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.

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.

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.

Design of Multiple Metal Doped Ni Based Catalyst for Hydrogen Generation from Bio-oil Reforming at Mild-temperature

A new kind of multiple metal （Cu, Mg, Ce） doped Ni based mixed oxide catalyst, synthesized by the co-precipitation method, was used for efficient production of hydrogen from bio-oil reforming at 250-500℃. Two reforming processes, the conventional steam reforming （CSR） and the electrochemical catalytic reforming （ECR）, were performed for the bio-oil reforming. The catalyst with an atomic mol ratio of Ni：Cu：Mg：Ce：AI=5.6：1.1：1.9：1.0：9.9 exhibited very high reforming activity both in CSR and ECR processes, reaching 82.8% hydrogen yield at 500℃ in the CSR, yield of 91.1% at 400℃ and 3.1 A in the ECR, respectively. The influences of reforming temperature and the current through the catalyst in the ECR were investigated. It was observed that the reforming and decomposition of the bio-oil were significantly enhanced by the current. The promoting effects of current on the decomposition and reforming processes of bio-oil were further studied by using the model compounds of bio- oil （acetic acid and ethanol） under 101 kPa or low pressure （0.1 Pa） through the time of flight analysis. The catalyst also shows high water gas shift activity in the range of 300-600 ℃. The catalyst features and alterations in the bio-oil reforming were characterized by the ICP, XRD, XPS and BET measurements. The mechanism of bio-oil reforming was discussed based on the study of the elemental reactions and catalyst characterizations. The research catalyst, potentially, may be a practical catalyst for high efficient production of hydrogen from reforming of bio-oil at mild-temperature.

Hydrogen Production by Low-temperature Steam Reforming of Bio-oil over Ni/HZSM-5 Catalyst

We investigated high catalytic activity of Ni/HZSM-5 catalysts synthesized by the impregnation method, which was successfully applied for low-temperature steam reforming of bio-oil. The influences of the catalyst composition, reforming temperature and the molar ratio of steam to carbon fed on the stream reforming process of bio-oil over the Ni/HZSM-5 catalysts were investigated in the reforming reactor. The promoting effects of current passing through the catalyst on the bio-oil reforming were also studied using the electrochemical catalytic reforming approach. By comparing Ni/HZSM-5 with commonly used Ni/Al2O3 catalysts, the Ni2O/ZSM catalyst with Ni-loading content of about 20% on the HZSM-5 support showed the highest catalytic activity. Even at 450 ℃, the hydrogen yield of about 90% with a near complete conversion of bio-oil was obtained using the Ni2O/ZSM catalyst. It was found that the performance of the bio-oil reforming was remarkably enhanced by the HZSM-5 supporter and the current through the catalyst. The features of the Ni/HZSM-5 catalysts were also investigated via X-ray diffraction, inductively coupled plasma and atomic emission spectroscopy, hydrogen temperature-programmed reduction, and Brunauer-Emmett-Teller methods.

Hydrogen Production From Crude Bio-oil and Biomass Char by Electrochemical Catalytic Reforming

We reports an efficient approach for production of hydrogen from crude bio-oil and biomass char in the dual fixed-bed system by using the electrochemical catalytic reforming method. The maximal absolute hydrogen yield reached 110.9 g H2/kg dry biomass. The product gas was a mixed gas containing 72%H2, 26%CO2, 1.9%CO, and a trace amount of CH4. It was observed that adding biomass char （a by-product of pyrolysis of biomass） could remarkably increase the absolute H2 yield （about 20%-50%）. The higher reforming temperature could enhance the steam reforming reaction of organic compounds in crude bio-oil and the reaction of CO and H20. In addition, the CuZn-Al2O3 catalyst in the water-gas shift bed could also increase the absolute H2 yield via shifting CO to CO2.

Production of Low-carbon Light Olefins from Catalytic Cracking of Crude Bio-oil

Low-carbon light olefins are the basic feedstocks for the petrochemical industry. Catalytic cracking of crude bio-oil and its model compounds （including methanol, ethanol, acetic acid, acetone, and phenol） to light olefins were performed by using the La/HZSM-5 catalyst. The highest olefins yield from crude bio-oil reached 0.19 kg/（kg crude bio-oil）. The reaction conditions including temperature, weight hourly space velocity, and addition of La into the HZSM-5 zeolite can be used to control both olefins yield and selectivity. Moderate adjusting the acidity with a suitable ratio between the strong acid and weak acid sites through adding La to the zeolite effectively enhanced the olefins selectivity and improved the catalyst stability. The production of light olefins from crude bio-oil is closely associated with the chemical composition and hydrogen to carbon effective ratios of feedstock. The comparison between the catalytic cracking and pyrolysis of bio-oil was studied. The mechanism of the bio-oil conversion to light olefins was also discussed.

Production of Hydrogen from Bio-oil Using Low-temperature Electrochemical Catalytic Reforming Approach over CoZnAI Catalyst

High-efficient production of hydrogen from bio-oil was performed by electrochemical catalytic reforming method over the CoZnAl catalyst. The influence of current on the hydrogen yield, carbon conversion, and products distribution were investigated. Both the hydrogen yield and carbon conversion were remarkably enhanced by the current through the catalyst, reaching hydrogen yield of 70% and carbon conversion of 85% at a lower reforming temperature of 500 ℃. The influence of current on the properties of the CoZnAl catalyst was also characterized by X-ray diffraction, X-ray photoelectron spectroscopy, thermal gravimetric analysis, and Brunauer-Emmett-Teller measurements. The thermal electrons would play an important role in promoting the reforming reactions of the oxygenated-organic compounds in the bio-oil.

