An Assessment of the Potential Use of Forest Residues for the Production of Bio-Oils in the Urban-Rural Interface of Louisiana

Louisiana is endowed with forest resources. Forest wastes generated after thinning, land clearing, and logging operations, such as wood debris, tree trimmings, barks, sawdust, wood chips, and black liquor, among others, can serve as potential fuels for energy production in Louisiana. This paper aims to evaluate the potential annual volumes of forest wastes established on detailed and existing data on the forest structure in the rural-urban interface of Louisiana. It also demonstrates the state’s prospects of utilizing forest wastes to produce bio-oils. The data specific to the study was deduced from secondary data sources to obtain the annual average total residue production in Louisiana and estimate the number of logging residues available for procurement for bioenergy production. The total biomass production per year was modeled versus years by polynomial regression curve fitting using Microsoft Excel. Results of the model show that the cumulative annual total biomass production for 2025 and 2030 in Louisiana is projected to be 80000000 Bone Dry Ton (BDT) and 16000000 (BDT) respectively. The findings of the study depict that Louisiana has a massive biomass supply from forest wastes for bioenergy production. Thus, the potential for Louisiana to become an influential player in the production of bio-based products from forest residues is evident. The author recommends that future research can use Geographic Information Systems (GIS) to create maps displaying the potential locations and utilization centers of forest wastes for bioenergy production in the state.

Ceria on alumina support for catalytic pyrolysis of Pavlova sp. microalgae to high-quality bio-oils

In this work,we report for the first time the in-situ catalytic pyrolysis of Pavlova sp.microalgae,which has been performed in a fixed-bed reactor in presence of Ce/Al2O3-based catalysts.The effects of pyrolysis parameters,such as temperature and catalyst were studied on the products yield distribution and biooil composition,among others.Results showed that all catalysts increased the bio-oil yield with respect to the non-catalytic runs and reduced the O/C ratio from 0.69（Pavlova sp.）to 0.1–0.15,which is close to that of crude oil.In terms of bio-oil oxygen content,Mg Ce/Al2O3presented the best performance with a reduction of more than 30%,from 14.1 to 9.8 wt%,of the oxygen concentration in comparison with thermal pyrolysis.However,Ni Ce/Al2O3gave rise to the highest aliphatics/aromatics fractions.The elemental and gas analysis indicates that N was partially removed from the catalytic bio-oils in the gas phase in forms of NH3and HCN.

Coconut Fiber Pyrolysis: Bio-Oil Characterization for Potential Application as an Alternative Energy Source and Production of Bio-Degradable Plastics

The current energy crisis could be alleviated by enhancing energy generation using the abundant biomass waste resources. Agricultural and forest wastes are the leading organic waste streams that can be transformed into useful alternative energy resources. Pyrolysis is one of the technologies for converting biomass into more valuable products, such as bio-oil, bio-char, and syngas. This work investigated the production of bio-oil through batch pyrolysis technology. A fixed bed pyrolyzer was designed and fabricated for bio-oil production. The major components of the system include a fixed bed reactor, a condenser, and a bio-oil collector. The reactor was heated using a cylindrical biomass external heater. The pyrolysis process was carried out in a reactor at a pressure of 1atm and a varying operating temperature of 150˚C, 250˚C, 350˚C to 450˚C for 120 minutes. The mass of 1kg of coconut fiber was used with particle sizes between 2.36 mm - 4.75 mm. The results show that the higher the temperature, the more volume of bio-oil produced, with the highest yield being 39.2%, at 450˚C with a heating rate of 10˚C/min. The Fourier transformation Infrared (FTIR) Spectroscopy analysis was used to analyze the bio-oil components. The obtained bio-oil has a pH of 2.4, a density of 1019.385 kg/m3, and a calorific value of 17.5 MJ/kg. The analysis also showed the presence of high-oxygenated compounds;carboxylic acids, phenols, alcohols, and branched oxygenated hydrocarbons as the main compounds present in the bio-oil. The results inferred that the liquid product could be bestowed as an alternative resource for polycarbonate material production.

