Pyrolysis of rapeseed in a free fall reactor for production of bio-oil

Pyrolysis experiments of rapeseed (Brassica napus L.) were performed in a free fall reactor at atmospheric pressure under nitrogen atmosphere. The effects of final pyrolysis temperature, particle size and sweep gas flow rate on the yields of products were investigated. The temperature of pyrolysis, particle size and sweep gas flow rate were varied in the ranges of 400—700 °C, −0.224 to 1.8 mm and 50–400 cm³ min⁻¹, respectively. The elemental analysis and calorific value of the bio-oil were determined, and compared with diesel fuel and then the chemical composition of the bio-oil was investigated using chromatographic and spectroscopic techniques (¹H NMR, IR, column chromatography and GC/MS). The chemical characterization has shown that the bio-oil obtained from rapeseed could be use as diesel fuel and chemical feeedstock.     

Pyrolytic characteristics of Jatropha seedshell cake in thermobalance and fluidized bed reactors

Pyrolytic kinetic parameters of Jatropha seedshell cake (JSC) were determined based on reaction mechanism approach under isothermal condition in a thermobalance reactor. Avrami-Erofeev reaction model represents the pyrolysis conversion of JSC waste well with activation energy of 36.4 kJ mol^?1 and frequency factor of 9.18 s^?1. The effects of reaction temperature, gas flow rate and feedstock particle size on the products distribution have been determined in a bubbling fluidized bed reactor. Pyrolytic bio-oil yield increases up to 42 wt% at 500 °C with the mean particle size of 1.7 mm and gas flow rate higher than 3U _mf , where the maximum heating value of bio-oil was obtained. The pyrolytic bio-oil is characterized by more oxygen, lower HHVs, less sulfur and more nitrogen than petroleum fuel oils. The pyrolytic oil showed plateaus around 360 °C in distribution of components’ boiling point due to high yields of fatty acid and glycerides.     

Characterization of products from slow pyrolysis of palm kernel cake and cassava pulp residue

Slow pyrolysis studies of palm kernel cake (PKC) and cassava pulp residue (CPR) were conducted in a fixed-bed reactor. Maximum liquid yield (54.3 wt%) was obtained from PKC pyrolysis at 700 °C, heating rate of 20 °C/min, N₂ gas flow rate of 200 cm³/min and particle size of 2.03 mm. Fuel properties of bi-oils were in following ranges: density, 1.01–1.16 g/cm³; pH, 2.8–5.6; flash point, 74–110 °C and heating value, 15 MJ/kg for CPR oil and 40 MJ/kg for PKC oil. PKC oil gave main contents of n-C₈–C₁₈ carboxylic acids, phenols, and esters, whereas CPR oil gave the highest amount of methanol soluble fraction consisting of polar and non-volatile compounds. On gas compositions, CPR pyrolysis gave the highest yield of syngas produced, while PKC pyrolysis offered the highest content of CO₂. Pyrolysis chars possessed high calorific values in range from 29–35 MJ/kg with PKC char showing a characteristic of reasonably high porosity material.     

Fixed-bed pyrolysis of cotton stalk for liquid and solid products

The pyrolysis of cotton stalk was studied for determining the main characteristics and quantities of liquid and solid products. Particular variables investigated were temperature (from 400 °C to 700 °C), particle sizes (from 0.25 mm to 1.8 mm) and nitrogen gas flow rate (from 50 and 400 cm³/min). All experiments were performed at a heating rate of 7 °C/min. The results showed that particle size and nitrogen flow rate did not exert a significant influence, whereas temperature was very significant. The liquid products and the subfractions of pentane-soluble fraction were characterized by elemental analysis, FT-IR spectroscopy, ¹H-NMR spectroscopy, and the pentane subfraction was analysed by gas chromatography. The characterization of char was performed in terms of its elemental composition, surface area and FT-IR spectroscopy. The H/C and O/C ratios of the chars decreased with the rise in the temperature. FT-IR showed that results the hydroxyl and carbonyl functionalities were lost at high temperatures. According to the experimental results the liquid products can be used as liquid fuels, whereas the solid products can be transformed to activated carbon for adsorption processes.     

