Search

Waste tires (WT) are produced in millions of tons per annum and their safe disposal is always a major environmental challenge because of fire hazards and the increasing cost of landfills. WT has high organic matter content that can be converted into fuels and chemicals if suitable technologies can be developed. Herein we report the in situ catalytic pyrolysis of WT using formulated red mud catalyst to produce low sulfur fuel that can be fractionated or can be used without fractionation. The in situ catalytic pyrolysis was conducted at 450–550 °C using formulated red mud catalyst. The yield of pyrolysis liquids ranged from 35 to 40 wt%. The liquid was very rich in limonene and long chain aliphatic hydrocarbons. The catalyst was effective in removing the sulfur compounds in the oil through reactive adsorption desulfurization mechanism. The sulfur species reacted with hematite, calcite, sodium hydroxide, and zinc oxide to form sulfides and were retained in the catalyst. The minimum sulfur content of the catalytic pyrolysis oil was 0.38 wt%. After catalyst regeneration in air through combustion, the catalyst activity was restored, and the catalyst was reused.

This study focuses on alternatives to the sustainable management of plastic wastes through the development of a pyrolyser model, adapted to the recycling of plastics into fuel. It is a batch reactor, fixed bed, designed and built for the extraction of pyrolysis oil that can be recycled into petrol or diesel. The pyrolyser consists of a reactor with a volume of 0.0424 m3 and a copper spiral condenser with 2.31 m length. The plastics used for this study were Low Density PolyEthylene (LDPE), polypropylene (PP), polystyrene (PS) and polyethylene terephthalate (PET). They were collected from surrounding companies, washed, sampled, cut and sieved. Two different sizes of pyrolysis material: 1–3 cm (G1) and 3–7 cm (G2) were obtained and tested. The pyrolysis reactor and the plastics entering at an ambient temperature of 25 °C were heated. Plastics were then melted at 110 °C and vaporised at 450 °C. The hot vapour produced circulated through a copper coil and condensed. The resulting liquid was called pyrolysis oil. The results of this study show that the pyrolysis of LDPE, PP and PS yields two liquids: the heavy and majority fraction which arelike the conventional diesel and the light fraction which is like gasoline. Yields of 6–12.4% for the light fraction and 43.2–63.8% corresponding to the heavy fraction are observed. PE has the highest yield, 63.8% for the heavy fraction and 12.4% for the light fraction. The study further underscores that the size of the pyrolysis material influences the yields, i.e. an increase of 12.5, 9.1 and 7 % for LDPE, PS and PP respectively when the size of the pyrolysis material is increased from G2 to G1. In contrast, the results of PET have shown a liquid that solidifies 46 s later. It was also noticed that 2061.34 kJ of energy was required to pyrolyse 1 kg of plastic and produce 0.762 l of fuel. The simple physico-chemical characterisation of the majority fraction shows a great similarity with diesel fuel, as the distillation went beyond 200 °C. Therefore, we can say that the diesel fraction is similar to diesel fuel. We equally observed a high cetane number (52.1–55.1) and a high calorific value (42.9–55.5 MJ/kg). Consequently, there are some points of non-conformity with the European 590 standard and Cameroonian specifications for diesel fuel. These include a low density (767.8–815.1 kg/m3) and a low viscosity at 40 °C (1.108–1.346 mm2/S). A thorough physico-chemical analysis will complete this study before any recommendation for appropriate use.

In this work, the low-temperature pyrolysis of a real plastic mixture sample collected at a WEEE-authorised recycling facility has been investigated. The sample was pyrolysed in a batch reactor in different temperature and residence time conditions and auto-generated pressure by following a factorial design, with the objective of maximising the liquid (oil) fraction. Furthermore, the main polymers constituting the real sample were also pyrolysed in order to understand their role in the generation of oil. The pyrolysis oils were characterised and compared with commercial fuel oil number 6. The results showed that in comparison to commercial fuel oil, pyrolysis oils coming from WEEE plastic waste had similar heating values, were lighter and less viscous and presented similar toxicity profiles in fumes of combustion. [ABSTRACT FROM AUTHOR]

