Search

Lignocellulosic biomass from crop residues is an abundant and inexpensive resource that can be converted into high-value platform chemicals. An effective approach is a two-step and "lignin-first" process, utilizing ionic liquid pretreatment followed by ethanol–water liquefaction. In this work, the corn stalk (CS) was pretreated with the ionic liquid [B2-HEA][OAc] to remove lignin. The optimal pretreatment conditions were determined to be 130 °C for 5 h at a liquid–solid ratio of 10:1, achieving delignification of 85.88 wt% while recovering 52.22 wt% of cellulose and 30.18 wt% of hemicellulose. The pretreated CS was then converted into ethyl levulinate (EL) via ethanol–water liquefaction at 190 °C for 90 min. This resulted in a maximum EL yield of 39.93 wt%. Furthermore, the structural and thermal analyses via XRD, FTIR, TGA and SEM revealed the effective lignin removal and increased cellulose accessibility in the pretreated CS, as well as significant changes in chemical structure following liquefaction. Compared to the original CS, the crystallinity index of pretreated CS increased from 66.85% to 74.87%. The combination of ionic liquid pretreatment and ethanol–water liquefaction serves as an efficient process to convert the lignocellulosic residue corn stalk into value-added platform chemicals. [ABSTRACT FROM AUTHOR]

Disposal of sewage sludge (SS) is one of the problems in treatment plants; however, SS has a high-water volume and lacks some compounds and can be mixed with other biomass. The present study analyzed co-hydrothermal carbonization of sewage sludge with sawdust and corn stalk. This research aimed to optimize the process parameters, the temperature in the range of 180–300 °C, the reaction time in the range of 30–60 min, and pH in the range of 5–9 on the mass yield, energy yield, and high heat value (HHV) to increase the quality of hydrochar, and to analyze the effect of hydrothermal carbonization (HTC) on the characteristics of raw materials and hydrochar. The response surface method and Benken's box model were conducted using Design Expert 10 software. The optimal conditions for HHV, mass yield, and energy yield were 15.802 MJ/kg, 63.754%, and 67.415% respectively which occurred in the 205.358 °C, 30 min reaction time, and pH of 5. The temperature was the most influential parameter. The morphological, physicochemical, thermal, and crystalline properties of the hydrochar with the maximum HHV, mass yield and energy yield were evaluated as well. These results demonstrate that HTC is a suitable process to produce hydrochar, which can be used as a direct solid fuel. Highlights : • Hydrothermal carbonization of sewage sludge with sawdust and cornstalk was investigated. • Response surface optimization hydrothermal carbonization process was studied. • The morphological, physicochemical, thermal, and crystalline properties of the hydrochar are reported. • The optimal HHV was 15.802 MJ/kg. • The process can produce hydrochar which can be used for direct combustion or activated carbon. [ABSTRACT FROM AUTHOR]

The present study deals with the valorization of corn stalks in an integrated processing strategy targeting two products: extracted hemicelluloses (HC) and papermaking fibers. Preliminary trials were conducted to assess the individual or the combined effects of biomass treatment on the quality of the obtained hemicelluloses and papermaking fibers. Depending on the hot alkaline extraction (HAE) conditions, the extracted HC had a xylan content between 44–63%. The xylan removal yield ranged between 19–35%. The recovery of HC from the extraction liquor and final black liquor was significantly affected by process conditions. The experimental approach continued with the study of HAE conditions on the obtained paper's mechanical properties. The optimization approach considered conserving paper strength properties while achieving an equilibrium with the highest possible HC extraction yield. The optimal values are sodium hydroxide concentration (1%), process time (33 min), and temperature (100 °C). The xylan content in the separated HC sample was ~55%. An extended extraction of HC from the resulting pulp under hot alkaline conditions with 5% NaOH was performed to prove the HC influence on paper strength. The xylan content in HC samples was 65%. The consequence of xylan content reduction in pulp leads to 30–50% mechanical strength loss. [ABSTRACT FROM AUTHOR]

In the current study, corn stalk rinds were used as feedstock for the production of solid-fuel pellets. In an effort to comprehensively analyze the effects of different operational parameters on the physical properties of pellets, response surface methodology (RSM) was employed in conjunction with a Box–Behnken experimental design (BBD). By assessing multiple variables simultaneously and examining their interactions, BBD facilitates the development of a reliable response model that can predict how changes in independent variables will impact response variables. The recorded responses included relaxed density, mechanical durability, and compressive strength. Based on the results, greater R2 values of 0.9467, 0.8669, and 0.9196, could be, respectively, attained for the quadratic regression models. The analysis of variance revealed that all independent variables had significant effects on the responses. The optimal processing condition for the pellets was established by determining the ideal combination of operational parameters. The process entailed the choice of a particle dimension measuring 0.5 mm, a moisture level of 11.35%, the application of heat at 125.7 °C on the die, and the utilization of a molding pressure of 154.2 MPa. Based on these factors, the predicted response values were determined to be 1639.61 kg/m3 for relaxed density, 97.95% for mechanical durability, and 10.18 MPa for compressive strength. The values obtained experimentally under the optimized conditions were similar to the predicted values with a desirability value of 1.00. [ABSTRACT FROM AUTHOR]