Catalytic pyrolysis of biomass in inert and steam atmospheres

The objective of this study was to investigate thermal conversion of a perennial shrub, Euphorbia rigida biomass sample with catalyst in inert (N₂) and steam atmospheres. Experimental studies were conducted in a well swept fixed bed reactor with a heating rate of 7 °C/min to a final pyrolysis temperature of 550 °C and with a mean particle size of 0.55 mm in order to determine the effect of different atmospheres with various catalyst ratios on pyrolysis yields and characteristics. The catalyst ratios were 5%, 10% and 20% (w/w) under nitrogen atmosphere with flow rates of 50, 100, 200 and 400 cm³/min and steam atmosphere with well-swept velocities of 12, 25 and 52 cm³/min. The optimum oil yield was obtained as 32.1% at the nitrogen flow rate of 200 cm³/min, while it was obtained as 38.6% at steam flow rate of 25 cm³/min when a 10% catalyst by weight according to the biomass was used. Higher oil yields were observed when biomass sample was treated in steam atmosphere than in inert (N₂) atmosphere. The oil composition was then analysed by elemental analyses techniques such as IR and GC-MS. The oil products were also fractionated by column chromatography. The bio-oils obtained at both atmospheres contain mainly n-alkanes and alkenes, aromatic compounds; mainly benzene and derivatives and PAHs, nitrogenated compounds and ketones, carboxylic acids, aldehydes, phenols and triterpenoid compounds. More oxygenated compounds and less substituted alkanes and alkenes were obtained in catalytic pyrolysis of E. rigida in the steam atmosphere. The experimental and chemical characterisation results showed that the oil obtained from perennial shrub, E. rigida can be used as a potential source of renewable fuel and chemical feedstock.     

Bio-oil from olive oil industry wastes: Pyrolysis of olive residue under different conditions

Olive residues were pyrolysed 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 7 °C/min. Final temperature range studied was between 400 and 700 °C and the highest liquid product yield was obtained at 500 °C. Liquid product yield increased significantly under nitrogen and steam atmospheres. Liquid products obtained under the most suitable conditions were characterised by elemental analyses, FT-IR and ¹H-NMR. In addition, column chromatography was employed and the yields of the sub-fractions were calculated. Gas chromatography was achieved on n-pentane fractions. The results show that it is possible to obtain liquid products similar to petroleum from olive residue if the pyrolysis conditions are chosen accordingly.     

Bio-oil from olive oil industry wastes: Pyrolysis of olive residue under different conditions

Olive residues were pyrolysed 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 7 °C/min. Final temperature range studied was between 400 and 700 °C and the highest liquid product yield was obtained at 500 °C. Liquid product yield increased significantly under nitrogen and steam atmospheres. Liquid products obtained under the most suitable conditions were characterised by elemental analyses, FT-IR and ¹H-NMR. In addition, column chromatography was employed and the yields of the sub-fractions were calculated. Gas chromatography was achieved on n-pentane fractions. The results show that it is possible to obtain liquid products similar to petroleum from olive residue if the pyrolysis conditions are chosen accordingly.     

Pyrolysis characteristics of Oriental white oak: Kinetic study and fast pyrolysis in a fluidized bed with an improved reaction system

The kinetic parameters for the pyrolysis of Oriental white oak were evaluated by thermogravimetric analysis (TGA). The white oak was pyrolyzed in a fluidized bed reactor with a two-staged char separation system under a variety of operating conditions. The influence of the pyrolysis conditions on the chemical and physical characteristics of the bio-oil was also examined. TGA showed that the Oriental white oak decomposed at temperatures ranging from 250 to 400 °C. The apparent activation energy ranged from 160 to 777 kJ mol^− 1. The optimal pyrolysis temperature for the production of bio-oil in the fluidized bed unit was between 400 and 450 °C. A much smaller and larger feed size adversely affected the production of bio-oil. A higher fluidizing gas flow and higher biomass feeding rate were more effective in the production of bio-oil but the above flow rates did not affect the bio-oil yields significantly. Recycling a part of the product gas as a fluidizing medium resulted the highest bio-oil yield of 60 wt.%. In addition, high-quality bio-oil with a low solid content was produced using a hot filter as well as a cyclone. With exception of the pyrolysis temperature, the other pyrolysis conditions did not significantly affect the chemical and physical characteristics of the resulting bio-oil.     

