Properties Of Bio-oil Research Articles

Preparation process of bio-oil and bio-asphalt, their performance, and the application of bio-asphalt: A comprehensive review

The objective of this paper is to establish the state of knowledge on fast pyrolysis of bio-oil and bio-asphalt binder and to facilitate efforts in improving the overall performance of bio-asphalt and maximizing its road application. On the basis of reviewing the relevant literature recently, the fast pyrolysis (FasP) preparation process of bio-oil and its main properties, the preparation process of bio-asphalt and its performance and the application of bio-asphalt have been summarized. Due to the variations in raw materials, the adopted methods of FasP to prepare bio-oil could be different, and the properties of bio-oil from different sources are also different. At present, the plant-based bio-oil (mainly derived from wood waste and sawdust) has been widely used to prepare the bio-asphalt. Research on the low-temperature flexibility, high-temperature rheology, workability and other performance of biological asphalt showed that the workability and high-temperature performance of most asphalt are improved after adding bio-oil. However, the low-temperature performance is found to relatively reduce. Also, with regards to its application as a rejuvenator, bio-oil can considerably rejuvenate the aged asphalt's mixture performance. By far, most of research on bio-asphalt is still focused on the performance of bio-asphalt binder in the laboratory; its application in practical road engineering is still to be examined. This review also provides an outlook for the future, for example, establishing an integrated preparation process from bio-oil to bio-asphalt, and evaluating the properties of bio-asphalt by new standards. • The bio-oil products are mainly affected by the source of biomass, preparation temperature and catalyst. • It is feasible to replace asphalt partly with bio-oil as the binder due to the similar chemical composition. • The high-temperature performance and workability of the base asphalt improved after adding bio-oil. • The bio-asphalt can be used as road binder, bitumen modifier and rejuvenator.

Evidence for cross-polymerization between the biomass-derived furans and phenolics

The high tendency of bio-oil towards polymerization is one of the key challenges in hydrotreatment of bio-oil for production of bio-fuels. However, such properties of bio-oil could be used to produce carbon materials, but the mechanism for the polymerization has not been clarified. Bio-oil contains sugars, derivatives of sugars (i.e. furans et al.), phenolic monomers and oligomers. Among of them, the furans and phenolics are the typical compounds in bio-oil. In this study, the potential cross-polymerization between the furans (furan, furfural and furfuryl alcohol (FA)) and the phenolics (vanillin and guaiacol) in bio-oil was explored in water with/without H2SO4. The furans could polymerize via ring-opening to produce reactive reaction intermediates. Furfural and FA contained branched functionalities in furan ring, which was more reactive towards polymerization, especially for furfuryl alcohol. In general, the furans were more reactive towards polymerization than vanillin and guaiacol. Nevertheless, the cross-polymerization between the furans and phenolics occurred and significantly enhanced its tendency towards polymerization. The reaction intermediates formed via opening of the furan ring were the key initiator for the cross-polymerizations. Additionally, the presence of H2SO4 could enhance consumption of the CO during the polymerization and the thermal stability of the resulting polymer.

Comprehensive evaluation of hydro-liquefaction characteristics of lignocellulosic subcomponents

This study investigated the hydro-liquefaction behaviors of cellulose, xylan and lignin in ethanol at various temperatures. The interactions between the reaction medium and individual biomass component under different temperatures were evaluated using the Monte Carlo method. The simulation results indicated that the compatibility from cellulose and xylan system was superior to that of lignin with the elevated temperature. The liquefaction characteristics of cellulose and xylan were highly affected by temperature variation due to the existence of active chemical region and functional groups in the structures. In comparison, the reaction behavior of lignin-containing complicated polyaromatic structure was slightly dependent on the elevated temperature. The variation trend of chemical structures from solid residues was highly related to the nature of the raw feedstock. The properties of bio-oil derived from liquefaction of single biomass composition were also associated with the inherent composition of each biomass subcomponent.

