Liquid Pyrolysis Products Research Articles

Comprehensive insights into the influences of acid-base properties of chemical pretreatment reagents on biomass pyrolysis behavior and wood vinegar properties

Pyrolysis of biomass is an effective approach to produce high-value added solid, liquid and gaseous products. Wood vinegar (WV) is obtained as one of the main liquid products of biomass pyrolysis and has been used as the sustainable chemicals in agriculture. In this study, the effects of acid-base properties of chemical reagents on the biomass pyrolysis behavior and WV properties were investigated, and the mechanism was further discussed. The results indicated that acid-base properties of chemical reagents exhibited the significant effects on pyrolysis behavior and WV properties. Alkaline compounds showed the more obviously effects on changes in biomass chemical structure rather than acids, while acids removed the metallic species more efficiently than alkaline compounds. All chemical pretreatments increased the cellulose crystallinity, and the alkaline compounds were more favorable than the acidic compounds for increasing the crystallinity. Meanwhile, chemical pretreatments changed the chemical structure of biomass and promoted the pyrolysis process. All chemical pretreatments increased the organic content of WV. The relative content of phenols increased after all pretreatments, which increased more obviously by the acids pretreatments. Whereas, the relative content of acids decreased after pretreated by inorganic acids, and increased after pretreated by organic acids and alkaline compounds.

Thermochemical conversion of Polyalthia longifolia leaves at different temperatures and characterization of their products

Lignocellulosic biomass is a renewable source of energy which can be harnessed to produce biofuels maintaining the carbon neutrality in the atmosphere. Thus, in this work, results of the pyrolysis of solid wastes of Polyalthia Longifolia (PL) leaves have been reported over a range of temperature from 450 °C to 600 °C at an interval of 50 °C. All experiments have been carried out three times in order to ensure repeatability and/or reduce measuring uncertainties; and the average values along with their standard deviation values are presented. The pyrolytic products have been thoroughly characterized by several advanced characterization techniques such as FTIR, GCMS, NMR, XRD, SEM, TGA, etc. as applicable to different products in addition to their physical and fuel properties. Further, the physical and fuel properties are reported for both individual organic and aqueous phases after separating liquid pyrolysis product; as well as based on raw liquid product obtained by pyrolysis before separating into organic and aqueous phases. The average higher heating value of organic phase bio-oil is varying in the range 21.74–24.28 MJ/kg for different pyrolysis temperatures. The moisture content of organic phase bio-oil varies between 0.36 mass % and 8.88 mass % over the temperature range of this study. The pH of organic phase bio-oil is in the range of 5.80 to 6.04 which indicate that the bio-oil is only marginally acidic; and further this range of pH is far better than their counterparts of open literature. From the GCMS analysis of bio-oil samples, it is found that phenol, 2,6-dimethoxy (syringol) is present with highest area % of 22.71 for the case of 600 °C pyrolysis temperature. Finally, the bio-oils produced from the pyrolysis of PL leaves are of good quality in terms of moderately large HHV, pH and low moisture content.

Study on Pyrolysis Characteristics and Kinetics of Bituminous Coal by Thermogravimetric Method

ABSTRACT During the underground coal gasification process, due to the particularity of the gasification channel, a large amount of coal pyrolysis will occur in the coal seam. By studying the characteristics of pyrolysis and gasification of bituminous coal, using the gaseous material containing C element in pyrolysis atmosphere as the way to calculate the conversion rate of lignite. In this paper, thermogravimetric simulation test bench is used to study the pyrolysis characteristics and kinetics of bituminous coal. The weight loss rate under different pyrolysis conditions is analyzed and studied. The following main conclusions are obtained: in the process of bituminous coal pyrolysis, rapid heat transfer to the interior is an important means to improve the pyrolysis efficiency of bituminous coal. The residence time of pyrolysis process is increased, so that the temperature is fully transferred in the coal sample. Therefore, more pyrolysis gas and liquid products can be obtained. The faster the heating rate, the higher the critical temperature of the bituminous coal and the lower the conversion rate. This is because the temperature transfer is lagging and the heating rate is fast, which results in the bituminous coal below the set temperature. The temperature of bituminous coal is shifted back. The formation of CH4 in bituminous coal mainly occurs in the depolymerizing stage. The formation of H2 mainly occurs in the condensation polymerization stage, and its formation requires higher temperatures.

