Flash pyrolysis of grape residues into biofuel in a bubbling fluid bed

The pyrolysis of two grape residues (grape skins and the mixture of grape skins and seeds) has been carried out in a pilot bubbling fluidized bed pyrolyzer operating under a range of temperature from 300 to 600 °C and three vapor residence time (2.5, 5, and 20 s), with the aim of determining their pyrolysis behavior including products yields and heat requirements. The composition of the product gases was determined, from which their heating value was calculated. The liquid bio-oil was recovered with cyclonic condensers and separated into two phases, an aqueous phase and an organic phase. The chemical composition of these liquid phases was characterized. In addition, the environmental parameters of the distilled fraction (85–115 °C) of the aqueous phase were tested, while the heating value of the organic phase was determined. Furthermore, the thermal sustainability of the pyrolysis process was estimated by considering the energy contribution of the product gases and of the liquid bio-oil in relation to the pyrolysis heat requirements. The optimum pyrolysis temperatures were identified in terms of maximizing the liquid yield, maximizing the energy from the product bio-oil, and maximizing the net energy from the product bio-oil after ensuring a self-sustainable process by utilizing the product gases and bio-oil as heat sources.     

Thermal self-sustainability of biochar production by pyrolysis

The pyrolysis of several agricultural and biofuel production residues (grape residues, sugarcane residues, dried distiller's grain, palm oil residues, apple pomace and forestry residue) has been carried out in a pilot bubbling fluidized bed pyrolyzer operating under a range of temperature from 300 to 600 °C and two vapor residence times (2 and 5 s), with the aim of determining their pyrolysis behavior including products yields and heat balance. The composition of the product gases was determined, from which their heating value was calculated. The liquid bio-oil was recovered with cyclonic condensers. The thermal sustainability of the pyrolysis process was estimated by considering the energy contribution of the product gases and of the liquid bio-oil in relation to the pyrolysis heat requirements. The most promising biomass feedstocks for the sustainable production of biochar were indentified. Furthermore, this study presented the char yield in relation to the excess heat that could be obtained by combusting the gas and bio-oil coproducts of biochar production, as functions of pyrolysis temperature and vapor residence time.     

Production of fungicidal oil and activated carbon from pistachio shell

The main objective of this study was to evaluate the feasibility of pistachio shell as a biomass feedstock for the production of fungicidal oil and a precursor for the production of activated carbon by physical activation. For this purpose, pistachio shell was pyrolyzed in a fixed bed reactor at the different temperatures (300-600 °C). The pyrolysis products were identified as gas, bio-oil, aqueous solution and char. The product distribution from pyrolysis process did not significantly change when the pyrolysis temperature was above 300 °C. The pyrolysis gas product had low calorific value since it contained the high proportion of carbon oxides. Because of their high oxygen content, the bio-oils were found not to be used as a fuel. Thus, the bio-oil was tested again four different types of fungi (pathogenetic, wood decaying and saprophyting). It was shown fungicidal activity again all tested fungi at the concentration of 10-50 mg ml⁻¹. The pyrolysis char was evaluated as a precursor for the production of activated carbon. The surface area and micropore volume of the activated carbon produced from the char by CO₂ activation at 900 °C were found to be 708 m² g⁻¹ and 0.280 cm³ g⁻¹, respectively.     

Recycling of carbon fibre reinforced polymeric waste for the production of activated carbon fibres

Composite waste composed of carbon fibres and polybenzoxazines resin has been pyrolysed in a fixed bed reactor at temperatures of 350, 400, 450, 500 and 700 °C. Solid residues of between 70 and 83.6 wt%, liquid yields 14 and 24.6 wt% and gas yields 0.7 and 3.8 wt% were obtained depending on pyrolysis temperature. The derived pyrolysis liquids contained aniline in high concentration together with oxygenated and nitrogenated aromatic compounds. The pyrolysis gases consisted mainly of CO₂, CO, CH₄, H₂ and other hydrocarbons. The carbon fibres used in the composite waste were separated from the char of the solid residue via oxidation of the char at two different temperatures and investigated for their mechanical strength properties. The carbon fibres recovered from the sample pyrolysed at 500 °C and oxidised at 500 °C exhibited mechanical properties which were 90% of that of the original virgin carbon fibres. Steam activation of the recovered carbon fibres was carried out at 850 °C at different times of activation. The effect of activation time on BET surface area, activated carbon fibres yield, porosity and the morphological structure of activated carbon fibres was evaluated. A maximum BET surface area of over 800 m² g⁻¹ was obtained for the activated carbon fibres produced at 850 °C for 5 h of activation. Nitrogen adsorption-desorption isotherms showed that the adsorption capacity increased as the activation time increased up to 5 h of activation and then after that decreased.     

