Highest Bio-oil Yield Research Articles

Fast pyrolysis corn husk for bio-oil production

The fast pyrolysis of corn husk was studied by using a tube pyrolysis unit. This research aimed to produce bio-oil from corn husk through a fast pyrolysis process. Pyrolysis is a thermochemical decomposition process of biomass at high temperatures with the absence of oxygen. The products in pyrolysis combustion are solids (bio-char), liquids (bio-oil), and gases. The major factors to get excellent products of pyrolysis are temperature and time. The corn husk was dried at 105 °C in the oven to reduce water content. The dried sample was burned at temperatures of 250, 300, 350, 400, 450, and 500 °C by flushing the nitrogen gas inside the tube for two h. The highest yield of bio-oil was reached of 33.3% at a temperature of 400 °C. Bio-oil characteristics such as density (1.007 gr/ml) and viscosity (0.9625 cSt) were observed. The composition of bio-oil was identified using Gas Chromatography-Mass Spectrometry. Its composition was composed of hydrocarbons such as acids, furfural, phenols, and ketones.

A novel production of monocyclic aromatic hydrocarbons via one-step catalytic conversion of pine sawdust and waste plastics over Pd/trap-HZSM-5

A novel method is proposed to one-step convert pine sawdust (PW) and high-density polyethylene (HDPE) into monocyclic aromatic hydrocarbons under solvent-free conditions. The aim is to strengthen the collision ability of small molecules and stabilize active oxygenates by using pressurization and hydrogen atmospheres, so as to significantly enhance the thermal interaction between PW and HDPE. A series of Pd/trap-HZSM-5 catalysts were prepared by different methods. Among them, self-reduction Pd/trap-HZSM-5 catalyst with smallest Pd nanoparticle size and highest hydrogen adsorption capabilities combined with hydrogenation ability and moderate acidity bi-functions, so it shows the highest activity. Under the optimal conditions (400℃, 1 MPa H2, Si/Al ratio of 50, catalyst-to-reactant ratio of 0.1, and plastics-to-biomass ratio of 4), both the high selectivity of aromatic hydrocarbons in bio-oil (88.9%) and the high yield of bio-oil (45.5 wt%) are ensured. The calculated total aromatic hydrocarbons yield reached 40.5 wt%, of which only 0.7 wt% were polycyclic aromatic hydrocarbons, and the vast majority were moncyclic aromatic hydrocarbons. The synergistic effect between PW and HDPE relatively increased the yield of aromatic hydrocarbons by 44.5%.

High-Yield Production of Deoxygenated Monomers from Kraft Lignin over ZnO-Co/N-CNTs in Water

Catalytic conversion of technical lignin to value-added chemicals and fuels is important for realizing economically viable lignocellulosic biomass refineries. The choice of catalysts and solvents is critical for the effective conversion of the technical lignin to chemicals and fuels by the cleavage of the C–C bonds. In this study, catalytic depolymerization and hydrodeoxygenation of Kraft lignin (KL) were investigated over bimetallic ZnO and Co deposited on N-doped carbon nanotubes (ZnO-Co/N-CNTs) in an aqueous medium. The catalytic activity of ZnO-Co/N-CNTs was compared with those of various noble and non-noble metal-based catalysts. Almost complete KL conversion with a very low solid residue yield (5 wt %), a high bio-oil yield (52 wt %), a high degree of deoxygenation (DOD, 59.0%), and a high monomeric yield (12.1 wt %) was achieved over ZnO-Co/N-CNTs at 350 °C and 6 h reaction time. The monomers mainly consisted of cyclohexanone and its alkyl-substituted derivatives and alkylated phenols. At 400 °C, the monomeric yield and DOD increased to 24.4 wt %and 61.0%, respectively. In addition, the produced bio-oil exhibited high-calorific values of 34.3–37.0 MJ kg–¹ because of the high activity of ZnO-Co/N-CNTs for hydrodeoxygenation. ZnO-Co/N-CNTs outperformed most of the metal-supported catalysts including 5 wt % Pd, 5 wt % Ru, 5 wt % Pt, 66 wt % Ni, and CoMo on various supports of activated carbon and alumina. The use of water as the solvent resulted in much higher bio-oil and monomeric yields than those using methanol, isopropyl alcohol, and n-hexane (12–37 and 3.2–4.1 wt %, respectively). The high bio-oil and monomeric yields with a high DOD in water make ZnO-Co/N-CNTs highly attractive in the development of an environmentally friendly technical lignin conversion process.