Pyrolysis bio‐oils, one of the products of lignocellulosic biomass pyrolysis, have the potential to be widely used as fuels. The chemical composition of bio‐oils is very complicated as they contain hundreds, if not thousands, of different, mostly oxygen‐containing, compounds with a wide distribution of physical properties, chemical structures, and concentrations. Detailed knowledge of bio‐oil composition is crucial for optimizing both the pyrolysis processes and for any subsequent upgrading into a more viable fuel resource. Here we report the successful use of low‐field, or benchtop, nuclear magnetic resonance (NMR) spectrometers in the analysis of pyrolysis oils. Pyrolysis oils from four different feedstocks were derivatized and analyzed using 19F NMR techniques. The NMR results compare favorably with titrations for total carbonyl content. In addition, the benchtop NMR spectrometer proves able to reveal key spectral features, thus allowing the quantification of different carbonyl groups, such as aldehydes, ketones and quinones. Benchtop NMR spectrometers are typically compact, cheaper than their superconducting counterparts and do not require cryogens. Their use will make NMR analysis of pyrolysis oils easier and more accessible to a wide range of different potential users. [ABSTRACT FROM AUTHOR]

In the modern world, energy and fuels are of utmost importance. Rapid characterization of petroleum and other hydrocarbon‐based fuel is a well‐researched field. Gas chromatography has traditionally been used to separate the different species and characterize the chemical content in fuels. Ideally, every molecule would be separated and characterized, but due to the complexity of the petroleum matrix, many compounds coelute. With the help of different detectors, more information can be gained, but there does not exist a single detector that can unambiguously differentiate and identify every compound. Vacuum ultraviolet spectroscopy (VUV) is a relatively new detector that can alleviate many limitations of other detectors. Based on spectroscopic absorption, VUV detection can provide qualitative and quantitative information regarding the composition of different fuels. It also provides certain advantages, allowing the deconvolution of coeluting peaks and differentiation between constitutional isomers. VUV has been used to classify the range of chemical components in many diverse fuel samples. Here, the contributions of VUV detection to petrochemical analysis to date are reviewed. [ABSTRACT FROM AUTHOR]

Commercial aviation is primarily reliant on fossil fuels, yet the depletion of these sources and the consequences of climate change necessitates the exploration of sustainable alternatives. The pyrolysis process offers a viable method for producing biofuels from various feedstocks. This research examines the combustion, emission, and performance characteristics of biofuels derived from agricultural residues, waste tyres, and plastics using pyrolysis. Pyrolysis oils derived from forestry or agricultural products exhibit high viscosity and moisture content, which impairs combustion efficiency and increases carbon monoxide (CO) from 70 % to 187 % and unburned hydrocarbon (UHC) emissions. Conversely, pyrolysis oils from plastics and waste tyres provide stable combustion with carbon monoxide and total hydrocarbon emissions (THC) comparable to those of commercial jet fuel. However, nitrogen oxide (NO X) emissions are significantly elevated from 57 % to 157 %. Engine performance tests demonstrated that forestry pyrolysis oils result in thrust loss due to their high viscosity value (14.3–113 mm2/s) and low calorific value (17.3–31.7 MJ/kg). In contrast, plastic and tyre pyrolysis oil perform similarly to commercial jet fuels but may potentially cause performance loss due to their high aromatic content (>47.67 %). Overall, upgrading the viscosity, moisture, and aromatic content of pyrolysis oils can enhance their suitability as alternative aviation fuels. These improvements could assist the aviation sector in achieving its carbon-neutral goals by making pyrolysis oils competitive with conventional jet fuels. [Display omitted] • FPO decreases combustion efficiency and increases CO and UHC emissions. • TPO and PPO are comparable to commercial jet fuel in combustion efficiency and CO and THC emissions. • FPO causes significant thrust loss, while TPO and PPO have thrust losses of less than 5 %. • Fuel upgrading may lead to an increased attraction to pyrolysis oils. [ABSTRACT FROM AUTHOR]