Selective fast pyrolysis of biomass impregnated with ZnCl2: Furfural production together with acetic acid and activated carbon as by-products

Fast pyrolysis of biomass materials impregnated with ZnCl₂ offered a promising way to obtain a liquid product rich in furfural (FF) and acetic acid (AA), and the pyrolytic solids could be used as the precursors to prepare activated carbons (ACs). In this study, a lab-scale fast pyrolysis set was designed and used for the quantitative production of the three chemicals. The maximum FF was produced from the corncob impregnated with at least 15 wt% ZnCl₂ and at the pyrolysis temperature around 340 °C, with the yield of more than 8 wt% compared with only 0.49 wt% from the raw corncob. Meanwhile, AA of around 4 wt% could be obtained. The content of the FF and AA was over 50 wt% and 25 wt% on the water-free basis of the pyrolytic liquids. In addition, ACs were prepared from the pyrolytic solids, and they exhibited similar properties as those prepared from direct activation of ZnCl₂-impregnated biomass materials.     

Pyrolysis behavior of pectin under the conditions that simulate cigarette smoking

In this paper, the formation mechanism of pyrolysis gases released during the pyrolysis of pectin under the conditions that simulate cigarette smouldering was investigated by thermogravimetric analysis coupled to Fourier transform infrared spectrometer (TG-FTIR). Moreover, the combustion behavior of pyrolysis gases was studied by micro-scale combustion calorimetry (MCC). TG-FTIR results illustrated that the composition of the gaseous products was mainly composed of CO₂, H₂O, CO, methanol, methane and carbonyl compounds. MCC results demonstrated that the combustion of pectin was mainly determined by the prolysis gases formed in the temperature range of 200-300 °C. Flash pyrolysis experiment in combination with high performance liquid chromatography (FPy-HPLC) was used to study the pyrolytic formation of eight carbonyl compounds (i.e. formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, crotonaldehyde, methyl ethyl ketone and butyraldehyde) during the pyrolysis of pectin under the pyrolysis conditions of cigarette puffing. Results demonstrated that pyrolysis temperature influenced the formation of acetaldehyde, acrolein, propionaldehyde and butyraldehyde greatly, while nitrogen flow affected the generation of formaldehyde, acetone, crotonaldehyde and methyl ethyl ketone deeply.     

Pyrolysis of cohesive meat and bone meal in a bubbling fluidized bed with an intermittent solid slug feeder

Meat and bone meal (MBM) is a mass-produced by-product of the meat rendering industry. It has great potential as a feedstock for the production of bio-fuels. Meat and bone meal, however, is a highly cohesive and temperature sensitive material and has traditionally been found to be very difficult, if not impossible, to feed properly into pyrolysis reactors or bubbling fluidized beds. This study showcases an application of the ICFAR intermittent solid slug feeder technology and its capability of successfully feeding the MBM regularly at an average feeding rate of 0.34 g/s into the reactor.A highly automated and instrumented fast pyrolysis pilot plant has been used to process meat and bone meal residues and to operate within a wide range of temperatures (450–600 °C). This is the first study dealing with the pyrolysis of pure meat and bone meal at various operating conditions continuously fed into a laboratory-scale fluidized bed reactor. All liquid and solid products have been analyzed (yields, HHV, GC–MS, elemental analysis, and ash mineral analysis). The homogenous bio-oil produced is an attractive fuel with a significant high heating value (HHV) of 31.5 MJ/kg and an average liquid yield of 43 wt% at 550 °C. The highest water-free HHV (36.7 MJ/kg) was found at 500 °C, with a liquid yield of 35 wt% at this temperature. The optimized pyrolysis temperature, at which the heat from the gas combustion can provide the heat required for processing MBM, while maximizing the bio-oil liquid yield and process energy yield, is 550 °C. Under these conditions, the pyrolysis process energy yield is 91%.The study also demonstrates a new technique to accurately determine the heat of pyrolysis reaction energy required by the process, using a non-invasive water calibration method.     

