Search Results (98)

In this study, we investigated the solvent performance of six heavy oils from Xinjiang, China, for coal–oil co-liquefaction (COCL). Autoclave experiments revealed that shale oil vacuum residue (SOVR) provided the best liquefaction performance. The oils were characterized using FT-IR, ¹³C-NMR, ¹H-NMR, and column chromatography, which revealed that they were mainly composed of aliphatic compounds, with minor aromatic and substituted aromatic compounds. The pyrolytic degradation quality indices (PDQIs), solubility parameter (δ_C), and polycyclic aromatic hydrocarbon content (H_A2 + H_A3) were calculated and correlated with liquefaction performance. The results showed a strong linear relationship between H_A2 + H_A3 and oil yield (R² = 0.90), and the aromatic content (AR) was also positively related to oil yield. This study suggests that AR content and H_A2 + H_A3 are effective indicators for evaluating the solvent performance of heavy oils in COCL. Full article

The present study investigates the catalytic conversion of low-density polyethylene (LDPE) into high-grade fuel oil using a semi-batch reactor at 350 °C under ambient pressure, with a catalyst-to-LDPE ratio of 1:20. Zeolite-based catalysts were synthesized by impregnating different metals (Fe, Zn, Cr, Mn, and Ga) onto ZSM-5 with a silica-to-alumina ratio of 30 (Z30). These catalysts were characterized using BET, XRD, and NH3-TPD techniques to evaluate their physicochemical properties. The results showed that catalytic pyrolysis of LDPE yielded less pyrolytic oil compared to non-catalytic pyrolysis. The obtained pyrolytic oil was analysed through elemental composition, gross calorific value (GCV), Simulated Distillation, and GC-DHA. The elemental analysis revealed a high carbon (85–86%) and hydrogen (13–14%) content, resulting in a high GCV of approximately 42 MJ/kg. GC-DHA analysis indicated that the pyrolytic oil was rich in aromatic and olefinic compounds. Among the catalysts, 5Fe/Z30 exhibited the highest aromatic selectivity (35%), a research octane number of 91, and 100% LDPE conversion. These findings underscore the potential of low-cost iron-based catalysts for efficiently converting LDPE waste into valuable chemicals and fuels. Full article

This paper presents the results of naturally aspirated compression ignition (CI) internal combustion engine (ICE) bench tests of fuels in the form of a blend of diesel oil with recycled oil (RF) in the form of tire pyrolysis oil (TPO) as an admixture with the content of pyrolytic oil with the blend being 10% m/m (D90+RF10). The results relate to reference conditions in which the engine is fed with pure diesel oil (D100). The experiment included the evaluation of engine performance and the determination of the content of selected substances in the exhaust gas for brake-set engine loads equal to 5 Nm, 10 Nm, 15 Nm, and 20 Nm. For each load, engine operating parameters and emissions of selected exhaust components were recorded at preset speeds in the range of 1400–2400 rpm for each engine load. The hourly fuel consumption and exhaust gas temperature were determined. The contents of CO₂, CO, and HC in the exhaust gas were measured. The consumption of D90+RF10 increased by 56%, and CO₂ emissions were 21.7% higher at low loads. The addition of sulfur-containing pyrolytic oil as an admixture to diesel oil resulted in SO_x emissions. The results show the suitability of pyrolytic oil and the possibility of using it as an admixture to fossil fuels. In order to meet SO_x emission levels in land-based installations and for vehicle propulsion, it is necessary to desulfurize fuel or desulfurize deSO_x exhaust gas systems. The CO and HC emission levels in the exhaust gases from the engine powered by the D90+RF10 fuel meet current requirements for motor vehicle exhaust composition. Full article

The aim of the article is to present the impact of blending diesel fuel with tire pyrolysis (TPO) oil on the changes in the fuel’s rheological properties and to evaluate these changes in the context of meeting legal requirements for various types of fuels. This research presents the impact of normative D100 diesel oil with TPO as an admixture on the rheological properties of the blends. Measurements are made for the content of TPO in the blend equal to 5, 7, 10, 15, and 20% m/m. In addition, the reference measurements are made for pure diesel oil and pure pyrolytic oil. Kinematic viscosity density, dynamic viscosity, viscosity index, pour point, cloud point, and cold filter plugging point are determined. The density of each sample is found at 15, 20, 30, 40, 50, 60, 70, 80, 90, and 100 °C. Viscosity is determined at the reference temperatures of 20, 40, and 100 °C, which are typically used as reference temperatures for petroleum products. Approximating models are built for all the analyzed parameters, which can be used in future studies. The fit of each model to empirical data is evaluated using the coefficient of determination R². At the same time, the individual values of the analyzed indicators are compared to the limit values specified in selected standards and regulations, thus allowing us to assess the usefulness of individual fuels in terms of compliance with effective and reliable engine operation requirements. The fuels under study fulfill the normative requirements for the parameters for marine distillate fuels for blends with a pyrolysis oil content of 0–20% m/m and the requirements for standard-grade diesel oils indicated in the Regulation of the Minister of Economy of Poland for blends with a pyrolysis oil content of 0–7% m/m. Full article