Coconut husk powder and corn stover powder were used as raw materials to produce formed particles, and four sets of uniaxial compression moulding devices were used to explore the effects of inner hole diameter of the forming moulds, depth of compression, and depth of conformal depth of the formed particles on the density of the particles. Sampling of the formed particles was carried out at the stage of stable compression force, the maximum pellet density of the coconut coir dust material is 1.53 g/cm3 (1530 kg/m3), and 1.23 g/cm3 (1230 kg/m3) of the corn stalk powder pellets are obtained. At the same time, in the process of the test, failure to compress the two biomass raw materials into pellets also occurred, indicating that the compression parameters studied in the experiment had a significant impact on the pellet quality. On the basis of the obtained pelleting test data, taking into account the nonlinear characteristics between pellet density and processing parameters involved, the adaptive neuro-fuzzy influence system (ANFIS) method was used to predict the pellet density of coconut coir dust and corn stover powder. The results show that the method is effective for predicting the density of biomass particles. [ABSTRACT FROM AUTHOR]

This work presents an experimental study of cutting corn stalks for thermal energy generation. The study was carried out for the values of blade angle in the range of α = 30–80°, distance between the blade and the counter-blade g = 0.1, 0.2, 0.3 mm and the velocity of the blade V = 1, 4, 8 mm/s. The measured results were used to determine shear stresses and cutting energy. The ANOVA variance analysis tool was used to determine the interactions between the initial process variables and the responses. Furthermore, the blade load-state analysis was carried out, together with determining the knife blade strength characteristic, based on the determination criteria for the strength of the cutting tool. Therefore, the force ratio Fcc/Tx was determined as the determinant of strength, and its variance characteristic in the function of the blade angle, α, was used in the performed optimization. The optimization criteria entailed the determination of such values of the blade angle, α, for which the cutting force value, Fcc, and the coefficient of knife blade strength approached the minimum value. Hence, the optimized value of the blade angle, α, within the range 40–60° was determined, depending on the assumed weight parameters for the above-mentioned criteria. [ABSTRACT FROM AUTHOR]

All-cellulose composite (ACC) was directly fabricated by the partial-dissolution welding of cellulose microfibers from agro-residual corn stalks treated with low-concentration ZnCl 2 solvent (10–40 %). The solvent infiltrated deeply into nano/micro-scaled pores of cellulose fibers to facilitate the free migration of the disordered chains among the cellulose network while leaving the fiber core undissolved. Then, these disordered chains would entangle and regenerate to serve as a welded layer to bond the undissolved microfibril core in the solvent removal process. Such welding achieved exceptional mechanical (the tensile strength and Young's modulus of 49.9 MPa and 6.6 GPa, respectively), antibacterial (log removal value (LRV) of 4.8 and 3.0 for E. coli and S. aureus , respectively) and biodegradable properties of the multifunctional ACCs. It is worthwhile noting that the excellent antimicrobial effect is attributed to the sufficient contact of these microbes with ZnO NPs that were converted from the residual Zn2+ in ACCs. After five recycling processes, the elimination efficiency could still maintain a high LRV of 2.0–3.8. This high durability of ACC microbicidal activity was originated from strong twining interactions of cellulosic fibrils with in-situ synthesized ZnO NPs. This strategy was proven to be a facile and economical pathway to fabricate functional all-cellulose composites. [ABSTRACT FROM AUTHOR]

Heavy metal pollution in the water supply is a serious environmental problem that affects human health around the world. The goal of this study was to investigate the adsorption behaviour of sugarcane bagasse (SB) and corn stalk (CS) biomass for Pb(II) and Cd(II) removal from metal-contaminated water. When the doses of biomass were increased in solutions containing Pb(II) and Cd(II), the SB and CS showed a trend of increasing metal removal efficiency. The removal efficiency of biomass for Pb(II) decreased as the pH of the solution increased from 5.0 to 7.0, with an optimum pH range of 5 to 6. However, pH has little influence on the removal efficiency of biomass for Cd(II). Adsorption equilibrium is reached in about 15 min. Adsorption for at least four cycles improves Pb(II) removal efficiency (up to 98 %) in solutions containing only Pb(II). The best fitness of the adsorption isotherm to Freundlich suggests multilayer adsorption of metal ions onto CS. Higher qmax and Kf suggest that SB and CS have a greater affinity for Pb(II) than for Cd(II). Pb(II) adsorption potential was found in biomass derived from SB and CS, but it was less effective as a Cd(II) adsorbent. For application in environmental clean-up, we suggest further study on the structural modification of biomass to enhance its metal removal capacity, the regeneration of biomass for better results, and field trials for practical application. [ABSTRACT FROM AUTHOR]

Gasification experiments on devolatilization (MTD) char derived from corn stalk in a steam atmosphere were conducted using a thermogravimetric analyzer. The gasification reactivity of MTD-char at different gasification stages was investigated, and the internal correlation between the gasification kinetics characteristics and physicochemical properties of MTD-char was explored. The results demonstrated that the reduction of H/C and O/C after the MTD of corn stalk increased the final gasification temperature, maximum gasification weight loss rate, and corresponding temperature, whereas the increase in alkali and alkaline earth metal elements, especially K, reduced the gasification initiation temperature and activation energy, thereby improving gasification reactivity. Furthermore, because of the formation of graphite intercalation compounds, the catalytic effect of K on biomass gasification reactivity was mainly concentrated in the middle and late stages of gasification, the average gasification reaction rates in the middle and late stages of gasification increased from 0.338 %/°C and 0.22 %/°C in corn stalk to 0.644 %/°C and 0.597 %/°C in the MTD-char obtained at 550 °C, respectively. This study is of great significance in revealing the gasification reaction mechanism of MTD-char and in the design of relevant gasification reactors. • K played a critical catalytic role in the gasification of corn stalk MTD-char. • Gasification kinetics characteristics of MTD-char at distinct stages was clarified. • Catalytic effect of K was more significant in middle and late gasification stage. • Gasification reactivity of biomass treated at 350–550 °C was significantly improved. • The catalytic mechanism of K is completely different at distinct gasification stage. [ABSTRACT FROM AUTHOR]