Hydrogen production from the aqueous phase derived from fast pyrolysis of biomass

Hydrogen production from the aqueous phase derived from fast pyrolysis of biomass was carried out by catalytic steam reforming in a fluidized bed reactor. The effects of reaction conditions such as reaction temperature, steam-to-carbon ratio (S/C) and weight hourly space velocity of the aqueous phase (WHSV) on the results of hydrogen yield, potential hydrogen yield and carbon selectivity of product gases were investigated. The effect of reaction temperature on the carbon deposition on catalyst was also studied. The hydrogen yield of 64.6%, potential hydrogen yield of 77.6% and the carbon selectivity for product gases of 84.3% can be obtained at the optimized conditions of reaction temperature 800 °C, S/C 10 and WHSV 1.0 h⁻¹.     

Pyrolysis of sweet orange (Citrus sinensis) dry peel

Three different products were obtained from the pyrolysis of dry peel sweet orange: bio-oil, char and non-condensable gases. The yield of each product was determined. The bio-oil was characterized by GC–MS to determine that can be used as a renewable source of valuable industrial chemicals or as a source of energy, high heating value was calculated by Channiwala and Parikh correlation based on Dulong's Formula.Thermogravimetric analysis at 1, 5, 10, 20, and 40 °C/min, shows three different overlapped steps resulting in an average mass loss of ∼80% within the temperature range of 114–569 °C. The bench scale pyrolysis experiments, produces average yields of 53.1, 21.1 and 25.8 wt.% for bio-oil, char and gases, respectively. Bio-oil characterization by GC–MS and FTIR identified limonene as its main component while other identified compounds included δ-limonene, alcohols, phenols, benzene, toluene, xylene and carboxylic acids.     

Pyrolysis of meat-meal and bone-meal blends in a mechanically fluidized reactor

Nowadays, meat and bone meal produced in animal slaughterhouses and farms has become an important waste. Landfilling this residue means that its energy is lost. The pyrolysis of meat and bone meal produces a solid fraction which can be used as a fuel or as solid adsorbent, a liquid fraction with possible chemical applications and a low heating value gas.In this work, meat and bone meal has been pyrolyzed with a new technology, a mechanically fluidized reactor (MFR). This MFR is a stainless steel cylinder with 7.7 cm i.d., and an internal height of 15.6 cm. The meat and bone meal pyrolysis was carried out at 500 °C of temperature. The effect of several factors (mixer speed, heating rate and feed composition) on the product yields, bio-oil phases yield, bio-oil heating value and char heating value was studied. The amount of pure meat meal in the feed had a strong impact on product yields and compositions. The liquid yield, which has two phases, varies from 22 wt% to 52 wt% when the raw material fed changed from pure bone meal to pure meat meal.     

Micro-pyrolysis of technical lignins in a new modular rig and product analysis by GC–MS/FID and GC × GC–TOFMS/FID

A new offline-pyrolysis rig has been designed to allow multifunctional experiments for preparative and analytical purposes. The system conditions can be set and monitored, e.g. temperature, its gradients and heat flux. Some special features include (1) high heating rates up to 120 °C/s with pyrolysis temperatures up to 850 °C at variable pyrolysis times and (2) the selection of different atmospheres during pyrolysis. A complete mass balance of products and reactants (gas, liquids and solids) by gravimetric methods and sequential chromatographic analyses was obtained.The pyrolytic behaviour and the decomposition products of lignin-related compounds were studied under different conditions: heating rates (from 2.6 °C/s up to 120 °C/s), pyrolysis temperatures at 500 °C and 800 °C in different atmospheres (N₂, H₂, and mixtures of N₂ and acetylene). Kraft lignin, soda lignin, organosolv lignin, pyrolytic lignin from pine bio-oil, residues from biomass hydrolysis and fermentation were studied.The obtained pyrolysis products were classified into three general groups: coke, liquid phase and gas phase (volatile organic compounds (VOC) and permanent gases). The liquid fraction was analysed by GC–MS/FID. In addition, comprehensive two-dimensional GC was applied to further characterise the liquid fraction. VOCs were semi-quantified by a modified headspace technique using GC–MS/FID analysis. The micro-pyrolysis rig proved to be an efficient and useful device for complex pyrolysis applications.     

