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.     

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.     

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.     

Evaluation of influence of two different catalysts on the pyrolysis of laurel (Laurus nobilis L.) extraction residues

Laurel extraction residues with zeolite and alumina catalysts were pyrolyzed in a fixed-bed reactor with a constant heating rate of 10°C min^–1. The final pyrolysis temperature and sweep gas flow rate were kept constant at 500°C and 100 ml min^–1 in all of the experiments, respectively. The influence of catalysts and their ratio (10, 20, 30, 40, and 50% w/w) on the pyrolysis conversion and product yields were investigated in detail. The physicochemical properties of the catalytic bio-oil were determined and compared to those of non-catalytic bio-oil. The catalytic bio-oils were examined using some spectroscopic and chromatographic techniques.     

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.     

Flash pyrolysis of palmyra palm (Borassus flabellifer) using an electrically heated fluidized bed reactor

Agriculture residues such as palmyra fruit bunch are one of the biomass categories that can be utilized for conversion to bio-oil by using pyrolysis process. Flash pyrolysis experiments have been conducted in the electrically heated fluidized bed reactor to determine the effect of pyrolysis temperature, particle size, and sweep gas flow rate on the pyrolysis product yield. In this study the maximum oil yield of 48.2% was achieved at a temperature of 500°C, particle size of 1 mm, and at a sweep gas flow rate of 2 m³/h. The results show that the effects of pyrolysis temperature and particle size on pyrolysis yields are more significant than that of sweep gas flow rate. Bio-oil was identified as a biofuel candidate and it was further upgraded for better-quality biofuel. Various physical and elemental analyses were performed for bio-oil and the same characteristics study was also carried out for biofuel.     

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).     

Rapid and slow pyrolysis of pistachio shell: effect of pyrolysis conditions on the product yields and characterization of the liquid product

This study reports the experimental results for the pyrolysis of pistachio shell under different conditions in a tubular reactor under a nitrogen flow. For the different conditions of pyrolysis temperature, nitrogen flow rate and heating rate, pyrolysis temperature of 773 K gave the highest bio-oil yield with a value of 27.7% when the heating rate and carrier gas flow rate were chosen as 300 K min⁻¹ and 100 cm³ min⁻¹, respectively. Column chromatography was applied to this bio-oil and its subfractions were characterized by elemental analysis, FT-IR and ¹H-NMR. Aliphatic subfraction was conducted to gas chromatography–mass spectroscopy for further characterization. The results for the characterization show that using pistachio shell as a renewable source to produce valuable liquid products is applicable via pyrolysis. Copyright © 2006 John Wiley & Sons, Ltd.     

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.     

Characterization of bio-oil obtained from fruit pulp pyrolysis

Apricot pulps was pyrolyzed in a fixed-bed reactor under different pyrolysis conditions to determine the role of final temperature, sweeping gas flow rate and steam velocity on the product yields and liquid product composition with a heating rate of 5 °C/min. Final temperature range studied was between 300 and 700 °C and the highest liquid product yield was obtained at 550 °C. Liquid product yield increased significantly under nitrogen and steam atmospheres. For the optimum conditions, pyrolysis of peach pulp was furthermore studied. Liquid products obtained under the most suitable conditions were characterized by FTIR and ¹H-NMR. In addition, gas chromatography/mass spectrophotometer was achieved on all pyrolysis oils. Characterization showed that bio-oil could be a potential source for synthetic fuels and chemical feedstock.     

Characterization of bio-oil and its sub-fractions from pyrolysis of Scenedesmus dimorphus

In the present study, microalgae Scenedesmus dimorphus was reported for pyrolysis in a fixed-bed reactor to determine the effects of temperature on products yield and the chemical compositions of the liquid and solid products. Experiments were carried out at a temperature range of 300–600 °C with heating rate of 40 °C/min and nitrogen flow rate of 100 ml/min. The yield of bio-oil was found to be maximum (39.6%) at the temperature of 500 °C and was further fractionated into n-hexane, toluene, ethyl acetate and methanol sub-fractions by using liquid column chromatography. Various characteristics of bio-oil and its sub-fractions were determined by ¹H NMR, FTIR and GC–MS. The biochar produced as a co-product can be a potential soil amendment with multiple benefits including soil fertility and C-sequestration. The present investigation suggests the suitability of Scenedesmus dimorphus as a potential feedstock for exploitation of energy and biomaterials through pyrolytic conversion.     

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.     