Covalent Organic Frameworks (COFs) are widely used for photocatalysis but limited by the aggregation of the catalysts, which limited the mass transfer. Herein, corn stalk cores were used as the substrate, and two kinds of biomass based COFs with different electronic structures of thiophene (C@SCOF) and pyridine (C@NCOF) were in-situ fabricated uniformly on the surface of the substrate. In this way, COFs expose more active sites rather than embedding in the agglomerated structure. Biomass based COFs, especially C@SCOF, exhibit a hierarchical porous structure containing micropores and macropores, which offer fast mass transfer channels for the catalytic and adsorbed substrates. Therefore, the biomass based COFs utilized more efficiently to achieve higher photocatalytic performance. The C@SCOF with D-A structure displays stronger photoresponse and lower impedance, which promote the dissociation of a photogenerated exciton and carrier separation efficiency, resulting remarkable photocatalytic performance for oxidation of benzylamine coupling reaction. This work could guide the design and preparation of biomass-based hybrids with promising performance. [Display omitted] • Two different electronic structured biomass based COFs were constructed. • Hierarchical porous structure exposes more active sites and improved mass transfer. • Biomass based COFs showed stable structure and good reusability. • C@SCOF with D-A structure and porosity showed better photocatalytic performance. [ABSTRACT FROM AUTHOR]

While torrefaction improves the fuel properties of biomass pellets, the chemical components of secondary products in liquid form are highly valuable in the industrial field. In addition, the components of the liquid have the potential to be used as biopesticides. In this study, corn stalk pellets were torrefied at 320 °C and torliquid was obtained as a secondary product from condensable gases during the process. Calorific value of the corn stalk pellets increased from 19.10 MJ kg−1 to 22.58 MJ kg−1 during torrefaction process. According to the Gas Chromatography-Mass Spectrometry findings, the torliquid contained mostly acidic components (52.20 %) due to the nearly complete degradation of hemicellulose. Potential bioactivity of the torliquid on the two-spotted spider mite Tetranychus urticae Koch, 1836 (Acari: Tetranychidae), worldwide major phytophagous pest, was investigated. Dipping method and half-treated leaf disc assay were used to determine lethal and repellent effects, respectively. The concentration series of 12.5, 25 and 50 % for the determination of bioactivity were prepared by torliquid using distilled water. The highest concentration caused 84 % and 100 % mortalities for eggs and adult stages, respectively. The repellant effects of the torliquid varied depending on concentrations and duration of exposure. The egg rates in the immersed half part of the cowpea discs at the increasing concentrations were found to be 15.5, 2.1 and 0.0 %, respectively, after 48 h. Research findings have revealed that corn torliquid may be a suitable biopesticide to be used in T. urticae management, as it has a significant effect, cost-effective and plant biomass origin. [Display omitted] • Biopesticidal effects were investigated of the liquid product from torrefaction. • Torrefaction liquid is significantly lethal to Tetranychus urticae eggs and adults. • Furthermore, the liquid has significant repellent effects on Tetranychus urticae. • The main component of the liquid was found to be acetic acid in GC/MS analysis. [ABSTRACT FROM AUTHOR]

To study the transformation and release of fuel K, the combustion of corn stalk and wheat straw were performed in a reactor with a fixed bed between 400–1000°C. Measurements of weight and elemental composition, chemical fractionation analysis, and low‐temperature ashing coupled with X‐ray diffraction (XRD) analysis were conducted on biomass and residual samples. The effects of biomass species, temperature and duration time of combustion, oxygen concentration, and pretreatment of water washing were evaluated. The results show that compared with wheat straw, corn stalk has a lower K release, which is much more sensitive to the combustion temperature than to the oxygen concentration. The inorganic potassium occurs as KClO3 and KClO4 in wheat straw and KCl and KClO4 in corn stalk. K2SO4 appears through sulphation of KCl as combustion happens at 800°C or above. When the combustion temperature reached 900°C for corn stalk and 1000°C for wheat straw, some KCl changed into K2Si2O5, which contains insoluble K. K2Ca(SO4)2 appears as corn stalk and wheat straw are burnt at 1000 and 900°C, respectively. Along with the proceeding of wheat straw combustion, more ion‐exchangeable and water‐soluble K transform to the insoluble K with the increasing temperature. The pretreatment of water washing removes nearly all the water‐soluble K from the corn stalk and significantly decreases the K release from 3.26–0.27 mg g−1 in quantity and from 26.74%–14.84% in ratio at 1000°C, respectively. [ABSTRACT FROM AUTHOR]

