Highest Bio-oil Yield Research Articles

IMPROVING BIO-OIL QUALITY VIA CO-PYROLYSIS EMPTY FRUIT BUNCHES AND POLYPROPILEN PLASTIC WASTE

The current consumption of fuel oil, especially gasoline and diesel oil, is increasing. Along with the decline in production, national oil production activities encourage efforts to find alternative fuels as a substitute for oil-based energy supplies. Bio-oil is an environmentally friendly alternative fuel for diesel that can be used as fuel. In this study, the raw materials were palm oil empty bunches and polypropylene plastic waste. The purpose of this study was to determine the effect of the ratio of raw material for oil palm empty fruit bunches and polypropylene, the effect of co-pyrolysis temperature on the yield of bio-oil and determine the characteristics of the resulting bio-oil. This study used the variable ratio of oil palm empty fruit bunches and polypropylene (100:0, 80:20, 70:30 and 60:40) and co-pyrolysis temperature (400, 450, 500 and 550 °C). The results showed that the highest yield of bio-oil was obtained, namely 41.6% with a ratio of EFB: PP (80:20) at temperature of 450 °C. The characterization of the product obtained was density of 0.891 g/ml, viscosity of 4.18 cSt, pH of 3.38 and calorific value of 43.2 MJ/kg.

Integrated approach for enhanced bio-oil recovery from disposed face masks through co-hydrothermal liquefaction with Spirulina platensis grown in wastewater.

Currently, the enormous generation of contaminated disposed face masks raises many environmental concerns. The present study provides a novel route for efficient crude bio-oil production from disposed masks through co-hydrothermal liquefaction (Co-HTL) with Spirulina platensis grown in wastewater. Ultimate and proximate analysis confirmed that S. platensis contains relatively high nitrogen content (9.13%dw), which decreased by increasing the mask blend ratio. However, carbon and hydrogen contents were higher in masks (83.84 and 13.77%dw, respectively). In addition, masks showed 29.6% higher volatiles than S. platensis, which resulted in 94.2% lower ash content. Thermal decomposition of masks started at a higher temperature (≈330 °C) comparing to S. platensis (≈208 °C). The highest bio-oil yield was recorded by HTL of S. platensis and Co-HTL with 25% (w/w) masks at 300 °C, which showed insignificant differences with each other. GC/MS analysis of the bio-oil produced from HTL of algal biomass showed a high proportion of nitrogen- and oxygen-containing compounds (3.6% and 11.9%, respectively), with relatively low hydrocarbons (17.4%). Mask blend ratio at 25% reduced the nitrogen-containing compounds by 55.6% and enhanced the hydrocarbons by 43.7%. Moreover, blending of masks with S. platensis enhanced the compounds within the diesel range in favor of gasoline and heavy oil. Overall, the present study provides an innovative route for enhanced bio-oil production through mask recycling coupled with wastewater treatment.Graphical abstract Supplementary InformationThe online version contains supplementary material available at 10.1007/s13399-021-01891-2.

Design and operation of a mobile fast pyrolysis system utilizing a novel double pipe fluidized bed reactor

A mobile fast pyrolysis system using a novel double pipe fluidized bed reactor with a capacity of 50 kg/h was designed and built. The structures of the main components, including the novel double pipe fluidized bed reactor, double bin pneumatic conveying feeder, jet/spray combined condenser, etc., are described in detail and experiments examining their performance are reported. Fast pyrolysis of larch sawdust was conducted at 400–550 °C to examine how temperature affects product yields and characteristics. The highest bio-oil yield was 68.6 wt% at 500 °C, and the yields of biochar and non-condensable gas were 19.2 wt% and 12.2% wt%, respectively. The chemical components of bio-oil included acids, aldehydes, ketones, phenols, furans, sugars, and other substances, and their proportions varied with temperature. Phenolic compounds were the most abundant components in the bio-oil with a peak content of 30.6% at 500 °C. The non-condensable gas was made mostly of CO2 and CO, which together peaked at 88.3 vol% at 400 °C. Furthermore, the energy performance of the pyrolysis process was analyzed. This research provides a reference for the industrial transformation of mobile fast pyrolysis technology.