Comparison of pyrolysis and hydrothermal liquefaction of Chlamydomonas reinhardtii. Growth studies on the recovered hydrothermal aqueous phase

The production of bio-oil by pyrolysis with a high heating rate (500 K s⁻¹) and hydrothermal liquefaction (HTL) of Chlamydomonas reinhardtii was compared. HTL led to bio-oil yield decreasing from 67% mass fraction at 220 °C to 59% mass fraction at 310 °C whereas the bio-oil yield increased from 53% mass fraction at 400 °C to 60% mass fraction at 550 °C for pyrolysis. Energy ratios (energy produced in the form of bio-oil divided by the energy content of the initial microalgae) between 66% at 220 °C and 90% at 310 °C in HTL were obtained whereas it was in the range 73–83% at 400–550 °C for pyrolysis. The Higher Heating Value of the HTL bio-oil was increasing with the temperature while it was constant for pyrolysis. Microalgae cultivation in aqueous phase produced by HTL was also investigated and showed promising results.     

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.     

Bio-oil production via fast pyrolysis of shrub residues in a fluidized-bed reactor

In this article, the shrub residues as raw materials were produced to fast pyrolysis oil (called bio-oil) in a 5-kg/h fluidized-bed reactor. The optimum conditions were obtained at 500°C, flow rate of fluidizing gas of 4 m³/h, and feed rate of 3 kg/h. The liquid yield was up to 60% at the optimum conditions. The bio-oil was easy to divide into two phases: oil phase and aqueous phase. The high heat value of the oil phase was up to 18.55 MJ/kg, but the high heat value of the aqueous phase was only 0.72 MJ/kg. The oil phase and aqueous phase both have lower pH values. The oxygen content was up to 50%, while the sulfur and nitrogen content were very low. Owing to the higher oxygen content and lower pH value in liquid products, it must be further upgraded to bio-oil before application.     

The characteristics of syngas production from bio-oil dry reforming utilizing the waste heat of granulated blast furnace slag

A two-stage utilization of the waste heat of granulated blast furnace slag (BFS) was proposed, and the characteristics of bio-oil dry reforming under different conditions were investigated. For the bio-oil dry reforming utilizing granulated BFS as the heat carrier, when the temperature was higher than 800 °C, changes in the characteristics as bio-oil conversion and lower heating value (LHV) were not pronounced in response to the increasing temperature. The bio-oil conversion reached its maximum value with a CO₂/C (molar ratio of CO₂ to carbon in bio-oil) of 0.85. When the liquid hourly space velocity (LHSV) was higher than 0.45 h^?1, the bio-oil conversion and LHV dropped quickly as the LHSV increased. At the optimal condition with a temperature of 800 °C, a CO₂/C of 0.85 and an LHSV of 0.45 h^?1, the bio-oil conversion and LHV reached 90.15% and 511.02 kJ per mole of bio-oil, respectively. Granulated BFS could be beneficial for the bio-oil dry reforming process. Combining biomass pyrolysis and bio-oil dry reforming, a feasible industry application utilizing the waste heat of granulated BFS was presented systematically.     

Production and detailed characterization of bio-oil from fast pyrolysis of palm kernel shell

Bio-oil has been produced from palm kernel shell in a fluidized bed reactor. The process conditions were optimized and the detailed characteristics of bio-oil were carried out. The higher feeding rate and higher gas flow rate attributed to higher bio-oil yield. The maximum mass fraction of biomass (57%) converted to bio-oil at 550 °C when 2 L min⁻¹ of gas and 10 g min⁻¹ of biomass were fed. The bio-oil produced up to 500 °C existed in two distinct phases, while it formed one homogeneous phase when it was produced above 500 °C. The higher heating value of bio-oil produced at 550 °C was found to be 23.48 MJ kg⁻¹. As GC–MS data shows, the area ratio of phenol is the maximum among the area ratio of identified compounds in 550 °C bio-oil. The UV–Fluorescence absorption, which is the indication of aromatic content, is also the highest in 550 °C bio-oil.     

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.     

Low energy consumption and high quality bio-fuels production via in-situ fast pyrolysis of reed straw by adding metallic particles in an induction heating reactor

An in-situ fast pyrolysis of biomass by adding metallic particles in an induction heating reactor was proposed to produce high quality bio-fuels. After adding metallic particles into biomass, the times required to reach complete pyrolysis during reed straw pyrolysis process were significantly reduced up to 28.9%. The yields of combustible gas and bio-oil products were significantly increased. Furthermore, higher-quality combustible gas and bio-oil products were obtained with the LHV of gas products and HHV of bio-oil (dry basis) increased by 14.2%–19.1% and 4.16%–16.35%, respectively, under 400–600 °C. The lower oxygen content and higher yields of aromatics, alkenes and alkanes contents in bio-oil were obtained after metallic particles addition. More importantly, up to 26.5% of the total energy consumption during pyrolysis process was reduced after adding metallic particles into biomass in an induction heating reactor. The results indicate that adding metallic particles into biomass in an induction heating reactor can significantly enhance the heat transfer, decomposition reaction intensity and energy utilization efficiency of biomass pyrolysis process with lower energy consumption and higher-quality bio-fuel production.     

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.