Transformations inside emulsion droplets of 82 µm have been studied by using laser diagnostics. Arrays of calibrated droplets of emulsion 70/30 w/w diesel oil/pyrolysis oil were injected in pre-heated air flow inside a tubular reactor. Four thermal regimes have been studied: room temperature, 150°C, 250°C, and 350°C. For comparison, droplets of the diesel oil used to form the emulsion were studied in the same experimental conditions. The investigation has been performed by applying the Generalized Scattering Imaging laser technique that allows the simultaneous determination of size and optical properties of droplets. This optical diagnostic technique permitted to infer the chemical-physical changes inside the emulsion droplet by measuring the imaginary part of their refractive index. At 150°C and 250°C, the emulsion droplets suffered progressive depletion of the diesel oil phase. The pyrolysis oil, dispersed in the diesel oil matrix in the form of microdroplets 2 µm sized, underwent partial evaporation, liquid phase pyrolysis, and polymerization. At 350°C almost all the diesel oil had evaporated and the pyrolysis oil microdroplets dispersed in the emulsion droplet had merged to form a single droplet. These residual droplets showed a very narrow size distribution and an absorption coefficient greater than that of the original PO in agreement with the assessment that they represent the combined outcome of evaporation, liquid phase pyrolysis and polymerization of the pyrolysis oil. Samples of residual droplets were captured at the exit of the reactor and analyzed by means of optical microscopy. The microscope analysis was consistent with the laser diagnostics results. [ABSTRACT FROM AUTHOR]

The present research study investigates the performance of pyrolysis oils recycled from waste tires as a collector in coal flotation. Three different types of pyrolysis oils (namely, POT 1 , POT 2 , and POT 3) were produced through a two-step pressure pyrolysis method followed by an oil rolling process. The characteristics of POTs were adjusted using various oil-modifying additives such as mineral salts and organic solvents. The chemical structure of POTs was explored by employing necessary instrumental analysis techniques, including microwave-assisted acid digestion (MAD), inductively coupled plasma atomic emission spectroscopy (ICP-AES), Fourier-transform infrared spectroscopy (FT-IR), and gas chromatography-mass spectrometry (GC-MS). The collecting performance of POTs in coal flotation was evaluated using an experimental design based on Response Surface Methodology (RSM), considering the ash content and yield of the final concentrate. The effect of the type and dosage of POTs was evaluated in conjunction with other important operating variables, including the dosage of frother, dosage of depressant, and the type of coal. Results of POTs characterization revealed that the pyrolysis oils were a complex composition of light and heavy hydrocarbon molecules, including naphthalene, biphenyl, acenaphthylene, fluorene, and pyrene. Statistical analysis of experimental results showed that among different POTs, POT 1 exhibited remarkable superiority, achieving not only a 15% higher coal recovery but also a 12% lower ash content. The outstanding performance of POT 1 was attributed to its unique composition, which includes a concentrated presence of carbon chains within the optimal range for efficient flotation. Additionally, the FT-IR spectra of POT 1 reveal specific functional groups, including aromatic and aliphatic compounds, greatly enhancing its interaction with coal surfaces, as confirmed by contact angle measurement. This research provides valuable insights into the specific carbon chains and functional groups that contribute to the effectiveness of POT as a collector, facilitating the optimization of coal flotation processes and underscoring the environmental advantages of employing pyrolysis oils as sustainable alternatives in the mining industry. [Display omitted] • Enhanced Flotation Performance: Pyrolysis oil derived from waste tire outperforms commercial collectors in yield. • Unique Composition Boosts Interaction: The distinctive composition of POT 1 enhances its interaction with coal, contributing to improved flotation efficiency. • Favorable PAH Concentration: POT 1 contains PAHs that enhance flotation efficiency. • Hydrophobic Surface Modification: POT 1 effectively modifies coal surfaces, increasing their hydrophobicity and optimizing the flotation process. • Optimized Flotation Conditions: Identification of optimal conditions for enhanced yield and reduced ash content, providing valuable insights for practical application. [ABSTRACT FROM AUTHOR]

Waste tires (WT) are produced in millions of tons per annum and their safe disposal is always a major environmental challenge because of fire hazards and the increasing cost of landfills. WT has high organic matter content that can be converted into fuels and chemicals if suitable technologies can be developed. Herein we report the in situ catalytic pyrolysis of WT using formulated red mud catalyst to produce low sulfur fuel that can be fractionated or can be used without fractionation. The in situ catalytic pyrolysis was conducted at 450-550 °C using formulated red mud catalyst. The yield of pyrolysis liquids ranged from 35 to 40 wt%. The liquid was very rich in limonene and long chain aliphatic hydrocarbons. The catalyst was effective in removing the sulfur compounds in the oil through reactive adsorption desulfurization mechanism. The sulfur species reacted with hematite, calcite, sodium hydroxide, and zinc oxide to form sulfides and were retained in the catalyst. The minimum sulfur content of the catalytic pyrolysis oil was 0.38 wt%. After catalyst regeneration in air through combustion, the catalyst activity was restored, and the catalyst was reused., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 Published by Elsevier Ltd.)

