Pyrolysis of Alternanthera philoxeroides (alligator weed): Effect of pyrolysis parameter on product yield and characterization of liquid product and bio char

In the present work, fast pyrolysis of Alternanthera philoxeroides was evaluated with a focus to study the chemical and physical characteristics of bio-oil produced and to determine its practicability as a transportation fuel. Pyrolysis of A.philoxeroides was conducted inside a semi batch quartz glass reactor to determine the effect of different operating conditions on the pyrolysis product yield. The thermal pyrolysis of A. philoxeroides were performed at a temperature range from 350 to 550 °C at a constant heating rate of 25 °C/min & under nitrogen atmosphere at a flow rate of 0.1 L/min, which yielded a total 40.10 wt.% of bio-oil at 450 °C. Later, some more sets of experiments were also performed to see the effect on pyrolysis product yield with change in operating conditions like varying heating rates (50 °C/min, 75 °C/min & 100 °C/min) and different flow rates of nitrogen (0.2, 0.3, 0.4 & 0.5 L/min). The yield of bio-oil during different heating rate (25, 50, 75 and 100 °C/min) was found to be more (43.15 wt.%) at a constant heating rate of 50 °C/min with 0.2 L/min N₂ gas flow rate and at a fixed pyrolysis temperature of 450 °C. The High Heating Value (HHV) value of bio-oil (8.88 MJ/kg) was very less due to presence of oxygen in the biomass. However, the high heating value of bio-char (20.41 MJ/kg) was more, and has the potential to be used as a solid fuel. The thermal degradation of A. philoxeroides was studied in TGA under inert atmosphere. The characterization of bio-oil was done by elemental analyser (CHNS/O analyser), FT-IR, & GC/MS. The char was characterized by elemental analyser (CHNS/O analysis), SEM, BET and FT-IR techniques. The chemical characterization showed that the bio-oil could be used as a transportation fuel if upgraded or blended with other fuels. The bio-oil can also be used as feedstock for different chemicals. The bio-char obtained from A. philoxeroides can be used for adsorption purposes because of its high surface area.     

Utilization possibilities of Albizia amara as a source of biomass energy for bio-oil in pyrolysis process

Pyrolysis is one of the potential routes to harmless energy and useful chemicals from biomass. The pyrolysis of Albizia amara was studied for determining the main characteristics and quantities of liquid products. Particular investigated process variables were temperature from 350 to 550°C, particle size from 0.6 to 1.25 mm, and heating rate from 10 to 30 °C/min. The maximum bio-oil yield of 48.5 wt% at the pyrolysis temperature of 450°C was obtained at the particle size of 1.0 mm and at the heating rate of 30 °C/min. The bio-oil product was analyzed for physical, elemental, and chemical composition using Fourier transform infrared spectroscopy and gas chromatography spectroscopy. The bio-oil contains mostly phenols, alkanes, alkenes, saturated fatty acids and their derivatives. According to the experimental results, the pyrolysis bio-oil can be used as low-grade fuel having heating value of 18.63 MJ/kg and feedstock for chemical industries.     

Pyrolysis of Xanthium strumarium in a fixed bed reactor: Effects of boron catalysts and pyrolysis parameters on product yields and character

Pyrolysis of Xanthium strumarium has been performed in a fixed-bed tubular reactor with boron minerals (ulexite, colemanite, and borax) and without catalyst at three different temperatures ranging from 350°C to 550°C with heating rate of 50°C/min. The amounts of bio-oil, bio-char, and gas generated, also the compositions of the resulting bio-oils were identified by GC-MS and FT-IR. The influences of pyrolysis parameters, such as temperature and catalyst on product yields were investigated. Temperature and catalyst were found to be the main factors affecting the conversion of Xanthium strumarium into solid, liquid, and gaseous products. The highest liquid yield (27.97%) including water was obtained with 10% colemanite (Ca₂B₆O₁₁.5H₂O) catalyst at 550°C temperature at a heating rate of 50°C/min when 0.224 > D_p > 0.150 mm particle size raw material and 100 cm³/min of sweeping gas flow rate were used.     