Sustainable hydrocarbons are one of the main methods of decreasing the use of fossil fuels and derivatives, contributing to the mitigation of environmental impacts and greenhouse gas emissions. Circular economic concepts focus on reusing waste by converting it into new products, which are then input again into industrial production lines, thus decreasing the necessity of fossils. Polypropylene-based plastic waste can be depolymerized into smaller chemical chains, producing a liquid phase rich in hydrocarbons. In the same way, triacylglycerol-based waste biomasses can also be converted into renewable hydrocarbons. Our research studied the co-processing of polypropylene (PP) and cottonseed oil dreg (BASOs) waste from the biodiesel industry using a micropyrolysis system at 550 °C, previously validated to predict the scale-up of the process. PP showed the production of alkanes and alkenes, while BASOs also produced carboxylic acids in addition to the PP products. The main impacts were observed in the conversion yields, reaching the highest values of pyrolytic liquid (64%), gas (14%), and solid product (13%) compared to the co-processing mixture of BASO:PP (1:2). Also, in this mixture, the production of carboxylic acids decreased to the lowest value (~10%), improving the conversion to sustainable hydrocarbons. Full article

In this study, Kerogen conversion and oil production laboratory modeling results in Bazhenov formation source rock samples (Western Siberia, Russia) are presented. Two samples from one well with a similar composition and immature type II kerogen, which were accumulated in the same deep-sea conditions, were used for this investigation. Hydrous pyrolysis was performed under 300 °C, with liquid products and a sample portion collected every 12 h to study kerogen parameters via pyrolysis and the synthetic-oil composition via GC–MS. The transformation of pyrolytic parameters was similar to the natural trend previously determined for Bazhenov source rocks with different maturities. The synthetic oils’ normal alkane composition and biomarker parameters transformed with time. Sedimentary conditions and lithology biomarker parameters presumed to be constant (Pr/Ph, Ph/C18, H29/H30, and DBT/Phen) changed depending on the heating duration. The oil maturation increased slightly. Differences between the samples were detected in hydrocarbon generation endurance (5 and 8 days), n-alkane composition, and C27/C29 and DBT/Phen. A hypothesis about the influence of kerogen variability and mineral matrix on oil production was made. This paper provides the basis for more detailed and accurate investigation of the factors affecting kerogen cracking and hydrocarbon formation. Full article

The global plastic production total has risen to more than 400 million tons per year; this number is mainly driven by industrial appliances. In the EU, where the annual production is about 30 million tons, only 32% of plastic waste is recycled. Therefore, a need for a robust and efficient waste management strategy has emerged. This study will introduce a novel logistic regression-based decision-making framework that focuses on the environment and the economy while also considering energy intensity and logistics. These factors reflect the use of Life Cycle Assessment (LCA) in this study, which is an approach that determines the selection of waste management strategies across different European countries. This study introduces a model with 94% sensitivity and 97% overall accuracy in order to compare pyrolysis and plastic waste recycling management methods. One of the main findings is the fact that pyrolysis demonstrated a maximum conversion efficiency of 88%; in comparison, the conversion efficiency for recycling was approximately 58%. Pyrolysis also generates by-products, such as syngas and pyrolytic oil, which are valuable. To conclude, this study is a tool for policymakers and industry leaders, so that they can make sustainable waste management decisions with data-driven and evidence-based reasoning. Full article

Biomass serves as a promising renewable and sustainable feedstock for energy production through thermochemical conversion. It can be transformed into sustainable biofuels by means of pyrolysis. Among these methods, the pyrolytic poly-generation of biomass, a novel biomass thermal conversion technology, can concurrently produce three valuable products, namely biochar, bio-oil, and combustible gas, without generating any byproducts. In contrast, conventional thermal conversion processes, such as carbonization for biochar, liquefaction for bio-oil, gasification for syngas, and combustion for heat, only yield single products, have limited efficiency, and give rise to byproducts. Clearly, pyrolytic poly-generation holds significant advantages over conventional thermal conversion processes. Nevertheless, the pyrolytic poly-generation process and its products are remarkably influenced by numerous factors, including the raw biomass properties, pretreatment methods, operating parameters, and catalysts. This article reviews the processing parameters and technology for biomass pyrolytic poly-generation, and also explores future research areas, with the aim of identifying research gaps and promoting its industrial implementation. Full article