• Experimental induction period and hydroperoxide content of oils produced by pyrolysis of polypropylene. • Low stability of reflux liquid oils compared to kerosene model and no-reflux liquid oils. • Significant positive influence of a stabilizer (BHT) on the stability of liquid oils. The instability of liquid oils issued from the pyrolysis of plastics usually leads to the degradation and the deterioration of their different properties. In this study, the stability of oils produced from the pyrolysis with and without reflux of polypropylene (PP) was investigated in a standard test device called PetroOxy. This work compares the stability of PP liquid oils with kerosene throughout their induction period and hydroperoxide (ROOH) content, two well-known stability parameters. Moreover, experimental investigations of the impact of a stabilizer (BHT = butylated hydroxytoluene) on the same stability parameters were achieved. A titration method and GC-MS were used to quantify ROOHs and to identify the oxidized liquid compounds, respectively. PetroOxy tests with BHT showed an enormous influence of BHT on the oxidation stability compared to all other oxidative tests. Adding 500 ppm of BHT multiplied the induction period by 5.9, 4.3, 10.7 and 6.7 for reflux liquid oils, no-reflux liquid oils mixed with kerosene, reflux liquid oils mixed with kerosene and pure kerosene respectively. The ROOH concentration was divided by up to 16.9 for reflux liquid oil when BHT was used. Based on the results, it can be concluded that the liquid oils obtained by pyrolysis with reflux are less stable than without reflux, and both of them are less stable than kerosene used as reference model. But using kerosene as solvent mixed with liquid oils obtained by pyrolysis with and without reflux increases their oxidative stability. The use of BHT as an antioxidant contributes to make these oils compatible for use as fuels. [ABSTRACT FROM AUTHOR]

This study focuses on alternatives to the sustainable management of plastic wastes through the development of a pyrolyser model, adapted to the recycling of plastics into fuel. It is a batch reactor, fixed bed, designed and built for the extraction of pyrolysis oil that can be recycled into petrol or diesel. The pyrolyser consists of a reactor with a volume of 0.0424 m 3 and a copper spiral condenser with 2.31 m length. The plastics used for this study were Low Density PolyEthylene (LDPE), polypropylene (PP), polystyrene (PS) and polyethylene terephthalate (PET). They were collected from surrounding companies, washed, sampled, cut and sieved. Two different sizes of pyrolysis material: 1-3 cm (G 1 ) and 3-7 cm (G 2 ) were obtained and tested. The pyrolysis reactor and the plastics entering at an ambient temperature of 25 °C were heated. Plastics were then melted at 110 °C and vaporised at 450 °C. The hot vapour produced circulated through a copper coil and condensed. The resulting liquid was called pyrolysis oil. The results of this study show that the pyrolysis of LDPE, PP and PS yields two liquids: the heavy and majority fraction which arelike the conventional diesel and the light fraction which is like gasoline. Yields of 6-12.4% for the light fraction and 43.2-63.8% corresponding to the heavy fraction are observed. PE has the highest yield, 63.8% for the heavy fraction and 12.4% for the light fraction. The study further underscores that the size of the pyrolysis material influences the yields, i.e. an increase of 12.5, 9.1 and 7 % for LDPE, PS and PP respectively when the size of the pyrolysis material is increased from G 2 to G 1 . In contrast, the results of PET have shown a liquid that solidifies 46 s later. It was also noticed that 2061.34 kJ of energy was required to pyrolyse 1 kg of plastic and produce 0.762 l of fuel. The simple physico-chemical characterisation of the majority fraction shows a great similarity with diesel fuel, as the distillation went beyond 200 °C. Therefore, we can say that the diesel fraction is similar to diesel fuel. We equally observed a high cetane number (52.1-55.1) and a high calorific value (42.9-55.5 MJ/kg). Consequently, there are some points of non-conformity with the European 590 standard and Cameroonian specifications for diesel fuel. These include a low density (767.8-815.1 kg/m 3 ) and a low viscosity at 40 °C (1.108-1.346 mm 2 /S). A thorough physico-chemical analysis will complete this study before any recommendation for appropriate use., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:DJOUKOUO DASSI Nadia Hillary reports administrative support was provided by None., (© 2024 The Authors.)