Rapid quantification of four major bioactive alkaloids in Corydalis decumbens (Thunb.) Pers. by pressurised liquid extraction combined with liquid chromatography-triple quadrupole linear ion trap mass spectrometry

A new method based on pressurised liquid extraction (PLE) followed by liquid chromatography-triple quadrupole linear ion trap mass spectrometry (LC-QTrap-MS) analysis has been developed for the identification and quantification of four major alkaloids in extracts of Corydalis decumbens (Thunb.) Pers. PLE extractions were performed using 90% ethanol; temperature was set at 100 °C and pressure at 1500 psi. HPLC analysis was performed on a Waters XBridge™ C₁₈ column (150 mm × 2.1 mm i.d., 3.5 μm) eluted by a mobile phase of acetonitrile and 0.2% acetic acid. Data acquisition was carried out in multiple reaction monitoring transitions (MRMs) mode, monitoring two MRM transitions to ensure an accurate identification of target compounds in the samples. Additional identification and confirmation of target compounds were performed using the enhanced product ion modus (EPI) of the linear ion trap. The novel LC-QTrap-MS platform offers the best sensitivity and specificity for characterization and quantitative determination of the four alkaloids in C. decumbens (Thunb.) Pers. and fulfils the quality criteria for routine laboratory application.     

Physical and chemical characteristics of aging pyrolysis oils produced from hardwood and softwood feedstocks

Pyrolysis oils were produced from hardwood or softwood feedstocks in a vacuum batch reactor and trapped at 0 °C. The vacuum process was used to intentionally avoid the presence of entrained char particles. The hardwood feedstock was a pelletized mixture of various Eastern tree species. The softwood samples were de-barked Lodgepole pine (Pinus contorta) and Douglas Fir (Pseudotsuga menziesii) wood cut into the same dimensions as the pellets. The oils’ physical (viscosity) and chemical (speciation) properties were measured as-produced and after aging. The total liquid and char yields ranged from ∼50 to 55% and 25 to 27% respectively. Measured water contents were 30% or more, which are greater typically reported from fast pyrolysis oils produced in fluidized beds. Aging took place in covered glass containers at room temperature over a period of 5 months. Gas chromatography-mass spectrometry (GCMS) was used to characterize the oils’ volatile components. Since bio-oils are mixtures of hundreds of different compounds with wide-ranging molecular weights and polarities, the oils were extracted using benzene followed by methanol. Out of ca. 80 non-polar and 100+ polar compounds GCMS showed a few chemical species present in the freshly produced oils were absent in the aged oils. The oils’ viscosities at shear rates (measured between 1 and 1000 s⁻¹) increased by approximately a factor of 2.5 during aging. To determine if this was due to polymerization reactions during aging or simply water and other volatile material losses, freshly made oils were aged at an accelerated rate by using elevated temperatures (65 °C and 85 °C) in a water-saturated environment between 1 and 7 days. The oils are fairly stable with respect to aging both over long periods of time (months) at room temperature and at elevated temperatures, 65 °C and 85 °C for shorter time periods (days). It is concluded that high water content and char-free characteristics act to slow polymerization reactions.     