Product distribution from solar pyrolysis of agricultural and forestry biomass residues

Solar pyrolysis of pine sawdust, peach pit, grape stalk and grape marc was conducted in a lab-scale solar reactor for producing fuel gas from these agricultural and forestry by-products. For each type of biomass, whose lignocellulose components vary, the investigated parameters were the final temperature (in the range 800°C–2000 °C) and the heating rates (in the range 10–150 °C/s) under a constant sweep gas flow rate of 6 NL/min. The parameter influence on the pyrolysis product distribution and syngas composition was studied. The experimental results indicate that the gas yield generally increases with the temperature and heating rate for the various types of biomass residues, whereas the liquid yield progresses oppositely. Gas yield as high as 63.5wt% was obtained from pine sawdust pyrolyzed at a final temperature of 2000 °C and heating rate of 50 °C/s. This gas can be further utilized for power generation, heat or transportable fuel production.     

Fixed-Bed Pyrolysis of Hazelnut (Corylus Avellana L.) Bagasse: Influence of Pyrolysis Parameters on Product Yields

Fixed-bed slow pyrolysis experiments have been conducted on a sample of hazelnut bagasse to determine particularly the effects of pyrolysis temperature, heating rate, particle size and sweep gas flow rate on the pyrolysis product yields. The temperature of pyrolysis, heating rate, particle size and sweep gas flow rate were varied in the ranges 350–550° C, 10 and 50° C/min, 0.224–1.800 mm and 50–200 cm³/min, respectively. Under the various pyrolysis conditions applied in the experimental studies, the obtained char, liquid, and gas yield values ranged between 26 and 35 wt%, 23 and 34.40 wt%, and 25 and 32 wt%, respectively. The maximum biooil yield of 34.40% was obtained at the final pyrolysis temperature of 500°C, with a heating rate of 10° C/min, particle size range of 0.425–0.600 mm and a sweep gas flow rate of 150 cm³/min.     

Understanding the pyrolysis behavior of agriculture,forest and aquatic biomass: Products distribution and characterization

Pyrolysis studies on agricultural (rice straw), forest (pine) and aquatic (Ulva lactuca) biomass were carried out in a fixed bed reactor at different temperature range of 300–550 °C. The product distributions and their characterization of products were compared among these biomasses. The maximum liquid product yield 29.4, 57.5 and 25.6 wt% obtained at 400, 500 and 400 °C respectively from rice straw (RS), pine (PN) and Ulva lactuca (UL) biomass. However, the higher conversion was observed in the case of pine wood biomass 77.0% at 550 °C. From the GC-MS analysis, it is observed that RS and PN bio-oil mostly composed of derivatives of phenolic compounds, while UL bio-oil composed of cyclopentenone derivatives compounds. The highest higher heating value (HHV) was found in pine bio-oil 34.8 MJ/kg. Also PN pyrolytic bio-oil had higher boiling point differences compounds. The bio-char analysis showed that the PN bio-char is a carbon rich and porous in nature as compared to the RS and UL bio-char.     

Investigating the potential for energy,fuel, materials and chemicals production from corn residues (cobs and stalks) by non-catalytic and catalytic pyrolysis in two reactor configurations

