Bio‐oil production from rapid pyrolysis of cottonseed cake: product yields and compositions

Fixed‐bed fast pyrolysis experiments have been conducted on a sample of cottonseed cake to determine the effects of pyrolysis temperature, heating rate and sweep gas flow rate on pyrolysis yields and chemical compositions of the product oil. The liquid products and the subfractions of pentane soluble part were characterized by elemental analysis, FT‐IR spectroscopy, ¹H‐NMR spectroscopy and pentane subfraction was analysed by gas chromatography. The maximum oil yield of 34.8% was obtained at final temperature of 550°C with a heating rate of 700°C min^?1 and nitrogen flow rate of 100 cm³ min^?1. Chromatographic and spectroscopic studies on bio‐oil have shown that the oils obtained from cottonseed cake can be used as a renewable fuel and chemical feedstock. Copyright © 2005 John Wiley & Sons, Ltd.     

Bio-oil Production from an Oilseed By-product: Fixed-bed Pyrolysis of Olive Cake

Abstract

A study of pyrolysis of olive cake at the temperature range from 400°C to 700°C has been carried out. The experiments were performed in a laboratory scale tubular reactor under nitrogen atmosphere. The yields of derived gases, liquids, and char were determined in relation to pyrolysis temperature and sweeping gas flow rates, at heating rates of about 300°C min^?1. As the pyrolysis temperature was increased, the percentage mass of char decreased whilst gas product increased. The oil products increased to a maximum value of ～39.4 wt% of dry ash free biomass at a pyrolysis temperature of about 550°C in a nitrogen atmosphere with flow rate of 100 mL min^?1 and with a heating rate of 300°C min^?1. Results showed that the bio-oil obtained under the optimum conditions is a useful substitute for fossil fuels or chemicals.     

Comparison of catalytic and noncatalytic pyrolysis and product yields of some waste biomass species

The products obtained by fast pyrolysis of biomass can be used as an energy source or chemical raw material. In this study, samples of hazelnut shells, tea bush, and hazelnut knot selected as waste biomass were from the cities of Trabzon and Rize in the Eastern Black Sea Region. Firstly, the waste biomass samples were granulated into four different particle sizes by milling and sieving operations. Fast pyrolysis of the samples with specific mixing rates was carried out in a fixed bed reactor. Additionally, 2 wt% vanadium (V) oxide (V₂O₅) was used as catalyst to maximize the yield of pyrolysis liquid products. The influence of temperature, heating rate, and particle size on fast pyrolysis yields under both catalytic and noncatalytic conditions were investigated and compared. While the amount of liquid product increased with the addition of catalyst, the amount of solid products decreased. It has been found that the temperature and heating rate parameters are very effective in liquid product yield. In all experiments, the maximum liquid yield was acquired at the same heating rate of 450°C min^?1 and the temperature of 450°C with particle size of 0.5 to 1.0 mm. The maximum pyrolysis liquid (bio‐oil) was obtained with catalytic pyrolysis, and this value was 60.58 wt%.     

Experimental analysis of pyrolysis of sewage sludge

Pyrolysis is a thermal process where organic materials such as biomass and oil are decomposed and lighter materials such as gas, vapor, liquid products, and char are produced. The aim of this study was to investigate the pyrolysis behavior of sewage sludge in different operating conditions. Using a fixed bed, the influence of some important parameters such as pyrolysis temperature, heating rate, particle size, and N₂ flow rate on product yields was studied. Results showed that with increase in temperature from 400 to 700°C, the char yield decreased from 30.1 to 7.50%, while the gas yield increased from 35.8 to 52.4%. The gas yield also increased from 46.9 to 49.1% as the heating rate increased from 20 to 60°C/s, while the oil yield increased from 45.2 to 46.8% as heating rate increased to 40°C/s and then the increase leveled off.     