Influence of the interaction of components on the pyrolysis behavior of biomass

There has been much interest in the utilization of biomass-derived fuels as substitutes for fossil fuels in meeting renewable energy requirements to reduce CO₂ emissions. In this study, the pyrolysis characteristics of biomass have been investigated using both a thermogravimetric analyzer coupled with a Fourier-transform infrared spectrometer (TG-FTIR) and an experimental pyrolyzer. Experiments have been conducted with the three major components of biomass, i.e. hemicellulose, cellulose, and lignin, and with four mixed biomass samples comprising different proportions of these. Product distributions in terms of char, bio-oil, and permanent gas are given, and the compositions of the bio-oil and gaseous products have been analysed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography (GC). The TG results show that the thermal decomposition of levoglucosan is extended over a wider temperature range according to the interaction of hemicellulose or lignin upon the pyrolysis of cellulose; the formation of 2-furfural and acetic acid is enhanced by the presence of cellulose and lignin in the range 350-500 °C; and the amount of phenol, 2,6-dimethoxy is enhanced by the integrated influence of cellulose and hemicellulose. The components do not act independently during pyrolysis; the experimental results have shown that the interaction of cellulose and hemicellulose strongly promotes the formation of 2, 5-diethoxytetrahydrofuran and inhibits the formation of altrose and levoglucosan, while the presence of cellulose enhances the formation of hemicellulose-derived acetic acid and 2-furfural. Pyrolysis characteristics of biomass cannot be predicted through its composition in the main components.     

Utilization of camellia oleifera shell for production of valuable products by pyrolysis

Camellia oleifera shell is used as the feedstock to prepare the valuable products by pyrolysis using microwave heating at 400-800 °C. The yield of pyrolysis product is influenced by pyrolysis temperature, which indicates that high pyrolysis temperature promotes to generate bio-gas and restrains the production of biochar. However, pyrolysis temperature little influences the yield of bio-oil. The main compound of bio-oil is phenols, hydrocarbons, ketones, aldehydes and furans, respectively. While, bio-oil produced at 600 °C has as high as 78 % of phenols, which has potential application in chemical industries. The pyrolysis temperature has significantly influenced the composition and heating value of bio-gas. The maximum heating value of bio-gas is 12.44 MJ/Nm³, which is achieved at 600 °C. The physiochemical properties of biochar are also influenced by pyrolysis temperature. Biochar could be used as an adsorbent to adsorb Ag⁺ from aqueous solution, which is formed the value-added ABiochar composite by reduction. The adsorption and reduction process of Ag⁺ are investigated. While, ABiochar composite can be used as the catalyst for methylene blue degradation. ABiochar composite can be also used in the lithium ion battery cathode material for energy storage.     

Selective extraction of alkaloids in human urine by on-line single drop microextraction coupled with sweeping micellar electrokinetic chromatography

A novel method of on-line single drop microextraction (SDME) coupled with sweeping micellar electrokinetic chromatography (MEKC) for the selective extraction and dual preconcentration of alkaloids was developed. In this technique, analytes of three alkaloids were firstly extracted from 4.0 mL basic aqueous sample solution (donor phase, 500 mM NaOH) into a layer of n-octanol at temperature 30 °C with the stirring rate of 1150 rpm, then back-extracted into the acidified aqueous acceptor (acceptor phase, 50 mM H₃PO₄) suspended at the tip of a capillary at 650 rpm. Then, the aqueous acceptor was introduced into capillary by hydrodynamic injection with a height difference of 15 cm between the inlet and outlet of capillary for 300 s, and analyzed directly by on-line sweeping MEKC. With the selective SDME, we were able to extract three alkaloids without any interfering components in human urine samples. Under the optimum conditions, the proposed method achieved limits of detections (LOD) of between 0.2 ng mL⁻¹ and 1.5 ng mL⁻¹ with 1583–3556-fold increases in detection sensitivity for three analytes, which indicated that it was a promising method for analysis of alkaloids in human urine.     

Development of an improved method to extract pesticide residues in foods using acetonitrile with magnesium sulfate and chloroform

A multiresidue method was developed based on extraction of 10 g sample with 10 mL acetonitrile and subsequent liquid–liquid partitioning formed by adding 4 g MgSO₄ plus 1 mL chloroform. During the partitioning process, the extraction recoveries of polar analytes were found to be essentially determined by the acetonitrile content in the aqueous phase. The use of MgSO₄ gave the least acetonitrile left in the aqueous phase (lower than 5%) and thus promoting complete partitioning of analytes into the organic phase. At the same time, removal of water from the acetonitrile phase was achieved by adding only a small amount of chloroform with no influence on the acetonitrile content in the aqueous phase, thus leading to decreasing the co-extraction of polar matrix components. The most complete mutual separation of acetonitrile and water was achieved by the joint use of MgSO₄ and chloroform and thus the optimal extraction recovery and analytical selectivity were obtained simultaneously. The new method, with higher recoveries of polar analytes, better analytical selectivity and simpler manipulation, is a claimed improvement to the original QuEChERS method. The proposed method was finally validated by the determination of 20 pesticides in a mixed food matrix by using liquid chromatography tandem mass spectrum (LC–MS/MS). Acceptable linearity, sensitivity, recovery, precision and selectivity results were obtained.     