Processing and properties of rigid polyurethane foams based on bio-oils from microwave-assisted pyrolysis of corn stover

A new kind of rigid polyurethane(PU)foam was synthesized from the oil phase of bio-oils from microwave-assisted pyrolysis of corn stover.The recipes for the PU foams consisted of polyol-rich bio-oils,water as blowing agent,polyethylene glycol(PEG)as both polyol donor and plasticizer,diphenylmethane-4,4’-diisocyanate(polymeric MDI)as cross-linking agent,silicon-based surfactant,and tin-based catalyst.The mechanical properties of rigid foams were measured with universal testing machine(Instron4206).The effects of individual ingredients on the physical and mechanical properties of the foams were studied.It was found that water content,bio-oil content,and isocyanate dosage were important variables in making PU foams in terms of mechanical strength,density,and cellular structure Under optimal conditions,the compression strength of the prepared PU foams reached 1130 kPa with a density of 152.9 g/L.The results show that bio-oils are potential renewable polyol sources for making rigid PU foams.

Rational design of Ni-MoO_(3–x) catalyst towards efficient hydrodeoxygenation of lignin-derived bio-oil into naphthenes

Design of a robust catalyst with high activity but the low cost for the hydrodeoxygenation(HDO) of biooils is of great importance to bring the biorefinery concept into reality.In this study,density functional theory(DFT) calculation was adopted to analyze the optimal location of Ni on MoO_(3-x) containing oxygen vacancy,and the corresponding result demonstrated that metallic Ni cluster located at the neighborhood of oxygen vacancies would significantly evoke HDO activity.Enlightened by DFT results,NiMoO_(4) was first hydrothermally synthesized and then employed to fabricate Ni-MoO_(3-x) catalyst via a low-temperature reduction,where Ni escaped from NiMoO_(4) and was reduced to its metallic state.Such an evolution of Ni species also induced the formation of oxygen vacancies around metallic Ni cluster.In the HDO of p-cresol,Ni-MoO_(3-x) exhibited high activity with a complete conversion and a methylcyclohexane selectivity of 99.4% at 150℃.Moreover,the catalyst showed good versatility in catalyzing HDO of diverse lignin-derived oxygenates and lignin oil.2D HSQC NMR,gas chromatograph and elemental analysis of the lignin oil demonstrated the high deoxygenation efficiency and saturation of the benzene ring over Ni-MoO_(3-x).In the upgrading of crude lignin oil,the deoxygenation degree was up to 99%,and the overall carbon yield of the naphthenes was as high as 69.4%.Importantly,the structures and carbon numbers of the naphthene products are similar to jet fuel-range cycloalka nes,which are expected to have a high density that can be blended into jet fuel to raise the range(or payload) of airplanes.This work demonstrates the feasibility for improving the targeted catalytic reactivity by rational tailoring the catalyst structure under the guidance of theoretical analysis,and provides an energy-efficient route for the upgrading of lignin crude oil into valuable naphthenes.

Hydrothermal hydrogenation/deoxygenation of palmitic acid to alkanes over Ni/activated carbon catalyst

To produce paraffin from hydrogenation/deoxygenation of palmitic acid,model compound of bio-oil obtained by hydrothermal liquefaction(HTL)of microalgae has been an attractive focus in recent years.In order to avoid energy-intensive separation process of water and bio-oil,it is of importance that deoxygenation upgrading of fatty acids under hydrothermal conditions similar to HTL process.Herein,it is the first time to explore the application of activated carbon(AC)-supported non-noble-metal catalysts,such as Ni,Co,and Mo,and so on,in the hydrothermal hydrogenation/deoxygenation of long-chain fatty acids,and the obtained Ni/AC-H(the Ni/AC was further H_(2)pre-reduced)is one of the best catalysts.In addition,it is found that the catalytic activity can be further improved by H_(2)pre-reduction of catalyst.Characterization results that are more low valences of nickel and oxygen vacancy can be obtained after H_(2)pre-reduction,thus significant promoting the deoxygenation especially the decarbonylation pathway of fatty acids.The total alkanes yield can reaches 95.9%at optimal conditions(280℃,360 min).This work confirmed that the low-priced AC-supported non-noble-metal catalysts have great potential compared with the noble-metal catalyst,in hydrothermal upgrading of bio-oil.