Hydropyrolysis of freshwater macroalgal bloom for bio-oil and biochar production: Kinetics and isotherm for removal of multiple heavy metals

In this study, hydropyrolysis was carried out using sodium carbonate to convert the green algal bloom into bio-oil, biochar, aqueous solution, and gases. The effect of supercritical conditions (400, 450, 500 °C) on the product yield, bio-oil composition, and structure, and functionalities of the biochar was determined. The high yield of biochar and bio-oil was reported at 400 °C. A significant reduction in bio-oil and increment in hydrocarbon content was reported on the elevation of temperature from 450 °C to 500 °C. After that, kinetic and isotherm analysis was investigated simultaneously to remove four heavy metals viz. Cu(II), Ni(II), Co(II), and Cd(II) from the mixture solution. Results show that kinetics data follow a pseudo-second-order kinetics model and adsorption isotherm is in better agreement with the Langmuir model, not with the Freundlich model. The maximum adsorption capacity was found 10.90, 5.74, 5.80, and 16.28 mg/g with the biochar prepared at 500 °C for Cu(II), Ni(II), Co(II), and Cd(II) metals, respectively. The current investigation provided a promising way for the utilization of freshwater algal bloom biomass for renewable products and simultaneously heavy metal removal from the water.

Hybrid microwave-ultrasound assisted catalyst-free depolymerization of Kraft lignin to bio-oil

In this study, the simultaneous effect of microwave-ultrasound (MW + US) irradiations was compared with those of microwave (MW) and ultrasound (US) applied individually for the depolymerization of Kraft lignin in a hybrid microwave-ultrasound high pressure chemical reactor. The bio-oils obtained upon depolymerization were analyzed by GC–MS, CHNS, MALDI-TOF-MS, 2D-HSQC NMR, TGA and FTIR techniques. The highest bio-oil yield of 48.2% was obtained upon depolymerization of Kraft lignin with hybrid MW + US irradiations for 1 h under autogenous pressure while only 42.1% and 25.5% bio-oil yields were obtained for MW and US irradiations, respectively. MALDI-TOF MS spectra suggested the presence of significant amount of dimers in the bio-oil obtained over hybrid MW + US process than US and MW processes. The simultaneous effect of MW and US reduced the repolymerization of reaction intermediates thus favoring relatively low residue and high bio-oil yield. 2D-HSQC NMR demonstrated considerable degradation of the representative inter-unit linkages (β-O-4 and β-5). The HHVBoie of the bio-oils obtained over US (29.28 MJ/Kg) and MW + US (29.21 MJ/Kg) irradiations were quite comparable. Although the thermal stability of the bio-oils followed the order MW > MW + US > US, the bio-oil obtained over hybrid MW + US was superior in both quality and quantity than obtained over MW and US irradiations.

Production of platform chemical and bio-fuel from paper mill sludge via hydrothermal liquefaction

As a kind of industrial hazardous solid waste, paper mill sludge (PMS) was hard to treated by conventional process because of its high moisture, high organic content and and high environmental risk. The hydrothermal liquefaction (HTL) shows excellent potential for the conversion to a wide variety of organic matter with high water contents including various kinds sludge into fuels or value-added chemicals. In this paper, the liquefaction potential for PMS under different reaction temperatures were investigated, and the products were classified into several main components based on the results of GC-MS. The results showed that the highest yield of bio-oil was 44 % (wt/wt dry PMS without ash) at 340 °C with simply compound composition. And the bio-oil product has above 26 % long chain hydrocarbon and 22 % cycloketones. It has potential for conversion to biomass platform compounds. It can be used as bio-fuel for heat recovery of alkali recovery system of paper mill. So, adjusting different reaction temperatures of HTL, the properties of products can meet the different requirements for platform chemical and/or bio-oil fuel.