The results of thermogravimetric analysis (TGA), non-catalytic and catalytic pyrolysis of corn cobs and corn stalks are reported in this paper. Pyrolysis took place in two different reactor configurations for both feedstocks: (1) fast pyrolysis in a captive sample reactor; and (2) non-catalytic slow pyrolysis and catalytic pyrolysis in a fixed-bed reactor. Experiments were carried out in atmospheric pressure at three temperatures: low temperature (360–380 °C), medium temperature (500–600 °C) and at high temperature (600–700 °C). The results of the experimental study were compared with data reported in the literature. Investigating the potential of corn residues for energy, fuel, materials and chemicals production according to their thermochemical treatment products yields and quality, it can be stated that: (a) corn stalks could be suitable raw material for energy production via gasification at high temperature, due to their medium low heating value (LHV) of pyrolysis gas (13–15 MJ/m³); (b) corn cob could be a good solid biofuel, due to the high LHV (24–26 MJ/kg) of the produced char; (c) additionally, corn cobs could be a good material for activated carbon production after being activated or gasified with steam, due to its high fixed carbon content(～74 wt%); (d) liquid was the major pyrolysis product from catalytic pyrolysis (about 40–44 wt% on biomass) for both feedstocks; further analysis of the organic phase of the liquid products were hydrocarbons and phenols, which make them interesting for chemicals production.     

Hydrogen from empty cotton boll agro-waste via thermochemical route and feasibility study of operating an IC engine in continuous mode

Hydrogen can be cited as prospective source of clean power. In this work hydrogen rich syn-gas generated from the agro-waste, empty cotton bolls was injected into an IC engine in continuous mode along with gasoline. At the air-fuel ratio of 23.40, specific fuel consumption of 0.35 kg kWh^?1, the engine could be operated with higher efficiency than with gasoline alone. A distinct reduction in emission characteristics could also be seen. Empty cotton bolls derived after removal of cotton from the flower in field, was first studied for fuel properties. The reasonably high heating value (HHV) of 17.54 MJ kg^?1 suggested that it could be a precursor to hydrogen via two stepped thermo-chemical process. The first step involved slow pyrolysis of the biomass at 500 °C for 60 min at a heating rate of 10 °C min^?1 yielding 39.71% bio-char by weight. The C, H, N, S and O contents of the produced bio-char was 59.91, 2.91, 0.72, 0.47 and 35.99% respectively and its HHV was 26.7 MJ kg^?1. Steam gasification of this bio-char, at 700 °C and water flowrate of 7 mL min^?1 exhibited maximum hydrogen yield of 67.42% (v/v) in the syn-gas mixture. Subsequent enrichment of the gas using ethanolamine/ethylene diamine and KMnO₄ solutions resulted in more than 90% (v/v) hydrogen in the combustible gas mixture and the test engine could be effectively operated.     

Pyrolysis of giant mullein (Verbascum thapsus L.) in a fixed-bed reactor: Effects of pyrolysis parameters on product yields and character

Slow pyrolysis of giant mullein (Verbascum thapsus L.) stalks have been carried out in a fixed-bed tubular reactor with (Al₂O₃, ZnO) and without catalyst at four different temperatures between 400 to 550°C with a constant heating rate of 50°C/min and with a constant sweeping gas (N₂) flow rate of 100 cm³/min. The amounts of bio-char, bio-oil, and gas produced were calculated and the compositions of the obtained bio-oils were determined by gas chromatography-mass spectrometry. The effects of pyrolysis parameters, such as temperature and catalyst, on the product yields were investigated. The results show that both temperature and catalyst have significant effects on the conversion of Verbascum thapsus L. into solid, liquid, and gaseous products. The highest liquid yield of 40.43% by weight including the aqeous phase was obtained with 10% zinc oxide catalyst at 500°C temperature. Sixty-seven different products were identified by gas chromatography-mass spectrometry in the bio-oils obtained at 500°C temperature.     

Study of bio-oil and bio-char production from algae by slow pyrolysis

This study examined bio-oil and bio-char fuel produced from Spirulina Sp. by slow pyrolysis. A thermogravimetric analyser (TGA) was used to investigate the pyrolytic characteristics and essential components of algae. It was found that the temperature for the maximum degradation, 322 °C, is lower than that of other biomass. With our fixed-bed reactor, 125 g of dried Spirulina Sp. algae was fed under a nitrogen atmosphere until the temperature reached a set temperature between 450 and 600 °C. It was found that the suitable temperature to obtain bio-char and bio-oil were at approximately 500 and 550 °C respectively. The bio-oil components were identified by a gas chromatography/mass spectrometry (GC–MS). The saturated functional carbon of the bio-oil was in a range of heavy naphtha, kerosene and diesel oil. The energy consumption ratio (ECR) of bio-oil and bio-char was calculated, and the net energy output was positive. The ECR had an average value of 0.49.     