Preparation and analysis of pyrolysis oils

A critical review of the methods for producing pyrolysis waste oils was carried out, the possibilities and limitations of each approach were discussed. Liquid pyrolysis products (pyrolysis oils) are promising source of valuable chemical compounds, and can be also used as a fuel. A reliable analysis of pyrolysis oils is necessary to study their component composition, basic characteristics and to select the most suitable methods for the extraction of the necessary compounds. It is known that the results of GC-MS analysis of liquid pyrolysis products are usually ambiguous: there are problems of peaks overlapping and incorrect interpretation of the data, due to the complexity of the matrix and the multicomponent composition of the object. The paper presents data on the chemical composition of pyrolysis oils obtained by elemental analysis, IR spectroscopy, NMR spectrometry, GC-MS, GC-GC/MS. Based on the presented results, pyrolysis oil usually contains aromatic compounds, water-soluble substances and hydrocarbons. It was found out that there are conflicting data on the chemical composition of the pyrolysis oils of waste tires in the scientific literature. It is proposed to carry out sequential extraction sample preparation of pyrolysis mixtures to increase the reliability and accuracy of the componential and quantitative composition of the GC-MS method. Obviously, a reliable analysis of complex pyrolysis mixtures without preliminary targeted sample preparation seems unlikely.

Ignition of Coal-Water Fuel with the Addition of the Liquid Fraction of Rubber Pyrolysis Products

The results of experimental studies of the ignition process of droplets of multicomponent coal-water suspensions based on long flame coal with the addition of liquid pyrolysis products of rubber waste are presented. The heating, ignition and combustion processes were observed using a high-speed video camera (up to 3600 frames per second), which provides highly reliable results. The experiments were performed in an oxidizing environment (still air) heated to high temperatures (873–1273 K). It was found that the value of the stable ignition delay time of droplets decreases by 21–54 % under conditions corresponding to the combustion chambers (temperature 1273 K) and with the mass concentration of the liquid combustible component at 3–8 %.

Formation mechanism of aromatics during co-pyrolysis of coal and cotton stalk

Pyrolysis experiments were conducted in a tubular furnace from room temperature to 600 °C at 5 °C /min, and kept for 15 min. The light tar was then derived from the liquid products of pyrolysis by n-hexane supersonic extraction. Gas chromatography–mass spectrometry was employed to analyze the light tars from cotton stalk (CS) pyrolysis, Shenmu coal (SM) pyrolysis, and co-pyrolysis of CS/SM. Microcrystalline cellulose (MCC) was selected as a model compound, and the light tar from co-pyrolysis tar of MCC/SM was investigated for comparison. The results indicated that CS improved the yields and quality of phenols and benzenes in co-pyrolysis tar and that MCC had excellent performance in the formation of mononuclear aromatics during the co-pyrolysis of MCC/SM. Based on the pyrolytic behavior of CS and SM, the mechanisms of aromatic formation were further determined. It was shown that the free radicals that cracked from CS accelerated the formation of aromatics. The alkyl and mononuclear aromatic radicals of CS pyrolysis combined with the radicals from the SM aromatic structure, which then converted to benzenes and phenols. Finally, the most favorable reaction routes of mononuclear aromatics formation were proposed.

Feasibility of anaerobic digestion as a treatment for the aqueous pyrolysis condensate (APC) of birch bark

Biooil produced via biomass pyrolysis includes an aqueous-acidic phase and a dense and rich organic phase. The aqueous phase has a low heating value and is considered a waste stream. In this study fractional condensation was employed to separate the liquid product of birch bark pyrolysis into an aqueous pyrolysis condensate (APC) and a dense biooil fraction. The APC contained high amounts (~100 g/kg) of acidic acid (AA) and was investigated for anaerobic digestion (AD). The AA in the APC could be converted to biogas, however, it contained elevated concentrations of microbial inhibitors (24 g/kg total phenolics). The inhibiting effect could be mitigated by acclimatization of the microbial population, which in turn converted some of the additional organics. The production of methane further improved with the addition of biochar to adsorb some of the inhibitors. The results imply that a waste product can be converted into a potential energy carrier.