Role of temperature in the biomass steam pyrolysis in a conical spouted bed reactor

The steam pyrolysis of pinewood sawdust has been conducted in a bench scale plant provided with a conical spouted bed reactor (CSBR). This process is of uttermost relevance for the in-line valorisation of pyrolysis volatiles, specifically for their catalytic steam reforming for hydrogen production. The influence of temperature on the product yields has been analyzed in the 500–800 °C range. A detailed analysis of the volatile stream (condensable and non-condensable components) has been carried out by chromatographic techniques, and the char samples have been characterized by ultimate and proximate analyses, N2 adsorption-desorption, and Scanning Electron Microscopy.A high bio-oil yield was obtained at 500 °C (75.4 wt%), which is evidence of the suitable features of the conical spouted bed reactor for this process. As temperature was increased, higher gas and lower liquid and char yields were obtained. Steam was fully inert at low pyrolysis temperatures (500-600 °C), and only had a little influence at 700 °C due to the low gas residence time in the conical spouted bed reactor. At 800 °C, the reaction mechanism was controlled by gasification reactions.The composition of the liquid fraction was considerably influenced by pyrolysis temperature, with a less oxygenated stream as temperature was increased. Thus, phenolic compounds accounted for the major fraction at low pyrolysis temperatures, whereas hydrocarbons prevailed at 800 °C. The char obtained in the whole temperature range can be further used as active carbon or energy source.

Influence of extraction solvents on the recovery yields and properties of bio-oils from woody biomass liquefaction in sub-critical water, ethanol or water–ethanol mixed solvent

In this work, the effects of extraction solvents: acetone, ethanol, dichloromethane (DCM) and ethyl acetate (EA), on the yields and characteristics of bio-oil products obtained from liquefaction of rubberwood sawdust (RS) at 300 ℃ for 30 min in water, ethanol or water–ethanol mixed solvent (50/50, v/v) were comparatively studied. When pure water or ethanol was used as the reaction medium, the highest bio-oil yield was obtained by acetone (30.41 wt%) or EA (31.69 wt%), respectively. Besides, significantly higher bio-oil yields were observed in RS liquefaction in water–ethanol mixed solvent with the maximum bio-oil yield of 56.67 wt% obtained by acetone. But ethanol was always the least efficient in recovering bio-oil in all cases. Besides, the elemental analysis showed that DCM was conducive to recover the bio-oil products with lower oxygen contents and the higher HHVs, while the acetone-extracted bio-oils were worse in quality. However, the highest carbon recovery (CR) and energy recovery (ER) were obtained by acetone due to its higher bio-oil yield produced in water–ethanol mixed solvent. As suggested by GC–MS, GPC and TGA analysis, the extraction solvents and reaction mediums both greatly affected the chemical compositions of the bio-oil products. Phenols were dominant in bio-oil products, followed by hydrocarbons, ketones, esters, etc. Acetone tended to extract the bio-oil with larger carbon numbers and molecular weights, which might explain its higher bio-oil recovery yield in water or water–ethanol mixed solvent. DCM was beneficial to recover the bio-oil was more light compounds with smaller molecular weights and lower boiling point distribution. But for the liquefaction in pure ethanol, more similar chemical compositions were observed among different samples when compared to the cases in other reaction mediums.

