Physicochemical Properties Of Bio-oil Research Articles

Pyrolysis and ex-situ vapor upgrading of pine nut shells over Ni- and Co-modified HZSM-5 catalysts to high-quality bio-oil and syngas

The ex-situ catalytic upgrading of pine nut shell pyrolysis vapor was conducted over Ni/HZSM-5 and Ni-Co/HZSM-5 catalysts using a fixed bed reactor. The effects of the catalytic temperature (500–800 °C) and pressure (0.1–0.6 MPa) on the yield and composition of the products were investigated. The physicochemical properties of bio-oil were visibly improved by increasing the temperature and pressure, and the products mainly contained light aromatic hydrocarbons, aliphatic hydrocarbons and phenolic compounds. The addition of Co significantly enhanced the deoxidation ability of the Ni-Co/HZSM-5 catalyst, and the BTXEN yield of the upgraded bio-oil increased to 15.3 mg/g with a heating value of 36.80 MJ/kg. Less water was generated in pressurized catalysts, and the syngas yield significantly increased with increasing pressure. Based on mechanistic considerations, atmospheric pressure catalysis favors alkylation, and high-pressure catalysis increases the syngas yield.

Extraction, characterization and kinetics of ultrasonic assisted extraction of biooil from Annona squamosa seeds

The current research work investigated the extraction of biooil from custard apple seed (Annona squamosa). The Biooil extraction process has been carried out using the method of ultrasonic-assisted solvent extraction. The process conditions for biooil extraction have been optimized for attaining the maximum yield of biooil. The presence of functional groups and fatty acids in the extracted Annona squamosa seed oil has been analyzed by FT-IR and GC-MS analysis. The predominant compound present in the extracted oil was oleic acid, which is confirmed by GC-MS. The kinetics study results indicated that the biooil extraction process fits very well into first order reaction kinetics. The physicochemical properties of biooil have also been analyzed. The maximum biooil yield of 23% (w/w) from Annona squamosa seed has been achieved under the optimal process conditions with the extraction time of 20 min, temperature of 50°C and hexane to biomass ratio of 3:1 v/w.

Elucidation of the effect of fast pyrolysis and hydrothermal liquefaction on the physico-chemical properties of bio-oil from southern yellow pine biomass as a chemical feedstock

Bio-oils obtained from southern yellow pine biomass from two thermochemical conversion processes, fast pyrolysis (FP) and hydrothermal liquefaction (HTL), were investigated. The effects of FP and HTL on the physical and chemical properties of the bio-oils were characterized. The HTL and FP bio-oil yields were 67 and 36 wt%, respectively. The results indicated that the physical properties of the HTL bio-oil and FP bio-oil were similar; however, there were variations in the composition of the bio-oils from the same biomass. The pH values of the FP and HTL bio-oils were 2.3 and 2.8, respectively. From the GC-MS (gas chromatography–mass spectrometry) analysis, esterified chemical compounds were prevalent in the HTL bio-oil, while phenols and phenolic derivatives were found in both bio-oils. The 31P-NMR (phosphorous nuclear magnetic resonance) analysis of the bio-oils further revealed that both FP and HTL bio-oils are rich in phenolic OH and aliphatic OH functionalities, which could serve as a potential bio-polyol.

Valorization of the spent catalyst from flue gas denitrogenation by improving bio-oil production from hydrothermal liquefaction of pinewood sawdust

Normally, the spent catalyst (V2O5-WO3/TiO2, denoted as VWTi) is dumped as a solid waste after denitrogenation of flue gas through selective catalyst reduction (SCR). However, this used catalyst contains an abundant amount of acid sites and thus can be potentially utilized as the catalyst in hydrothermal liquefaction (HTL) to produce bio-oil. Thus, in this study, the influences of operational variables on the main HTL products distribution and physicochemical properties of bio-oil were evaluated at 240–320 °C for 0–60 min and 0–20 wt% of catalyst dosage. The results demonstrated that the spent VWTi catalyst significantly promoted the production of bio-oil, yielding the highest bio-oil yield (33.9 wt%) at 300 °C for 30 min with a 10 wt% of catalyst loading. The bio-oil obtained with catalyst under the optimal conditions has a HHV of 28.69 MJ/kg, along with an energy recovery of 51.93%. In addition, the use of the spent VWTi catalyst in the HTL could obtain a higher fraction of phenolics compounds with lower boiling point and lower molecular weight, as identified by TGA and GPC analysis. Overall, this study provides an alternative route to valorize the spent catalyst from flue gas denitrogenation by applying as a catalyst to produce high quality bio-oil production in the biomass HTL process.

