization reactions. The analysis of the pyrolysis oils obtained from the horizontal tubular reactor showed that the liquid products derived from all three oil sludges had very low ash contents and viscosities, and the water-free pyrolysis oils had higher HHVs than the parent dried oil sludges.

Study of HDPE plastic pyrolysis characteristics using high pressure autoclave

In this study, the experiments of HDPE pyrolysis were carried out using an autoclave at the temperatures ranging from 470 °C to 550 °C. The effects of temperature, pressure and atmosphere on the production of pyrolysates were investigated. The pyrolysates were analyzed using GC, GC-MS and GC-FID. The major components of pyrolysis oil were alkanes, olefins, diolefins, mono aromatics, and cycloalkane, while the pyrolysis gas was mainly composed of hydrogen and C1–C5 hydrocarbons. As the pyrolysis temperature increased, the oil yields decreased, resulting in the increased production of gas and residual. For the composition of pyrolysis oil, the contents of alkane and olefin reduced while the yields of aromatic, diolefin and cycloalkane increased with increasing temperature. In the pyrolysis gas, increasing temperature promoted the generation of total alkanes and prohibited the production of total olefins. The increasing pressure improved the generation of diolefin, aromatics and cycloalkane to decrease the yield of pyrolysis oil and to increase the production of gas and residue. Under water vapor atmosphere, more liquid hydrocarbons with small molecules were obtained, resulting in the higher oil yields. The yields of alkane and olefin were higher in the presence of water vapor. Under the nitrogen atmosphere, the formation of diolefins, aromatics and cycloalkanes was promoted. The effects of different atmospheres on gas composition was negligible.

Co-pyrolysis of oil palm trunk and polypropylene: Pyrolysis oil composition and formation mechanism

Pyrolysis oil can be used as a precursor to synthesize value-added biochemicals. Co-pyrolysis of two or more feedstocks generally improves the selectivity and yield of the target compounds. In this work, oil palm trunk (OPT) was subjected to single-feed pyrolysis and co-pyrolysis with polypropylene (PP) from 500 to 700 °C. The highest pyrolysis oil yield of 26.33 wt.% was obtained from OPT at 700 °C, which mainly contributed by the lignin decomposition in OPT. Phenolics (51.77–57.78%) and oxygenates (36.31–46.99%) were the major compounds detected in the OPT-derived pyrolysis oil. The addition of PP enhanced the formation of hydrocarbons (5.19–10.22%) and decreased the contents of phenolics (34.01–41.85%) in the co-pyrolysis oil. In the case of co-pyrolysis, the intermolecular reactions between PP and OPT-derived radicals led to the formation of ketones and alcohols, which contributed to the increase of oxygenates content. The highest oil yield of 16.17 wt.% was obtained at 600 °C from co-pyrolysis, the oil of which contained mainly phenolic compounds, oxygenated compounds (i.e., ketones and furans), and hydrocarbons. These findings highlighted the potential of oil derived from the pyrolysis of OPT (single feed) and co-pyrolysis of OPT and PP (binary feed) for the production of value-added chemicals.

Production and physico-chemical characteristics of pyrolyzed bio-oil derived from cow hooves

Pyrolysis is becoming increasingly popular as a method of producing liquid yield from biomass. It has the potential to help build a sustainable renewable fuel market while simultaneously maintaining environmental sustainability. In the present study, cow hooves are pyrolyzed in a fixed-bed batch reactor to investigate product dispersion and determine optimal temperature parameters for optimizing pyrolysis oil yield. Temperature effects on the distribution, elemental content, and physical qualities of major pyrolysis products, such as pyrolysis oil and bio-char, are investigated. At a pyrolysis temperature of 500 °C, the maximum pyrolysis oil production was found to be 50.50 wt%, with the amount of bio-char excluding the gas being 27.20 wt%. A CHNS analyzer, Gas chromatography-mass spectrometry (GC-MS), and Fourier-transform infrared (FTIR) spectroscopy are used to investigate the chemical composition of pyrolysis oil generated under optimal conditions. The fuel properties of the pyrolysis oil are also determined, and it was discovered that it has a favourable fire point, flash point, and pour point. The density of the pyrolysis oil was 1.03 kg/L, the viscosity was 10.2 cSt, and the heating value was 22.7 MJ/kg. The FTIR analysis of the pyrolysis oil reveals that it contains functional groups, such as alkene, carboxylic acid, alcohol, ether, and ketone. According to the GC-MS analysis, the principal components are ester (40%), fatty acids (31%), phenol (3.8%) and p-Cresol (2.9%). Unsaturated fatty acids are abundant in the pyrolysis oil from cow hooves, while saturated fatty acids are in short supply. According to the findings of this study, cow hoof pyrolysis oil has the potential to be used as a source of biodiesel.