Recently, efficient synthesis of furan-based chemicals from biomacromolecule via chemoenzymatic approaches have been widely recognized. In this work, an efficient conversion of biomacromolecule (e.g., xylan in biomass) to furfurylamine (FLA) was developed in a tandem reaction by bridging with chemocatalysis and biocatalysis. Various biomasses (e.g., corncob, bagasse, bamboo shoot shell, corn stalk, rice straw stalk, reed, water bamboo and sunflower stalk) could produce different titer of furfural due to the diverse xylan content in biomass. After being catalyzed by shrimp shell-supported solid acid catalyst (Sn-DAT-SS) in deep eutectic solvent choline chloride:ethylene glycol (ChCl:EG) − water (10:90, v/v) at 170 °C after 30 min, corncob gave the highest furfural yield of 52.4 %. The potential catalytic mechanism for Sn-DAT-SS-catalyzing the conversion of biomass into furfural in ChCl:EG − water was proposed. It was found that by-products (formic acid, levulinic acid, 5-hydroxymethylfurfural) and soluble sugars (glucose, xylose, arabinose, cellobiose) produced during the conversion of biomass to furfural had certain inhibition effects on the biotransamination of furfural to FLA. Biomass-derived furfural (36.7–92.3 mM) could be fully aminated to FLA by E. coli CCZU-XLS160 cells harboring ω-transaminase after 24–72 h. The established chemoenzymatic strategy for converting biomacromolecules into valuable furan-based products was successfully developed in an eco-friendly system. [ABSTRACT FROM AUTHOR]

The production of methane-enriched gas via thermo-chemical process is an important approach for biomass valorization. However, current pyrolysis processes generally give low yield of value-added gas product. Herein, a series of Ni-based materials with hydroxyapatite (HAP) and titanium silicate (TS) as supports were prepared and investigated as catalysts to boost CH 4 production from pyrolysis-steam reforming of corn stalk. The surface element composition, chemical state and crystal structure of materials were characterized by transmission electron microscope (TEM), N 2 adsorption-desorption, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. The expected loading of Ni, La and Ce were successfully loaded onto HAP via simple impregnation method, while the loading of active metals on TS is finite. Ni-5La 2 O 3 /HAP exhibited the best catalytic activity for pyrolysis-steam reforming of corn stalk, attaining CH 4 yield (19.41 mmol/g) that is 89.9 % and 46.2 % higher than control experiment and Ni-5CeO 2 /MCM-41, indicating that loading high-density Ni and La species onto HAP supports can greatly boost the CH 4 formation. However, the catalysts lost activity obviously during recycling experiment probably due to carbon accumulation. [Display omitted] • High loading of Ni, La and Ce were successfully loaded onto HAP to construct composite catalyst. • Both supports and promoter affect the performance of pyrolysis-steam reforming of corn stalk. • Ni-5La 2 O 3 /HAP gave CH 4 yield (19.41 mmol/g) 89.9 % and 46.2 % higher than control experiment and Ni-5CeO 2 /MCM-41. [ABSTRACT FROM AUTHOR]

With the purpose of quantifying and understanding the elastoplastic flexural behaviour of corn stalks, this work presents a novel three-point cyclic bending test for characterizing the biomechanical properties of controlled corn stalks. The tests have resulted the first-of-its-kind biomechanical database of corn stalks subjected in repeated bending. Moreover, an experiment-informed bending stiffness model is introduced to calculate the elastic bending angle limits, elastoplastic bending angle limits, elastic bending stiffnesses (or effective bending stiffness), and plastic ratios as well as their variabilities in the tested samples, revealing unique insights into the corn stalk flexural properties. The overall elastic bending limit decreased (from 3.4 to 1.7°) with increasing stalk size, whilst the effective bending stiffness increased (from 7.0 to 43 N m rad−1 in median value). The elastoplastic behaviour of the stalks is more consistent and independent of stalk size where in median value the elastoplastic bending limit ranged from 6.9 to 8.8° and the ratio of elastoplastic stiffness to elastic stiffness ranged from 0.40 to 0.42. Furthermore, statistical analysis of the samples and empirical results have presented insightful expressions to relate the stalk scales to responses, or distributions in properties for a population of corn stalks. The database and statistical analysis and regression expression from this work also allow for parameterizing existing numerical models for simulations of corn stalks and development of more sophisticated deformation models. • First-of-its-kind biomechanical database of corn stalks in repeated bending. • Corn stalk bending strength is dominated by the properties of the shell. • The corn stalk bending stiffness increases with increasing stalk diameter. • Experiment-informed bending properties ready for supplying discrete element modeling. [ABSTRACT FROM AUTHOR]

The conversion of lignocellulose into a value-added chemical with high selectivity is of great significance but is a big challenge due to the structural diversities of biomass components. Here, we have reported an efficient approach for the one-step conversion of raw lignocellulose into diethyl maleate by the polyoxometalate ionic liquid [BSmim]CuPW12O40 in ethanol under mild conditions. The results reveal that all of the fractions in biomass, i.e., cellulose, lignin and hemicellulose, were simultaneously converted into diethyl maleate (DEM), achieving a 329.6 mg g−1 yield and 70.3% selectivity from corn stalk. Importantly, the performance of the ionic liquid catalyst [BSmim]CuPW12O40 was nearly twice that of CuHPW12O40, which can be attributed to the lower incorporation of the Cu2+ site in [BSmim]CuPW12O40. Hence, this process opens a promising route for producing bio-based bulk chemicals from raw lignocellulose without any pretreatment. [ABSTRACT FROM AUTHOR]

Hard carbon is considered to be the most promising anode material for potassium‐ion batteries (PIBs) because of its high storage capability and inexpensive cost, but most of them have a high operating potential. Herein, a highly graphitic nitrogen‐doped hard carbon (NHC) is prepared by soaking a corn stalk in urea solution and calcination. NHC can deliver a reversible capacity of 402 mAh g−1 in the first charge–discharge cycle and 87% of the total capacity is measured below 1 V versus K+/K. Simultaneously, it can retain a capacity of 263 mAh g−1 after 100 cycles at 200 mA g−1. Even at 1 A g−1, it can still provide a capacity of 176 mAh g−1 after 260 cycles. These superior electrochemical performances are attributed to the doping of graphitic nitrogen. Noticeably, such a biomass‐derived NHC is not only environment friendly but also easy to prepare, which makes it a competitive anode material candidate for PIBs. [ABSTRACT FROM AUTHOR]