Experimental investigation on the production of bio-oil from maize straw at a pilot scale

The production of biofuel from agricultural crop residue via fast pyrolysis is becoming a popular option. It can help to build a robust renewable fuel market and ensure environmental sustainability. In this study, the widely available maize straw was used for the production of bio-oil in a fluidized bed reactor at a pilot scale. The effect of pyrolysis parameters such as temperature, biomass particle size, and carrier gas flow rate on the production of bio-oil, char, and syngas was investigated. The maximum bio-oil yield of 44.6 wt.% was achieved at a pyrolysis temperature of 500℃. The physicochemical properties of bio-oil were determined, and the heating value was found to be 18.5 MJ/kg. Furthermore, the chemical composition of maize straw bio-oil was analyzed by GC-MS and FTIR. The compounds such as phenol (22.83%), carboxylic acids (27.36%), ketone (19.14%) alcohols (2.09%), esters, furfural, hydrocarbon and aromatic compounds, etc. were identified in the bio-oil. The cost analysis of the developed system showed that the cost of production of bio-oil from maize straw was 0.47 US$/L and the calculated payback period was 1.47 year.

Effect of Storage Time on the Physicochemical Properties of Waste Fish Oils and Used Cooking Vegetable Oils

Waste fish oils (FOs) and used cooking vegetable oils (UCOs) are increasingly becoming alternative renewable fuels. However, different physicochemical aspects of these renewable fuels, including the effect of storage, are not well-known. In this work, the effect of the storage period on physicochemical properties of selected samples of FOs and UCOs was investigated. The bio-oils were stored at 4 °C for up to five years before each experimentation. The chemical properties were characterized using capillary gas chromatography with flame ionization detection (GC-FID) and high-performance size exclusion chromatography including an evaporative light scattering detector (HPSEC-ELSD). Water contents and acid numbers of the bio-oils were determined using the Karl Fischer (KF) titration and the ASTM D 664 methods. Furthermore, the average heating values and surface tension of the bio-oils were determined. According to the results obtained, for all bio-oil types, the concentrations of polymerized triglycerides, diglycerides, and fatty acids and monoglycerides had increased during the storage periods. The physical properties of the bio-oils also showed a small variation as a function of the storage period. The overall results observed indicate that the deterioration of the physicochemical properties of bio-oils can be controlled through storage in dark, dry, and cold conditions.

Sludge as a relinquishing catalyst in Co-Pyrolysis with palm Empty Fruit Bunch Fiber

Bio-oil from the fast pyrolysis of biomass has the potential to be an effective and reliable renewable energy source. A common issue faced is the high acidity of bio-oil, which obstructs bio-oil storage and processing. This study utilized fast co-pyrolysis of oil palm Empty Fruit Bunch Fiber (EFBF) with Palm Oil Sludge (sludge) at different ratios (10, 20, 35 and 50 wt.% sludge with EFBF) to produce bio-oil with higher pH. The sludge with high ash content acted as a catalyst for esterification at higher percentages. Bio-oil yields decreased from 41.2 ± 3.4 wt.% (for EFBF) to 28.8 ± 1.4 wt.% (for sludge) as the sludge percentage increased from 0 to 100%. The catalytic effect posed by mineral metals in sludge led to a negative synergistic effect in terms of yields of bio-oil. Physicochemical properties of bio-oils were analyzed and compared to ASTM standards. An increase in pH value (7.2 ± 0.0) was achieved for bio-oil that was derived from the blend with 50 wt.% sludge. However, the bio-oil yield was compromised. Based on the yield and physical properties of bio-oil, the blend with 35 wt.% of sludge was selected as the desired ratio to further study the co-pyrolysis of EFBF and sludge. A bio-oil with pH 4.5 was successfully produced in one of the most economical method.

Solvothermal Liquefaction of Corn Stalk: Physico-Chemical Properties of Bio-oil and Biochar

This study investigated the conversion of corn stalk to bio-oil by solvothermal liquefaction using ethanol as a solvent. Effect of reaction temperature, time and solvent to biomass ratio on the yield and the properties of bio-oil and biochar was studied. Analysis of corn stalk and bio-oil were done to determine the surface functional groups, existing bonds and molecular structure of specified compounds. Investigations were done to identify different compounds in bio-oil, the thermal stability, and weight loss kinetics of biochar. Study shows that percentage yield of bio-oil increases with increase in temperature and time, up to a specific level, and then starts declining. Further, the heating value, carbon content, and fixed carbon content of both bio-oil and biochar increased to 30.52, 22.8 MJ/kg, and 66.42 and 61.25%, 26.10 and 27.97% respectively from those (19.55 MJ/kg, 51.12 and 6.36%) of the corn stalk. This study suggests that the bio-oil contained mostly phenolic compounds and its derivatives. Two major DTG peaks were observed at 380 and 620 °C indicating the improvement in thermal stability of the biochar after solvolysis liquefaction process. Investigation results can be very useful in optimizing process parameters for solvothermal liquefaction.