The main objective of the present work is to investigate the influence of catalyst to biomass ratio (C:B) on pyrolysis sugarcane bagasse over cerium loaded Hydrogen exchanged Zeolite Socony Mobil-5 (HZSM-5, Si/Al = 23) catalyst via in-situ fixed bed reactor. HZSM-5 catalyst was used as a support with 1 wt.% of Ce as promoter loaded via incipient wetness impregnation method. The pyrolysis oil (PO) yield and coke yield were significantly affected by the use of Ce/HZSM-5 at various C:B ratio than the none catalytic pyrolysis, in which generating low PO yields (50.0 wt.%). The increasing Ce/HZSM-5 loading has an additional effect with respect to PO and coke yields. Among the tested C:B ratio, a catalyst to biomass ratio of 1:1 has demonstrated to be potential candidates in the catalytic pyrolysis of SB into a higher yield of condensable pyrolysis oil with lower coke contents. [ABSTRACT FROM AUTHOR]

The main objective of the present work is to study the effect of molybdenum (Mo) loading amount on Hydrogen exchanged Zeolite Socony Mobil-5 (HZSM-5, Si/Al = 23) catalyst on pyrolysis of sugarcane bagasse via in-situ fixed bed reactor. HZSM-5 zeolite catalyst was used as a support with Mo as promoter modified at varying metal loading (0.5, 1.0 and 1.5 wt.%) via incipient wetness impregnation method. The pyrolysis oil (PO) yields and aromatic hydrocarbons (AHCs) yields were significantly affected by the use of all synthesized catalysts than the none catalytic pyrolysis, in which generating lower PO yields (11.7 wt.%) and AHCs yields (1.1 wt.%). The impregnation of Mo in the framework of HZSM-5 has an additional effect on the performance of the support HZSM-5 catalyst, with respect to PO and AHCs yields. Among all the catalysts tested, Mo(1 wt.%)/HZSM-5 catalyst has demonstrated to be potential candidates in the catalytic pyrolysis of sugarcane bagasse into a higher yield of ACHs in PO. [ABSTRACT FROM AUTHOR]

Automotive shredder residue (ASR) can create difficulties when managing, with its production increasing. It is made of different type of plastics, foams, elastomers, wood, glasses and textiles. For this reason, it is complicated to dispose of in a cost effective way, while also respecting the stringent environmental restrictions. Among thermal treatments, pyrolysis seems to offer an environmentally attractive method for the treatment of ASR; it also allows for the recovery of valuable secondary materials/fuels such as pyrolysis oils, chars, and gas. While, there is a great deal of significant research on ASR pyrolysis, the literature on higher scale pyrolysis experiments is limited. To improve current literature, the aim of the study was to investigate the pyrolysis of ASR in a bench scale rotary kiln. The Italian ASR was separated by dry-sieving into two particle size fractions: d < 30 mm and d > 30 mm. Both the streams were grounded, pelletized and then pyrolyzed in a continuous bench scale rotary kiln at 450, 550 and 650 °C. The mass flow rate of the ASR pellets was 200–350 g/h and each test ran for about 4–5 h. The produced char, pyrolysis oil and syngas were quantified to determine product distribution. They were thoroughly analyzed with regard to their chemical and physical properties. The results show how higher temperatures increase the pyrolysis gas yield (44 wt% at 650 °C) as well as its heating value. The low heating value (LHV) of syngas ranges between 18 and 26 MJ/Nm 3 dry. The highest pyrolysis oil yield (33 wt.%) was observed at 550 °C and its LHV ranges between 12.5 and 14.5 MJ/kg. Furthermore, only two out of the six produced chars respect the LHV limit set by the Italian environmental regulations for landfilling. The obtained results in terms of product distribution and their chemical-physical analyses provide useful information for plant scale-up. [ABSTRACT FROM AUTHOR]