A synergistic co-carbonization method based on the use of corn stalk (CS), wood shavings (WS) and bituminous coal (BC) is proposed as a green and low-cost technology. The preparation parameters included a co-carbonization temperature of 600 °C, a co-carbonization time of 30 min, and a biomass/coal ratio of 4/6. The high calorific value (HCV) and bulk density of the CS/BC synfuel were 29.81 MJ kg−1 and 495 kg m−3, respectively, and those of the WS/BC synfuel were 30.11 MJ kg−1 and 485 kg m−3, respectively. The results indicated that the microcrystalline structure was ordered and that the proportion of the graphitic structure increased during the synergistic co-carbonization process. In addition, the co-carbonization process changed the contents of the functional groups on the surface. The amount of aromatic C–O increased during the synergistic co-carbonization process. Decreases in the O-containing functional groups and increases in the graphitic carbon content in the synfuel demonstrated that the interactions of the biomass volatiles with the bituminous coal generated a more regular structure for the carbon-based synfuel and changed the carbon type of the synfuel. This work provides a mechanism for the biomass and coal interactions occurring during the preparation of carbon-based synfuels. [Display omitted] [ABSTRACT FROM AUTHOR]

An extended population balance model (PBM) and a deep learning-based enhanced deep neural operator (DNO+) model are introduced for predicting particle size distribution (PSD) of comminuted biomass through a large knife mill. Experimental tests using corn stalks with varied moisture contents, mill blade speeds, and discharge screen sizes are conducted to support model development. A novel mechanism in the extended PBM allows for including additional input parameters such as moisture content, which is not possible in the original PBM. The DNO+ model can include influencing factors of different data types such as moisture content and discharge screen size, which significantly extends the engineering applicability of the standard DNO model that only admits feed PSD and outcome PSD. Test results show that both models are remarkably accurate in the calibration or training parameter space and can be used as surrogate models to provide effective guidance for biomass preprocessing design. [Display omitted] • An extended population balance model (PBM) is developed for biomass comminution. • Biomass feed moisture is added in the PBM as a new input parameter. • An enhanced deep neutral operator (DNO+) model is developed for biomass comminution. • DNO+ allows for influencing factors such as moisture and screen size as extra inputs. • Both models are remarkably accurate in the calibration or training parameter space. [ABSTRACT FROM AUTHOR]

Agroforestry biomass involving cedar wood (CW), polar wood (PW), corn stalk (CS) and wheat straw (WS) was torrefied in a fixed-bed reactor under the torrefaction temperature (T) of 200–300 °C and the holding time (τ) of 10–60 min to prepared straw biochars (WSC, CSC) and woody biochars (PWC and CWC). The effects of biomass species, torrefaction temperature and holding time on the hygroscopicity of biochars were investigated under constant temperature and humidity. Combined with the results of N 2 adsorption/desorption and FTIR of raw biomass and its biochars, the mechanism of torrefaction conditions on the hygroscopicity of biochar was discussed. The obtained results indicated that water absorption process of biochar can be divided into two stages of initial rapid water absorption and the later slow water absorption. The equilibrium moisture content (EMC) decreases, the hygroscopicity reduction extent (HRE) increases gradually, and hydrophobicity of biochar is enhanced with increasing torrefaction temperature. However, too high torrefaction temperatures (T ≥ 275 °C) has little or even adverse effect on the hydrophobicity of biochars. The longer holding time has a certain influence on the hydrophobicity of biochar, but the overall effect is not significant. The hydrophobicity of woody biochars (PWC and CWC) is better than that of straw biochars (WSC and CSC) at the same torrefaction conditions. The severe torrefaction of T ≥ 275 °C and τ ≥ 40 min are able to improve the hydrophobicity of woody biochars, however it has negative effect on straw biochars. The hydrophobicity of four biochars is ordered as PW > CW > WS ≈ CS at the same torrefaction conditions. The water adsorption mechanism of biochars is influenced by the coupling effects of physical structure evolution, release of hydrophilic oxygen-containing functional groups and pyrolytic tar condensation, and the severer the torrefaction, the more significant the influence is. • Water absorption process of biochar involves two stages of initial rapid water absorption and later slow water absorption. • The effect of torrefaction temperature on hydrophobicity of biochar is significantly stronger than that of holding time. • The order of hydrophobicity of biochar torrefied at same condition is poplar wood > cedar wood > wheat straw ≈ corn stalk. [ABSTRACT FROM AUTHOR]