Catalytic fast pyrolysis of corn stover in a fluidized bed heated by hot flue gas: Physicochemical properties of bio-oil and its application

Fast pyrolysis of corn stover was performed at temperatures in the range of 450°C-525°C in a fluidized bed. The chemical composition of the bio-oil acquired was analyzed by GC/MS, and its pH, kinetic viscosity and calorific values were determined. In the pyrolysis system used in this experiment, some improvements to former pyrolysis systems were done. Two screw feeders were used to prevent jamming the feeding system, and the condenser was equipped with some nozzles and a heat exchanger to cool quickly the cleaned hot gas into bio-oil. The results showed that the bio-oil yield increased with increasing pyrolysis temperature and then declined with a further increase in pyrolysis temperature. The highest bio-oil yield of 43.3 wt.% was obtained at 500°C with the dolomite as bed material. The char yield always decreased with the increase of temperature. The major chemical compounds of bio-oil included acetol, butanone, acetic acid, propionic acid, ethylene glycol, phenol, etc. Pyrolysis oil was completely immiscible in diesel, but homogeneous emulsions were obtained when mixing the pyrolysis oil, emulsifier with diesel in different ratios. Keywords: corn stover, pyrolysis, bio-oil, fluidized bed, hot flue gas, GC/MS DOI: 10.25165/j.ijabe.20171005.2473 Citation: Yang W, Fu P, Yi W M. Catalytic fast pyrolysis of corn stover in a fluidized bed heated by hot flue gas: Physicochemical properties of bio-oil and its application. Int J Agric & Biol Eng, 2017; 10(5): 226–233.

Deoxy-liquefaction of Corn Stalk in Subcritical Water with Hydrogen Generated in Situ via Aluminum–Water Reaction

To reduce the oxygen content and increase the higher heating value (HHV) of bio-oil, this paper proposed a new method for deoxy-liquefaction of corn stalk in subcritical water with hydrogen generated in situ via aluminum–water reaction. The effects of aluminum on the physicochemical properties of bio-oil were investigated. The bio-oil was analyzed by elemental analysis, Fourier transform infrared spectroscopy (FT-IR), and gas chromatography–mass spectrometry (GC–MS). The results showed that, when the aluminum content was 30 wt %, the yield of bio-oil reached 26.54 wt %, the deoxidation ratio was 47.92%, and the calorific value increased from 28.86 to 33.77 MJ/kg. The viscosity, acid value, and water content were also significantly improved. FT-IR analysis showed that the types of functional groups in bio-oil were almost unchanged. GC–MS analysis showed that the main components of bio-oil were phenols, ketones, hydrocarbons, and indoles. In addition, the content of aliphatic hydrocarbons and aromatic hydro...

Catalytic fast pyrolysis of corn stover in a fluidized bed heated by hot flue gas: Physicochemical properties of bio-oil and its application

Catalytic fast pyrolysis of corn stover in a fluidized bed heated by hot flue gas: Physicochemical properties of bio-oil and its application

Valorization of Bambara groundnut shell via intermediate pyrolysis: Products distribution and characterization

This study provides first report on thermochemical conversion of residue from one of the underutilized crops, Bambara groundnut. Shells from two Bambara groundnut landraces KARO and EX-SOKOTO were used. Pyrolysis was conducted in a vertical fixed bed reactor at 500, 550, 600 and 650 °C; 50 °C/min heating rate and 5 L/min nitrogen flow rate. The report gives experimental results on characteristic of the feedstock, impact of temperature on the pyrolysis product distribution (bio-oil, bio-char and non-condensable gas). It evaluates the chemical and physicochemical properties of bio-oil, characteristics of bio-char and composition of the non-condensable gas using standard analytical techniques. KARO shell produced more bio-oil and was maximum at 600 °C (37.21 wt%) compared to EX-SOKOTO with the highest bio-oil yield of 32.79 wt% under the same condition. Two-phase bio-oil (organic and aqueous) was collected and analyzed. The organic phase from both feedstocks was made up of benzene derivatives which can be used as a precursor for quality biofuel production while the aqueous from KARO consisted sugars and other valuable chemicals compared to the aqueous phase from EX-SOKOTO which comprised of acids, ketones, aldehydes and phenols. Characteristics of bio-char and composition of the non-condensable were also determined. The results show that bio-char is rich in carbon and some minerals which can be utilized either as a solid fuel or source of bio-fertilizer. The non-condensable gas was made up of methane, hydrogen, carbon monoxide and carbon dioxide, which can be recycled to the reactor as a carrier gas. This study demonstrated recovery of high quality fuel precursor and other valuable materials from Bambara groundnut shell.