Production and characterization of bio-oil and biochar from ablative pyrolysis of lignocellulosic biomass residues

Abstract

Agricultural residues are one of the large untapped sources of bio-energy in Thailand, with over 30 million tons available per year. They may be utilized to generate renewable liquid and solid fuels. In this work, pyrolysis of lignocellulosic biomass residues (corncobs, coconut shells, and bamboo residue) was carried out in an ablative pyrolysis reactor with rotating blades. Influences of inert carrier gas flows (5–15?L/min) and rotating frequency (4–8?Hz) at a fixed hot plate temperature of 500?°C on generating bio-oil were investigated. Characterization of bio-oil as well as biochar products was performed. Maximum bio-oil yield was found to be about 50% w/w for coconut shell at 5?L/min of flowrate and 8?Hz of the rotating frequency, and 45% w/w for bamboo residues at the same condition. For corncob, the highest bio-oil yield was 72% w/w at 5?L/min of flowrate and 6?Hz of the rotating frequency. Solid char yields were around 23–28% w/w. The heating values of the liquid oil and solid char were about 20–25 and 23–30?MJ/kg, respectively. Rotating blade ablative reactor was able to generate high yields of bio-oil for agricultural residues. The main compounds of the bio-oil obtained were phenolics, including furfuran, organic acids, aldehydes, alcohols, ethers, and ketones.     

Biofuel production using slow pyrolysis of the straw and stalk of the rapeseed plant

Amongst the renewable alternative energy sources, biomass has a large potential for commercial usage. Pyrolysis is the most important among the thermal conversion processes of biomass. In this study, slow pyrolysis of the straw and stalk of the rapeseed plant was investigated within a tubular reactor under the conditions of static atmosphere, varying temperatures of 350°, 450°, 550° and 650°C and at heating rates of 10°C min⁻¹ and 30°C min⁻¹. The maximum liquid yield was observed to be evolving at 650°C pyrolysis temperature and at a heating rate of 30°C min⁻¹. The various characteristics of pyrolytic oil obtained under these conditions were identified. Following the chemical characterization, the pyrolytic oil originated from the straw and stalk of the rapeseed plant is presented as a biofuel candidate.     

The pyrolysis of waste mandarin residue using thermogravimetric analysis and a batch reactor

A study on the pyrolysis of waste mandarin residue, with the aim of producing bio-oil, is reported. To elucidate the thermodynamics and temperature-dependency of the pyrolysis reaction of waste mandarin residue, the activation energy was obtained by thermogravimetric analysis. Mass loss occurred within the temperature range 200–750 °C, and the average activation energy was calculated to be 205.5 kJ/mol. Pyrolysis experiments were performed using a batch reactor, under different conditions, by varying the carrier gas flow rate and temperature. When the carrier gas flow rate was increased from 15 to 30 and finally to 50ml/min, the oil yield slightly increased. Experiments performed within the temperature range 400–800 °C showed the highest oil yield (38.16 wt%) at 500 °C. The moisture content in the bio-oil increased from 35 to 45% as the temperature increased from 400 to 800 °C, which also resulted in reduction of the oxygenates content and increase in the phenolics and aromatics content, indicating that temperature is an important operating parameter influencing the yield and composition of bio-oil.     

Evaporation of pyrolysis oil: Product distribution and residue char analysis

The evaporation of pyrolysis oil was studied at varying heating rates (～1–10⁶°C/min) with surrounding temperatures up to 850°C. A total product distribution (gas, vapor, and char) was measured using two atomizers with different droplet sizes. It was shown that with very high heating rates (～10⁶°C/min) the amount of char was significantly lowered (～8%, carbon basis) compared to the maximum amount, which was produced at low heating rates using a TGA (～30%, carbon basis; heating rate 1°C/min). The char formation takes place in the 100–350°C liquid temperature range due to polymerization reactions of compounds in the pyrolysis oil. All pyrolysis oil fractions (whole oil, pyrolytic lignin, glucose and aqueous rich/lean phase) showed charring behavior. The pyrolysis oil chars age when subjected to elevated temperatures (≥700°C), show similar reactivity toward combustion and steam gasification compared with chars produced during fast pyrolysis of solid biomass. However, the structure is totally different where the pyrolysis oil char is very light and fluffy. To use the produced char in conversion processes (energy or syngas production), it will have to be anchored to a carrier. © 2010 American Institute of Chemical Engineers AIChE J, 2010     