The corn crop is one of the most important crops worldwide. However, the management of the residues generated is not efficient enough, which diminishes the competitiveness of this crop. An interesting option for the valorization of these wastes is their thermal use. In order to make the management of this residue as much efficient as possible, it is vital to know the different processes related to a corn harvest, and try to adapt the use of this waste depending on its characteristics. Thus, in this work, and on the basis of a conventional corn harvest, a differentiated analysis of the residue generated was carried out, including its characterization and assessing its behavior during pyrolysis and combustion. The results pointed out the importance of collecting residue immediately after its generation and avoiding its contact with the soil as this factor tends to worsen its thermal properties and ash content. Concerning the selective collection, it is highly advisable if the subsequent thermal use is going to be a pyrolytic process. In the case of combustion, even though the samples that contain corn stalk showed better combustion properties, this improvement did not outweigh the adverse effects related to the increase in ash content, especially for its pelletizing. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Soil Sciences & Agricultural Engineering is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Water washing can effectively remove Na, K, and Cl in biomass, which can cause fouling, slagging, and corrosion during thermal conversion process of biomass fuels. However, it is necessary to dispose the leachates appropriately after water washing. Characterization of organic matters in leachates should be performed first, which is beneficial to find an effective way to dispose the leachate. In this study, four biomass materials are washed with the deionized water at 30°C, 60°C, and 90°C. The release of toluene and styrene is studied. The results show that yields of organic matters for corn stalk and wheat straw are the highest relatively, of which the eventual values are 8% and 15%, respectively. Less toluene and styrene are released at 30–60°C than that at 90°C for wheat straw. But the release of toluene and styrene in rice hull leachate shows the opposite trend. The concentration of styrene in leachates reaches a minimum value at 60°C. The corresponding values are 0.017 mg L−1 for wheat straw and 0.15 mg L−1 for rice hull. But none is detected in corn stalk and sorghum stalk leachates. In addition, variations of toluene and styrene concentrations are obviously different with different washing temperatures. [ABSTRACT FROM AUTHOR]

Alkaline organic liquid waste was introduced to activate Fe 2 O 3 and provide sufficient steam to boost biomass chemical looping gasification (CLG) for H 2 production. Experiments under different excess oxygen ratios, temperatures, and alkali contents were performed to investigate the reaction characteristics of alkaline organic waste - biomass CLG. The highest H 2 yield of 1.71 L and carbon conversion rate of 83.8% were obtained at the excess oxygen ratio of 0.2, the alkali concentration of 6%, and the reaction temperature of 800 °C. Moreover, the kinetic and thermodynamic analysis under the optimized condition have cast light on the fundamental understanding of alkaline organic liquid waste - biomass CLG. Results demonstrate that this novel approach has the potential to enhance energy conversion. Image 1 • Dual effect of K 2 CO 3 -containing ethanol solution - corn stalk chemical looping gasification. • K 2 CO 3 in ethanol solution activates Fe 2 O 3 /Al 2 O 3. • Ethanol solution provides efficient gasification agent. • Reasonable operational condition contributes to high hydrogen yield and carbon conversion. [ABSTRACT FROM AUTHOR]

The effect of added coal ash on the gasification behavior of corn stalk char by using the thermalgravimetric analysis and a lab-scale horizontal fixed bed furnace was investigated. For comparison, synthetic ash with different chemical composition was used for studying the effect of difference ash composition on promoting/inhibiting the gasification reactivity. The results show that the slagging-control preferred coal ash additive has a negative impact on the gasification performance. Interestingly, a relatively less slagging-control preferred coal ash additive has a beneficial impact on promoting the gasification performance under low gasification temperature. This could be due to the difference composition between the two coal ash additives, where the former coal ash type has much lower content in the calcium and iron. In addition, the findings in the synthetic ash suggest that iron can have a better performance in promoting gasification than calcium/magnesium. Two types of coal ash show an inhibiting effect under higher temperature due to temperature might be the dominant factor and the restraining effect of additive. These observations are also supported by the evolution of char structure by using the Raman spectroscopy. Further, the modified random pore model can correlate well with the gasification kinetics data. • Two coal ashes were used to evaluate its effect on biomass gasification reactivity. • The minerals in coal ash play an important role on biomass gasification reactivity. • Iron have better performance in promoting gasification than calcium/magnesium. • Temperature become the key factor to effect the reactivity after 1223 K. • The trend of coal ash effect on char structure change is same with that on reactivity. [ABSTRACT FROM AUTHOR]

• The positive interactions between semi-coke and biomass will promote the combustion of semi-coke in advance during co-combustion. • Blending biomass can decrease the NO emission of semi-coke effectively in fluidized bed. • The ash deposition problem may occur when more than 20% corn stalk and rice stalk are blended. • The optimal blending ratios of corn stalk and rice stalk are considered as 20% to co-combust with semi-coke, while the appropriate blending ratio for pine wood is 40%. In order to realize the integrated utilization of semi-coke (SC) and biomass, the co-combustion behavior of SC and three typical biomass (corn stalk (CS), rice stalk (RS) and pine wood (PW)) was experimentally studied in terms of combustion, NO emission and ash characteristics. The results of thermogravimetric (TG) analysis show that the positive interactions between SC and biomass mainly occur at the later combustion stage of blends, leading to the combustion of SC in advance. Based on the ignition and comprehensive combustion indexes, the optimal blending ratios of CS and RS are considered as 20%. The co-combustion experiments conducted at the biomass blending ratio of ≤40% in an electrical-heated fluidized bed rig also prove that the combustion performance of SC can be improved by biomass, and the NO emission decreases with the biomass blending ratio. The ash deposition problem should be paid attention when more than 20% CS or RS is blended, which is related to the alkali aluminosilicates and K 3 Na(SO 4) 2 in the fly ash of SC/CS and SC/RS blends, respectively. Meanwhile, the effect of PW in this regard is limited due to its extreme low ash content. In summary, the blending ratio for CS and RS is suggested as 20% when co-combusting with SC, while the appropriate PW blending ratio is 40%. The achievements of this study are conducive to the clean and high-efficiency utilization of semi-coke and CO 2 emission reduction. [ABSTRACT FROM AUTHOR]