Bio-oil production from hydrothermal liquefaction of high-protein high-ash microalgae including wild Cyanobacteria sp. and cultivated Bacillariophyta sp.

Decomposition behavior of two kinds of high-protein high-ash microalgae, including wild Cyanobacteria sp. and cultivated Bacillariophyta sp., was examined via hydrothermal liquefaction (HTL). Physicochemical properties of bio-oil were extensively investigated through various techniques. Special attention was paid on transfer behavior of elements (i.e. C and N) during HTL process. A maximum bio-oil yield of 21.10wt% (Cyanobacteria sp.) and 18.21wt% (Bacillariophyta sp.) on dry basis was achieved at 325°C for 45–60min, accompanying with the maximum (51.38% and 48.76%) of energy recovered in bio-oil. Although high HHV (33.87–36.51MJkg−1) and high H/C ratio (1.37–1.62) were estimated for bio-oil products, high N/C ratio (0.06–0.09) and nitrogen content (5.31–7.50%) negatively affected its quality. GC–MS analysis combining with FTIR and NMR detection revealed that components and functional structure of bio-oils were greatly distinguished from other algae bio-oil. TG analysis showed approximate 72.32–75.79% of bio-oils was distilled in the range of 200–550°C. Large fraction of carbon and small fraction of nitrogen were recovered in bio-oils, together with high portion of nitrogen was enriched into aqueous liquid. This study demonstrated the feasibility of applying HTL to produce bio-oil from high-protein high-ash microalgae, and the findings on bio-oil properties and transfer behavior of carbon and nitrogen supplied useful information for downstream utilization.

Biofuel production using Pd/Zn synergistically catalyzed hydrodeoxygenation applied at bio oil extracted in biomass pyrolysis process

Raw bio oil includes multicomponents. In order to avoid the interference between complex reactions, the model compounds, instead of the real bio oil, have been widely used for the study of raw bio-oil upgrade. In this work, the hydrodeoxygenation (HDO) of raw pine pyrolysis bio oil was investigated at 200 °C using Pd/Zn synergistic catalysis under hydrogen pressures of 200, 300, and 400 psi, separately. The resulting product included gas, liquid, and coke. The gas was characterized using a gas chromatography. The liquid was characterized using a gas chromatography–mass spectrometry. The results showed that the HDO performance achieved promotion to some extent by the Pd/Zn synergistic catalysis compared with use of Pd/C or Zn2+, independently. The HDO also gave rise to improvements on physicochemical properties of bio oils. Notably, the highest water content (13.16 wt%) revealed that deoxygenation reaction could be promoted by Pd/Zn synergistic catalysis compared with use of Pd/C or Zn2+, independently. More importantly, the highest hydrocarbon yield (19.15% on the base of liquid part) could be obtained by the treatment of 300 psi pressure and 200 °C temperature over Zn/Pd/C synergistic catalysis. Copyright © 2016 John Wiley & Sons, Ltd.

Characterization of bio-oils and bio-chars obtained from the catalytic pyrolysis of alkali lignin with metal chlorides

The pyrolysis experiments were carried out in a fixed bed reactor at a reaction temperature of 873K and gas residence time of 1.0s. The physicochemical properties of bio-oils and bio-chars obtained from alkali lignin pyrolysis with and without KCl, CaCl2, and FeCl3 additives were studied. The compositions of bio-oils were examined using gas chromatography–mass spectrometry (GC–MS). Characterizations of bio-chars were performed using X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area and scanning electron microscopy (SEM) techniques. Adding KCl caused a sharp decrease in bio-oil yield while an increase in bio-char yield was found as a result. The addition of CaCl2 and FeCl3 significantly increased the yield of bio-oil and phenol content while inhibited the formation of char residues. The bio-char generated after FeCl3 addition has a much high BET surface area. This result indicates that the addition of FeCl3 in alkali lignin significantly improves the quality of both bio-oil and bio-char, which is beneficial to the usage of bio-oil for chemical materials and bio-char for activated carbon species.