Fuel gas production from dusty tar pyrolysis

Dusty tar is an undesired product obtained from a coal pyrolysis/combustion system. Thermal conversion of dusty tar into fuel gas was studied with a fixed-bed reactor. It is found that C₂-C₅ hydrocarbons are mainly derived from the cracking of long-chain aliphatics, while CH₄ from the decomposition of long-chain aliphatics and alkyl-substituted aromatic chemicals. The yield of the gas product increases monotonously, but the heating value of gas gradually decreases as temperature increases from 400 to 950°C. Decomposition of chemicals with a boiling point over 360°C contributes to 50–90% C₁-C₅ hydrocarbons and CO_x when pyrolysis temperature is lower than 600°C.     

Co-pyrolysis of waste polypropylene and rice bran wax‒ production of biofuel and its characterization

The present study aims to investigate the interaction during co-pyrolysis of Polypropylene (PP) and Rice bran wax (RBW). Initial characterization of feedstock was found to be suitable to carry out further experimental sets. Further, the pyrolysis experiments of PP, RBW and different blends (1:1, 1:2, 1:3, 2:1 and 3:1) were carried out in a semi-batch reactor. As per TGA analysis the temperature range between 400 °C and 650 °C at a constant heating rate of 25 °C/min was determined. The maximum liquid yield of PP, RBW was approximately 76%, 86% at the temperature of 500 °C and 600 °C respectively. Whereas maximum liquid yield from co?pyrolysis was obtained at 1:3 blend i.e. 81% at 550 °C.GC?MS results inferred the highest percentage of hydrocarbon whereas 1:3 blends has lower oxygen containing groups than RBW in liquid products. FTIR data of all blends indicates higher range of alkyl and aromatic compounds. H1 NMR results also confirmed the higher compounds into aliphatic region than aromatics or heteroaromatics groups. Further, most of the fuel properties of 1:3 blend falls within the range of gasoline and diesel properties. Study was extended to know crystallization behaviour of fuel by DSC analysis from two consecutive heating and cooling cycles of ?50 to 60 °C and reversed till ?50 °C at 10 °C min ?1. Two peaks at ?24 °C and 26 °C were observed during heating cycle whereas single peak at 23 °C during cooling cycle. 1:3 blend residual char characterization was also included in the work. Unfortunately, the SEM and BET results inferred that the char was not highly porous.     

Pyrolysis of waste pomegranate peels for bio-oil production

In order to obtain bio-oil from the pomegranate peel which is a by-product of juice production process, the dried pomegranate peel was pyrolyzed at a heating rate of 10°C/min and different temperatures between 400 and 550°C. The highest pyrolytic oil yield of 40.47 wt% was obtained at the final temperature of 550°C. The oil product was characterized by various analysis techniques. The results showed that the oil product mostly contained fine chemicals with oxygen like phenols, furfural, and its derivatives with the carbon number in a range of C₃-C₁₀. The oil product had the potential for producing fine chemicals.     