The gas production effect of two kinds of straws mixed with pig manure via anaerobic fermentation under two sets of temperatures 32°C and 52°C has been studied in this experiment. In the process, sunflower and corn straw were used as raw materials with activated sludge as inoculum in a batch anaerobic fermentation reactor. The results showed that the average methane content of sunflower straw reached 62.55% at 37°C, which was 20.41% higher than that of sunflower straw at 52°C.The cumulative methanogenic yield of corn stalks was higher than that of sunflower stalks at different temperatures. The cumulative methane production of corn stalks was the highest at 52°C, and 67.99 L of methane was produced in 54 days. The cumulative methane production of sunflower stalks was the lowest at 52 °C, and the methane production was 34.09 L in 53 days. The results showed that corn stalks produce more methane than sunflower stalks and are more suitable for high temperature anaerobic fermentation. On the other hand, sunflower stalks were found suitable for medium temperature fermentation. [ABSTRACT FROM AUTHOR]

Copyright of Indonesian Journal of Forestry Research is the property of Indonesian Journal of Forestry Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The bifunctional Ga/HZSM-5 catalyst has been proven having the capability to increase the selectivity of aromatics production during catalytic pyrolysis of furan and woody biomass. However, the reaction chemistry and kinetics of pyrolysis of herbaceous biomass promoted by Ga/HZSM-5 is rarely reported. Pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) analysis and non-isothermal thermogravimetric analysis at four heating rates were carried out to investigate the decomposition behavior and pyrolysis kinetics of corn stalk without and with Ga/HZSM-5. The effective activation energies for corn stalk pyrolysis were calculated by using the Friedman isoconversional method. The Py–GC/MS analysis results indicated that the Ga/HZSM-5 catalyst had a high selectivity toward producing the aromatic chemicals of xylene, toluene and benzene, whereas the major products from non-catalytic pyrolysis of corn stalk were oxygenated compounds. The presence of Ga/HZSM-5 could significantly reduce the effective activation energies of corn stalk pyrolysis from 159.9–352.4 kJ mol−1 to 41.6–99.8 kJ mol−1 in the conversion range of 0.10–0.85. [ABSTRACT FROM AUTHOR]

Introduction. The aim of this work is to determine the influence of dispersion modes of plant biomass of raw materials in the rotor-pulsating apparatus by the method of discrete-impulse energy input Materials and methods. The material of the studies was wheat straw and corn stalks, grinded on a disintegrator, which were mixed with water in certain proportions. The suspension was treated in a rotor-pulsating apparatus under different modes. The particle size distribution of the obtained particles was determined by the sieve method and the laser diffraction method. Results and discussion. It is determined that under the same conditions of treatment granulometric composition of the mixture of milled biomass of corn stalks with water after milling in the rotor-pulsating apparatus has a dispersity of 3–5% lower than the mixture of wheat. This can be explained by the different strengths of lignocellulosic fibers in the investigated plants. It was found that with the increase of a solid/water ratio from 1: 5 to 1:15, a dispersity of particles is reduced by 35–40%, and from 1: 5 to 1:10 by 3–5%. According to the authors, this is due to changes in the viscosity of the solution. Reducing the solid/water ratio from 1:15 to 1:10 for 10 cycles of the dispersion treatment in the rotor-pulsating apparatus leads to a decrease in temperature from 47 to 42º C (≈ 10%), but the productivity of the equipment increases 1.5–2 times, energy consumption decreases by 25–30%. The optimum parameters for milling of wheat straw or corn stalks in a rotor-pulsating apparatus are: the solid/water ratio is 1:10; the shear flow rate is 40∙103 s-1; the frequency of flow pulsations is 3 kHz. The number of processing cycles is 25–30. It was determined that the granulometric composition of an aqueous dispersion of wheat straw or corn stalks at a solid/water ratio of 1:10 and treated in the rotor-pulsating apparatus with the frequency of pulsations of 3 kHz, shear flow rate 40∙103 s-1 for 25– 30 cycles allows the conclude that about 50% of the particles have a size in the range of 30–50 μm. Conclusions. Dispertion of plant biomass by the method of discrete-pulse energy input provides for obtaining 80% of particles with a size of 1–50 μm. [ABSTRACT FROM AUTHOR]

Introduction. Sugar’s molecules of lignin-cellulosic biomass make them inaccessible for carrying-out of polysaccharose depolymerization. The aim of investigation is power of physical-chemical parameters on the process of organosolv delignification of lignin-cellulosic biomass. Materials and methods. Target of research is the way of organosolv lignin dilution. As a raw stuff we used a wheat straw, afterharvesting maize shruffs and halm of sugar broomcorn. Lignin was determined by the hydrolysis of mixed of concentrate hydrochloric acid and 72% sulphuric acid, polysaccharides - in amount of monosaccharide by the Machen and Schoorl method. Results and discussion. For maximum lignin dilution a solvent composition, fineness degree of row, treatment temperature and a process time were investigated. Depending on concentration change of sulphuric acid (from 1 to 3,9%) in solvent, lignin yield from maize’chaff is increased from 14,4 to 29,2%, content of undissolved remainder is decreased from 66,7 to 55,4%. The lignin yield is changed from 19,3 to 32,4% in stalk of sugar sorghum in the same condition. Treatment temperature rising of chopped wheat straw from 70 to 100 °С contributed to an increase in the degree of conversion of lignin by 3%, and for the stalks of corn - this indicator changed from 6.8% to 17.1%. Maximum lignin dissolution is at the temperature of 100 C°, wherein the highest yield of reducing substances is achieved within 1:00, regardless of the type of plant material. Lignin conversion increases at increase processing time to 6:00, but at the same time there is a destruction of sugar molecules, the content of which is almost halved. Conclusions. The hydrolysis degree of lignin by an organosolvent solvent can be adjusted by choosing rational modes of grinding of raw materials, temperature and duration of the process. [ABSTRACT FROM AUTHOR]