Catalytic pyrolysis of nutrient-stressed Scenedesmus obliquus microalgae for high-quality bio-oil production

Pyrolysis of nutrient-stressed Scenedesmus obliquus microalgae over various supported metal M/Fe3O4-HZSM-5 catalysts (M = Zr, W, Co and Mo) was investigated at a temperature of 500 °C and catalyst to biomass ratio of 1:1. The synthesized catalysts were characterized using XRD, TGA and HRSEM/EDS. The influence of temperature (400 °C, 500 °C, 600 °C and 700 °C) and catalyst to biomass ratio (0.25:1, 0.5:1 and 1:1) on pyrolysis product yield was also investigated. The results showed that all the supported metal catalysts during pyrolysis promote aromatization and acid ketonization of bio-oils. The total amounts of acids present in pyrolytic bio-oil significantly decreased from 26.68% (non-catalytic) to between 0.58 and 9.68% (catalytic). Also, production of 2-pentanone was observed to increase from ∼10% (non-catalytic) to 27.36–53.90% (catalytic). In terms of energy recovery, Co/Fe3O4-HZSM-5 had about 40% energy recovery, which was the highest while the least performing catalyst was W/Fe3O4-HZSM-5 with 24.18% energy recovery in bio-oil. Overall, Co/Fe3O4-HZSM-5 catalyst showed better activity in enhancing the bio-oil quality and yield; it had the lowest nitrogen content (4.77 wt%) and highest bio-oil yield (17.73 wt %) as well as highest HHV (39.12 MJ/kg) which is almost similar to that of crude petroleum.

Pyrolysis of mustard straw: Evaluation of optimum process parameters, kinetic and thermodynamic study

The aim of this work was to evaluate the pyrolysis of mustard straw (MS) in a thermogravimetric analyser and in a tubular reactor to recognize its bioenergy capability. The model free methods of Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS) and Vyazovkin were employed for kinetic analysis and Coats-Redfern (CR) method for elucidating the reaction mechanism. Response surface methodology (RSM) with central composite design technique was employed to optimize the pyrolysis process parameters to gain maximum amount of bio-oil. The highest bio-oil yield (44.69%) was obtained at the heating rate of 25 °C/min and at 500 °C under inert condition (N2 gas flow rate = 100 ml/min). Further, FTIR and GCMS analysis of bio-oil revealed the presence of different functional groups and valuable chemicals, whereas physicochemical characterization revealed its fuel characteristic. The results confirmed the suitability of mustard straw as a feed-stock for obtaining a cleaner fuel and value added products.

Use of a Lewis acid, a Brønsted acid, and their binary mixtures for the hydrothermal liquefaction of lignocellulose

The main objective of the present study is to investigate the effect of a Lewis acid, Brønsted acid, and their combined use on the hydrothermal liquefaction of lignocellulosic biomass. Hydrothermal liquefaction of teak wood was conducted at 250, 300 and 350 °C for 15, 30 and 60 min. Hydrothermal liquefaction of teak wood was carried out at 300 °C for 30 min (the best optimum conditions) without and with the use of Mg(ClO4)2, HClO4, and HClO4/Mg(ClO4)2 at various loadings (2–10 mmol/15 g wood). The highest bio-oil yield was obtained with the non-catalytic run. All tested catalysts have negative effect on bio-oil yields. The bio-oil yields generally decreased with increasing the catalyst loadings. The deoxygenation degree in bio-oils changed depending on the type of catalyst and loading. A high degree of de-oxygenation took place with Mg(ClO4)2 catalysts. An increased catalyst loading led to decreased aromatic contents of bio-oils catalysed by either Mg(ClO4)2 or HClO4. The use of a catalyst increased total naphtha fractions in bio-oils. The highest heating value of the bio-oil was estimated to be approximately 30 MJ/kg. Gas chromatography–mass spectrometry analysis revealed that the bio-oils from the non-catalytic and catalytic runs contained aldehydes, ketones, phenols, acids, esters and alcohols. The relative yields of the oxygenated compounds were affected by catalyst type.