Comparative analysis of pyrolysis oils and its subfractions under different atmospheric conditions

In this paper comparative analysis of bio-oils and their subfraction from static, sweeping gas and steam pyrolysis of apricot pulp, a food industry waste, was investigated. Experimental studies were conducted in a well-swept fixed-bed reactor with a heating rate of 5 °C min^{− 1}, to a final pyrolysis temperature of 550 °C. The oil yield which was 22.4% at the static atmosphere reached to the value of 23.2% in the sweeping gas atmosphere by using 100 cm³ min^{− 1} N₂ flow rate. The yield of liquid product in steam pyrolysis was higher (27.2%) than the static and inert gas atmosphere.The elemental analyses of the pyrolysis oils were determined, and the chemical compositions of the oils were investigated using chromatographic and spectroscopic techniques. The liquid products were fractionated into pentane solubles and insolubles (asphaltenes). Pentane solubles were then solvent fractionated into pentane, toluene, and methanol subfractions by fractionated column chromatograpy. The aliphatic subfractions of the oils were then analysed by capillary column gas–liquid chromatography and GC/MS. For further structural analysis, the pyrolysis oils' aliphatic, aromatic and polar subfractions were conducted using FTIR and ¹H NMR spectra.     

Char morphology and behaviour of Australian vitrinites of various ranks pyrolysed at various heating rates

This study concerns the relative importance of rank and heating rate on the development of plasticity during pyrolysis of several Australian vitrinites. Dispersed vitrinite particles, 100 μm in diameter, were heated to 1000 °C in nitrogen at linear heating rates ranging from 10^?1 to 10⁴ °Cs^?1 in a special electrical strip furnace. When pyrolysed at 10⁴ °C s^?1 all vitrinites became plastic and vesiculated except for vitrinite from anthracite, and gelinite from brown coal. The greatest plasticity developed in bituminous-rank vitrinite. Brown coal textinite and the lower-rank sample of the two subbituminous-rank vitrinites behaved similarly, whereas the behaviour of the higher-rank subbituminous coal resembled that of the semi-anthracite sample. At heating rates of 10^?1 °C s^?1 all the vitrinites retained their original morphologies. Cenospheres began to form in the vitrinites within the heating rate range of 1 °C s^?1 (for bituminous rank) to 10² °C s^?1 (for brown coal and semi-anthracite ranks). During pyrolysis, the differences in plastic behaviour attributable to rank could largely be eliminated by changing the heating rate by two orders of magnitude. The effects attributable to plasticity related to increasing heating rates reach a limit within five orders of magnitude of heating rate (for the conditions used in this study).     

云南松热解及其热解产物的研究

采用自制固定床反应器对云南松木粉进行热解,探讨了热解温度、原料颗粒尺寸和氮气流速对云南松热解特性的影响,并采用GC-MS对生物油的组分含量进行分析。结果表明:在热解温度为500 ℃,原料颗粒尺寸为0.250~0.420 mm,氮气流速为150 mL/min条件下,生物油的产率最高为50%,液体组分主要以2,6-二叔丁基对甲酚、2-甲氧基-4-甲基苯酚、异丁香酚、愈创木酚为主,占液体总量的39.24%。     

高粱秸秆热解产物的研究

研究了热解温度、气体流量、加热速率和保温时间三个操作因素对高粱秸秆热解产物(生物油和残炭)分布的影响。结果表明,对高粱秸秆热解产物的分布有很大影响的因素是热解温度和气体流速。在热解升温速率为10℃/min、热解温度为450℃,氮气流速为100mL/min、保温时间为1h的条件下,液体收率最高。     

Breakthrough Data Analysis of Adsorption of Toluene Vapor in a Fixed‐Bed of Granular Activated Carbon

Abstract

Toluene vapor was adsorbed in a laboratory‐scale packed‐bed adsorber using granular activated carbon (GAC) at constant pressure (101.3 kPa). The adsorber was operated batchwise with the charge of GAC in the range of 2–4 g to obtain the breakthrough curves of toluene vapor. Experiments were carried out at different adsorption temperatures (25–50°C), sparger temperatures (20–30°C), and the flow rates of nitrogen (80–150 cm³/min) to investigate the effects of these experimental variables on the breakthrough curves. The deactivation model was tested for these curves by combining the adsorption of toluene vapor and the deactivation of adsorbent particles. The observed values of the adsorption rate constant and the deactivation rate constant were evaluated through analysis of the experimental breakthrough data using a nonlinear least squares technique. The experimental breakthrough data were fitted very well to the deactivation model than the adsorption isotherm models in the literature.     

