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 Biomass Conversion and Biorefinery   [10 followers]  Follow         Partially Free Journal    ISSN (Print) 2190-6815 - ISSN (Online) 2190-6823    Published by Springer-Verlag  [2329 journals]
• Pulsed fed-batch strategy towards intensified process for lactic acid
production using recycled paper sludge
• Authors: S. Marques; F. M. Gírio; J. A. L. Santos; J. C. Roseiro
Pages: 127 - 137
Abstract: Abstract A process has previously been optimized for production of lactic acid from recycled paper sludge (RPS), the ultimate solid waste obtained in the wastewater treatment plant of a local paper recycling mill. In this work, both separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes were improved under batch mode in bench-scale bioreactor. The use of bioreactor was advantageous, providing higher conversion rates, together with increased yield. By running SSF in bioreactor, 73.2 g L−1 of lactic acid has been produced by Lactobacillus rhamnosus ATCC 7469 from 179 g L−1 RPS, corresponding to 76 % of maximum theoretical yield. Further process intensification, with improved kinetics and final product concentration, was achieved by applying a pulsed fed-batch strategy. With six pulsed additions of RPS (40 g at each 5 h), 108.2 g L−1 of lactic acid was produced (after 120 h, corresponding to 62 % yield). This achievement contributes to make more realistic the large-scale upgrading of RPS, a waste raw material exhibiting negative cost.
PubDate: 2017-06-01
DOI: 10.1007/s13399-016-0211-0
Issue No: Vol. 7, No. 2 (2017)

• Optimizing GHG emission and energy-saving performance of miscanthus-based
value chains
• Authors: Florian Meyer; Moritz Wagner; Iris Lewandowski
Pages: 139 - 152
Abstract: Abstract Miscanthus is a high-yielding lignocellulosic crop providing up to 40 t of dry matter per hectare and year. Its biomass can be used in energetic or material utilization pathways. The goal of this study was the comparison of three different conversion techniques (combustion, second-generation bioethanol, and insulation material) for miscanthus biomass produced at five locations throughout Europe using a life cycle assessment approach. In particular, the interdependencies between the cropping location, the miscanthus genotypes, and the utilization pathways were investigated. The potential savings of greenhouse gas (GHG) emissions and fossil energy were analyzed through comparison with a corresponding substituted product system. The highest GHG savings of all scenarios investigated were achieved by heat and power production in Portugal (42.7 t CO2-eq ha−1 a−1). However, at the other four locations (Sweden, Denmark, Germany, England), bioethanol production gave the highest GHG savings. In contrast, the highest energy savings were achieved by combined heat and power generation via combustion at all five locations (up to 642 GJ ha−1 a−1). A high correlation was found between yield and both GHG-emission savings and energy savings. Biomass composition and quality showed a comparatively low impact on the results. However, the composition is assumed to have a high relevance for other impact categories not assessed within this study, such as acidification and eutrophication.
PubDate: 2017-06-01
DOI: 10.1007/s13399-016-0219-5
Issue No: Vol. 7, No. 2 (2017)

• Development and experimental validation of a water gas shift kinetic model
for Fe-/Cr-based catalysts processing product gas from biomass steam
gasification
• Authors: Michael Kraussler; Hermann Hofbauer
Pages: 153 - 165
Abstract: Abstract This paper introduces an improved kinetic model for the water gas shift reaction catalyzed by an Fe-/Cr-based catalyst. The improved model is based on a former model which was developed previously in order to consider the composition and the catalyst poisons (H2S) of product gas derived from dual fluidized bed biomass steam gasification. $$\begin{array}{c}r\left({\varphi}_i,T\right)=117.8\ \frac{\mathrm{mol}}{g\ {Pa}^{1.71}\ s}\cdot \mathit{\exp}\left(\frac{-126.6\ \frac{\mathrm{kJ}}{\mathrm{mol}}}{R\cdot T}\right)\cdot {p}_{CO}^{1.77}\cdot {p}_{\mathrm{H}2\mathrm{O}}^{0.23}\cdot {p}_{CO2}^{-0.17}\cdot {p}_{\mathrm{H}2}^{-0.12}\\ {}\left(1-\frac{K_{MAL}}{K_g}\right)\end{array}.$$ Furthermore, this improved model has been validated with experimental data. The data was generated by a WGS reactor which employed a commercial Fe-/Cr-based catalyst and which processed real product gas from the dual fluidized bed biomass steam gasification plant in Oberwart, Austria. Basically, the validation showed good agreement of the measured and the calculated values for the gas composition (absolute errors of the volumetric fractions of up to 1.5 %) and the temperature profile (absolute errors of up to 21 °C) of the WGS reactor. Of all considered gas components, the CO concentration showed the highest error. The results qualify the improved kinetic model for basic design and engineering of a WGS reactor employing a commercial Fe-/Cr-based catalyst which processes product gas from an industrial scale biomass steam gasification plant.
PubDate: 2017-06-01
DOI: 10.1007/s13399-016-0215-9
Issue No: Vol. 7, No. 2 (2017)