Effective deoxygenation for the production of liquid biofuels via microwave assisted co-pyrolysis of agro residues and waste plastics combined with catalytic upgradation

Rice straw and sugarcane bagasse were co-pyrolyzed with polypropylene and polystyrene using microwaves, and the pyrolysis vapors were catalytically upgraded using HZSM-5 catalyst. The product yields, composition and properties of bio-oil from pyrolysis of individual feedstocks and equal composition mixtures before and after catalytic upgradation were thoroughly investigated. The pyrolysis oil yields from polypropylene (82 wt%) and polystyrene (98 wt%) were high compared to that from rice straw (26 wt%) and bagasse (29 wt%). Catalytic upgradation at weight hourly space velocity of 11 h−1 resulted in higher selectivity to unsaturated aliphatics and aromatic hydrocarbons. Properties of upgraded bio-oil from biomass-polypropylene mixtures were similar to that of light fuel oil with high calorific value (43 MJ/kg), low viscosity (1 cP), optimum density (0.850 g/cm3) and flash point (70 °C). Oxygen content in catalytically upgraded co-pyrolysis bio-oil was low (<5%) as compared to upgraded pyrolysis bio-oil (14–18%), and pyrolysis bio-oil without upgradation (20–24%).

Olive mill wastewater: From a pollutant to green fuels, agricultural water source and bio-fertilizer. Biofuel production

Olive mill wastewater (OMWW) management is recognized as the major defy that olive oil industry is facing. Recently, we have established an eco-friendly strategy for the OMWW conversion into irrigation water sources, green biofuels and biofertilizers. This work is a part of a series of papers detailing the different steps established in this environmental friendly strategy for OMWW management. It deals with the bio-oil production and characterization during the pyrolysis of OMWW impregnated on olive pomace (OP) in a pyrolyzer pilot.Results show a bio-oil production yield of 36 wt% during the pyrolysis test. This yield could be attributed to the recovery of organic compounds from OMWW through OP impregnation and their conversion to bio-oil. The bio-oil properties show that viscosity and flash point values could reach the European standards. However, the lower heating values (26 MJ/kg) and the acidic character limit its direct use. These values are attributed to the higher water and oxygen contents. The GC/MS analysis confirms these properties showing the presence of phenolic molecules and long chain organic acids. Therefore, OMWW impregnation on OP and pyrolysis could be considered as a promising issue for bio-oil production. However, this bio-oil requires an upgrading step for a better valorization.

Thermochemical liquefaction of pig manure: Factors influencing on oil

This study used thermochemical liquefaction technology to prepare bio-oil from pig manure with ethanol as liquefaction solvent. The work investigated the effects of liquefaction temperatures (T), solid–liquid rates (R1) and solvent filling rates (R2) on the yield, composition and property of bio-oil. The yield of bio-oil enhanced initially and then declined slightly with the enhancement of T and R2, nevertheless, the yield of bio-oil decreased constantly with the increase of R1, and the topmost yield of bio-oil in this experiment was 35.56% when the solid–liquid rate was 5%. The work studied the properties of bio-oil generated by pig manure under different liquefaction temperatures. The results of gas chromatography–mass spectroscopy analysis revealed that the dominating composition of bio-oil from pig manure were esters, long-chain hydrocarbons, ketones, ethanol, organic acids and nitrogen compounds. The heating value of bio-oil (34.39 ~ 37.03 MJ/kg) obtained by thermochemical liquefaction of pig manure was close to the heating value of gasoline (46 MJ/kg). Electronic scanning of liquefaction residue has also been reported.