Pyrolysis bio-oils, one of the products of lignocellulosic biomass pyrolysis, have the potential to be widely used as fuels. The chemical composition of bio-oils is very complicated as they contain hundreds, if not thousands, of different, mostly oxygen-containing, compounds with a wide distribution of physical properties, chemical structures, and concentrations. Detailed knowledge of bio-oil composition is crucial for optimizing both the pyrolysis processes and for any subsequent upgrading into a more viable fuel resource. Here we report the successful use of low-field, or benchtop, nuclear magnetic resonance (NMR) spectrometers in the analysis of pyrolysis oils. Pyrolysis oils from four different feedstocks were derivatized and analyzed using 19 F NMR techniques. The NMR results compare favorably with titrations for total carbonyl content. In addition, the benchtop NMR spectrometer proves able to reveal key spectral features, thus allowing the quantification of different carbonyl groups, such as aldehydes, ketones and quinones. Benchtop NMR spectrometers are typically compact, cheaper than their superconducting counterparts and do not require cryogens. Their use will make NMR analysis of pyrolysis oils easier and more accessible to a wide range of different potential users., (© 2023 The Authors. ChemSusChem published by Wiley-VCH GmbH.)

The objective of this paper is the upgrading of chlorinated oils coming from the pyrolysis of mixed plastic waste, in order to use them as fuel or feedstock for refineries. Two different samples of pyrolysis oils have been thermally and catalytically cracked in a 300 mL autoclave at 325 °C and the auto-generated pressure. Thermal cracking converts the plastic pyrolysis heavy oils into light liquid fractions which are only composed of alkanes and aromatics. These light fractions present a very low quantity of chlorine compared to the initial oils and resemble gasoline and diesel-like products. Besides, a gaseous fraction rich in methane and with very high heating value is also produced, together with a fuel-like viscous product which remains in the autoclave. The relative proportions of each of these three fractions depend on the nature of the initial oils. Red Mud has proved to be a dehydrochlorination and cracking catalyst, since it gives rise to higher quantity of gases and light liquid fractions with a very low chlorine content (< 0.1 wt.%). Therefore, dechlorinated light oils can be obtained by Red Mud low temperature catalytic cracking of plastic derived chlorinated pyrolysis oils. [ABSTRACT FROM AUTHOR]

In this work, we report on the catalytic valorization of sugar fractions, obtained by aqueous phase extraction of fast pyrolysis oils, in supercritical methanol (scMeOH) and ethanol (scEtOH) over a copper doped porous metal oxide (Cu-PMO). The product mixtures obtained are, in principle, suitable for direct co-feeding in methanol to hydrocarbon (MTH) processes, as fuel additives, or can be further fractionated or transformed to useful bulk chemicals. The main components of the obtained product mixtures in scMeOH are aliphatic mono-alcohols (51%), diols (22%), esters (15%), ethers (9%) and furanics (3%). Similar product suite is obtained by converting concentrated, 15 wt% sugar fractions with added 50 bar H 2 in scEtOH. The extensive depolymerization of the sugar polymers and oligomers contained in the sugar fraction is verified by gel permeation chromatography (GPC) and product stability upon catalytic treatment is confirmed by thermogravimetric analysis (TGA). In addition, model compound studies, using levoglucosan and d -cellobiose allow for more specific insight into the chemical pathways taking place during these transformations. The catalyst is characterized by various techniques, including XRD, NH 3 -TPD, BET, and TEM. The stability of the catalyst using 5 wt% sugar fraction in scMeOH is also evaluated. [ABSTRACT FROM AUTHOR]

Abstract: Phenol, cresols, guaiacol and eugenol were studied to describe the effect of substituent position and type on the reactivity of these phenolic compounds. Conversion of cresols under deoxygenation/hydrogenation reactivities increased in order m->o->p-cresol over Pt/Beta zeolite with Si/Al=12.7 and o->m->p-cresol over the Pt/Beta with lower Al content (Si/Al=20.7). Major products of cresols hydrogenation were methyl cyclohexanols. Phenol was converted into a mixture of cyclohexane, cyclohexanol and cyclohexanone. An increase in Si/Al ratio of the parent zeolite-based catalysts resulted in a decrease in the overall conversion of cresols and phenol. On the other hand, an increase in Si/Al ratio of catalysts prepared by dealumination led to accelerated conversion of phenol to cyclohexane. Using the lab-prepared mesoporous Beta catalyst with a comparable Si/Al ratio to the commercial one (ca. 20), higher yields of cyclohexanol were obtained in conversion of phenol. [Copyright &y& Elsevier]

Abstract: There is considerable interest in investigating the deoxygenation process, due to the high oxygen content of the feed-stocks used for the production of renewable fuels. This review addresses studies related to the catalytic hydrodeoxygenation of two feed-stocks (a) oils with high content of triglycerides and (b) oils derived from high pressure liquefaction or pyrolysis of biomass. Future research directions that could potentially bridge the existing gaps in these areas are provided. [Copyright &y& Elsevier]