• Comparative biochemical methane potential of some varieties of residual
banana biomass and renewable energy potential
• Authors: Florent Awedem Wobiwo; Thomas Happi Emaga; Elie Fokou; Maurice Boda; Sebastien Gillet; Magali Deleu; Aurore Richel; Patrick A. Gerin
Pages: 167 - 177
Abstract: Abstract The biochemical methane potential (BMP) of peduncles, bulbs, and peels of three banana varieties (Grande Naine (GN; export dessert banana), Pelipita (PPTA; locally used plantain), and CRBP969 (phytopathogen resistant hybrid-plantain)) was investigated as an assessment of the bioconversion potential of these residues to renewable energy or biorefined chemicals. Biogas production was monitored manometrically for 132 days and its composition was analyzed using gas chromatography. The BMP ranged from 162 to 257 ml_CH4/g_DM for peduncles, from 228 to 304 ml_CH4/g_DM for bulbs, and from 208 to 303 ml_CH4/g_DM for green peels, with methane content of the biogas in the range 56 to 60 %. Bulbs and green peels showed bioconversion yields of 95 % of the chemical oxygen demand (COD). The GN variety was generally more biodigestible than PPTA, which appeared richer in lignocellulosic fibres. The peels biodigestibility reduced with maturation and was already limited to 56 % of the COD at the yellow stage. The energy resource available in the residues of banana production is very significant, increasing by 91 % the energy resource offered by banana crop, which is generally limited to the nutritional value of the fruit pulp. In the study case of the African leading producer of bananas and plantains (Cameroon), the amount of available residues from the sole export variety GN could feed about 4 % of the annual electricity consumed by the country, i.e., a supply of electricity to an additional 9 × 105 people. Such valorization of the residual banana biomass could help banana-producing countries to become less dependent on fossil fuels and less prone to energy shortages.
PubDate: 2017-06-01
DOI: 10.1007/s13399-016-0222-x
Issue No: Vol. 7, No. 2 (2017)

• Pilot-scale pretreatments of sugarcane bagasse with steam explosion and
mineral acid, organic acid, and mixed acids: synergies, enzymatic
hydrolysis efficiencies, and structure-morphology correlations
• Authors: Siddhartha Pal; Shereena Joy; Pramod Kumbhar; Kalpana D. Trimukhe; Rishi Gupta; Ramesh C. Kuhad; Anjani J. Varma; Sasisanker Padmanabhan
Pages: 179 - 189
Abstract: Abstract In lignocellulosic (LC) ethanol processes, to facilitate enzymatic hydrolysis of cellulose, a physical chemical pretreatment is vital. In this study, we explored a single as well as a two-step physical-chemical pretreatment involving steam and mixed acid on unwashed sugarcane bagasse at pilot-scale level in a continuous horizontal reactor. To serve as a large-scale model, pretreatments were carried out at high solid levels of 18–20 % w/w. For the pretreatment, partial replacement of corrosive sulfuric acid with a milder acid-like oxalic acid was explored to derive possible advantages and synergies accruing by using a mixture of mineral acid and organic acid. The results of this work showed that first-step pretreatment carried out by the mixing of sulfuric acid (1.5 % w/w) and oxalic acid (1.5 % w/w) at 150 °C followed by a second-step steam explosion pretreatment at 180 °C gave significant synergies and advantages over other variants of pretreatments investigated, such as lower inhibitor levels and lower reaction severity. On post-pretreated bagasse, this study conducted comparative enzymatic hydrolysis study using a simple lab enzyme and a robust commercial enzyme. It was found that the addition of Tween 80 to the lab enzyme improved its performance to match the performance of the commercial enzyme. Scanning electron microscopy (SEM) studies were further carried out to correlate the morphology of pretreated samples with efficiency of enzyme hydrolysis. Besides morphological study, Fourier transform infrared (FTIR) studies of pretreated samples showed higher syringyl/guaiacyl ratio for all pretreatments, indicating lower levels of pseudo-lignins, which is beneficial for improved enzyme hydrolysis.
PubDate: 2017-06-01
DOI: 10.1007/s13399-016-0220-z
Issue No: Vol. 7, No. 2 (2017)