Reactive and non-reactive solvents as bio-oil blends: a computer-aided molecular design approach

This paper presents a systematic framework of computer-aided molecular design (CAMD), to design solvents that can improve the critical properties of bio-oil. CAMD tools have been used in this work to improve the key properties of bio-oil such as heating value, water content, viscosity, acidity and stability in storage. The design of both non-reactive and reactive solvents has been covered in this work. In both cases, the main objective was to design solvents that form the bio-oil solvent blend with minimum solvent content. In order to model the bio-oil, five major components in the bio-oil are used and the solvent design problem focussed on designing this surrogate solvent. Mixing rules have been employed to estimate the properties of various bio-oil solvent blends. The main objective is to compute the minimum amount of solvent needed by identifying the optimal combination of functional groups for the solvent molecules. The improvement in properties had been tracked using group contribution models. This work also presents a framework to design solvents that improve bio-oil properties by undergoing chemical reactions with the bio-oil components. In order to ensure the homogeneity after solvent addition, miscibility test between solvent and bio-oil is conducted using appropriate thermodynamic models. Based on the results, the use of mixtures of alkene and alcohol is more recommended as the optimal blend solvents since the mass fraction and viscosity could be balanced to meet the final heating value target and viscosity constraints of the blends.

Utilization of oil palm fronds for bio-oil and bio-char production using hydrothermal liquefaction technology

Hydrothermal liquefaction technology carried out on local Malaysian oil palm fronds (OPF) in a batch autoclave reactor to produce solid bio-char as well as liquid bio-oil is reported in this study. The parameters taken in consideration for study encapsulated variable reaction temperature (160–260 °C) and reaction times (20–100 min). Observations showed that the bio-oil yield percentage increased from 27.3% at 160 °C to 41.9% at 260 °C, whereas bio-char yield percentage decreased from 65.2% at 160 °C to 43.2% at 260 °C. Similarly, higher reaction time also produces higher yield bio-oil percentage and lower bio-char yield percentage. The characterization results showed that the combustion properties of bio-char and bio-oil were improved after hydrothermal liquefaction due to decrease in percentage of oxygen of bio-oil and bio-char and an increase in percentage of carbon content. The carbon percentage increased from 42.73% for OPF to 59.42% and 60.47% for bio-char and bio-oil, respectively. Whereas, the percentage of oxygen decreased from 52.51 for OPF to 36.30% and 35.61 for bio-char and bio-oil. The main chemical compounds identified in bio-oil by GC-MS were phenolic compounds and their derivatives, alcohols, ketones, and esters.

Insight into Co-pyrolysis of Palm Kernel Shell (PKS) with Palm Oil Sludge (POS): Effect on Bio-oil Yield and Properties

Bio-oil a carbon based liquid fuel from fast pyrolysis of biomass, can bring prospective changes in the renewable energy field gradually. However, the bio-oil ought to be upgraded since it possesses several negative attributes such as high corrosiveness, high acidity, and high content of water. Catalytic pyrolysis and co-pyrolysis are able to improve some of the properties of bio-oil during production. The fast pyrolysis of palm kernel shell (PKS) produces acidic bio-oil whereas the fast pyrolysis of palm oil sludge (POS) liberates basic bio-oil. Therefore, current study investigated the fast co-pyrolysis of PKS with POS at different blend ratios (10, 20, 35 and 50 wt% POS with PKS) with the aim to produce bio-oil with improved pH. The corresponding blends were pyrolyzed at 507 ± 13 °C in a fixed bed reactor. As the amount of POS in the blends increased from 0 to 100 wt%, a negative synergistic effect (SP) was observed and so a decrease in bio-oil yield. The observation was attributed to the presence of AAEMs found in POS. The total acid number (TAN) of bio-oils decreased with increasing POS ratio in the blends as well. At PKS to POS mass ratio of 50:50, the pH value of the bio-oil produced was 4.6 ± 0.1. Based on the yield and physical properties of bio-oil, the blend with 20 wt% of POS was chosen as the desired ratio as it yielded 40.8 ± 3.7 wt% of bio-oil with a slight negative synergistic effect (SP) of 3.26.