Abstract: This paper describes the use of Differential Scanning Calorimetry (DSC) to evaluate the impact of varying mix ratios of bio-oil (pyrolysis oil) and bio-diesel on the oxidation stability and on some cold flow properties of resulting blends. The bio-oils employed were produced from the semi-continuous Auger pyrolysis of pine pellets and the batch pyrolysis of pine chips. The bio-diesel studied was obtained from poultry fat. The conditions used to prepare the bio-oil/bio-diesel blends as well as some of the fuel properties of these blends are reported. The experimental results suggest that the addition of bio-oil improves the oxidation stability of the resulting blends and modifies the crystallization behavior of unsaturated compounds. Upon the addition of bio-oil an increase in the oxidation onset temperature, as determined by DSC, was observed. The increase in bio-diesel oxidation stability is likely to be due to the presence of hindered phenols abundant in bio-oils. A relatively small reduction in DSC characteristic temperatures which are associated with cold flow properties was also observed but can likely be explained by a dilution effect. [Copyright &y& Elsevier]

Abstract: ROI BioOil plants can be made modular and transportable, allowing them to be located close to the source of biomass and the subsequent transportation of high energy density BioOil to a central plant. Conversely, one central BioOil plant could supply several energy users in distributed locations, or several plants could supply numerous end-users, just as in the petroleum industry. Renewable Oil International® LLC (ROI) is one of several developers of fast pyrolysis technology. The production of BioOil can convert raw biomass into a low-viscosity liquid that, depending on the moisture content of the feedstock, increases the energy density of biomass by a factor of 6 to 7 times over green wood chips. The increase in energy density increases the amount of energy that can be hauled by standard tanker trucks versus a chip trailer van by a factor of two. Capital costs, exclusive of land costs, are comparable for a 50MWe biomass handling system at the power plant. Land area requirements for fuel storage and handling are reduced roughly half for BioOil systems versus solid fuel handling systems. No analysis was made of operating and maintenance costs. [Copyright &y& Elsevier]

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. [Display omitted] • Thermo-chemical degradation of RDF samples was studied using a rotary kiln reactor. • Quality of product was dependent on the RDF composition and operating temperature. • Phenols, ketones and acids were the major compounds in the aqueous phase. • Char consists of good amount of micro-nutrients such as K, S, N, Ca and Mg. [ABSTRACT FROM AUTHOR]

Catalytic hydrotreatment (HT) is one of the most important refining steps in the actual petroleum-based refineries for the production of fuels and chemicals, and it will play also a crucial role for the development of biomass-based refineries. In fact, the utilization of HT processes for the upgrading of biomass and/or lignocellulosic residues aimed to the production of synthetic fuels and chemical intermediates represents a reliable strategy to reduce both carbon dioxide emissions and fossil fuels dependence. At this regard, the catalytic hydrotreatment of oils obtained from either thermochemical (e.g., pyrolysis) or physical (e.g., vegetable seeds pressing) processes allows to convert biomass-derived oils into a biofuel with properties very similar to conventional ones (so-called drop-in biofuels). Similarly, catalytic hydro-processing also may have a key role in the valorization of other biorefinery streams, such as lignocellulose, for the production of high-added value chemicals. This review is focused on recent hydrotreatment developments aimed to stabilizing the pyrolytic oil from biomasses. A particular emphasis is devoted on the catalyst formulation, reaction pathways, and technologies. [ABSTRACT FROM AUTHOR]