Slow catalytic pyrolysis of rapeseed cake: Product yield and characterization of the pyrolysis liquid

The performance of three catalysts during slow catalytic pyrolysis of rapeseed cake from 150 to 550 °C over a time period of 20 min followed by an isothermal period of 30 min at 550 °C was investigated. Na₂CO₃ was premixed with the rapeseed cake, while γ-Al₂O₃ and HZSM-5 were tested without direct biomass contact. Catalytic experiments resulted in lower liquid and higher gas yields. The total amount of organic compounds in the pyrolysis liquid was considerably reduced by the use of a catalyst and decreased in the following order: non-catalytic test (34.06 wt%) > Na₂CO₃ (27.10 wt%) > HZSM-5 (26.43 wt%) > γ-Al₂O₃ (21.64 wt%). In contrast, the total amount of water was found to increase for the catalytic experiments, indicating that dehydration reactions became more pronounced in presence of a catalyst. All pyrolysis liquids spontaneously separated into two fractions: an oil fraction and aqueous fraction. Catalysts strongly affected the composition and physical properties of the oil fraction of the pyrolysis liquid, making it promising as renewable fuel or fuel additive. Fatty acids, produced by thermal decomposition of the biomass triglycerides, were converted into compounds of several chemical classes (such as nitriles, aromatics and aliphatic hydrocarbons), depending on the type of catalyst. The oil fraction of the pyrolysis liquid with the highest calorific value (36.8 MJ/kg) was obtained for Na₂CO₃, while the highest degree of deoxygenation (14.0 wt%) was found for HZSM-5. The aqueous fraction of the pyrolysis liquid had opportunities as source of added-value chemicals.     

7-ethylindole: A new efficient liquid organic hydrogen carrier with fast kinetics

We report a discovery of a new member of the liquid organic hydrogen carrier (LOHC) family, 7-ethylindole (7-EID), with a low melting point of ?14 °C and a decent hydrogen content of 5.23 wt%. Hydrogenation of the compound was carried out over a commercial 5 wt% Ru/Al₂O₃ catalyst in the H₂ pressure range of 5–8 MPa and a temperature range of 120–160 °C, respectively. It was found that the hydrogenation rate positively correlates with the reaction temperature. However, the rate was barely effected by the H₂ pressure if the pressure exceeds 6 MPa. The estimated apparent activation energy of 7-EID hydrogenation is 51.5 kJ/mol. The fully hydrogenated product, octahydro-7-ethylindole (8H-7-EID), was used as the reactant for the dehydrogenation reaction at 170–200 °C over a 5 wt% Pd/Al₂O₃ catalyst. Full dehydrogenation of 8H-7-EID to 7-EID can be achieved within 270 min at 190 °C. The apparent activation energy of 8H-7-EID dehydrogenation was calculated to be 101.9 kJ/mol at 170–200 °C. The liberated H₂ was found to be of high purity, which meets the requirement of proton exchange membrane fuel cells.     

A comparative study on the quality of bioproducts derived from catalytic pyrolysis of green microalgae Spirulina (Arthrospira) plantensis over transition metals supported on HMS-ZSM5 composite

This study investigated three different types of catalysts: Ni/HMS-ZSM5, Fe/HMS-ZSM5, and Ce/HMS-ZSM5 in the thermochemical decomposition of green microalgae Spirulina (Arthrospira) plantensis. First, non-catalytic pyrolysis tests were conducted in a temperature ranges of 400–700 °C in a dual-bed pyrolysis reactor. The optimum temperature for maximized liquid yield was determined as 500 °C. Then, the influence of acid washing on bio-products upgrading was studied at the optimum temperature. Compared to the product yields from the pyrolysis of raw spirulina, a higher bio-oil yield (from 34.488 to 37.778 %wt.) and a lower bio-char yield (from 37 to 35 %wt.) were observed for pretreated spirulina, indicating that pretreatment promoted the formation of bio-oil, while it inhibited the formation of biochar from biomass pyrolysis. Finally, catalytic pyrolysis experiments of pretreated-spirulina resulted that Fe as an active phase in catalyst exhibited excellent catalytic activity, toward producing hydrocarbons and the highest hydrogen yield (3.81 mmol/gr spirulina).     