직접 및 간접열교환에 따른 연속식 반응기 내 바이오매스 저속열분해 특성에 대한 실험적 연구

Biochar from pyrolysis is emerging as a new option for biomass utilization for various purposes including soil amelioration and carbon sequestration. This study investigated the slow pyrolysis characteristics of wood pellet in a continuous reactor varying the heat transfer type (direct and indirect contact) at various temperatures (400~700℃) with different carrier gas compositions (inert, O₂ 2%, and O₂ 4%). Direct contact heat transfer by preheated carrier gas accelerated the heat up of biomass, promoting the pyrolysis process as well as the temperature increase of indirect contact cases. The presence of O₂ in the carrier gas resulted in limited oxidation reactions with pyrolytic vapor, increasing the reactor temperature to 529.4℃ and 591.7℃ at 2% and 4% O₂, respectively, compared to the inert case having a final temperature of 492.4℃. This can be exploited to save the external heat supply but a careful temperature control is required to yield uniform biochar properties. The pyrolysis products from different test conditions were characterized for mass yield and detailed properties of biochar, bio-oil, and non-condensable gases.

Properties of Bio-Oil Derived from Eucalyptus Liquefaction with n-Octanol

Properties of Bio-Oil Derived from Eucalyptus Liquefaction with <i>n</i>-Octanol

Catalytic pyrolysis of cellulose with oxides: effects on physical properties and reaction pathways

Fast pyrolysis is a potential technology for converting lignocellulosic biomass into bio-oil, a potential substitute for crude oil and a source of chemicals. Nevertheless, the high amounts of acid, oxygenated compounds, and water content cause the bio-oil to be unsuitable for direct usage. Catalytic fast pyrolysis (CFP) is able to improve bio-oil properties so that downstream upgrading processes may be economically feasible. The catalytic effects of calcium oxide (CaO), magnesium oxide (MgO), and zinc oxide (ZnO) on the pyrolysis of lignocellulosic biomass were investigated and were found to be attractive. However, the reaction pathways involved have not been comprehensively compiled to our knowledge. This study aimed to study the change in physical properties of bio-oils at the simplest form upon the addition of the oxides and to provide an understanding on the catalytic reaction pathways. Such study is beneficial to further explore the potential of selected oxides in enhancing the properties of bio-oil from biomass with different lignocellulosic compositions. Experiments were carried out in a fixed-bed reactor at laboratory scale to mimic large-scale processes in a controlled environment. The catalysts exhibited strengths at different bases. CaO catalyst showed the most favorable physical effects in terms of reducing the acidity of cellulose-derived bio-oils without increasing the water content significantly and without compromising with the yield. As for deoxygenation ability, ZnO catalyst exhibited better performance.

담뱃잎(Tobacco leaves)과 커피박(Coffee ground)의 급속열분해에 의해 제조된 바이오오일의 특성에 관한 연구

담뱃잎(Tobacco leaves)과 커피박(Coffee ground)의 급속열분해에 의해 제조된 바이오오일의 특성에 관한 연구

Effect of oxide catalysts on the properties of bio-oil from in-situ catalytic pyrolysis of palm empty fruit bunch fiber

Fast pyrolysis is a potential technology for converting lignocellulosic biomass into bio-oil. Nevertheless, the high amounts of acid, oxygenated compounds, and water content diminish the energy density of the bio-oil and cause it to be unsuitable for direct usage. Catalytic fast pyrolysis (CFP) is able to improve bio-oil properties so that downstream upgrading processes can be economically feasible. Here, calcium oxide (CaO), magnesium oxide (MgO), and zinc oxide (ZnO) were employed due to their potential in enhancing bio-oil properties. The results showed that overall, all three catalysts positively impacted the empty fruit bunch fibre-derived bio-oil properties. Among the catalysts, CaO showed the most favorable effects in terms of reducing the acidity of the bio-oil and anhydrosugar. Thermal stability of bio-oils produced in the presence of CaO was studied as well.