Importance of oxygen-containing functionalities and pore structures of biochar in catalyzing pyrolysis of homologous poplar

Biochar and bio-oil are produced simultaneously in one pyrolysis process,and they inevitably contact and may interact,influencing the composition of bio-oil and modifying the structure of biochar.In this sense,biochar is an inherent catalyst for pyrolysis.In this study,in order to investigate the influence of functionalities and pore structures of biochar on its capability for catalyzing the conversion of homologous volatiles in bio-oil,three char catalysts(600C,800C,and 800AC)produced via pyrolysis of poplar wood at 600 or 800℃or activated at 800℃,were used for catalyzing pyrolysis of homologous poplar wood at 600℃,respectively.The results indicated that the 600C catalyst was more active than 800C and 800AC for catalyzing cracking of volatiles to form more gas(yield increase by 40.2%)and aromatization of volatiles to form more light or heavy phenolics,due to its abundant oxygen-containing functionalities acting as active sites.The developed pores of the 800AC showed no such catalytic effect but could trap some volatiles and allow their further conversion via sufficient aromatization.Nevertheless,the interaction with the volatiles consumed oxygen on 600C(decrease by 50%),enhancing the aromatic degree and increasing thermal stability.The dominance of deposition of carbonaceous material of a very aromatic nature over 800C and 800AC resulted in net weight gain and blocked micropores but formed additional macropores.The in situ diffuse reflectance infrared Fourier transform spectroscopy characterization of the catalytic pyrolysis indicated superior activity of 600C for removal of -OH,while conversion of the intermediates bearing C=O was enhanced over all the char catalysts.

Aqueous-phase catalytic hydrogenation of furfural to cyclopentanol over Cu-Mg-Al hydrotalcites derived catalysts:Model reaction for upgrading of bio-oil

A series of Cu-Mg-Al hydrotalcites derived oxides with a(Cu+Mg)/Al mole ratio of 3 and varied Cu/Mg mole ratio(from 0.07 to 0.30) were prepared by co-precipitation and calcination methods, then they were introduced to the hydrogenation of furfural in aqueous-phase. Effects of Cu/Mg mole ratio, reaction temperature, initial hydrogen pressure, reaction time and catalyst amount on the conversion rate of furfural as well as the selectivity toward desired product cyclopentanol were systematically investigated. The conversion of furfural over calcined hydrotalcite catalyst with a Cu/Mg mole ratio of 0.2 was up to 98.5% when the reaction was carried out under 140 ?C and the initial hydrogen pressure of 4 MPa for 10 h, while the selectivity toward cyclopentanol was up to 94.8%. The catalysts were characterized by XRD and SEM. XRD diffraction of all the samples showed characteristic pattern of hydrotalcite with varied peak intensity as a result of different Cu content. The catalytic activity was improved gradually with the increase of Cu component in the hydrotalcite.

Hydrogen production via steam reforming of bio-oil model compounds over supported nickel catalysts

The steam reforming of four bio-oil model compounds（acetic acid,ethanol,acetone and phenol） was investigated over Ni-based catalysts supported on Al2O3 modified by Mg,Ce or Co in this paper.The activation process can improve the catalytic activity with the change of high-valence Ni（Ni2O3,NiO） to low-valence Ni（Ni,NiO）.Among these catalysts after activation,the Ce-Ni/Co catalyst showed the best catalytic activity for the steam reforming of all the four model compounds.After long-term experiment at 700°C and the S/C ratio of 9,the Ce-Ni/Co catalyst still maintained excellent stability for the steam reforming of the simulated bio-oil（mixed by the four compounds with the equal masses）.With CaO calcinated from calcium acetate as CO2 sorbent,the catalytic steam reforming experiment combined with continuous in situ CO2 adsorption was performed.With the comparison of the case without the adding of CO2 sorbent,the hydrogen concentration was dramatically improved from 74.8% to 92.3%,with the CO2 concentration obviously decreased from 19.90% to 1.88%.