Catalytic pyrolysis of rice husk with SnCl2, Al2O3.4SiO2.H2O, and MoS2 for improving the chemical composition of pyrolysis oil and gas

Pyrolysis of Indian variety rice husk was carried out in a semi-batch reactor in the presence of SnCl2, Al2O3.4SiO2.H2O, and MoS2 catalysts at a fixed temperature (550 °C), heating rate (50 °C min−1), and N2 flow rate (0.3 L min−1). The yield of pyrolysis oil increased in the presence of Al2O3.4SiO2.H2O catalyst but deteriorated in presence of SnCl2, and MoS2 catalyst. At 550 °C, the maximum pyrolysis oil yield from non-catalytic pyrolysis (NCP) was 37.46 wt% and with Al2O3.4SiO2.H2O catalyst it was 38.41 wt%. The yield of H2 (7.27 mol %) in pyrolysis-gas after catalytic pyrolysis (CP) was 0.72 mol% higher than NCP (6.55 mol %). The gross calorific value (GCV) of pyrolysis-gas after CP increased to 5.99 MJ m−3 from 3.84 MJ m−3 (NCP). High lignin contained in rice husk gave a better CH4 yield of 10.13 mol. %. Reduction in water content (3.07–5.77 wt %) of pyrolysis oil after CP elevated the high heating value (HHV) to 28.61 from 22.41 MJ kg−1. A 3.0–4.58 mol. % reductions in the acidic compound content after CP impacted the pH and TAN of pyrolysis oils. The Al2O3.4SiO2.H2O catalyst elevated the area percentage of naphthenic (0.54 mol. %), olefinic (1.98 mol. %), aromatic (4.18 mol. %), and paraffinic (4.42 mol. %) compounds in pyrolysis oil. A 3.86 mol. % increase in the phenolic compounds was observed in presence of MoS2 catalyst. Approximately, 22 wt% loss in oxygen with 21 and 2.65 wt% increases in the carbon and hydrogen content of biochar elevated the HHV to 30.60 MJ kg−1 after CP.

Co-pyrolysis of neem wood bark and low-density polyethylene: influence of plastic on pyrolysis product distribution and bio-oil characterization.

In this study, the investigation on the effect of plastic during co-pyrolysis with biomass was carried out in a fixed reactor. Pyrolysis of neem wood bark (NB), low density polyethylene (LDPE) and their blends at different ratios was performed in order to evaluate the product distribution. The effects of reaction temperature and NB-to-LDPE blend ratio on product distribution and the chemical compositions of pyrolysis oil were examined. The co-pyrolysis of NB and LDPE increased the yield and quality of the bio-oil. The experiments were conducted under different LDPE addition percentages such as 20%, 40%, 50%, 60% and 80%. Under the optimum experimental condition of 60% addition of LDPE and a temperature of 450 °C, the maximum yield of bio-oil (64.8 wt%) and hydrocarbon (75.2%) was achieved with the lowest yield of oxygenated compounds. The calorific value of the co-pyrolysis oil was found to be higher than that of the NB pyrolysis oil. The relationship between NB and LDPE during co-pyrolysis was validated with the help of gas chromatography-mass spectrometry (GC-MS) analysis, which showed decreased oxygenated compounds.