Impact of fast and slow pyrolysis on the degradation of mixed plastic waste: Product yield analysis and their characterization

This work primarily investigated the pyrolysis of post-consumer mixed plastic wastes during slow pyrolysis (non-isothermal) in a batch reactor to assess the effect of different heating rates on the product yield and its composition. The effect of residence time during fast pyrolysis (Isothermal) in Pyro-GC was also investigated. Initially, TG analysis was performed to investigate the degradation temperature range at different heating rates of 5, 10, 20 and 40 °C/min. Two different heating rates of 10 and 20 °C/min were selected for examining the effect on products such as oil and gases (H₂, CO, CO₂ and C₁-C₆ hydrocarbons) during slow pyrolysis. The oil obtained at higher heating rate had higher density (0.743 kg/m³) while the amount of residue decreased with the increase in heating rate. Also, the effect of residence time during fast pyrolysis was investigated using Pyro-GC at 500 °C for the product formation. It was observed that an optimum residence time of 10sec was favourable for the higher production of lower hydrocarbons (C₁-C₃) and less production of heavier hydrocarbons (C₆). This work represents the combined analysis of fast and slow pyrolysis and their impact on the product yield. Also, the effect of heating rate on non-isothermal condition and the effect of the residence time of volatiles in isothermal condition was analysed and reported.     

Energy Applications of Biomass: Pyrolysis of Apricot Stone

Apricot stone (Prunus armeniaca L.) was pyrolyzed in a directly heated fixed-bed reactor under nitrogen atmosphere. Effects of sweeping gas flow rates and pyrolysis temperature on the pyrolysis of the biomass were also studied. Pyrolysis runs were performed using reactor temperatures between 400°C and 700°C with heating rate of about 300°C min^?1. As the pyrolysis temperature was increased, the percentage mass of char decreased while gas product increased. The product yields were significantly influenced by the process conditions. The bio-oil obtained at 550°C, at which the liquid product yield was maximum, was analyzed. It was characterized by Fourier transform infrared spectroscopy (FT-IR). In addition, the solid and liquid products were analyzed to determine their elemental composition and calorific value. Chemical fractionation of bio-oil showed that only low quantities of hydrocarbons were present, while oxygenated and polar fractions dominated.     

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.     

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.     

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.     

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.     

Energy production from the pyrolysis of waste biomasses

Pyrolysis of waste biomasses was carried out at the temperatures of 450 and 500°C by heating at 5°C min^?1. Products were collected from emitted gases in a nitrogen purge stream; condensable liquids in the gases were collected by condensation. Gaseous, condensed liquid products and residual solids were collected and analyzed. Condensates were extracted with ether to recover the bio oils (BOs). The maximum liquid yield was obtained from the pyrolysis of soybean oil cake (SBOC) at 500°C with a yield of 60% ca. The BO was higher in the case of SBOC than that of sunflower oil cake (SFOC) at the temperatures of 450 and 500°C. With increasing temperature, bio char yield from the pyrolysis of SFOC decreased, while the liquid yield increased. The increase in temperature did not significantly affect the product distribution for the pyrolysis of SBOC. The compositions of BOs were similar for both SBOC and SFOC. Phenols, phenol derivatives including guaiacols and alkyl‐benzenes were the most common and predominant in BOs from both the pyrolysis of SBOC and SFOC. Carbon dioxide was the major gas product for both SBOC and SFOC. Copyright © 2008 John Wiley & Sons, Ltd.     

Transformation and release of potassium during fixed-bed pyrolysis of biomass

To study the release and transformation of fuel K during rapid pyrolysis of biomass, wheat straw, corn stalk and rice hull are pyrolyzed in a fixed-bed reactor system during 400–1000 °C, and weight measurement, elemental composition analysis, and chemical fractionation analysis are performed. The effects of fuel type, pyrolysis temperature, co-pyrolysis of different fuels, and water washing pretreatment are discussed. The results show that for all biomass fuels, the released K is far less than the water-soluble K and a sudden increase occurs in the fraction of ion-exchangeable K at 400 °C, whereas a significant increase happens in the fraction of insoluble K above 800 °C. Wheat straw releases less than 5% of K at 400 and 500 °C. As temperature rises, the K release increases abruptly and around 40% of K enters the gas phase at 1000 °C. Rice hull has a slow and linear K release with increasing pyrolysis temperature. Corn stalk has the lowest K release during 400–800 °C. Co-pyrolysis of wheat straw and rice hull reduce the K release at 1000 °C, and the biggest decrement is 0.76 mg g^?1. Water washing removes all the water-soluble K of corn stalk and part of ion-exchangeable K enters the gas phase during pyrolysis of the washed sample. Water washing decreases the K release from 2.77 to 0.18 mg g^?1 at 1000 °C.     