• Bioethanol production from Eucalyptus grandis hemicellulose recovered
before kraft pulping using an integrated biorefinery concept
• Authors: Mairan D. Guigou; Florencia Cebreiros; María N. Cabrera; Mario D. Ferrari; Claudia Lareo
Pages: 191 - 197
Abstract: Abstract Pre-extraction of hemicelluloses prior to pulping and its conversion to other by-products can provide additional profits to traditional pulp and paper industry. In this study, hemicelluloses removed from Eucalyptus grandis with green liquor (2 %) at 155–160 °C for 150 min prior to kraft pulping were fermented by Scheffersomyces stipitis NBRC 10063 to produce bioethanol. These conditions were selected to obtain an extract rich in xylose without changing the quality of pulp produced: best xylose extraction yield and minor pulp viscosity degradation. Fermentation of hemicellulose hydrolysate containing 7.5 g/L xylose and 5.0 g/L acetic acid presented an ethanol yield of 0.19 g/g and sugar conversion of 89 %. However, the fermentation of hydrolyzates after concentration proved to be difficult or even impossible. Ethyl acetate extraction, used for removal of inhibitory compounds in concentrated hydrolyzates containing 19 g/L xylose, improved fermentability (final ethanol concentration of 5.0 g/L, ethanol yield of 0.21 g/g and 94 % sugar conversion, ethanol production of 4.4 Lethanol/t of dry wood) and made possible the recovery of a valuable product as acetic acid.
PubDate: 2017-06-01
DOI: 10.1007/s13399-016-0218-6
Issue No: Vol. 7, No. 2 (2017)

• Bioconversion of soybean and rice hull hydrolysates into ethanol and
xylitol by furaldehyde-tolerant strains of Saccharomyces cerevisiae ,
Wickerhamomyces anomalus , and their cofermentations
• Authors: Nicole Teixeira Sehnem; Lilian Raquel Hickert; Fernanda da Cunha-Pereira; Marcos Antonio de Morais; Marco Antônio Záchia Ayub
Pages: 199 - 206
Abstract: Abstract The aims of this work were to evaluate the ability of furaldehyde-tolerant yeast strains Saccharomyces cerevisiae P6H9 and Wickerhamomyces anomalus WA-HF5.5 and their cofermentations and to convert soybean and rice hull hydrolysates into ethanol and xylitol. In batch shaker cultures, the strains showed the ability to tolerate high osmotic pressure (1918 mOsmkg−1), completely depleting furaldehyde in the first 12 h of cultivations, while converting the hydrolysate sugars into ethanol. Highest ethanol yields of 0.37 g g−1 and productivity of 0.31 g L−1 h−1 were obtained in the cofermentation using rice hull hydrolysate as substrate. The concentration of sugars in soybean hull hydrolysate proved to be inadequate as substrate for the cultivation of these strains, showing a low ethanol productivity of 0.08 g L−1 h−1. Bioreactor cultivations of S. cerevisiae on rice hull hydrolysate under anaerobiosis showed a relatively high ethanol productivity of 6.7 g L−1 h−1, whereas the bioreactor cofermentation produced xylitol to yields of 0.86 g g−1 under conditions of oxygen limitation.
PubDate: 2017-06-01
DOI: 10.1007/s13399-016-0224-8
Issue No: Vol. 7, No. 2 (2017)