Assessment of the pyrolysis products from halophyte Salicornia bigelovii cultivated in a desert environment

The development of bioenergy in marginal environments has been hampered by the lack of sustainable sources of biomass. The halophyte Salicornia bigelovii, has been found to adapt extremely well in a desert climate. In this study, the S. bigelovii seed and the seedless-plant have been assessed, for the first time, for biofuel and biochar production through thermochemical conversion (pyrolysis) in an auger reactor operated at 550 °C. Both feedstocks showed significant differences in chemical composition, with the seed being closer to the characteristics of seeds from common oilseed crops. The S. bigelovii seed produced high bio-oil yield (79.9% of total liquid) of high pH predominated with fatty acids commonly found in vegetable oils. The S. bigelovii seedless-plant produced a liquid of significantly low bio-oil (10% of total liquid) with an aqueous phase of pH and salinity close that of brackish water. The biochars were of moderate heating value and limited potentials for soil amendment due to the high ash content in the biomass, but are reasonably stable for long term carbon sequestration due to their low O/C and H/C ratios (<0.1 and <1.0, respectively). Comparative assessment in terms of the conversion efficiency and renewability indicated that pyrolysis of the S. bigelovii seed offers a good opportunity for biofuel production in arid/semi-arid saline regions against the alternative option of transesterification conversion.

Catalytic pyrolysis of ulva lactuca macroalgae: Effects of mono and bimetallic catalysts and reaction parameters on bio-oil up-gradation

Catalytic pyrolysis of ulva lactuca (UL) macroalgae was studied over a series of ZrO2 supported metal such as Co, Ni and Co-Ni metal catalysts at temperature range of 300–500 °C. Highest bio-oil yield (47.8 wt%) was found with Co-Ni/ZrO2 (10 wt%) catalyst while non-catalytic yielded 42.5 wt% bio-oil. Moreover with increases the metal amount to 15 wt%, the bio-oil yield slightly increased (49.2 wt%). The bio-oil quality significantly improved with using the catalysts compared to the non-catalytic pyrolysis. Catalytic pyrolysis also revealed that introducing Co-Ni into the ZrO2 could result in higher surface area and which increased active sites. Catalytic bio-oils were consisted of mainly long chain hydrocarbon in the range of C6-C16. Moreover, the catalytic bio-oils were showed the higher ‘high heating value’ (HHV) 38.1 MJ/kg as compare to non-catalytic bio-oils (29.4 MJ/kg). Catalysts have been showed excellent recyclability on bio-oil yield and compounds selectivity.

Comparative study of zeolites matrices in bio-wastes pyrolytic valorization

Considering the importance of bio-wastes thermo-chemical conversion to fuel and platform molecules, three types of zeolites (ZSM-5, Beta and Y) were tested as heterogeneous catalysts. Peanut shell is a high volume agricultural waste. Its pyrolysis mediated by different catalysts was evaluated. The effect of the zeolite matrix over the bio-oil yield and products selectivities was carefully considered. Fresh and used materials were widely characterized by XRD, FTIR, ICP and BET techniques. Pyrolysis reactions were done at 500 °C under N2 flow. The use of zeolites in biomass pyrolysis showed interesting results in terms of bio-oil composition. When H-ZSM-5 catalyst was employed, higher bio-oil yields and greater concentration of aromatic hydrocarbons and furans were obtained.