Semi-quantitative and multivariate analysis of the thermal degradation of carbon-oxygen double bonds in biomass

The aim of this paper was to investigate biomass pyrolysis using diffuse reflectance infrared Fourier transform (DRIFT) studies. The pyrolysis tests were conducted in a nitrogen atmosphere from room temperature (RT) to 600 °C. Infrared techniques provide fast, low-cost and non-destructive analysis. A combination of qualitative and quantitative analysis was applied. Pyrolysis was conducted in an environmental chamber which enabled in-situ spectral measurement. The mass of samples used in DRIFT tests was 3.0 ± 0.1 mg. A semi-quantitative analysis of the oxidation stage was performed for each biomass sample. For a variety of biomass samples, pyrolysis in the temperature range of 250–350° lead to an increase in carbon-carbon double bonds which were formed from cellulose decomposition. The research results showed that the wavenumber assigned to the CO band in carboxylic acids and esters (1742 cm^?1) depends on the temperature and varies with different biomass samples. Also, the intensity of the CO band for ketones and aldehydes (1665 cm^?1) varies with the type of biomass and the pyrolysis temperature. Principal component analysis (PCA) gave information about the similarity of reactions occurring during the pyrolysis of various biomass samples. Efficient conversion of biomass resources to energy requires accurate and detailed knowledge of chemical behaviour during degradation.     

Effect of mineral matter removal on pyrolysis of wood sawdust from an invasive species

Kinetics of the pyrolysis of wood sawdust from the invasive species Parkinsonia aculeata, untreated and demineralized by a mild acid treatment, is comparatively investigated in order to examine the effect of the removal of minerals naturally present in the biomass. Non-isothermal thermogravimetric analysis from room temperature up to 500°C is applied for this purpose. Demineralization shifts the process onset and the maximum degradation rate to higher temperatures, and leads to enhance the activation energy from 56 to 60 kJ mol^–1, pointing to a catalytic role of alkaline and alkaline earth metals in the biomass. Likewise, the three kinds of pyrolysis products (gas, bio-char, and bio-oil) are obtained from experiments performed in a bench-scale installation at 500°C. Yields and physicochemical characteristics of the pyrolysis products are determined. The pronounced reduction in the content of metals in the sawdust leads to increase bio-oil yield in around 10%, the specific surface area of the bio-char, from ≈ 2 to ≈ 74 m² g^–1, and the higher heating value of all the pyrolysis products.     

Fixed-bed pyrolysis of safflower seed: influence of pyrolysis parameters on product yields and compositions

Fixed-bed slow pyrolysis experiments have been conducted on a sample of safflower seed to determine particularly the effects of pyrolysis temperature, heating rate, particle size and sweep gas flow rate on the pyrolysis product yields and their chemical compositions. The maximum oil yield of 44% was obtained at the final pyrolysis temperature of 500°C, particle size range of +0.425–1.25 mm, with heating rate of 5°C min⁻¹ and sweep gas (N₂) flow rate of 100 cm³ min⁻¹ in a fixed-bed lab-scale reactor. Chromatographic and spectroscopic studies on the pyrolytic oil showed that the oil obtained from safflower seed can be used as a renewable fuel and chemical feedstock with a calorific value of 41.0 MJ/kg and empirical formula of CH_1.92O_0.11N_0.02.     