Co-pyrolysis of pine nut shells with scrap tires

The co-pyrolysis of pine nut shells (PNS) with scrap tires (ST) at different blend ratios was carried out at 500°C. The addition of ST into PNS in the co-pyrolysis process not only increased bio-oil yields but also improved bio-oil characteristics when compared with the pyrolysis of PNS. The carbon content in bio-oils from all PNS/ST blend ratios was higher and oxygen content was lower than that of PNS-derived oil. This is an indication of the improved characteristics of bio-oils from the co-pyrolysis of biomass with scrap tires. The blend ratio in the feedstock of co-pyrolysis had a significant effect on the product distributions and physico-chemical properties of bio-oils. When heating values of bio-oils produced from the pyrolysis of PNS were compared with bio-oils obtained from the co-pyrolysis of PNS with ST, the addition of ST into PNS led to increase heating values of bio-oils with the exception of PNS/ST (4:1)-derived bio-oil. In addition, the heating values of gas products and levels of hydrogen and hydrocarbons (from C1 to C4) in the gas products from the co-pyrolysis of PNS/ST blends were higher than that of the pyrolysis of PNS. The heating values of chars produced from the co-pyrolysis of PNS/ST blends were found to be in the range of 31.1 and 32.9MJkg−1.

Physico-Chemical Properties of Bio-Oils from Pyrolysis of Lignocellulosic Biomass with High and Slow Heating Rate

Bio-oil is a major product of biomass pyrolysis that could potentially be used in motor engines, boilers, furnaces and turbines for heat and power. Upon catalytic upgrading, bio-oils can be used as transportation fuels due to enhancement of their fuel properties. In this study, bio-oils produced from lignocellulosic biomasses such as wheat straw, timothy grass and pinewood were estimated through slow and high heating rate pyrolysis at 450 °C. The slow heating rate (2 °C/min) pyrolysis resulted in low bio-oil yields and high amount of biochars, whereas the high heating rate (450 °C/min) pyrolysis produced significant amount of bio-oils with reduced biochar yields. The physico-chemical and compositional analyses of bio-oils were achieved through carbon-hydrogen-nitrogen-sulfur (CHNS) studies, calorific value, Fourier transform-infra red (FT-IR) spectroscopy, gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) spectroscopy. The yields of bio-oils produced from the three biomasses were 40-48 wt.% through high heating rate pyrolysis and 18-24 wt.% through slow heating rate pyrolysis. The chemical components identified in bio-oils were classified into five major groups such as organic acids, aldehydes, ketones, alcohols and phenols. The percent intensities of hydrogen and carbon containing species were calculated from 1H and 13C-NMR. The study on bio-oils from herbaceous and woody biomasses revealed their potentials for fossil fuel substitution and bio-chemical production.

Physicochemical properties of bio-oil and biochar produced by fast pyrolysis of stored single-pass corn stover and cobs

Short harvest window of corn (Zea mays) stover necessitates its storage before utilization; however, there is not enough work towards exploring the fast pyrolysis behavior of stored biomass. This study investigated the yields and the physicochemical properties (proximate and ultimate analyses, higher heating values and acidity) of the fast pyrolysis products obtained from single-pass stover and cobs stored either inside a metal building or anaerobically within plastic wraps. Biomass samples were pyrolyzed in a 183cm long and 2.1cm inner diameter free-fall fast pyrolysis reactor. Yields of bio-oil, biochar and non-condensable gases from different biomass samples were in the ranges of 45–55, 25–37 and 11–17wt.%, respectively, with the highest bio-oil yield from the ensiled single-pass stover. Bio-oils generated from ensiled single-pass cobs and ensiled single-pass stover were, respectively, the most and the least acidic with the modified acid numbers of 95.0 and 65.2mgg−1, respectively.

Experimental Study on the Physico-Chemical Properties of Bio-Oil and Diesel Emulsification

Experimental study on the physico-chemical properties of bio-oil and diesel emulsification has been carried out in this paper, which was based on the preliminary experiment. The effect of surface tension and viscosity on the stability of emulsions were particular concerned. It was found that the longest stable time, the lowest viscosity and lowest surface tension can be obtained simultaneously when the hydrophile and lipophile balance (HLB) value was of the optimal value, i.e. 6.5. Experimental results indicated that the stable time of emulsion decreased rapidly with the increase of bio-oil content, while the value of surface tension and viscosity increased. Meantime, it was shown that the most stable emulsions had the lowest value of viscosity and surface tension.

Effect of Particle Size of Corn Stalk Fast Pyrolysis on Physicochemical Properties of Bio-Oil

Effect of Particle Size of Corn Stalk Fast Pyrolysis on Physicochemical Properties of Bio-Oil