Bio-oil production by pyrolysis of Azolla filiculoides and Ulva fasciata macroalgae

BACKGROUND AND OBJECTIVES: In this study, the characteristics of bio-oil samples produced through slow pyrolysis of two different macroalgae, i.e. Azolla ‎filiculoides and Ulva fasciata, at optimized conditions were determined and compared.METHODS: For this purpose, the effects of temperature (300-500 °C), carrier gas flow rate (0.2-0.8 L/min), ‎and heating rate (10-20 °C/min) on the final bio-oil production were optimized using response ‎surface methodology established by a central composite design.FINDINGS: The highest bio-oil yield from U. fasciata (34.29%) was obtained at the temperature of 500 °C, ‎‎ nitrogen flow rate of 0.2 L/min, and heating rate of 10 °C/min. As for A. filiculoides feedstock, the highest bio-oil ‎yield (30.83%) was achieved at the temperature of 461 °C, nitrogen flow rate of 0.5 L/min, and heating rate of 20 °C/min. Both bio-oil samples contained ‎saturated and unsaturated hydrocarbons. However, the average hydrocarbon chain length was ‎relatively shorter in U. fasciata bio-oil (C4-C16) than in bio-oil from A. filiculoides (C6-C24). Although both bio-oils had almost ‎identical heating values, the U. fasciata bio-oil showed more appropriate properties, i.e. lower viscosity and ‎density. Furthermore, the energy recovery from U. fasciata pyrolysis was calculated as 56.6% which was ‎almost 1.5 times higher than the energy recovery from A. filiculoides pyrolysis.CONCLUSION: The results indicated that U. fasciata bio-oil, with its superior characteristics, could be proposed as a promising candidate for application in diesel-based automotive industries. ‎

Effect of compound additive on microwave-assisted pyrolysis characteristics and products of Chlorella vulgaris

In this paper, the microwave-assisted pyrolysis of Chlorella vulgaris was studied by thermogravimetric analyzer (TGA) using absorbent SiC and catalyst TiO2 (compound additive). The effects of compound additive on microwave pyrolysis characteristics, products yield and composition of C. vulgaris were studied under different addition amounts (5%, 10% and 15%) and the mixing ratios (SiC/TiO2 = 10:0, 7:3, 5:5, 3:7, 0:10) of compound additive. The pyrolytic bio-oil were studied by GC-MS analysis. The results showed that the effect of 5% addition amount was better when the mixing ratio was SiC/TiO2 = 5:5 (S5T5). S7T3, S3T7 and S0T10 with 10% addition groups showed a good promoting effect on the pyrolysis of C. vulgaris. The pure TiO2 experimental group with 5% addition had the highest bio-oil yield. With the increase of the TiO2 content in the compound additive at same addition amount, the yield of bio-oil increased. The bio-oil yield of S7T3 and S5T5 experimental groups gradually increased with the increase of addition amount, while that of S3T7 group decreased at first and then increased. SiC, TiO2 and compound additive promote the production of ketones and reduce the acidic substances in bio-oil. Compound additive experimental group had the least amount of acid substances in the pyrolysis bio-oil.

Preparation of bio-oil from Scenedesmus acutus using thermochemical liquefaction in a 1 L reactor

Biomass from microalgae is a potential feedstock for biofuels production. It poses no threat to food security as it does not compete with agricultural crops for arable land. Scenedesmus acutus was used as feedstock to produce bio-oil in a large liquefaction reactor. The influence of reaction temperature (280–360ºC), reaction atmosphere (N2 or CO2) and solvent on bio-oil yield, C-16 fatty acid yield and oil properties were investigated. Oils were characterised using gas chromatography, Fourier transform infrared (FTIR) spectroscopy and ultimate analysis. Higher bio-oil yields were obtained in a CO2 atmosphere (250 g.kg-1 dry microalgae) than in a N2 atmosphere (210 g.kg-1 dry microalgae) whilst higher C16 fatty acid concentrations (600 g.kg-1 bio-oil) were recorded in N2 atmosphere compared to oil prepared in a CO2 atmosphere (500 g.kg-1 bio-oil). The oil yield increased to a maximum at 320°C, after which there were no significant changes. Highest bio-oil yields (425 g.kg-1 dry microalgae) were obtained in ethanol as solvent. FTIR spectroscopy and ultimate analysis showed that proteins present in the feedstock were degraded by breakage of peptide linkages, and nitrogen present in the oils is peptide fragments from protein degradation. The carbon content of all produced oils was high, but the hydrogen content was low, leading to low hydrogen/carbon ratios. Energy consumption and energy efficiency calculations showed that liquefaction in both reaction atmospheres results in a net energy gain, and a CO2 atmosphere is best for high energy efficiency.