Co-pyrolysis of biomass and plastic: Synergistic effects and estimation of elemental composition of pyrolysis oil by analytical pyrolysis–gas chromatography/mass spectrometry

This paper presents a study on the pyrolytic behavior of mixtures of lignocellulosic biomass with hydrocarbon plastics using analytical pyrolysis-GC/MS. Semi-quantitative analysis using chromatographic peak areas was used to investigate the composition of the pyrolysis oils and to highlight the occurrence of synergistic effects. A new method is also proposed to estimate the elemental composition of the pyrolysis oil based on the peak areas and brute formulas of the pyrolysis products. The results indicate that synergistic effects during co-pyrolysis favor secondary pyrolysis of holocellulose and polystyrene oligomers, and hinder radical chain-scission of polyethylene chains. H/C and O/C values of the pyrolysis oils were improved by the addition of plastic, indicating a decrease in the content of oxygenated pyrolysis products. The best performances were observed for the mixture containing 70% fir wood and 30% polyethylene, in which synergistic effects led to both an increase of H/C and a decrease of O/C.

Comprehensive analysis of pyrolysis oil obtained from waste tire in a water vapor environment

Determination of the composition of pyrolysis products of organic compounds is a very difficult task due to their multicomponent nature [1–3]. Pyrolysis oils formed from rubber products and organic polymer wastes contain various classes of organic compounds with a huge spread in molecular weight and polarity: hydrocarbons, amides, phenols, amines, organosulfur compounds, etc. [1]. At the same time, the results of qualitative and quantitative chromatographic analysis of pyrolysis oils are often ambiguous: there are problems of overlapping peaks and misinterpretation of the data obtained due to the complexity of the matrix and the multicomponent composition [2–5]. Pyrolysis products can be used as valuable hydrocarbons or additives to hydrocarbon fuels. Therefore, the analysis of the chemical composition of pyrolysis oils is important both for assessing the degree of their toxicity and for finding an effective method for their purification.

Valorization of Hazardous Organic Solid Wastes towards Fuels and Chemicals via Fast (Catalytic) Pyrolysis

The management of municipal and industrial organic solid wastes has become one of the most critical environmental problems in modern societies. Nowadays, commonly used management techniques are incineration, composting, and landfilling, with the former one being the most common for hazardous organic wastes. An alternative eco-friendly method that offers a sustainable and economically viable solution for hazardous wastes management is fast pyrolysis, being one of the most important thermochemical processes in the petrochemical and biomass valorization industry. The objective of this work was to study the application of fast pyrolysis for the valorization of three types of wastes, i.e., petroleum-based sludges and sediments, residual paints left on used/scrap metal packaging, and creosote-treated wood waste, towards high-added-value fuels, chemicals, and (bio)char. Fast pyrolysis experiments were performed on a lab-scale fixed-bed reactor for the determination of product yields, i.e., pyrolysis (bio)oil, gases, and solids (char). In addition, the composition of (bio)oil was also determined by Py/GC-MS tests. The thermal pyrolysis oil from the petroleum sludge was only 15.8 wt.% due to the remarkably high content of ash (74 wt.%) of this type of waste, in contrast to the treated wood and the residual paints (also containing 30 wt.% inorganics), which provided 46.9 wt.% and 35 wt.% pyrolysis oil, respectively. The gaseous products ranged from ~7.9 wt.% (sludge) to 14.7 (wood) and 19.2 wt.% (paints), while the respective solids (ash, char, reaction coke) values were 75.1, 35, and 36.9 wt.%. The thermal (non-catalytic) pyrolysis of residual paint contained relatively high concentrations of short acrylic aliphatic ester (i.e., n-butyl methacrylate), being valuable monomers in the polymer industry. The use of an acidic zeolitic catalyst (ZSM-5) for the in situ upgrading of the pyrolysis vapors induced changes on the product yields (decreased oil due to cracking reactions and increased gases and char/coke), but mostly on the pyrolysis oil composition. The main effect of the ZSM-5 zeolite catalyst was that, for all three organic wastes, the catalytic pyrolysis oils were enriched in the value-added mono-aromatics (BTX), especially in the case of the treated wood waste and residual paints. The non-condensable gases were mostly consisting of CO, CO2, and different amounts of C1–C4 hydrocarbons, depending on initial feed and use or not of the catalyst that increased the production of ethylene and propylene.