Production and Characterization of Bio Oil from Bamboo

The quest for renewable energy sources have been the major concerns worldwide due to depletion of fossil fuel and ozone layer as a result of fossil fuel combustion. Bio oil or fuel production from different natural plants have been researched over the years in different regions of the world. Thus, this research study focused on production and characterization of bio oil from Nigerian bamboo plant (Ogoni bamboo), which involved fresh bamboo preparation and its pyrolysis and characterization. The fresh bamboo plant was used since it’s not edible unlike other studies that applied edible fruits as source of bio diesel production. The prepared fresh bamboo plant was pyrolysed at a temperature range of 300°C to 600°C and the gaseous products condensed to temperature of 25°C. The applied temperature range was used to evaluate the effect of fast, intermediate and slow pyrolysis, while high yield of bio oil was deduced at 450°C. The produced bio oil was characterized by investigating its density, specific gravity, viscosity with gas chromatography and ASTM distillation D86 analysis carried out on the produced bio oil. The pyrolysis result yielded 59.5wt% of bio oil at reactor bed temperature of 450°C, which is heavy in nature, highly viscous with calorific valuer. Thus, bio oil can be produced from Nigeria bamboo plant as an alternate energy source with further product upgrading process required for effective and commercial use of the produced bamboo bio oil.

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 temperature in the 500-800 oC range has on the product yields has been analysed. A detailed analysis of the gaseous streamhas been carried out by chromatographic techniques, and the char samples have been characterized by several techniques.A high bio-oil yield was obtained at 500 oC (75.4 wt.%), which is evidence of the suitable features of the CSBR 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 (500-600oC), and only had a little influence at 700oC due to the low gas residence time in the CSBR. At 800 oC, 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. The char obtained in the whole temperature range can be further used as active carbon or energy source.

Study on the hydrothermal liquefaction of antibiotic residues with molecular sieve catalysts in the ethanol-water system: focus on product distribution and characterization.

In this study, the antibiotic residue was used as a raw material to catalyze hydrothermal liquefaction (HTL) in an ethanol–water system to prepare bio-oil. The study explored the effects of ethanol–water ratio and three kinds of molecular sieve catalysts (HZSM-5, MCM-41, and γ-Al2O3) on the yield and characterization of bio-oil. The experimental results showed that the highest bio-oil yield was obtained at the ethanol–water ratio of 1 : 1 and the three kinds of molecular sieve catalysts of 15%. GC-MS, 1H NMR, TGA, and CHNS were used for the characterization of bio-oil. Higher carbon (up to 71.44%), hydrogen (up to 9.376%), and a high heating value (HHV, 34.714 MJ kg−1) were observed for catalytically liquefied bio-oil compared to non-catalytically liquefied bio-oil. The analysis of aqueous phase products indicated the existence of valuable nutrients. Besides, the reusability of three kinds of molecular sieve catalysts indicated that catalysts could be successfully reused several times and continuously exhibited the catalyst effect.

Study of rice husk continuous torrefaction as a pretreatment for fast pyrolysis

Rice husk (RH) is one of the most available biomasses in southern Brazil. One possible solution is to carry out the fast pyrolysis of RH. To improve the quality of liquid products biomass can be torrefied before being pyrolyzed. The influence of torrefaction on the physical and chemical properties of pyrolysis products was explored. Both torrefaction and pyrolysis reactions were performed in a fluidized bed reactor in a continuous mode. Sample with torrefaction and pyrolysis at 500 °C presented the highest biochar yield (44.2 wt.%). The torrefaction step produced a lower yield of bio-oil. In contrast, the highest bio-oil yield (43.6 wt.%) was achieved in the sample without torrefaction at 500 °C. The increase in temperature to 750 °C provided a specific area of 16.7 m²/kg for biochar. The highest value of HHV for bio-oil, 28 MJ/kg, was obtained via direct pyrolysis at 750 °C, which also led to the lowest water content of 5.9 wt%. According to the NMR analysis, the torrefaction liquid (TL) presented a high quantity of water and alcohols in its composition (92.5 %).

Solvolysis of Kraft Lignin to Bio-Oil: A Critical Review

Lignin, a component of lignocellulosic biomass, is abundant and is produced extensively as a waste product of the Kraft pulping process, lignin obtained from this process is called Kraft lignin (KL). Lignin’s three-dimensional structure composed of aromatic alcohols (monolignols) makes it a potential source of renewable aromatic chemicals or bio-oil, if depolymerized. Among all the depolymerization methods for KL, solvolysis is the most popular, showing consistently high bio-oil yields. Despite the large number of studies that have been carried out, an economically feasible industrial process has not been found and comparison among the various studies is difficult, as very different studies in terms of reaction media and catalysts report seemingly satisfactory results. In this review, we compare and analyze KL solvolysis studies published, identify trends in bio-oil composition and give a comprehensive explanation about the mechanisms involved in the processes. Additional commentary is offered about the availability and future potential of KL as a renewable feedstock for aromatic chemicals, as well as logistical and technical aspects.