Soot formation and oxidation during bio-oil gasification:experiments and modeling

A model is proposed to describe soot formation and oxidation during bio-oil gasification.It is based on the description of bio-oil heating,devolatilization,reforming of gases and conversion of both char and soot solids.Detailed chemistry (159 species and 773 reactions) is used in the gas phase.Soot production is described by a single reaction based on C2H2species concentration and three heterogeneous soot oxidation reactions.To support the validation of the model,three sets of experiments were carried out in a lab-scale Entrained Flow Reactor (EFR) equipped with soot quantification device.The temperature was varied from 1000 to 1400 C and three gaseous atmospheres were considered:default of steam,large excess of steam(H2O/C=8),and the presence of oxygen in the O/C range of 0.075–0.5.The model is shown to accurately describe the evolution of the concentration of the main gas species and to satisfactorily describe the soot concentration under the three atmospheres using a single set of identified kinetic parameters.Thanks to this model the contribution of different mechanisms involved in soot formation and oxidation in various situations can be assessed.

Fractional pyrolysis of Cyanobacteria from water blooms over HZSM-5 for high quality bio-oil production

Fractional pyrolysis and one-step pyrolysis of natural algae Cyanobacteria from Taihu Lake were comparatively studied from 200 to 500 ℃. One-step pyrolysis produced bio-oil with complex composition and low high heating value （HHV〈30.9 MJ/kg）. Fractional pyrolysis separated the degradation of different components in Cyanobacteria and improved the selectivity to products in bio-oil. That is, acids at 200 ℃, amides and acids at 300 ℃, phenols and nitriles at 400 ℃, and phenols at 500 ℃, were got as main products, respectively. HZSM-5 could promote the dehydration, cracking and aromatization of pyrolytic intermediates in fractional pyrolysis. At optimal HZSM-5 catalyst dosage of 1.0 g, the selectivity to products and the quality of bio-oil were improved obviously. The main products in bio-oil changed to nitriles （47.2%） at 300 ℃, indoles （51.3%） and phenols （36.3%） at 400 ℃. The oxygen content was reduced to 7.2 wt% and 9.4 wt%, and the HHV was raised to 38.1 and 37.3 MJ/kg at 300 and 400 ℃, respectively. Fractional catalytic pyrolysis was proposed to be an efficient method not only to provide a potential solution for alleviating environmental pressure from water blooms, but also to improve the selectivity to products and obtain high quality bio-oil.

Roles of furfural during the thermal treatment of bio-oil at low temperatures

The reactive O-containing species in bio-oil could induce the polymerization of bio-oil during its thermal treatment, which affects the relevant utilization of bio-oil significantly. Furans, as the highly reactive Ocontaining species in bio-oil, play important roles during the thermal treatment of bio-oil. In this study,furfural was chosen as the representative of the furans in bio-oil to investigate its roles during the thermal treatment of bio-oil. The raw bio-oil with and without the addition of extra furfural(10 wt% of bio-oil) and pure furfural were pyrolyzed in a fixed-bed reactor at 200–500 ℃. The results show that the interactions among furfural and bio-oil components can take place prior to the evaporation of furfural(<140 ℃) to form the intermediates, then these intermediates could be further polymerized to form large molecular compounds, and coke can be formed via the interactions at temperatures ≥ 300 ℃. At temperatures ≤ 300 ℃, furfural mainly interacts with anhydrosugars. As the temperature further increases, the aromatics are involved in the interactions to form coke. The increased percentage of the coke formed via the interactions is in a linear relation with the conversion of furfural during the pyrolysis at 300–500 ℃(no coke formed at 200 ℃). Meanwhile, more non-aromatic light components(≤ C6) and less aromatics in the tars could be formed due to the interactions.

Catalytic conversion of guaiacol to alcohols for bio-oil upgrading

Guaiacol was chosen to represent O-containing chemicals with lower effective hydrogen carbon ratio（H/Ceff factor） in bio-oil,and the hydrodeoxygenation of guaiacol was investigated over non-precious and nonsulfided catalysts. Effects of metal composition,reaction temperature,and hydrogen pressure on conversion and selectivity were investigated systematically. Among various compositions of catalysts,Ni Co/CNT exhibited best performance of guaiacol conversion with higher selectivity towards desired alcohols with higher H/Cefffactor. The reaction pathways of guaiacol in aqueous were proposed based on the product analyzed.Results show that metal composition and temperature have great effects on the conversion of guaiacol and the yields of desired products.