• Towards a plastics circular economy. • PIONA-type quantification of pyrolysis oils from mixed plastic waste. • Hydrocarbon composition comparison of fossil-based hydrocarbon streams and pyrolysis oils. • Expanding the capabilities of GC-VUV. The conversion of waste streams into a useable material through a recycling process is a hot topic. Waste streams can originate from domestic and industrial sources and range from plastic waste to medical waste to various industrial waste streams, both solid and liquid. In addition to waste circularity, circularity for bio-based waste streams and renewable sources are also being investigated. To simplify this complexity, this article presents a case study evaluating the output from the feedstock recycling of plastic waste originating from municipal solid waste. Plastic waste entering the environment is undesired, and many initiatives are working towards a plastics circular economy. Once disposed of, ideally, plastic waste should be either re-used or recycled in order to avoid incineration or disposal in landfills. Recycling waste plastic can occur either via mechanical recycling or feedstock (chemical) recycling, where feedstock recycling can occur for example, through gasification or pyrolysis technologies. This article will focus only on the oils obtained from the pyrolysis of mixed waste plastic. The output from pyrolysis has a different composition than traditional fossil-based hydrocarbon streams, and therefore, must be evaluated to correctly process as feedstock. The authors have previously shown that gas chromatography coupled to vacuum ultraviolet detection (GC-VUV) provides accurate identification and quantification of the hydrocarbon composition (paraffins, isoparaffins, olefins, naphthenes, and aromatics – PIONA) of fossil-based liquid hydrocarbon streams. 1 1 M.N. Dunkle, P. Pijcke, B. Winniford, G. Bellos, Quantification of the composition of liquid hydrocarbon streams: Comparing the GC-VUV to DHA and GCxGC, Journal of Chromatography A, 1587 (2019) 239-246. https://doi.org/10.1016/j.chroma.2018.12.026. Therefore, GC-VUV was evaluated for analysis of the pyrolysis oils from plastic waste. Using an in-house modified spectral library in combination with the PIONA+ software, accurate identification and quantification of the hydrocarbon composition of pyrolysis oils from C 4 through C 30+ was possible with a limit of detection of 0.1 wt.%. To the best of our knowledge, this article is the first example of accurate PIONA-type quantification of pyrolysis oils by GC-VUV. [ABSTRACT FROM AUTHOR]

The pyrolysis behavior of corn stover and polypropylene during co-pyrolysis was studied using a tube furnace reactor. The effects of mixing ratio of corn stover and polypropylene, pyrolysis temperature, addition amount of catalyst (HZSM-5) and reaction atmosphere (N2 and CO2) on the properties of pyrolysis products were studied. The results showed that co-pyrolysis of corn stover and polypropylene can increase the yield of pyrolysis oil. When corn stover:polypropylene = 1:3, the yield of pyrolysis oil was as high as 52.1%, which was 4.5% higher than the theoretical value. With the increase of pyrolysis temperature, the yield of pyrolysis oil increased first and then decreased, and reached the optimal yield at 550 °C. The addition of catalyst (HZSM-5) reduced the proportion of oxygenates and promoted the generation of aromatic hydrocarbons. CO2 has a certain oxidation effect on the components of pyrolysis oil, which promoted the increase of oxygen-containing aromatics and the reduction of deoxy-aromatic hydrocarbons. This study identified the theoretical basis for the comprehensive utilization of plastic and biomass energy. [ABSTRACT FROM AUTHOR]

Pyrolysis of raw pine bark, pine, and Douglas-Fir bark was examined. The pyrolysis oil yields of raw pine bark, pine, and Douglas-Fir bark at 500 °C were 29.18%, 26.67%, and 26.65%, respectively. Both energy densification ratios (1.32–1.56) and energy yields (48.40–54.31%) of char are higher than pyrolysis oils (energy densification ratios: 1.13–1.19, energy yields: 30.16–34.42%). The pyrolysis oils have higher heating values (~25 MJ/kg) than bio-oils (~20 MJ/kg) from wood and agricultural residues, and the higher heating values of char (~31 MJ/kg) are comparable to that of many commercial coals. The elemental analysis indicated that the lower O/C value and higher H/C value represent a more valuable source of energy for pyrolysis oils than biomass. The nuclear magnetic resonance results demonstrated that the most abundant hydroxyl groups of pyrolysis oil are aliphatic OH groups, catechol, guaiacol, and p-hydroxy-phenyl OH groups. The aliphatic OH groups are mainly derived from the cleavage of cellulose glycosidic bonds, while the catechol, guaiacol, and p-hydroxy-phenyl OH groups are mostly attributed to the cleavage of the lignin β–O-4 bond. Significant amount of aromatic carbon (~40%) in pyrolysis oils is obtained from tannin and lignin components and the aromatic C–O bonds may be formed by a radical reaction between the aromatic and aliphatic hydroxyl groups. In this study, a comprehensive analytical method was developed to fully understand and evaluate the pyrolysis products produced from softwood barks, which could offer valuable information on the pyrolysis mechanism of biomass and promote better utilization of pyrolysis products. [ABSTRACT FROM AUTHOR]