Effect of Calcium-Based Catalysts on Pyrolysis Liquid Products from Municipal Sludge

Aimed to obtain high-quality pyrolysis liquid products, the effects of different calcium-based catalysts and temperatures on liquid products from catalytic pyrolysis of municipal sludge (moisture of 50%) were studied. Results showed that the liquid product yield reached maximum at 600 °C and then decreased. The catalyst capability of catalysts decreased the yield of liquid products in the order of poorly soluble in water (Ca(OH)2, CaCO3, CaO) > soluble in water (CaCl2, Ca(H2PO4)2·H2O). High temperature strengthened the aromatization, and the breaking of the oxygen-containing functional group in liquid products resulted in the decrease of O/C and H/C molar ratios and the increase of four components yield in gaseous products. At 600 °C, the catalysts significantly reduced the O content of liquid products and increased hydrocarbon content. Meantime, CaO additive increased the content of C to 85.34%, and the relative content of aromatics reached 83.99% at 800 °C, which is suitable as chemical raw materials. However, the Ca(OH)2 group had the highest aliphatics content, and the H/C molar ratio was 1.42 at 400 °C, which is suitable as fuel.

Low-Temperature Deoxidization of Lignin and Its Impact on Liquid Products from Pyrolysis

In this study, low-temperature deoxidization of lignin in the temperature range of 200–390 °C as a pretreatment method had been exploited to gain high-quality pyrolysis products. Two-dimensional infrared correlation spectroscopy (2D-PCIS) was used to analyze the evolution of the functional groups of lignin in the process of low-temperature deoxidization, and the deoxidized samples were pyrolyzed by pyrolysis-gas chromatography–mass spectrometry (Py-GC/MS). The results of 2D-PCIS showed that the decomposition of lignin was accelerated from 320 °C, and it was dominated by the elimination reaction. Notably, the aromatization reaction was intensified at 350 °C, whereas the structure of the lilac aromatic ring was more stable than the guaiac aromatic. It was also found that the alcoholic hydroxyl group was significantly removed, and because of this removal, other functional groups also underwent changes during deoxidization. The results of Py-GC/MS experiments showed that deoxidization treatment at temperatures lower than 230 °C had an insignificant effect on the pyrolysis products. However, when the deoxidization temperature was 230 °C and above, the oxygen-containing compounds in the pyrolysis liquid products (mainly phenols) decreased significantly, and when the deoxidization temperature was above 290 °C, hydrocarbons were the main compounds in the pyrolysis liquid product.

The Study of the Distillation Volume of the Liquid Tire Pyrolysis Product

At present, the disposal of polymer and rubber waste, and especially automobile tires, is one of the most acute environmental problems. These types of waste pollute the environment both when they are stored at landfills and during subsequent disposal, especially if it is carried out in the form of incineration. Therefore, at present, much attention is paid to thermal methods of their processing. The results of the study of liquid product of pyrolysis of tires of Kuznetskecology+ LLC are presented in the work. During its distillation, the following fractures were obtained (the yield wt% is indicated in parentheses): petroleum (4), gasoline (21), kerosene (18), diesel (47), fuel oil (10), for which the refractive index was determined and a conclusion about their chemical composition was drawn. When analyzing the data obtained during the analysis of liquid pyrolysis product and its fractions, as well as on the basis of published data, possible chemical reactions occurring during vulcanized rubber pyrolysis are proposed. Research results show that pyrolysis products are valuable chemical raw materials that have great prospects for industrial use, including the production of synthetic motor fuels.