Liquid phase equilibrium of phenol extraction from bio-oil produced by biomass pyrolysis using thermodynamic models

Utilization of biomass as a new and renewable energy source is being actively conducted by various parties. One of the technologies for utilizing or converting biomass as an energy source is pyrolysis, to convert biomass into a more valuable product which is bio-oil. Bio-oil is a condensed liquid from the vapor phase of biomass pyrolysis such as coconut shells and coffee shells. Biomass composition consisting of hemicellulose, cellulose, and lignin will oxidize to phenol which is the main content in bio-oil. The total phenolic compounds contained in bio-oil are 47.03%(coconut shell) and 45%(coffee shell). The content of phenol compounds in corrosive bio-oils still quite high, the use of this bio-oil directly will cause various difficulties in the combustion system due to high viscosity, low calorific value, corrosivity, and instability. Phenol compounds have some benefits as one of the compounds for floor cleaners and disinfectants which are contained in bio-oil.The correlation between experimental data and calculations shows that the UNIQUAC Functional-group Activity Coefficients(UNIFAC) equilibrium model can be used to predict the liquid–liquid equilibrium in the phenol extraction process of the coconut shell pyrolysis bio-oil. While the Non-Random Two Liquid(NRTL) equilibrium model can be used to predict liquid–liquid equilibrium in the extraction process of phenol from bio-oil pyrolysis of coffee shells.

Characterization of pyrolytic lignins with different activities obtained from bio-oil

Pyrolytic lignin, the water-insoluble fraction in bio-oil, often shows a high content and has strong intermolecular interactions with other compounds in bio-oil. In order to obtain pure pyrolytic lignin and facilitate the utilization of aqueous phase obtained from water extraction of bio-oil, methanol–water extraction method was employed to further separate the bio-oil water-insoluble phase in this paper. Different technologies, including Fourier transform infrared spectroscopy, gel permeation chromatography, and nuclear magnetic resonance, were adopted to characterize the structures of pyrolytic lignins with different activities obtained through this method. Both the heating value and the polymerization degree of high-molecular-weight pyrolytic lignin were higher than those of low-molecular-weight pyrolytic lignin. The molecular weight distribution of high-molecular-weight pyrolytic lignin was relatively wider, among which the contents of dimers to pentamers all accounted for 12% –18%,while the low-molecular-weight pyrolytic lignin mainly consisted of trimers(75.38%). The pyrolytic lignins had similar basic structures, both of which contained syringyl and guaiacyl units, whereas the low-molecular-weight pyrolytic lignin had more abundant syringyl units, reactive carbonyl groups and hydroxyl groups. Meanwhile,thermogravimetric study revealed that the final char residue yield of low-molecular-weight pyrolytic lignin was lower than that of high-molecular-weight pyrolytic lignin.

Effects of Microwave Torrefaction with Mg（OH）2 on Characteristics of Bio-oil from Co-pyrolysis of Straw Stalk and Soapstock

This study investigated the effects of torrefaction with Mg(OH)2 on the properties of bio-oil formed from the microwave-assisted catalytic fast co-pyrolysis of straw stalk and soapstock.The effects of torrefaction temperature and residence time on the yield and composition of bio-oil were discussed.Results showed that the torrefaction temperature and residence time remarkably influenced the yield and composition of bio-oil.With the increase in temperature and time,the bio-oil yield and the proportion of oxygen-containing compounds decreased,while the proportion of aromatic compounds increased.When the feedstocks were subject to torrefaction reaction for 20 min at 260°C,the proportion of oxygen-containing compounds decreased from 29.89%to 16.49%.Meanwhile,Mg(OH)2 could render the deoxidization function of torrefaction process increasingly noticeable.The proportion of the oxygen-containing compounds reached a minimum(14.41%),when the biomass-to-Mg(OH)2 ratio was 1:1.

Hydrodeoxygenation of Bio-Oil on Bimetallic Catalysts: From Model Compound to Real Feed

Two series of bimetallic Ni-Co catalysts and corresponding monometallic catalysts with ca. 20 wt% metal loading were evaluated in hydrodeoxygenation (HDO) of phenol as a model compound for bio-oil. The bimetallic catalysts outperformed the corresponding monometallic catalyst in terms of conversion and cyclohexane selectivity. This could be attributed to the formation of Ni-Co alloy, which caused a decrease in metal particle size and stabilized Ni active sites in the near surface region. The balanced combination of formed Ni-Co alloy with acidity from supports allowed performing all individual steps in the reaction network toward desired products at high rate. Consequently, the two best-performing catalysts were tested in HDO of wood based bio-oil, showing that the bimetallic catalyst 10Ni10Co/HZSM-5 was more effective than 20Ni/HZSM-5 in terms of degree of deoxygenation and upgraded bio-oil yield. These findings might open an opportunity for development of a novel cheap but effective catalyst for a key step in the process chain from biomass to renewable liquid fuels.