• Moisture effect on fluidization behavior of loblolly pine Wood grinds
• Authors: G Olatunde.; O Fasina.; T McDonald.; S Adhikari.; S Duke.
Pages: 207 - 220
Abstract: Abstract The impact of moisture content (MC of 8 to 27 % wet basis) on physical properties (particle size distribution, average size using Feret, chord, Martins, surface-volume, and area diameter measurement schemes, bulk density, and particle density), fluidization behavior, and minimum fluidization velocities (U mf) of loblolly pine wood grinds were studied. A new correlation for predicting the U mf of loblolly pine wood grinds at different moisture contents was also developed. Results showed that bulk density, particle density, and porosity of grinds were significantly affected by increase in MC (p < 0.05). Diameter of the grinds measured using Feret measurement scheme was consistently the highest while those measured by surface-volume scheme were consistently the lowest with the measured Feret-based diameter about three times the surface-volume based diameters. Particle size data showed that variations in sizes of particle within a sample reduced with increase in MC (coefficient of variation value was 90 at 8.45 % MC and 40 at 27.02 % MC). Generally, as MC increased, the minimum fluidization velocity values increased. The minimum fluidization velocity (Umf) was found to be 0.2 m/s for 8 % MC, 0.24 m/s at 14.86 % MC, 0.28 m/s at 19.86 % MC, and 0.32 m/s for 27.02 % MC. The correlation developed predicted the experimental data with mean relative deviation that was less than 10 %.
PubDate: 2017-06-01
DOI: 10.1007/s13399-016-0223-9
Issue No: Vol. 7, No. 2 (2017)

• The nutritional aspects of biorefined Saccharina latissima , Ascophyllum
nodosum and Palmaria palmata
• Authors: Peter Schiener; Sufen Zhao; Katerina Theodoridou; Manus Carey; Karen Mooney-McAuley; Chris Greenwell
Pages: 221 - 235
Abstract: Abstract The chemical profile of biorefined Saccharina latissima, Ascophyllum nodosum and Palmaria palmata after carbohydrate and polyphenol extraction was analysed with the aim to evaluate the nutritional aspects of biorefined seaweeds as a novel animal feed supplement. Optimised enzymatic saccharification has been used to show that the protein concentration in the residue of P. palmata and A. nodosum can be increased by more than 2-fold. Nutritional value of the residue was further enhanced through an increase in total amino acids and fatty acids. As a consequence of removal of inorganic elements such as sodium, potassium and chloride, the total solid and ash content of all three seaweeds was reduced by around 40%. In contrast, divalent metals such as iron and zinc, as well as silicon, accumulated in all three residues. Potentially harmful components such as arsenic and iodine were reduced only in brown biorefined seaweeds, whilst in biorefined P. palmata, iodine increased by 39% compared to a 24% decline of arsenic. Nutritional values such as total fatty acid and total amino acid content increased in all three seaweeds after enzymatic saccharification. Polyphenol removal in all three seaweeds was >80% using aqueous acetonitrile and, in combination with enzymatic saccharification, did not impact on protein recovery in A. nodosum. This highlights the potential of biorefinery concepts to generate multiple products from seaweed such as extracts enriched in polyphenols and carbohydrates and residue with higher protein and lipid content.
PubDate: 2017-06-01
DOI: 10.1007/s13399-016-0227-5
Issue No: Vol. 7, No. 2 (2017)

• Pyrolysis kinetics of Sal ( Shorea robusta ) seeds
• Authors: Ranjan R. Pradhan; Pragyan P. Garnaik; Bharat Regmi; Bandita Dash; Animesh Dutta
Pages: 237 - 246
Abstract: Abstract Thermal kinetics of Sal seeds during pyrolysis process was investigated as feedstocks for chemical, material, and bioenergy industries. The physicochemical properties of the seeds were examined. Results showed that Sal seed can be characterized as high calorific values, low ash, and high volatile content biomass to suit pyrolysis applications. Kinetic analysis for thermal degradation of this biomass was given particular attention. Two major degradation zones were identified with T max at about 321 and 405 °C, and activation energy was evaluated using various methods. Model-free pyrolysis kinetic approach was verified to be appropriate and indicated that unprocessed Sal seed biomass can directly become potential renewable feedstock of energy, chemicals, and biochar.
PubDate: 2017-06-01
DOI: 10.1007/s13399-017-0240-3
Issue No: Vol. 7, No. 2 (2017)

• Pretreatment technologies of lignocellulosic biomass in water in view of
furfural and 5-hydroxymethylfurfural production- A review
• Authors: David Steinbach; Andrea Kruse; Jörg Sauer
Pages: 247 - 274
Abstract: Abstract Lignocellulosic biomasses are strongly connected composites of cellulose, hemicelluloses, and lignin. A pretreatment is required in order to make these components available for their later conversion into chemicals. At this point, two strategies have to be considered: to either produce chemicals via microorganism or enzymes (1), or by chemical conversion (2). The focus of this article is the second strategy, which is chemical conversion, performed in water to produce the final products furfural and 5-hydroxymethylfurfural (HMF). Reviewed first is the composition of cellulose and hemicelluloses as well as their degradation chemistry in water. Then, fundamental modes of action and process parameters of pretreatment methods in aqueous solution are summarized. The pretreatment methods discussed here are steam explosion, treatment with hot liquid water, diluted and concentrated acids, as well as alkaline solutions. Finally, the advantages and disadvantages of these pretreatments are discussed for lignocellulosic biomass.
PubDate: 2017-06-01
DOI: 10.1007/s13399-017-0243-0
Issue No: Vol. 7, No. 2 (2017)