This research presents the impact of diesel blends with tire pyrolysis oil (TPO) as an additive for minimizing the wear and tear of engine components. This study investigates the blends of normative diesel oil with TPO content ranging from 5% m/m to 20% m/m. Reference measurements are made for pure diesel oil (D100) and pure TPO. This investigation included an evaluation of the corrosion effect and the effect of the fuels tested on abrasive wear. For each fuel, the sulfur content, water content, lubricity (which is defined as the corrected average diameter of the wear trace during the high-frequency reciprocating rig (HFRR) test), and impurity content are determined. Impurities are assessed using indicators such as ash residue, coking residue from 10% distillation residue, determination of wear metals and contaminants, insoluble impurity content, and total sediment by hot filtration. All parameters are determined using recognized methods described in international standards. Approximation models are built for all the analyzed parameters, which can be used in future studies. At the same time, the individual values of the analyzed factors are compared with the threshold values specified in selected standards and regulations. Consequently, it is possible to assess the usefulness of individual fuels in terms of meeting the requirements for minimum wear of engine components. The results show the suitability of pyrolysis oil and the potential for its use as an additive to fossil fuels in terms of meeting most factors. Some of the fuels tested did not meet the standards for acceptable sulfur content. However, in terms of sulfur content, all of the analyzed fuels can be used to power watercraft and land-based power and thermal power plants equipped with flue gas desulphurization systems. A second indicator for not meeting the standards is the ash residue value, which indicates the high content of non-combustible, mainly metallic, substances in the pyrolysis oil used for the tests. Post-recycled oils must, therefore, undergo appropriate purification before being used as an additive to diesel fuels for internal combustion engines. Once the post-recycling oil has been subjected to desulfurization and advanced filtration, it can be used as a fuel additive for land vehicles, which fits in with closed-loop economies and sustainable development strategies. Full article

The results of testing the ignition properties of fuels in the form of blends of diesel oil with pyrolysis oil produced from tires, used as an additive at concentrations of 0, 5, 7, 10, 15, and 20% m/m, are presented in this paper. The experiment included the preparation of distillation curves and the determination of the flash points, derived cetane number, and calculated cetane ratios. The results are related to the limits indicated in selected standards and regulations on requirements for marine- and land-based compression ignition engine fuels. The obtained results show the suitability of pyrolysis oil and the possibility of its use as an additive to fossil fuels, which fits in with the requirements of the policies currently being developed for reducing the use of fossil fuels and building a circular economy. Full article

A coal seam from the Fushun Basin in NE China was investigated pertaining to its bulk and molecular compositions to elucidate its hydrocarbon generation potential. Eocene Guchengzi Formation coals and carbonaceous mudstones were deposited in oxic environments and fell within the subbituminous A rank. Hydrogen index (HI) values spanned within a range from 139 to 495 mg HC/g total organic carbon (TOC), indicating the presence of Type II2-III kerogens. The pyrolytic hydrocarbon yield (S₂) linearly increased with TOC content in carbonaceous mudstones, while there was no evident correlation between S₂ and TOC in the coals. Molecular compositions revealed that the input of algae and aquatic biomass did not enhance the hydrocarbon generation potential of the coals. Moreover, the hydrocarbon generation potential of the coals was not influenced by changes in flora. However, the degree of terpenoid aromatization showed a clear correlation with the HI values. A higher hydrocarbon generation potential is associated with a lower degree of aromatization, even though the Pristane/Phytane ratio does not indicate such a correlation. Bacterial transformation played a pivotal role in the structural rearrangement of the coal matrix, resulting in hydrogen incorporation into the coal. This ultimately led to a relatively hydrogen-rich composition with high oil-generating potential. Full article

This paper reports the results of a study on the significance of the inertization system configuration of a laboratory-scale fixed bed batch reactor with regard to the yield of pyrolysis oil and reactor conversion. Two typical reactor inertization systems were investigated depending on whether the carrier gas (nitrogen in this study) was added from the top or from the bottom of the reactor. Polypropylene (PP) packaging waste (100 g) was used as a model sample. A factorial experimental design was adopted for one categorical parameter, the arrangement of parts of the reactor inertization system. All experiments were conducted at 475 °C, with a carrier gas flow rate of 0.1 L/min and a reaction time of 90 min. Statistical analysis and processing of the results showed that the configuration of the inertization system had a remarkable impact on the pyrolysis oil and gas yield, while its impact on the overall reactor conversion was negligible. When applying the two observed methods of reactor inertization, the average yields of pyrolysis oil and gas differed by 1.7% and 1.8%, respectively. All of the applied statistical treatments had a significance level of 0.05, i.e., there was only a 5% chance of incorrectly rejecting the hypothesis of equality of arithmetic means of pyrolysis yields when the two different methods of reactor inertization were applied. The explanation of this behavior is attributed to the temperature change inside the reactor, which shows that this particular fixed bed reactor suffers from local overheating in its middle part. Local overheating of the middle part of the reactor is more pronounced in the case of inerting the reactor from the bottom, which leads to greater excessive cracking of volatile products compared to the mode of inerting the reactor from the top part and thus greater formation of non-condensable gases, i.e., a reduction in the yield of pyrolytic oil. Full article