Catalytic co-liquefaction of sugarcane bagasse and polyethylene for bio-oil production under supercritical conditions: Effect of catalysts

Catalytic co-liquefaction of high-density polyethylene and sugarcane bagasse over metal salt and oxide catalysts in ethanol solvent was investigated. The obtained bio-oil samples were analyzed and characterized by gas chromatography–mass spectroscopy (GC–MS), nuclear magnetic resonance (NMR), ultimate analysis (CHNS/O), Fourier transform infrared spectroscopy (FTIR) and different solid products characterized by x-ray fluorescence (XRF) and Scanning Electron Microscope (SEM) analysis. The results suggested that adding ZnSO4 gives the highest HHV (34.61 MJ/kg), while CuSO4 gives the highest bio-oil yield (38.42 %) and conversion (69.54 %). GC–MS analysis suggested that the bio-oils contained large amounts of hydrocarbons, phenols, ketone aldehydes, alcohols and esters. The 1H and 13C NMR spectra were integrated over spectral regions to quantify classes of carbon and hydrogen atoms in each bio-oil and suggested that bio-oils largely contain alkanes, aliphatics and alcohols. The liquid products are promising bio-fuel precursors for further utilization.

Effect of different pre-treatments and addition of plastic on the properties of bio-oil obtained by pyrolysis of greenhouse crop residue

The bio-oil properties and yields during pyrolysis at 400, 500 and 600 °C of the residues from the cultivation of the pepper in greenhouse (Capsicum annuum L.) were studied. Different solid samples were investigated: the biomass fraction of the residue, the water-washed biomass sample, the cobalt-loaded biomass sample and three mixtures made with the biomass and plastic fractions of the residue. Results showed that temperature of pyrolysis has a moderate impact on the products’ yields and bio-oil properties for all solid samples. In general, the highest bio-oil yield was achieved operating at 600 °C while the higher char yield was reached at 400 °C. The pH of all the bio-oil samples was low, specially bio-oil from the cobalt-loaded biomass sample. Density, viscosity, cetane number, average boiling temperature, flashpoint, elemental analysis and ash content of the samples were analyzed and compared.The highest higher heating value was achieved for bio-oil (4218.6 kcal/kg) obtained from pyrolysis of the cobalt-loaded biomass sample. Infrared spectra and chromatography analysis revealed the presence of numerous compounds. Acetic acid is the main acid component of the bio-oil samples obtained from the biomass, the water-washed biomass and the cobalt-loaded biomass, although there are some differences in relative area. Other compounds such as ketones, phenolic or furans were also found. In bio-oils obtained from biomass and plastic mixtures, in general there was a decrease in the content of oxygenated compounds and acidic compounds, favoring the presence of non-oxygenated compounds. This work shows the feasibility of the obtaining of bio-oil from the greenhouse crop residue at the temperature range between 400 and 600 °C.

Investigations into distribution and characterisation of products formed during hydrothermal carbonisation of paunch waste

Paunch waste is the wet waste generated from the cattle/sheep yard, paunch material, skin-shed, boning rooms, blood stream and rendering plant in an abattoir. It contains around 3% solids. It mainly consists of grass, grain, grease, fat, protein, blood, intestinal content, manure and cleaning products. In this study, paunch waste was treated under hydrothermal carbonisation conditions at different temperatures (160 to 240℃), residence time (5–150 min) and initial N2 pressure (10–30 bar) in a laboratory scale 600 mL Parr reactor system. The main objective of this study was to quantify the product distribution and further characterise the products produced from the hydrothermal carbonisation of paunch waste. The product distribution results reveal that higher bio-oil yield was obtained at relatively mild hydrothermal carbonisation conditions which is mainly attributed to fragile nature of paunch waste, higher water, volatile matter and carbohydrate content, and lower lignin and ash content. The resultant hydrochar was found to have higher HHV (∼24.48 MJ kg-1) and BET surface area (68.1 m2 g-1) which demonstrates their suitability as a coal substitute (in energy generation processes) or a porous medium (in soil conditioning, remediation or catalysts applications). Biodiesel-like compounds were found in the heavy bio-oil with the HHV of around 38 MJ kg-1. Higher bio-oil production and excellent physico-chemical properties of hydrochar at milder hydrothermal carbonisation conditions have demonstrated significant improvement in the commercial viability of hydrothermal carbonisation of the paunch waste.