• Catalytic deoxygenation of C18 fatty acids over HAlMCM-41 molecular sieve
• Authors: F. C. M. Silva; M. S. Lima; C. O. Costa Neto; J. L. S. Sá; L. D. Souza; V. P. S. Caldeira; A. G. D. Santos; G. E. Luz Jr
Abstract: Abstract The large demand for energy combined with ecological, economic, and social reasons encouraged the studies for alternative sources of fuel. The deoxygenation process of oils and fatty acids has emerged as a promising resource in obtaining fuels. This paper studied the deoxygenation process of oleic and stearic acids carried out in a distillation system, under the temperature of 450 °C over MCM-41, AlMCM-41-41, and HAlMCM-41 molecular sieves, which were synthesized by direct hydrothermal synthesis method and characterized by X-ray diffraction (XRD) spectroscopy in the infrared site (FTIR), adsorption and desorption of N2, and scanning electron microscopy (SEM). The products were analyzed by gas chromatography (GC) and acid-base titration. The results showed that stearic acid deoxygenates more than the oleic acid, and that the performance of HAlMCM-41 was superior to AlMCM-41, indicating that the total acidity positively influenced the process. Furthermore, from the stearic acid deoxygenation, it obtained mainly heptadecanes (C17:0) structures, while the oleic acid produces heptadecenes (C17:1).
PubDate: 2017-05-13
DOI: 10.1007/s13399-017-0263-9

• Conversion of a wet waste feedstock to biocrude by hydrothermal processing
in a continuous-flow reactor: grape pomace
• Authors: Douglas C. Elliott; Andrew J. Schmidt; Todd R. Hart; Justin M. Billing
Abstract: Abstract Wet waste feedstocks present an attractive opportunity for biomass conversion to fuels by hydrothermal processing. In this study, grape pomace slurries from two varieties, Montepulciano and cabernet sauvignon, have been converted into a biocrude by hydrothermal liquefaction (HTL) in a bench-scale, continuous-flow reactor system. Carbon conversion to gravity-separable biocrude product up to 56% was accomplished at relatively low temperature (350 °C) in a pressurized (sub-critical liquid water) environment (20 MPa) when using grape pomace feedstock slurry with a 16.8 wt% concentration of dry solids processed at a liquid hourly space velocity of 2.1 h−1. Direct biocrude recovery was achieved without the use of a solvent and biomass trace mineral components were removed by precipitation and filtration so that they did not cause processing difficulties. In addition, catalytic hydrothermal gasification (CHG) was effectively applied for HTL byproduct water cleanup using a Ru on C catalyst in a fixed bed producing a gas composed of methane and carbon dioxide from water-soluble organics. Conversion of 99.8% of the chemical oxygen demand (COD) left in the aqueous phase was demonstrated. As a result, high conversion of grape pomace to liquid and gas fuel products was found with residual organic contamination in byproduct water reduced to <150 mg/kg COD.
PubDate: 2017-05-13
DOI: 10.1007/s13399-017-0264-8

• The impact of sorbent geometry on the sulphur adsorption under
supercritical water conditions: a numerical study
• Authors: Florentina Maxim; Bojan Niceno; Andrea Testino; Christian Ludwig
Abstract: Abstract A numerical model to show the impact of the adsorption bed geometry on the desulfurization process of wet biomass under supercritical water (SCW) gasification process has been developed. Three different geometries, straight channels (pipe), sharp-edged channels (sharp) and packed bed of particles (pebbles) have been considered for the sorbent bed. The influence of the flow patterns on the sulphur distribution inside the bed and on the saturation of the sorbent has been analysed. The results show that, when the flow is unidirectional with a parabolic profile, as in the pipe geometry, the adsorption process can be explained based on the 1D plug-flow model. In the case of more complex flow structures, when torus-shaped vortices appeared in the sharp or pebbles geometries, the 3D flow effects should be considered. The present work might provide useful information for the evaluation of sulphur sorption under SCW conditions. The models obtained by computational fluid dynamic, which are under experimental validation using neutron imaging, will help for the sorbent design and production by 3D printing techniques, which represent an advanced engineered tool to improve the process efficiency and sorbent material selection.
PubDate: 2017-05-12
DOI: 10.1007/s13399-017-0265-7