Исследование кинетики термодеструкции сшитого полиэтилена

This paper presents a study of the process of thermal degradation of crosslinked polyethylene. The kinetics of polymer decomposition was studied by thermogravimetry. Crosslinked polyethylene showed high heat resistance to temperatures of 400 °C. The temperature range of 430–500 °C was determined for the loss of the bulk of the sample. According to thermogravimetric data, the decomposition process proceeds in a single stage and includes a large number of fracture, cyclization, dehydrogenation, and other reactions. The process of pyrolysis of a crosslinked polymer in a stationary-bed metal reactor was investigated. The influence of the process temperature on the yield of solid, liquid, and gaseous pyrolysis products was investigated. The optimum process temperature was 500 °C. At this temperature, the yield of liquid and gaseous products was 85.0 and 12.5% (mass.), Respectively. Samples of crosslinked polyester decomposed almost completely. The amount of carbon–containing residue was 3.5% by weight of the feedstock. With increasing temperature, the yield of liquid products decreased slightly and the yield of gaseous products increased, but their total yield did not increase. For gaseous products, a qualitative and quantitative composition was determined. The main components of the pyrolysis gas were hydrocarbons C1–C4. The calorific value of pyrolysis gas obtained at a temperature of 500 °C was 17 MJ/m3. Thus, the pyrolysis process can be used to process crosslinked polyethylene wastes to produce liquid hydrocarbons and combustible gases.

Manufacturing gaseous products by pyrolysis of microalgal biomass

Algal biomass is considered as an alternative raw material for biofuel production. The search for new types of raw materials including high-energy types of microalgae remains relevant, since the share of motor fuels in the world energy balance remains consistently high (about 35%) with the oil price characterized by high volatility. The authors have considered the advantages of microalgae as raw materials for fuel production. Biochemical and thermochemical conversion are proposed as technologies for their processing. The paper presents the results of the study on the pyrolysis of the biomass of the blue-green microalgae/cyanobacterium Arthrospira platensis rsemsu 1/02-P clonal culture from the collection of the Research Laboratory of Renewable Energy Sources of the Lomonosov Moscow State University. The experimental investigation on the pyrolysis process of microalgal biomass has been carried out with the experimental setup made at the Institute of High Temperatures RAS in pure nitrogen 6.0 to create an oxygen-free medium with a linear heating rate of 10°С/min from room temperature to 1,000°С. The entire pyrolysis process has proceeded in the endothermic region. The specific values for solid residue, pyrolysis liquid and gaseous products have been experimentally determined. The following products have been manufactured by pyrolysis of microalgal biomass weighing 15 g: 1) char with a solid residue mass of 2.68 g, or 17.7% of MAB initial mass (while 9.3% of MAB initial mass has remained in the reactor); 2) pyrolysis liquid with a mass of 3.3 g, or 21.9% of initial mass; 3) noncondensable pyrolysis gases, 1.15 L. The specific volumetric gas yield (amount of gas released from 1 kg of RM) has amounted to 0.076 nm³/kg.In the paper, the analysis of the composition and specific volumetric yield of non-condensable pyrolysis gases produced in the pyrolysis process depending on temperature has been carried out. It is shown that the proportion of high-calorific components of the gas mixture (hydrogen, methane and carbon monoxide) increases with the temperature increase. The heating value assessment for the mixture of these gases has been performed as well.

Thermocatalytic Biomass Processing

The main achievements and procedures in the field of catalytic thermal processing of biomass are considered. Preparation of various valuable liquid products by catalytic biomass pyrolysis is described. The effect of various cations and anions on the yield of liquid and gaseous products of biomass pyrolysis is demonstrated. Catalytic treatment of biomass pyrolysis vapor allows improvement of the quality of liquid products. Modern procedures for catalytic biomass gasification to obtain syngas are analyzed. Production of resin-free syngas requires additional treatment steps. Problems of using catalysts in thermal biomass processing are discussed.

Oil Residue Pyrolysis Process in the Presence of Aluminosilicates

This paper presents a study of the pyrolysis process of oil residues in the presence of catalysts based on natural and synthetic aluminosilicates. The process of fast thermal decomposition was studied in a continuous reactor at a residence time of feedstock in the reaction zone less than 20 s. The optimum temperature of oil-sludge decomposition was determined taking into account the yield of gaseous and liquid pyrolysis products. The optimal pyrolysis temperature for the studied feedstock was found to be 600 °C. The study of the effect of the aluminosilicates on the oil-sludge thermal decomposition showed that among the studied catalysts, zeolites were found to be the most active. The highest yield of gaseous and liquid products was observed In the presence of three-dimensional porous pentasil zeolite H-ZSM-5. H-ZSM-5 was found to provide the 40 wt. % yield of liquid and 13.5 wt/ % of gaseous products during the fast oil-sludge pyrolysis at the optimal temperature. In order to reduce the cost of the catalyst used, a catalyst representing a mixture of zeolite H-ZSM-5 and bentonite clay was synthesized. This catalyst also showed high activity in the process of oil-containing residue composition providing 36 w. % yield of liquid products and 10 wt. % of gaseous products. It is interesting to note, that in the presence of the mixed catalyst the highest yield of light liquid fraction (50 wt. %) was obtained.