Conversion of refuse derived fuel from municipal solid waste into valuable chemicals using advanced thermo-chemical process

In this study, thermo-chemical decomposition of Refuse Derived Fuel (RDF) from municipal solid waste pre-treatment plant has been conducted in pyrolytic conditions. Due to high heterogeneity, individual RDF samples are not necessarily representative of the full variety of different components present. To overcome this, five different samples of RDF with varying compositions were treated in a rotary kiln reactor. RDF feed has been characterized based on the amount of biomass and plastic content. Product (oil & char) composition and quality were analysed using different characterization techniques. It was observed that the quality of pyrolysis products varied with the feed composition and operating temperature. Maximum oil yield of oil ∼43% was obtained from RDF containing ∼77% of plastics at 500 °C. This study showed that the interaction of RDF components has a major role in the pyrolysis oil composition. The oil phase mainly consisted of n-aliphatic, branched aliphatic compounds and primary alcohols while, the aqueous phase consisted of organic acids, furans, methanol, phenols, and their derivatives along with ketones. At higher temperatures, the phenolic compounds decreased and the alcohol content was found to increase. Using solvent extraction, phenolic compounds were extracted with hexane while, ketones and acids were extracted using acetone. With high plastic content (∼85%), the char yield reduced from 55% to 30% with increase in temperature. Char samples consisted of different functional groups such as –OH and –COOH along with the micronutrients such as K, Mg and P, with pH in the range of 7.8–9.5 making it suitable for soil applications. Detailed chemical composition analysis of pyrolysis oil and char is the key to design pyrolysis process and evaluating its importance for producing the value-added chemicals.

The effect of thermal aging on the composition of pyrolysis oil fuel derived from typical waste plastics

This study reveals the influence of thermal aging on the pyrolysis oil fuel components of typical waste plastics, including polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC). Plastic samples were continuously heated in an aging oven at 100 °C to simulate thermal aging. The pyrolysis volatile compositions of fresh and aged plastic samples were comparatively studied by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) at 500 °C. The volatile composition analysis results showed that thermal aging changes the pyrolysis oil composition, and the influence strongly depends on the type of plastic. For PE and PP, which underwent random scission after thermal aging treatment, the influence of thermal aging on the heavy oil fraction was more obvious than that on the light oil and diesel oil fractions. For PVC samples, the thermal aging process caused structural defects and turned the color of the PVC light yellow. After 128-h thermal aging, the maximum weight loss rate decreased by 35.8%, and the fraction of C5-C9 components and aromatics first increased and then decreased. The maximum values were 80.21 ± 1.62% and 73.69 ± 0.73%, and the minimum values were 65.58 ± 2.63% and 63.98 ± 0.39%, respectively.

Catalytic upgrading and enhancing the combustion characteristic of pyrolysis oil

ABSTRACT Bagasse’s pyrolysis oil has low calorific value, high water content, and acidity. The main components of the pyrolysis oil are acids/esters, alcohols, aldehydes/ketones, furan compounds, phenol compounds, and guaiacols, and there is not an aromatic hydrocarbon in composition. Pyrolysis oil evaporates only 66.73 wt% at a temperature of 300°C and carbonaceous residue formed is 13.41 wt%. The carbonaceous residue will limit the utilization of pyrolysis oil because it generates soot while burning and made secondary emission. Upgrading the pyrolysis oil to enhance the vaporization, prevent the formation of carbon residue, and improve combustion behaviors has been investigated in this paper. Using catalyst HZSM5, Zn/HZSM-5, and Fe/HZSM-5 for upgrading pyrolysis oil, the quality of upgrading oil is enhanced with higher heating value, lower acidity, and viscosity. The modification of chemical composition of pyrolysis oil has generated better components for evaporation. At 300 °C, 91.97 wt%, 92.93 wt%, and 94.71 wt% of upgrading oil are evaporated for HZSM-5, Zn/HZSM-5, and Fe/HZSM-5, respectively. Carbonaceous residue decreases significantly to only 4.74 wt% with HZSM-5 catalyst, 4.39 wt% with Zn/HZSM-5, and 3.39 wt% with Fe/HZSM-5. Evaluation of the upgrading oil combustion by thermal analysis method, the total combustion characteristics index increases and it is more flammable than fuel oil. The results prove that upgrading oil might be used as a fuel oil in industrial application.