Superior sewage sludge disposal with minimal greenhouse gas emission via fast pyrolysis in a fluidized bed reactor

In response to global carbon footprint reduction efforts, the promising waste-to-energy sludge disposal is assessed according to greenhouse gas emissions and biofuel production. Life cycle assessment and GEsTABouses were used in quantifying the CO 2 eq emissions of sludge disposal routes. In energy content assessment, fast pyrolysis experiment was done using a fluidized bed reactor, and the energy contents of derived biofuels were accounted for. The result shows that sewage sludge disposal through fast pyrolysis is the most environmentally sustainable route with the lowest emissions (696.7 kg CO 2 eq) compared to liming and land application (833.3 kg CO 2 eq), composting and land application (756.3 kg CO 2 eq), and incineration with household wastes (2805.3 kg CO 2 eq) per ton of dried sludge. The fast pyrolysis supremacy is illustrated by net negative emission balance (–1070.9 kg CO 2 eq), manifesting its significant contribution to emission mitigation. Fast pyrolysis has a high bio-oil yield (35.68 wt%) with a high heating value of 36.43 MJ/kg. Energy contents per ton of dried sludge are: bio-oil = 13.0 GJ, biogas = 2.73 GJ, biochar = 1.75 GJ. Overall, this study demonstrated fast pyrolysis as a superior sludge disposal route contributing to the environment and energy sustainability.

Study of pequi peel pyrolysis: Thermal decomposition analysis and product characterization

The consumption of pequi generates a considerable amount of waste (peel) which is not used efficiently. Pyrolysis can be a viable alternative for the use of this food waste, by converting pequi peel into energy in the form of biofuels and compounds of great interest to the chemical industry. This study evaluates the potential of pequi peel waste in the production of bioenergy through pyrolysis and characterization of the obtained products. The biomass was characterized and revealed to be a viable raw material for pyrolysis. From thermogravimetry (TG) data, we determined kinetic parameters according to Friedman's global reaction and Flynn-Wall-Ozawa (FWO) models, which led to the mean experimental value of activation energy (Ea) of 239.2 and 224.4 kJ mol−1, respectively. The pyrolysis was carried out at 400, 500 and 600 °C, and the highest bio-oil yield (43.6%) was obtained at 500 °C. The classes of compounds quantified in higher amount in the bio-oils were ketones, furans, acids, alcohols and phenols. The bio-oil compounds from pequi peel pyrolysis can be a source of energy and raw materials of great interest for the chemical industry to produce high-added value products. The biochar shows potential for application as adsorbent and solid fuel. The pyrolysis is a feasible process for the pequi peel waste by adding value and reducing the environmental impact caused by the inadequate disposal of lignocellulosic materials.

Pyrolysis of aquatic fern and macroalgae biomass into bio-oil: Comparison and optimization of operational parameters using response surface methodology

Effect of temperature (300–500 °C), carrier gas flow rate (0.2–0.8 L min−1), and the heating rate (10–20 °C min−1) on the final bio-oil production from the Salvinia auriculata (SA) and Ulva lactuca (UL) was optimized using response surface methodology (RSM), established by a central composite design (CCD). The maximum bio-oil yield from UL was 34.8%, reached at 500 °C, 0.2 L min−1 nitrogen flow rate, and 10 °C min−1 heating rate. However, in the case of SA feedstock, the highest bio-oil yield was 32.3% at 400 °C, 0.5 L min−1 nitrogen flow rate, and 20 °C min−1 heating rate. Both bio-oil samples contained saturated and unsaturated hydrocarbons; but the average hydrocarbon chain length in UL bio-oil (C4–C16) was relatively shorter than bio-oil from SA (C6– C24). The bio-oil from A. filiculoides exhibited higher HHV values than that of UL derived bio-oil due to its relative large carbon and hydrogen concentration and small oxygen content. Although both the bio-oils showed different heating values, the UL biooil had more appropriate properties, i.e. lower viscosity and density.