Study of Oil Sludge Pyrolysis in the Presence of Calcium Oxide

The study of thermal processing of oil sludge from the Ukhta oil field (Russia) was conducted in order to assess the possibility of extracting liquid products and their simultaneous purification from sulfur compounds. Proximate and ultimate analyzes of the feedstock as well as its thermogravimetric study were performed. The data on the yield of pyrolysis products were obtained in the fixed bed retorting system, depending on the process temperature and the addition of calcium oxide (CaO). The presence of calcium oxide allows to clean the pyrolysis gas of oil sludge from hydrogen sulfide (H2S), as well as to reduce the sulfur content in the liquid products of the pyrolysis.

Analysis of light components in pyrolysis products by comprehensive two-dimensional gas chromatography with PLOT columns

The most successful method for pyrolysis liquids analysis is comprehensive two-dimensional gas chromatography. Columns with a stationary liquid phase are used for this purpose. However, when is necessary to analyze a gas phase containing C3–C5 hydrocarbons over a liquid pyrolysis product, the use of columns with a liquid phase in CG*CG will not result to separation of light hydrocarbons. In this case, it is necessary to use PLOT columns with a porous layer of sorbents of various nature. Today this approach with two PLOT columns in GC*GC is not described, as well as its use for the analysis of light hydrocarbons resulting from pyrolysis. This paper describes an application of two PLOT columns in GC*GC mode. This paper describes an application of two PLOT columns in GC*GC mode. The next columns of different nature that have different selectivity were used: Rt-Q-BOND, Rt-S-BOND, Rt-U-BOND (columns based on divinylbenzene styrene copolymer), column with sorbent poly- (1-trimethylsilyl-1-propyne) (PTMSP) and an Agilent GASPRO silica column.The most suitable pair of the columns was determined by finding of their orthogonality. The numerical orthogonality data was found by studying of the correlation coefficients between compounds retention time on the first and second columns. It is shown that the best combination of columns are PTMSP - GASPRO and Rt-Q-BOND - GASPRO, however, the first combination of columns allows separation at the same temperature conditions about twice as fast as the second. Examples of the separation of С3-С8 hydrocarbons in the gas phase over pyrolysis mixtures of different origin are given.

Perbandingan Bahan Bakar Premium Dengan Produk Cair Hasil Pyrolisis Plastik PET dan PP

Salah satu alternative penanganan sampah plastik yang saat ini banyak diteliti dan dikembangkan adalah mengubah sampah plastik menjadi bahan bakara alternatif. Tujuan penelitian ini adalah untuk memperoleh bahan bakar cair dari pirolisis sampah plastik, dengan nilai kalor dan mutu bahan bakar minyak yang baik. Metode yang digunakan adalah menggunakan proses pirolisis. Pirolisis atau devolatilisasi adalah proses fraksinasi material oleh suhu. Proses pirolisis dimulai pada temperature sekitar 500°C, ketika komponen yang tidak stabil secara termal, dan volatile matters pada sampah akan pecah dan menguap bersamaan dengan komponen lainnya. Hasil dari proses pirolisis ini berupa cairan yang bisa digunakan sebagai bahan bakar alternatif, selain itu gas yang dihasilkan dari proses pirolisis juga dapat dimanfaatkan sebagai bahan bakar saat proses pirolisis berlangsung. Berdasarkan hasil eksperimen dan analisa data yang telah dilakukan, maka dapat diambil kesimpulan bahwa konsumsi bahan bakar plastik PET dan PP lebih rendah dari bahan bakar premium dengan perbedaan yang signifikan. Dimana bahan bakar plastik PET dan PP dengan nilai konsumsi bahan bakar rata-rata untuk kecepatan 2000 rpm selama 2 menit sebesar 8,7 ml sedangkan nilai konsumsi rata-rata bahan bakar premium dengan kecepatan dan waktu yang sama sebesar 13 ml, sehingga dapat dipastikan hasil produk pirolisis plastik PET dan PP lebih irit daripada bahan bakar premium.