Thermogravimetric characteristics of <Emphasis Type="Italic">α</Emphasis>-cellulose and decomposition kinetics in a micro-tubing reactor

The pyrolysis characteristics and kinetics of α-cellulose were investigated using thermogravimetric analyzer (TGA) and micro tubing reactor, respectively. Most of the α-cellulose decomposed between 250 and 400 °C at heating rate of 5–20 °C/min. The apparent activation energy was observed in the range of 263.02 kJ mol^?1 to 306.21 kJ mol^?1 at the conversion of 10-80%. The kinetic parameters were determined by nonlinear least-squares regression of the experimental data, assuming first-order kinetics. It was found from the kinetic rate constants that the predominant reaction pathway was A(α-cellulose) to B(bio-oil) rather than A(α-cellulose) to C(gas; C₁-C₄) and/or to B(bio-oil) to C(gas; C₁-C₄) at temperatures of 340-360 °C.     

Pyrolysis of microalgae biomass over carbonate catalysts

Microalgae are seen as potential biomass to be used in a biorefinery concept. Several technologies can be used to convert microalgal biomass, but pyrolysis is viewed as a unique pathway to obtain valuable chemicals distributed in three phases: liquid (bio-oil), gas (bio-gas) and solid (bio-char). The liquid phase, bio-oil, usually presents higher heating value than raw biomass, but acidity and oxygen content are major drawbacks. In situ catalyzed pyrolysis can help to decrease the oxygen content and acidity of pyrolytic bio-oils. Chlorella vulgaris and Scenedesmus obliquus were pyrolyzed in a fixed-bed reactor using commercial carbonate catalysts (Li₂CO₃, Na₂CO₃, K₂CO₃, MgCO₃, SrCO₃ and MnCO₃). The catalysis pyrolysis temperature (375 °C) was selected from thermal degradation profiles obtained using thermogravimetry under nitrogen flow and corresponds to the maximum degradation rate for both microalgae. In spite of similar volatile and fixed carbon contents, microalgae performed differentially during pyrolysis mainly due to the different contents of carbohydrates, oils and proteins. Chlorella vulgaris and Scenedesmus obliquus showed bio-oil yield in the range 26–38 and 28–50 wt%, respectively. Only sodium carbonate was able to decrease the bio-char yield, confirming that carbonate catalysts prompt simultaneously gasification and carbonization reactions. Fourier transform infrared spectra of produced bio-oils showed a net decrease of acidity, associated with carbonyl species when carbonate catalysts were used. Bio-char morphology, for both microalgae, showed evidence of melting and resolidification of cell structures, which might be due to the lower melting points of the pyrolysis products obtained from proteins and lipids. © 2020 Society of Chemical Industry     

Copyrolysis of block polypropylene with waste wood chip

In this study, the copyrolysis of waste wood chip (WC) and block polypropylene (PP) was studied to investigate how the characteristics of bio-oils are affected by copyrolysis. The thermogravimetric analysis performed with a temperature rise of 20 °C/min, from room temperature to 600 °C, showed that the decomposition temperature of PP was a little higher via copyrolysis than the single-component pyrolysis. This result suggests that the characteristics of the pyrolysis of PP were affected by the pyrolysis products of WC. The Py-GC/MS analysis of the copyrolysis products detected some new compounds that had not been detected in the single-component pyrolysis products, indicating interactions between the products of WC and PP pyrolyses. The results of the experiments using a fixed bed reactor showed improved properties of the bio-oil obtained from the copyrolysis compared to those of the bio-oil obtained from the single-component pyrolysis: increased carbon and hydrogen contents, decreased water content and a significantly increased heating value.