Effect of temperature on the fast pyrolysis of organic-acid leached pinewood; the potential of low temperature pyrolysis

In this paper, we have evaluated the potential of organic acid (mixture of acetic, formic and propionic acid) leaching of biomass and subsequent fast pyrolysis to increase the organic oil, sugars and phenols yield by varying the fluidized bed temperature between 360 °C and 580 °C (360 °C, 430 °C, 480 °C, 530 °C, and 580 °C). The pyrolysis of acid leached pinewood resulted in more organic oil and less water and residue compared to untreated pinewood over the whole temperature range. Below 500 °C the difference was most profound; for acid leached pinewood at 360 °C the organic oil was already 650 g kg⁻¹ pine with a sugar yield of 230 g kg⁻¹ pine. At this low pyrolysis temperature no bed agglomeration was observed for acid leached pine whereas at the higher temperatures tested agglomerates were found, which were identified to be clusters of fluidization sand glued together by sticky pyrolysis products (melt). Low reactor temperatures also favored the production of monomeric phenols, though their absolute yields remained low for both untreated and leached pine (maximum: 23 g kg⁻¹ pine, 80 g kg⁻¹ lignin). GPC, GC/MS and UV-fluorescence spectroscopy showed that acid leaching did not influence significantly the yield and molecular size of the aromatic fraction in the produced pyrolysis oils. Back impregnation of the removed AAEMs into leached biomass revealed that the effects of the applied acid leaching, both with respect to the product yields and bed agglomeration, can be mainly assigned to the removal of AAEMs.     

Microwave-induced pyrolysis of waste truck tyres with carbonaceous susceptor for the production of diesel-like fuel

Microwave-induced pyrolysis technique was utilised to pyrolyse waste truck tyres (TT) into useful pyrolysis oil with the aid of activated carbon. The effect of temperature was studied to determine the truck-tyre pyrolysis oil (TTPO) yield, hydrocarbon fractions, chemicals composition, energy yield and fuel properties. The activated carbon functions as microwave absorber to elevate the pyrolysis temperature for enhancing production of pyrolysis oil. The optimal pyrolysis temperature of 500 °C produces highest TTPO yield of 38.12 wt% with calorific value of 42.39 MJkg^?1 and energy yield of 40.55 wt%. Detailed analysis shows the TTPO contained large amount of aromatic hydrocarbons and limonene (14.29%) compared to pyrolysis oil from personal car tyre. Among the important chemical compounds also discovered in TTPO are benzene, toluene, xylene (BTX). The relative yields of toluene obtained at 400 °C is 14.85%, whereas the relative yields of benzene and xylene at 450 °C were 0.85 and 7.60%, respectively. The physiochemical properties of TTPO500 are rather similar to conventional diesel, except the slightly lower flash point and calorific value for the former. This work shows that microwave-induced pyrolysis is a promising technique to recover diesel-like fuel for use as supplemental alternative fuel.     

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.     

Catalytic co‐pyrolysis of Eichhornia Crassipes biomaѕѕ and polyethylene using waste Fe and CaCO3 catalysts

A wild aquatic plant, Eichhornia Crassipes, and polyethylene have been converted into liquid product thermo‐catalytically and cost effectively through co‐pyrolysis using batch steel pyrolyzer. The Fe and CaCO₃ catalysts were obtained as wastes from various mechanical processes. The catalytic process was compared with non‐catalytic pyrolysis. The effect of various reaction conditions was investigated in order to find out the optimized process conditions. It was found that the favorable reaction conditions were 450 °C temperature and 1‐h reaction time at a heating rate of 1 °C/s and 0.4‐mm biomass particle size. The bio‐oil yield was found to be 34.4% and 26.6% using Fe and CaCO₃ respectively with catalysts particle size of 0.4 mm at the optimized reaction conditions and 5 wt% of biomass. The non‐catalytic and catalytic co‐pyrolysis using Fe as catalyst produced 23.9% and 28.7% oil respectively. Thus the efficiency of processes in terms of bio‐oil production was found in order of: Fe > CaCO₃ > non‐catalytic pyrolysis. The GC/MS analysis of n‐hexane extract of bio‐oil shows that Fe catalyst favors formation of aliphatic hydrocarbons while CaCO₃ and non‐catalytic pyrolysis favors formation of aromatic hydrocarbons. Mostly unsaturated aliphatic hydrocarbons were formed in case of co‐pyrolysis reactions. The calorific value of bio‐oil was also measured in order to find out the fuel properties of the products. Copyright © 2016 John Wiley & Sons, Ltd.