Production of Aryl Oxygen-Containing Compounds by the Pyrolysis of Bagasse Alkali Lignin Catalyzed by LaM0.2Fe0.8O3 (M = Fe, Cu, Al, Ti)

A series of LaM0.2Fe0.8O3 (M = Fe, Cu, Al, Ti) samples synthesized by the sol–gel method were used to catalyze the pyrolysis of bagasse alkali lignin (BAL) to produce aryl oxygen-containing compounds. The effects of doping metal ions in the B-site of LaFeO3 were investigated by X-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller, and X-ray photoelectron spectrometer. Furthermore, the catalytic pyrolysis performances of the perovskites were evaluated by thermogravimetric analysis and the fixed-bed microreactor, and the gaseous and liquid pyrolysis products were analyzed by GC and gas chromatography/mass spectrometry (GC/MS), respectively. The results indicated that the perovskites have a cubic crystal phase, porous structure, and large specific surface area. After doping Cu, Al, and Ti ions in the B-site of perovskites, the grain sizes were refined, the performance of catalyzing BAL pyrolysis was improved, and the yields of liquid pyrolysis products increased by 24.1–39.1%. The selectiv...

The Utilization of Fiddle-Leaf Fig Waste Into Food Preservative

Fiddle-leaf Fig is a tree that is widely used as a protective or plants or shade. This plant is usually found on the side of the road, in the office area and as houseplants. The presence of fiddle-leaf fig leaves that fall from the tree will be a waste for the environment. This study proposes utilization of fiddle-leaf fig waste by pyrolysis method using pyrolysis triple condenser. Thermal analysis was done before experiments using a thermo gravimetric analyzer in the range of temperature of room temperature until 1000 ºC. Process was carried out at heating temperature of 350ºC, 375ºC, 400ºC, 425ºC, 450ºC, 475ºC and 500ºC. The product of pyrolysis were obtained from liquid coming out from the residue container, the first and second condenser, and the smoke is coming out from the third condenser. The smokes were absorbed with water. Further, all of the liquid were analyzed by gas chromatography mass spectrometry (GCMS). The analysis results show that the main components of pyrolysis liquid products are carboxylic acids, ketones, alcohols, and alkanes. There is gasoline and kerosene in the liquid, so it has the potential to become bio-oil. The largest potential of fiddle-leaf fig waste is as raw material for food preservative because it contains many carboxylic acid compounds.

Characterization of tobacco stalk lignin using nuclear magnetic resonance spectrometry and its pyrolysis behavior at different temperatures

Utilization of tobacco stalk is one of the most challenging issues in tobacco agriculture. This work investigated the pyrolysis behaviors of tobacco stalks lignin using thermogravimetric (TG) analysis, and the resultant liquid products of fast pyrolysis at various temperatures were thoroughly analyzed using GC–MS for promoting tobacco stalk valorization. In addition, lignin structure was characterized using two-dimensional heteronuclear single-quantum coherent nuclear magnetic resonance (2D HSQC NMR) spectroscopy. The results revealed that tobacco stalk lignin had higher contents of resistant structure like guaiacyl-type units, resinols, and phenylcoumarans than other straw lignin. The differential thermogravimetric (DTG) analysis showed that the pyrolysis of tobacco stalk lignin can be described by a two-stage kinetic model, which had the apparent activation energy of 61.64 and 66.42 KJ/mol for the first and the second stage, respectively. The fast pyrolysis of tobacco lignin showed narrower product distribution at medium temperature (600 ℃) than at high (900 ℃) and low temperature (300 ℃), which majorly produced guaiacyl-type mono-phenols. Three high-value products, namely creosol, 2-methoxyphenol and trans-isoeugenol, were selectively produced by the pyrolysis of tobacco stalk lignin. The studies thus paved a new path for valorizing tobacco waste into value-added products through fast pyrolysis.