This study focuses on the collection and UV characterization of the bio-oil phase from primary aerosols ejected from the liquid intermediate phase during the fast pyrolysis of biomass in a hot plate reactor. The effects of the reactor pressure and aerosol-collecting surface temperature on the bio-oil yield and characteristics were evaluated. The study found that lower reactor pressures and a lower temperature of the collecting surface significantly enhanced the aerosol yield (up to 85%). UV-fluorescence was employed to assess the influence of these parameters on the light-to-heavy compound ratio (monomers vs. oligomers). The heavy fraction of bio-oil from the hot plate reactor was predominantly composed of dimers and trimers (340–370 nm), similar to pyrolytic lignin and the heavy fraction of the bio-oil, which also showed peaks in this range. In contrast, pyrolysis oils from auger and fluidized bed reactors displayed two peaks in the UV spectrum, with a maximum around 300 nm, indicating that they are mainly composed of light monomeric compounds. The UV characterization of the primary aerosols and the comparison with the UV spectra of the bio-oil and its fractions (light and heavy fraction and pyrolignin) revealed similar UV prints, highlighting the importance of aerosol ejection in the final composition of bio-oil. Full article

Using agricultural waste biomass pyrolysis to produce energy sources and biochar may support local economies in rural areas and enhance sustainability in the agricultural sector, reducing dependence on traditional energy sources and fertilisers. To obtain liquid and gaseous forms of biomass fuel, wheat straw pellets were pyrolysed in a screw reactor at temperatures of 300, 400, 500, 600, and 700 °C. An analysis was conducted to assess the influence of process temperature on the physicochemical composition of the raw material and the resulting biochar, pyrolysis liquid, and synthesis gas. The presence of potentially harmful substances in the biochar, whose addition to soil can improve soil properties, was assessed by quantitatively determining polycyclic aromatic hydrocarbons (PAHs). Similar tests were carried out for pyrolysis fluid. The assessments were based on the standards for the most dangerous PAHs: fluorene, anthracene, fluoranthene, benzo[b]fluorine, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene. The results indicated that the total content of polycyclic aromatic hydrocarbons in the biochar ranged from 346.81 µg·kg⁻¹ at 300 °C to 1660.87 µg·kg⁻¹ (700 °C). In the pyrolytic fluid, the PAH content ranged from 58,240.7 µg·kg⁻¹ (300 °C) to 101,889.0 µg·kg⁻¹ (600 °C). It was found that the increase in PAH content in both the biochar and the liquid progressed with increasing pyrolysis temperature. After finding a correlation between the increase in the PAH content in biochar and the increase in the content of high-energy gases in the synthesis gas, it was concluded that it is difficult to reconcile the production of PAH-free biochar in the pyrolysis of biomass with obtaining high-energy gas and pyrolysis oil. Full article

The rapid accumulation of polymer waste presents a significant environmental challenge, necessitating innovative waste management and resource recovery strategies. This study investigates the potential of chemical recycling via pyrolysis of plastic waste, specifically polystyrene (PS) and polypropylene (PP), to produce high-quality pyrolytic oils (WPPOs) for use as alternative fuels. The physicochemical properties of these oils were analyzed, and their performance in a gas turbine engine was evaluated. The results show that WPPOs increase NO_x emissions by 61% for PSO and 26% for PPO, while CO emissions rise by 25% for PSO. Exhaust gas temperatures increase by 12.2% for PSO and 8.7% for PPO. Thrust-specific fuel consumption (TSFC) decreases by 13.8% for PPO, with negligible changes for PSO. The environmental-economic analysis indicates that using WPPO results in a 68.2% increase in environmental impact for PS100 and 64% for PP100, with energy emission indexes rising by 101% for PS100 and 57.8% for PP100, compared to JET A. Although WPPO reduces fuel costs by 15%, it significantly elevates emissions of CO₂, CO, and NO_x. This research advances the understanding of integrating waste plastic pyrolysis into energy systems, promoting a circular economy while balancing environmental challenges. Full article