Biomass fast pyrolysis in an innovative gas-solid vortex reactor: Experimental proof of concept

Biomass fast pyrolysis has been considered one of the best alternatives for the thermal conversion of biomass into bio-oil. This work introduces a new reactor technology for biomass fast pyrolysis, the Gas-Solid Vortex Reactor (GSVR), to obtain high bio-oil yields. The GSVR was designed to decrease the residence time of the pyrolysis vapors; thus, the secondary cracking reactions are reduced, to enhance the segregation of the char and the unreacted biomass and to improve the heat transfer rate. Biomass fast pyrolysis experiments have been carried out for the first time in a Gas-Solid Vortex Reactor (GSVR) at 773 K, using softwood (pine) and hardwood (poplar) as feedstock. Char yields as low as 10 wt. % in the GSVR were comparable to those reported for the same feedstocks processed in conventional fluidized bed reactors. The yields of non-condensable gases in the range of 15–17 wt. % were significantly lower than those reported for other commonly used biomass fast pyrolysis reactors. Two-dimensional gas chromatography (GC × GC) revealed noticeable differences at the molecular level between the bio-oils from the GSVR and bio-oils from other reactors. The aromatics in the pine bio-oil consist almost entirely (85 wt. %) of guaiacols. For poplar bio-oils no predominant group of aromatics was found, but phenolics, syringols, and catechols were the most pronounced. The experimental results highlight the advantages of the GSVR for biomass pyrolysis, reaching stable operation in around 60 s, removing the formed char selectively during operation, and enabling fast entrainment of pyrolysis vapors. Results indicate a great potential for increasing yield and selectivity towards guaiacols in softwood (e.g., pine) bio-oil. Likewise, decreasing pyrolysis temperature could increase the yield of guaiacols and syringols in hardwood (e.g., poplar) bio-oil.

A study of optimization of solar pyrolysis and catalyst recovery and reuse

The use of renewable energy sources in the pyrolysis process for bio-oil production has gained a renewed interest. In this work, ex-situ catalytic solar pyrolysis (ECSP) of microalgae was performed using Mg-Al mixed oxides catalyst derived from hydrotalcite. The effects of biomass loading, reaction time, and catalyst percentage on the pyrolysis product were investigated. The condition that maximizes simultaneously the bio-oil yield and its hydrocarbon content was obtained in an optimization study. A study of the effect of catalyst reuse on the pyrolysis process was also performed. The results showed that high yields of bio-oil were found when intermediary values of independent variables were used. The use of the catalyst derived from hydrotalcite improved the quality of bio-oil, promoting a reduction of oxygenated compounds and forming aromatic and long-chain aliphatic hydrocarbons. High bio-oil yield (38.55%) with high hydrocarbon content (32.65%) was achieved under the optimal conditions. The study of the catalyst reuse showed that the structure and surface area of fresh and regenerated catalyst were very similar. In addition, the hydrocarbon content of bio-oil did not significantly change after three pyrolysis cycles.

Kinetic studies and performance analysis of Indonesian rice husk pyrolysis

Rice husk is abundantly available biomass in Indonesia and it can be a potential source of high-value energy source. In the present work, pyrolysis of rice husk was subjected to various temperature and used as a method to produce bio-oil. The decomposition profile of rice was examined at different heating rates (10, 20, 30, and 40°C/min) using a thermogravimetric analysis (TGA) method. The pyrolysis kinetics were evaluated using three different kinetic models: Kissinger-Akahira-Sunose (KAS), Ozawa-Flynn-Wall (OFW), and Coats-Redfern (CR). The activation energy for KAS, OFW, and CR was centered at 251.62 kJ/mol, 253.32 kJ/mol, and 33.92 kJ/mol, respectively. Varying activation energy with conversion was observed, which reveals that the pyrolysis of rice husk processes through complex reaction. The production of bio-oil from rice husk using pyrolysis method was studied at different temperature conditions (300, 400, 500, 600°C). Results showed that bio-oil and gas products increase at higher temperature. The highest yield of bio-oil was produced at 600°C with 46.3 grams (37%-wt). The specific test showed that the density, viscosity, and acid value of bio-oil decreased at higher temperatures indicating that different pyrolysis conditions might lead to the different bio-oil quality.