Properties of Bio-oil from Fast Pyrolysis of Rice Husk

Physicochemical properties of bio-oil obtained from fast pyrolysis of rice husk were studied in the present work.Molecular distillation was used to separate the crude bio-oil into three fractions viz.light fraction,middle fraction and heavy fraction.Their chemical composition was analyzed by gas chromatograph and mass spectrometer（GC-MS）.The thermal behavior,including evaporation and decomposition,was investigated using thermogravimetric analyzer coupled with Fourier transform infrared spectrometer（TG-FTIR）.The product distribution was significantly affected by contents of cellulose,hemicellulose and lignin.The bio-oil yield was 46.36%（by mass） and the yield of gaseous products was 27%（by mass）.The chemicals in the bio-oil included acids,aldehydes,ketones,alcohols,phenols,sugars,etc.The light fraction was mainly composed of acids and compounds with lower boiling point temperature,the middle and heavy fractions were consisted of phenols and levoglucosan.The thermal stability of the bio-oil was determined by the interactions and intersolubility of compounds.It was found that the thermal stability of bio-oil was better than the light fraction,but worse than the middle and heavy fractions.

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.

Catalytic Transformation of Bio-oil to Olefins with Molecular Sieve Catalysts

Catalytic conversion of bio-oil into light olefins was performed by a series of molecular sieve catalysts, including HZSM-5, MCM-41, SAPO-34 and Y-zeolite. Based on the light olefins yield and its carbon selectivity, the production of light olefins decreased in the following order： HZSM-5〉SAPO-34〉MCM-41〉Y-zeolite. The highest olefins yield from bio-oil using HZSM- 5 catalyst reached 0.22 kg/kgbio-oil with carbon selectivity of 50.7% and a nearly complete bio-oil conversion. The reaction conditions and catalyst characterization were investigated in detail to reveal the relationship between the catalyst structure and the production of olefins. The comparison between the pyrolysis and catalytic pyrolysis of bio-oil was also performed.

Transformation of Bio-oil into BTX by Bio-oil Catalytic Cracking

Production of benzene, toluene and xylenes （BTX） from bio-oil can provide basic feedstocks for the petrochemical industry. Catalytic conversion of bio-oil into BTX was performed by using different pore characteristics zeolites （HZSM-5, HY-zeolite, and MCM-41）. Based on the yield and selectivity of BTX, the production of aromatics decreases in the following order： HZSM-5〉MCM-41〉HY-zeolite. The highest BTX yield from bio-oil using HZSM-5 reached 33.1% with aromatics selectivity of 86.4%. The reaction conditions and catalyst characterization were investigated in detail to make clear the optimal operating parameters and the relation between the catalyst structure and the production of BTX.

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%.

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.

Characterization of Pyrolytic Lignin Extracted from Bio-oil

Bio-oil is a new liquid fuel produced by fast pyrolysis,which is a promising technology to convert bio-mass into liquid. Pyrolytic lignin extracted from bio-oil,a fine powder,contributes to the instability of bio-oil. The paper presents the structural features of three kinds of pyrolytic lignin extracted from bio-oil with different methods(WIF,HMM,and LMM) . The pyrolytic lignin samples are characterized by Fourier transform infrared spectrometer(FTIR) and X-ray photoelectron spectroscopy(XPS) . FTIR data indicate that the three pyrolytic lignin samples have similar functional groups,while the absorption intensity is different,and show characteristic vibra-tions of typical lignocellulosic material groups O H(3340-3380 cm-1) ,C H(2912-2929 cm-1) and C O(1652-1725 cm-1) . Comparison in the region(3340-3380 cm-1) indicates that WIF has more O H stretch groups than HMM and LMM. The carbon spectra are fitted to four peaks:C1,C C or C H,BE 283.5 eV;C2,C OR or C OH,BE 284.5-285.8 eV;C3,C O or HO C OR,BE 286.10-287.10 eV;C4,O C O,BE 287.5-287.7 eV. The absence of C1,C C or C H indicates the dominant polymerization structure of aro-matic carbon in pyrolytic lignin samples. For HMM and WIF,C2a and C2b can not be separated,so there is no free hydroxyl group in the samples. The oxygen peaks are also fitted to four peaks:O1,OH,BE = 530.3 eV;O2,RC O,BE 531.45-531.72 eV;O3,O C O,BE = 532.73-533.74 eV;O4,H2O,BE 535 eV. The absence of O1 and O4 indicates that little hydroxyl groups and adsorbed water are present in the samples.

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.

Hydrogen Production by Catalytic Steam Reforming of Bio-oil, Naphtha and CH4 over C12A7-Mg Catalyst

Hydrogen production by catalytic steam reforming of the bio-oil, naphtha, and CH4 was investigated over a novel metal-doped catalyst of （Ca24Al28O64）^4＋·4O^-/Mg （C12A7-Mg）. The catalytic steam reforming was investigated from 250 to 850℃ in the fixed-bed continuous flow reactor. For the reforming of bio-oil, the yield of hydrogen of 80% was obtained at 750℃, and the maximum carbon conversion is nearly close to 95% under the optimum steam reforming condition. For the reforming of naphtha and CH4, the hydrogen yield and carbon conversion are lower than that of bio-oil at the same temperature. The characteristics of catalyst were also investigated by XPS. The catalyst deactivation was mainly caused by the deposition of carbon in the catalytic steam reforming process.

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.

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.