• Thermochemical valorization of camelina straw waste via fast pyrolysis
• Authors: H. Hernando; J. Fermoso; I. Moreno; J. M. Coronado; D. P. Serrano; P. Pizarro
Abstract: Abstract The present work investigates the thermochemical valorization of camelina straw, which is a waste generated during the harvesting of Camelina sativa, an oilseed crop for the production of biodiesel or hydrotreated vegetable oil (HVO). In particular, it is focused on obtaining bio-oil via thermal or catalytic fast pyrolysis, which would be the first stage on a sequence of chemical processes for biofuel production. The catalytic interference of the inorganic matter present in the biomass was studied by preparing a batch of de-ashed camelina straw by washing with diluted nitric acid. Chemical analysis revealed this treatment effectively removed alkaline (K and Na) and alkaline earth (Ca and Mg) metals. Pyrolysis of de-ashed camelina straw led to higher mass and energy yields of bio-oil in water-free basis (bio-oil*), but with higher oxygen concentration. Catalytic pyrolysis over HZSM-5 was also studied in both raw and de-ashed feedstocks. This catalyst promoted mainly decarbonylation and decarboxylation reactions of the pyrolysis vapors, leading to much higher gas yields and lower of bio-oil*, but with better quality. Catalytic pyrolysis of untreated camelina straw exhibited a synergetic effect between both the inorganic matter and the external HZSM-5 catalyst, so that bio-oil* yield was the lowest (20 wt%) due to an extensive deoxygenation (18 wt% oxygen content), which resulted in the highest HHV obtained (37.3 MJ/kgdb). Significant differences were also found on the molecular composition of the bio-oils* with larger proportion of anhydro sugars when the biomass was de-ashed, while HZSM-5 strongly promoted the formation of oxygenated aromatics and aromatic hydrocarbons.
PubDate: 2017-05-07
DOI: 10.1007/s13399-017-0262-x

• Erratum to: Hydrogen-enhanced catalytic hydrothermal gasification of
biomass
• Authors: J. Reimer; S. Müller; E. De Boni; F. Vogel
PubDate: 2017-04-24
DOI: 10.1007/s13399-017-0260-z

• The effects of air velocity, temperature and particle size on
low-temperature bed drying of wood chips
• Authors: Niranjan Fernando; Mahinsasa Narayana; W. A. M. K. P. Wickramaarachchi
Abstract: Abstract This paper describes a mathematical model for wood chip packed bed drying process with the effects of hot air flow velocity, temperature and particle size. A single-particle drying model was developed by considering impacts of external and internal parameters. External parameters are hot air flow velocity and air temperature. Internal parameters are porosity and particle size. These parameters are incorporated to the present model by introducing two mass transfer coefficients. The model was fine-tuned by comparing simulation results and experimental data. Effects of a factor relating to internal mass transfer coefficient were found for three wood types, and a functional dependence of internal mass transfer on temperature was suggested in this study. The model was implemented in computational fluid dynamics (CFD) to evaluate spatial variation of moisture in the packed bed drying process. The CFD model was validated by results of lab-scale packed bed. Drying performance of the packed bed was estimated by CFD simulations for variations of external hot air flow velocity, flow temperature and particle size. Sensitivity of these parameters for dying performance was evaluated by design of experiment (DOE) method. It was clarified that air temperature is most critical for the drying process. Interaction of between external hot air flow velocity and particle size for dying performance is also significant.
PubDate: 2017-04-07
DOI: 10.1007/s13399-017-0257-7