Effect of Different Zeolite Supported Bifunctional Catalysts for Hydrodeoxygenation of Waste Wood Bio-oil

Effects of various types of zeolite on the catalytic performance of hydrodeoxygenation (HDO) of bio-oil obtained from waste larch wood pyrolysis were investigated herein. Bifunctional catalysts were prepared via wet impregnation. The catalysts were characterized through XRD, BET, and SEM. Experimental results demonstrated that HDO enhanced the fuel properties of waste wood bio-oil, such as higher heating values (HHV) (20.4–28.3 MJ/kg) than bio-oil (13.7 MJ/kg). Water content (from 19.3 in bio-oil to 3.1–16.6 wt% in heavy oils), the total acid number (from 150 in bio-oil to 28–77 mg KOH/g oil in heavy oils), and viscosity (from 103 in bio-oil to 40–69 mm2/s in heavy oils) also improved post HDO. In our experiments, depending on the zeolite support, NiFe/HBeta exhibited a high Si/Al ratio of 38 with a high specific surface area (545.1 m2/g), and, based on the yield of heavy oil (18.3–18.9 wt%) and HHV (22.4–25.2 MJ/kg), its performance was not significantly affected by temperature and solvent concentration variations. In contrast, NiFe/zeolite Y, which had a low Si/Al ratio of 5.2, exhibited the highest improved quality for heavy oil at high temperature, with an HHV of 28.3 MJ/kg at 350 °C with 25 wt% of solvent.

Study on the effect of condensing temperature of walnut shells pyrolysis vapors on the composition and properties of bio-oil

The effect of condensing temperature on composition of bio-oil obtained via fractional condensation was investigated by pyrolysis-condensation experiments of walnut shells at condensing temperatures from 290 K to 370 K. The condensing efficiency of the first stage condenser decreased from 0.59 to 0.12 with increasing temperature. Moisture of bio-oil decreased from 40% to 5%, but the C/O ratio increased from 0.50 to 1.50. Compared with contents observed at the lowest condensation temperature, the maximum content of each component increased by 50%–500%. Combined with variations in condensing efficiency and composition content, the optimum condensing temperature range for declining water in bio-oil was 340–350 K. The condensing temperature associated with the enrichment of acetic acid and furfural was 345 K. The 355 K optimum condensing temperature could be selected to achieve the maximum enrichment of guaiacol and its derivatives.

Comparative study on the pyrolysis behaviors of rice straw under different washing pretreatments of water, acid solution, and aqueous phase bio-oil by using TG-FTIR and Py-GC/MS

Washing pretreatment is a promising method for upgrading biomass by removing alkali metal and alkaline earth metals (AAEMs). In this study, three types of solution with different pretreatment severities (i.e., water (H2O), dilute hydrochloric acid (HCl) solution, and aqueous phase bio-oil (APBO)) were used to study the effects of the washing pretreatment on the pyrolysis behaviors and kinetics of rice straw. The pyrolysis experiments of raw and pretreated rice straw (Raw-RS, H2O-RS, HCl-RS, and APBO-RS) were carried out using TG-FTIR and Py-GC/MS. Results show that among the three types of washing pretreatment methods, the APBO washing pretreatment has the highest removal efficiency of AAEMs: 99.7% of K, 91.7% of Na, 96.6% of Mg, and 95.2% of Ca. According to TG-FTIR results, only one sharp mass loss peak was present in the DTG curves of Raw-RS and H2O-RS, whereas two mass loss peaks (one sharp peak and one shoulder peak) were observed in HCl-RS and APBO-RS. The evolution pattern of the volatile compounds (H2O, CH4, CO, CO2, and CO stretching) was thoroughly investigated, and the absorbance intensity of these components increased with the washing pretreatment of APBO and HCl. The APBO washing pretreatment had the highest activation energy in the conversion rate of 0.2–0.75, followed by HCl and H2O washing pretreatment. According to the Py-GC/MS results, the washing pretreatment reduced the relative contents of acids, ketones, furans, and phenols in bio-oil, whereas removing of AAEMs increased the relative contents of anhydrosugars (mainly levoglucosan). Among the three types of washing pretreatments, the APBO washing pretreatment had the most remarkable influence on the property of bio-oil, and this indicates that the APBO washing pretreatment is a promising method for upgrading biomass and its pyrolytic product.