Kinetic Modeling of the Ignition of Droplets of Fast Pyrolysis Bio-oil: Effect of Initial Diameter and Fuel Composition.

Fast biomass pyrolysis is an effective and promising process for high bio-oil yields, and represents one of the front-end technologies to provide alternative, sustainable fuels as a replacement of conventional, fossil-based ones. In this work, the effect of droplet initial diameter on the evaporation and ignition of droplets of crude fast pyrolysis bio-oil (FPBO) and FPBO/ethanol blend (50% vol) at ambient pressure is discussed. The experimental tests were carried out in a closed single droplet combustion chamber equipped with optical accesses, using droplets with a diameter in the range of 0.9–1.4 mm. The collected experimental data show a significant effect of droplet diameter and initial fuel composition on the evaporation and combustion of the droplets. At the same time, 1-dimensional modeling of the evaporation and ignition of different droplets of crude FPBO and its blend with ethanol is performed to understand the complex physical and chemical effects. To this purpose, an 8-component surrogate was adopted, and a skeletal mechanism (170 species and 2659 reactions) was obtained through an established methodology. The comparison of numerical and experimental results shows that the model is able to capture the main features related to the heating phase of the droplet and the effect of fuel composition on droplet temperature and evaporation, particularly the increased reactivity following ethanol addition and the variation of diameter with time. Also, a sensitivity analysis highlighted the reactions controlling the autoignition of the droplets in the different conditions. It was found that the autoignition of pure FPBO droplets is governed by dimethyl furane (DMF), because of its high volatility and in spite of not being the most abundant species. On the other side, ethanol chemistry drives the gas-phase ignition in the case of the blended (50/50 v/v) mixtures, due to its higher volatility and reactivity.

Tannery fleshing wastes conversion into high value-added biofuels and biochars using pyrolysis process

• Pyrolysis of TFW was conducted at 500, 600, 700 °C and at 10, 15, 20 °C/min as HR. • The highest bio-oil yield (60 wt%) was reached at 600 °C and 15 °C/min. • The bio-oil HHV is 39.36 MJ/kg and the syngas energetic content is 10 MJ/Nm 3 . • Biochar properties suggest its use as biofertilizer or bioadsorbent.

Effect of algae (Scenedesmus obliquus) biomass pre-treatment on bio-oil production in hydrothermal liquefaction (HTL): Biochar and aqueous phase utilization studies.

Environmental concerns due to fossil fuel usage has turned the research interest towards biomass and bioenergy field. Renewable biomass such as microalgae provides numerous advantages as they can grow in wastewater; sequester carbon dioxide, economical and eco-friendly. In this study, effect of pretreatment of microalgae (Scenedesmus obliquus) biomass using post-hydrothermal liquefaction wastewater (PHWW) for bio-oil production through hydrothermal liquefaction at a temperature of 300°C was studied. Results showed liquefaction of pre-treated biomass yielded 48.53% bio-oil whereas 28.35% was resulted from biomass without pretreatment. The analysis of higher heating value of bio-oil showed that pretreated biomass oil has 36.19MJ.Kg-1 against non-pretreated biomass oil, which has 28.88MJ.Kg-1. Bio-oil (pretreated biomass) analysis revealed that 60% of compounds are in diesel and gasoline range with 58.09% of energy recovery. Bio-oil was rich in hydrocarbons of C7-C21 range with less oxygenated compounds. Carbon balance showed that an increase of 13% of carbon was sequestered in solid residue obtained from pretreated biomass and about 146% of increase also obtained in bio-oil.