• Thermochemical characterization of biochar from cocoa pod husk prepared at
low pyrolysis temperature
• Authors: Chi-Hung Tsai; Wen-Tien Tsai; Sii-Chew Liu; Yu-Quan Lin
Abstract: Abstract In this work, cocoa pod husk (CPH), a processing by-product from the cocoa industry, was evaluated as a potential feedstock for preparing biochar fuel at relatively low pyrolysis temperature. First, its thermochemical characteristics, including the calorific value and mineral component analyses, were investigated, showing that the bioresource obviously contained a large percentage of volatile matter. It thus had a higher heating value of 17.8 MJ/kg but showed a higher potassium content in ash (i.e., 4.03 wt%). A series of CPH-based biochars (i.e., CPHBC) were produced at different temperatures (i.e., 190, 220, 250, 280, 310, 340, and 370 °C) and residence times (i.e., 30, 60, 90, and 120 min). The resulting biochars were subject to the analyses of chemical and thermal properties. The calorific value of resulting biochar indicated an increasing trend with pyrolysis temperature, but there was slightly decreasing change at the longer residence time under the fixed pyrolysis temperature (i.e., 370 °C). The optimal biochar product had a thermochemical characteristics with high carbon (>60 wt%) and calorific value (>25 MJ/kg, dry basis). Furthermore, the CPH-based biochar showed a lignite-like feature based on the O/C and H/C molar ratios, but it would not be appropriate to be fired in boilers because of its high mineral contents (i.e., potassium).
PubDate: 2017-04-06
DOI: 10.1007/s13399-017-0259-5

• On the influence of Si:Al ratio and hierarchical porosity of FAU zeolites
in solid acid catalysed esterification pretreatment of bio-oil
• Authors: Amin Osatiashtiani; Begoña Puértolas; Caio C. S. Oliveira; Jinesh C. Manayil; Brunella Barbero; Mark Isaacs; Chrysoula Michailof; Eleni Heracleous; Javier Pérez-Ramírez; Adam F. Lee; Karen Wilson
Abstract: Abstract A family of faujasite (FAU) zeolites with different Si:Al ratio, and/or hierarchical porosity introduced via post-synthetic alkaline desilication treatment, have been evaluated as solid acid catalysts for esterification pretreatments of pyrolysis bio-oil components. Acetic acid esterification with aliphatic and aromatic alcohols including methanol, anisyl alcohol, benzyl alcohol, p-cresol and n-butanol was first selected as a model reaction to identify the optimum zeolite properties. Materials were fully characterised using N2 porosimetry, ICP, XRD, XPS, FT-IR, pyridine adsorption, NH3 TPD, In-situ ATR and inverse gas chromatography (IGC). IGC demonstrates that the surface polarity and hence hydrophobicity of FAU decreases with increased Si:Al ratio. Despite possessing a higher acid site loading and acetic acid adsorption capacity, high Al-content FAU possess weaker acidity than more siliceous catalysts. Esterification activity increases with acid strength and decreasing surface polarity following the order FAU30>FAU6>FAU2.6. The introduction of mesoporosity through synthesis of a hierarchical HFAU30 material further enhances esterification activity through improved acid site accessibility and hydrophobicity. Methanol was the most reactive alcohol for esterification, and evaluated with HFAU30 for the pretreatment of a real pyrolysis bio-oil, reducing the acid content by 76% under mild conditions.
PubDate: 2017-04-05
DOI: 10.1007/s13399-017-0254-x

• Integral valorization of tagasaste ( Chamaecytisus proliferus ) under
thermochemical processes
• Authors: J. M. Loaiza; F. López; M. T. García; J. C. García; M. J. Díaz
Abstract: Abstract The generation of compounds derived from lignocellulosic biomass fractionation has a boost in recent years. An interesting plant could be tagasaste (Chamaecytisus proliferus) due to its high biomass production and its leguminous nature. A sequence of acid hydrolysis, as pretreatment, and pyrolysis of the solid residue, as treatment, has been used in its valorization. An experimental design (H2SO4 acid concentration 0.5–2%, temperature 130–170 °C, and time 30–60 min) has been used to study the hydrolysis process. In the proposed acid hydrolysis process, under 170 °C as operational temperature, 0.5% of H2SO4 and 30 min for the operation time, 91.75% of the initial xylose have been extracted. The thermal behavior of both tagasaste trunks-large branches and some solid residues after hydrolysis (furthest and center points in the experimental design) process and raw material have been studied by thermogravimetric analysis under nitrogen atmosphere at different heating rates (5, 10, 15, and 20 °C min−1). The thermal degradation of the studied materials is influenced by its initial composition. Then, the higher reactivity of hemicelluloses can accelerate the pyrolysis degradation reaction. However, higher cellulose content implies lower activation energy in pyrolysis process.
PubDate: 2017-04-04
DOI: 10.1007/s13399-017-0258-6

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