Non-isothermal pyrolysis of the mixtures of waste automobile lubricating oil and polystyrene in a stirred batch reactor

Kinetic tests on pyrolysis of the mixture of waste automobile lubricating oil (WALO) and polystyrene (PS) were carried out with a thermogravimetric analysis (TGA) technique at a heating rate of 0.5 °C/min, 1.0 °C/min and 2.0 °C/min in a stirred batch reactor. WALO and PS were mainly decomposed 400–455 °C and 370–410 °C, respectively. The mixture of WALO and PS, however, was decomposed between 355 °C and 470 °C, and decomposition proceeded in two broad steps. The apparent activation energies for the pyrolysis of WALO/PS mixture were in the range of 176 kJ mol⁻¹–369 kJ mol⁻¹ at various conversions of 1–100%. The effect of heating rate on the product distribution was studied. The carbon number distribution of the produced oil shifted slightly to light hydrocarbons with a decrease in heating rate. The selectivity of hydrocarbons corresponding to the styrene monomer was high for the pyrolysis of the WALO/PS mixture.     

Pyrolysis of pressure-sensitive adhesive wastes in a fixed-bed reactor

Pyrolysis of pressure-sensitive adhesive (PSA) wastes have been investigated in a fixed-bed reactor with a heating rate of 20°C/min. PSA pyrolysis mainly occurs between 300 and 600°C. The maximum liquid yield was obtained at 550°C with a yield of 55.69%. Liquid product can be used as fuel or raw material for purifying 2-ethyl-1-hexanol, dehydroabietic acid, 2,4-dimethyl-1-heptene, and styrene. The main composition in gas is CO and CO₂, followed by CH₄ and H₂. High content of ash in char limits the application in fuel, but might be used as an adsorption material after upgrading.     

Thermal – Catalytic cracking of real MSW into Bio-Crude Oil

The thermal decomposition method has been able to convert of real municipal solid waste (MSW) into Bio-Crude Oil (BCO) which is mainly contained hydrocarbon fuel such as light oil (gasoline) and heavy oil (diesel). By this method, sustainable MSW management and energy problem can be considered. Hence, this research was conducted the pyrolysis experimental to BCO production from the real MSW under thermal and catalytic pyrolysis at 400 °C and 60 min for time reaction. To increase the BCO yield in this study, the natural activated zeolite as a catalyst was employed. BCO was analyzed by Gas chromatography–mass spectrometry (GC–MS) which it can be used to identify carbon number range by percentage of peak areas. It was found that the catalytic pyrolysis has performances better than the thermal pyrolysis. Both of thermal and catalytic pyrolysis were the produce of BCO around 15.2 wt% and 21.4 wt% respectively with the main organic components are gasoline and diesel. Furthermore, paraffin and olefin fraction are major species in the gasoline and diesel. It can be concluded that the content of MSW and their processes has an impact on the fuel produced. In the thermal cracking produce BCO with higher content in the gasoline range. More plastic in MSW is also produce more gasoline while more biomass produces more in diesel range.     

Thermal decomposition behavior,characterization and evaluation of pyrolysis products of agricultural wastes

Thermal decomposition behavior during pyrolysis, the composition and the physicochemical characteristics of the pyrolysis products were studied for four agricultural wastes from Southern Greece. These wastes are produced in abundance in the Mediterranean Region but still remain relatively unexploited, while there is also lack or little relevant scientific information. Pyrolysis process for the examined samples was studied using a TGA analyzer and a properly tested and calibrated TG/MS setup, at a heating rate of 10 °C/min up to 850 °C. Determination of important quantitative parameters of pyrolysis as a function of temperature, on an instantaneous or integral basis, and correlation of the evolved gas results with the degradation of pseudocomponents of raw biomass was made possible. The average higher heating value of the pyrolysis light gases was found to be in a satisfactory for energy purposes range of 11.2–14.4 MJ/Nm³. Furthermore, biochars produced at 450, 550 and 650 °C in a fixed bed reactor were found to exhibit calorific value ranging from 20.1 to 28.7 MJ/kg and structural stability. They were also found to have a high nutrients content and below limits or negligible heavy metals content for soils applications, regardless of production temperature.