Catalytic hydrothermal liquefaction of lignin over carbon nanotube supported metal catalysts for production of monomeric phenols

The catalytic hydrothermal liquefaction (HTL) of lignin was studied at different temperature (260, 280 and 300 °C) with different metal supported (Co, Ni and Fe) on carbon nanotube (CNT) in the presence of different solvents including water, ethanol and methanol for 30 min Reaction time. In comparison with water solvent liquefaction, the bio-oil yield significantly increased under alcoholic solvent (ethanol and methanol). As the reaction temperature increased from 260 to 300 °C, there was an increase in the conversion (70.9–86.9 wt%) of lignin. The highest bio-oil yield (66.2 wt%) was found with 10.wt.% Co/CNT catalyst using an ethanol solvent system at 280 °C. Moreover lower temperature showed lower yield of bio-oil. Catalyst acidity and surface area were seen to affects the alkali lignin depolymerization. Co/CNT and Ni/CNT catalysts are mainly responsible for the depolymerization of lignin into higher monomer phenolic compounds. A higher area percentage of vanillin obtained during catalytic liquefaction reaction as the presence of a catalyst, and alcoholic solvent accelerated the β-O-4 bond cleavages. Also elemental and GPC analysis showed that during the liquefaction reaction promotes the hydrogenation/hydrodeoxygenation and produced lower molecular weight bio-oils.

Effects of carbamide pretreatment on product distribution and bio-oil composition from fast pyrolysis of pine powder

The nitrogen-rich pyrolysis is a significant technique to improve the utilization and value addition of biomass. The bio-oil derived from the biomass nitrogen-rich pyrolysis is abundant in high-value nitrogenous compounds. Carbamide-pretreated pine powder was used to produce bio-oil through fast pyrolysis in this paper. Effects of pyrolysis temperature and the concentration of carbamide solution on the product distribution and the content of important compounds (e.g., phenols, amines, indoles, pyrroles) in pine powder–derived bio-oil were investigated. The results showed that the bio-char yield decreased as the concentration of carbamide solution increased. The highest bio-oil yield (51.8%) appeared at a temperature of 400 °C and an impregnated carbamide solution concentration of 10%. The contents of acids, ketones, and aldehydes in the bio-oil obtained by carbamide-impregnated pine powder significantly decreased while the content of phenols observably increased. Compared with the bio-oil derived from raw pine powder, there were various nitrogenous compounds generated in the bio-oil produced by carbamide-impregnated pine powder. As the concentration of carbamide solution increased, the varieties of nitrogenous compounds increased.

Study on two-step hydrothermal liquefaction of macroalgae for improving bio-oil

In this work, the conversion of Enteromorpha clathrata into bio-oil through hydrothermal liquefaction (HTL) was investigated under different preparation conditions. A two-step reaction method was compared with single-step reaction. At a high temperature, bio-oil produced through the two-step hydrothermal reaction displayed slight changes in yield, but solid residue rate was low. The liquid-to-material ratio of the optimal preparation condition was 40/4 (mL/g). Bio-oil produced in each experiment at this ratio was further analyzed using GC/MS. Furthermore, density functional theory (DFT) quantitative calculation was used in analyzing and proving the possible reaction path of the conversion of furan compounds to aromatic compounds during a direct high-temperature liquefaction process. Results revealed that the two-step method can ensure a high bio-oil yield, while preventing the occurrence of side reactions caused by long-term high-temperature reactions, and improve the bio-oil quality.