Evaluation of Aqueous Product from Hydrothermal Liquefaction of Cardboard as Bacterial Growth Medium: Co-Liquefaction of Cardboard and Bacteria for Higher Bio-Oil Production

Hydrothermal liquefaction (HTL) processing of lignocellulosic biomass to bio-oil produces aqueous co-product (AP) which contains significant (~40 wt%) carbon from the original feedstock. This study evaluates macro and micronutrient composition of AP from Ca(NO3)2 catalyzed HTL of cardboard (CbAP) to cultivate bacteria. HPLC, GC-MS and ICP-MS analysis of CbAP revealed presence of C1-C3 carboxylic acids, aldehydes, ketones, phenolics, sub-optimal phosphorous and bio-incompatible levels of calcium. Dilutions (5 - 80 vol%) of detoxified CbAP (DTP-CbAP) in potassium phosphate buffer (pH 7.2) were supplemented with 50 mg·mL-1 of yeast extract and inoculated with metabolically versatile Enterobacter species. The cultures were incubated at 25°C under aerobic conditions. A maximum 9.4 fold increase in the dry cell weight was observed in DTP-CbAP-15 vol%. Co-liquefaction of the bacteria with cardboard in 1:1 and 1:3 weight ratios each produced ~33% more total bio-oil. These had higher HHVs of 34.11 and 31.05 MJ·kg-1, respectively compared with bio-oil from cardboard feedstock alone which had HHV of 30.61 MJ·kg-1. The study highlights the challenges in cultivating microbes in AP from HTL of lignocellulosic biomass (LCB) and the possibility to integrate microbial capture and recycle of the AP carbon for enhanced bio-oil production and quality.

Overview of Bio-Oil from Sewage Sludge by Direct Thermochemical Liquefaction Technology

Sewage sludge is an unavoidable secondary pollution produced in the process of sewage treatment. At present traditional methods of treating sludge (e.g. landfill, incineration or land application) have some disadvantages and shortages. Direct thermochemical liquefaction of sludge is a new treatment method, which has the advantage of both treatment and energy recovery. Research progress and application prospect of sludge liquefaction technology are widely reported, typical liquefaction process with bio-oil production and its main influencing factors are introduced. Besides, the devel- opment of this process is illustrated, and resource and energy recovery of this technology are pointed out to be the ten- dency of sludge treatment in the future.

The Effect of Bio-Oil on High-Temperature Performance of Bio-Oil Recycled Asphalt Binders

Bio-oil recycled asphalt binders in road engineering can help solve the problem of oil shortage and reduce the environmental pollution and sustainability.This paper investigated the road performance of the aged asphalt binder by adding bio-oil so that the aged asphalt binder could be reused to reach purpose of reuse.The residual soybean oil was selected as rejuvenator and blended with aged asphalt binder at 0%,2%,4%,and 6%,respectively.The results showed that bio-oil increased the penetration of aged asphalt binder,the penetration of bio-oil recycled asphalt binder with a bio-oil content of 6%reached the standard of 70#matrix asphalt binder.The addition of bio-oil reduced the viscosity,mixing and compaction temperature of aged asphalt binder.As a common knowledge,bio-oil helps to increase the lightweight components of the aged asphalt binder,which diminishes the high-temperature rutting resistance of bio-oil recycled asphalt binders.The high-temperature deformation resistance of bio-oil recycled asphalt binders had not decreased linearly with the bio-oil dosage.Meanwhile,the hightemperature performance of the bio-oil recycled asphalt binder with a 6%bio-oil was superior to matrix asphalt binder.Bio-oil increased the light components of the aged asphalt binder,thus reducing the high-temperature rheological properties of bio-oil recycled asphalt binders as the bio-oil dosage increases.The above test results showed that the bio-oil could restore the aged asphalt binder to the initial level to reach the reuse target.