Bio-oil from fast pyrolysis of rice husk: Yields and related properties and improvement of the pyrolysis system

Rice husk was fast pyrolysed at temperatures between 420 °C and 540 °C in a fluidized bed, and the main product of bio-oil is obtained. The experimental result shows that the highest bio-oil yield of 56 wt% was obtained at 465 °C for rice husk. Chemical composition of bio-oil acquired was analyzed by GC–MS and its heat value, stability, miscibility and corrosion characteristics were determined. These results showed that bio-oil obtained can be directly used as a fuel oil for combustion in a boiler or a furnace without any upgrading. Alternatively, the fuel can be refined to be used by vehicles. Furthermore, the energy performance of the pyrolysis process was analyzed.     

Bio-oil from Jackfruit Peel Waste

Fossil fuels such as petroleum, charcoal, and natural gas sources are the main energy sources at present, but considering their natural limitation in availability and the fact that they are not renewable, there exists a growing need of developing bio-fuel production. Biomass has received considerable attention as a sustainable feedstock that can replace diminishing fossil fuels for the production of energy, especially for the transportation sector. JackfruitwasteisabundantinIndonesiamake itpotentiallyas one of thegreenrefineryfeedstockforthe manufacture ofbio-fuel.As intermediate of bio-fuel,jackfruitpeelsisprocessed intobio-oil. Pyrolysis, a thermochemical conversion process under oxygen-absent condition is an attractive way to convert biomass into bio- oil.In this study, the pyrolysis experiments were carried out ina fixed-bedreactor at a range of temperature of400-600 °C, heating rate range between 10-50 °C/min, and a range of nitrogen flow between 2-4litre/min. The aims of this work were to explore the effects of pyrolysis conditions and to identify the optimum condition for obtaining the highest bio-oil yield.The effect of nitrogen flow rate and heating rate on the yield of bio-oil were insignificant. The most important parameter in the bio-oil production was the temperature of the pyrolysis process.The yield of bio-oil initially increased with temperature (up to 550 °C) then further increase of temperature resulting in the decreased of bio-oil yield. Results showed that the highest bio-oil yield (52.6%)wasobtainedat 550 °C with nitrogen flow rate of 4L/min and heating rate of 50 °C/min. The thermal degradation of jackfruit peel was also studied using thermogravimetric analysis (TGA). Gas chromatography (GC-MS) was used to identify the organic fraction of bio-oil. The water content in the bio-oil product was determined by volumetric Karl-Fischer titration. The physicochemical properties of bio-oil produced from pyrolysis of jackfruit peels such as gross calorific value, pH, kinematic viscosity, density, sulfur content, ash content, pour point and flash point were determined and compared to ASTM standard of bio-oil (ASTM 7544).     

Thermal degradation of polymethylsilsesquioxane and microstructure of the derived glasses

The present work aims to elucidate the physicochemical factors determining the microstructure of Si-O-C glasses derived from a polymethylsilsesquioxane powder pyrolyzed at 200-1300 °C in helium atmosphere. The pyrolysis behavior of the powder was studied by thermogravimetry coupled with mass spectrometry. The chemical composition of the glasses was determined by elemental analysis while the microstructure was studied by optical microscopy combined with scanning and transmission electron microscopy. The degradation of the polymer proceeds by a three-stage decomposition characterized by different mass losses as well as by different amount and type of evolved gaseous species. The derived glasses contain networks of pores and bubbles with diameters more than 0.1 mm. The increasing thermal treatment of the polymer above 200 °C does not lead to the disappearance of macropores. Micrometer-sized amorphous filaments are observed in porous interiors. A formation mechanism of pores and filaments is proposed. Polymer swelling accompanied by pore coagulation and gas release is believed to be responsible for the spatial separation of oligomers forming filaments.