Catalytic co-pyrolysis of red cedar with methane to produce upgraded bio-oil

Fast pyrolysis is a promising route to transform biomass into bio-oil for further refining into transportation fuels and chemicals. However, bio-oil applications suffer from several challenges due to its adverse properties. This study reports improving bio-oil properties through co-pyrolysis of biomass with methane over molybdenum/zinc (MoZn/ZHSM-5) and HZSM-5 catalysts that promote deoxygenation, decarbonylation, hydrogen transfer and aromatization reactions. The co-pyrolysis was conducted at 650 °C and 750 °C in a micro-scale reactor and a bench-scale reactor. The highest bio-oil yield, energy content, and energy yield of 53.4%, 10.2 MJ/kg, and 29.9%, respectively, were obtained with methane over MoZn/HZSM-5 at 650 °C. Acids, alcohols, aldehydes, benzene derivatives, BTEXs, furans, ketones, PAHs, and phenols were detected in bio-oils while phenols dominated under most conditions. Oxygenated compounds decreased using MoZn/HZSM-5 with methane at 750 °C. The results demonstrate that methane used with catalysts can reduce oxygenated compounds and improve properties and yield of bio-oil.

Catalytic Upgrading of Bio-oil Produced from Pyrolysis of Rice Husk

Rice husk is one of the most widely available agriculture residues. It was a promising eco-friendly alternative source of renewable energy in the context of current energy scenarios. Fast pyrolysis technologies can transform rice husk into bio-oil considering its physical and chemical properties. Catalytic pyrolysis experiments have been carried out on Japanese rice husk to obtain bio-oil using a fixed-bed pyrolysis reactor with the use of the catalyst and comparison was done to analyze the changes in the bio-oil properties and yield. The fast pyrolysis of rice husk has been performed in the temperature range of 400-600 °C using the experimental pyrolysis reactor. The objective of this research is to explore the possibility to upgrade bio-oil produced from rice husk. The catalytic cracking is the most promising bio-oil upgrading processes, and it can remove oxygenated compounds from bio-oil via H2O, CO and CO2. The result showed that by using two heating units, even without catalyst, the upgrading was achieved well. In this research, two heating units were employed so that the raw bio-oil will separate in the first heating unit and the cracking in the second heating unit. The raw rice husk bio-oil produced and the upgraded bio-oil were characterized by measuring their element content, water content and the chemical composition of its organic fraction. The catalysts used were HZSM-5 zeolite and other non-commercial catalyst like rice husk ash which were appropriately effective in the bio-oil crack upgrading to reduce cost.

Design of bio-oil additives using mathematical optimisation tools considering blend functionality and sustainability aspects

In this work, a computer-aided molecular design based technique has been developed to upgrade bio-oil properties via solvent addition by targeting both functionality and sustainability targets. The direct application of bio-oils as a fuel is often constrained by their inferior properties such as high water content, high viscosity, low heating values, low miscibility, and storage instability as compared to conventional fuels. One promising method to upgrade bio-oil is the use of solvents as additives to generate a solvent–oil blend capable of meeting both its fuel functionality and sustainability targets in health, safety, and environmental aspects from production to point of application. Suitable solvents were formulated using computer-aided molecular design (CAMD) techniques by solving a two-stage multi-objective optimisation problem based on the defined targets. In the first stage, an optimisation model for solvent–oil blend functionality was constructed to optimise solvent functionality. In the second stage, a fuzzy optimisation approach aimed to optimise environmental, health, and safety (EHS) aspects via an index-based method. By implementing a max–min aggregation approach, an optimised solution has been generated by determining trade-off points that allowed significant EHS improvements at minimal expense of blend functionality. Lastly, the optimal solvent–oil blend was evaluated against conventional diesel in terms of carbon savings. This allowed the quantification of environmental savings through utilising biofuels while ensuring minimal compromise on fuel performance. Altogether, this approach has enabled the identification of feasible solvents for bio-oil upgrade and design of blends for application while allowing multi-objective optimisation of EHS targets.