Abstract The work reports a comparative study on the pyrolysis of five agricultural crop residues (peanut straw, cotton straw, sorghum stalk, corn stalk and reed) using a gas-sweeping fixed bed reactor. The study aims at clarifying the role played by the neutral extractives and inherent active minerals in the pyrolysis characteristics, product distributions and bio-oil compositions. Among five crop residues, reed showed the highest bio-oil yield but with the highest oxygen content and the lowest HHV (higher heat value), in relation to the least alkali and alkaline earth metals (AAEMs) in it. Peanut straw had a content of neutral extractives as high as 47.4%, which contributed to the formations of a significantly higher proportion of long chain aliphatic hydrocarbons and liquid nitrogenous compounds, distinct from four other crop residues. Peanut straw was also highly enriched with AAEMs, which was responsible for a strong catalytic activity for the selective deoxygenation of bio-oil. Neutral extractives in sorghum stalk and corn stalk formed some long chain fatty oxygenates and less nitrogenous compounds. The bio-oils derived from these two biomasses contained oxygenates as dominant compounds, however, they had a lower fraction of heavy constituents, lower oxygen contents, and higher HHVs than those of reed and cotton straw. This result was attributed to the catalyzed bio-oil deoxygenation by the relatively abundant AAEMs in sorghum stalk and corn stalk. Highlights • Pyrolysis of five crop residues were studied with a focus on bio-oil production. • Neutral extractives are an important contributor to bio-oil formations. • Inherent potassium showed a catalytic effect on deoxygenation of bio-oil. • Peanut straw showed a distinctly selective bio-oil deoxygenation. [ABSTRACT FROM AUTHOR]

Large quantities of crop stalk resources are produced in China every year, and some of the stalks are incinerated, which pollutes the environment. Biomass gasification is attracting a great deal of attention as a way of utilizing biomass waste. In this study, a circulating fluidized bed experimental system was designed and constructed with a treating capacity of 150 kg/h, which equipped with secondary back-feeding device, steam generator and air preheater. The influences of secondary back-feeding device on the gasification performance were investigated with corn stalk after crushing and drying pretreatment as biomass feedstock. The effects of air equivalence ratio (ER) within 0.20～0.35 on gasifier temperature, tar content, gas composition, carbon conversion rate and gasification efficiency were investigated when the secondary back-feeding device was closed and open. The gasification reaction was promoted by increasing ER, and gasification efficiency and carbon conversion showed a trend of increasing firstly and then decreasing. The results showed that good gasification results were both obtained at ER of 0.26. When the secondary back-feeding device was closed, the maximum carbon conversion rate and gasification efficiency were 91.19% and 72.95%, respectively. Whereas the carbon conversion rate and gasification efficiency were higher when the secondary back-feeding device was open, which was up to 93.54% and 77.06%, respectively. The experimental results also showed that secondary back-feeding device had a good effect on tar cracking. When the secondary back-feeding device was closed and open, the tar content in gas was 7.5 g/Nm3 and 4.5 g/Nm3 at ER of 0.26, respectively, which meant that tar content can be decreased by 40% when secondary back-feeding system was open. The effects of steam/biomass ratio (S/B) on gasification characteristics were investigated when the secondary back-feeding device was open. The results showed that gas quality and gasification efficiency were improved with air as main gasifying agent and steam assisted. The better operation conditions of the corn stalk gasification were 0.26 of ER and 0.2 of S/B, and gas calorific value and gasification efficiency reached to maximum value of 5.89 MJ/3 and 81.45%, respectively. The results of tar distillation analysis under typical operating conditions indicated that the pyrolysis conversion of tar was promoted by increasing the reaction temperature of gasifier and maintaining a certain amount of water vapor in the gasifier. The experiment can provide reference for efficient and clean transformation and utilization of straw biomass. [ABSTRACT FROM AUTHOR]

Biomass-coal blending combustion is an effective method for utilizing biomass; however, its pollutant emission requires attention. Herein, the effect of biomass-coal blending combustion on lead (Pb) transformation was explored. Combustion experiments were conducted in a fixed-bed reactor, using coal, corn stalk, rice stalk, bamboo flour and their mixtures as fuels, at 1000, 1100, 1200 and 1300 °C. The Pb release ratios were determined by measuring its content in the fuels and solid-phase combustion products. The distribution of Pb forms was analyzed using sequential chemical extraction. The results indicate that blending combustion significantly enhanced the release of Pb. At blending ratio 1:1, the release ratios increased by 1.54–27.2%, 5.30–15.6%, and 2.31–7.76% at 1000, 1100, and 1200 °C, respectively. The potassium (K) components in biomass, mainly KCl and K 2 CO 3 , had a significant promoting effect on Pb release. K compounds facilitated the release of residual Pb through reactions with aluminosilicates. The promotion effect weakened as the temperature increased due to the faster evaporation rate of K. When the mass fractions of K in the fuels were equal, K 2 CO 3 exhibited a stronger promoting effect. HCl had minimal impact on the transformation of Pb. The results are helpful for optimizing the combination of biomass and coal to control Pb emission from the blending combustion source. [Display omitted] • The effect of biomass-coal blending combustion on lead (Pb) transformation was studied. • The release of Pb in coal was promoted during blending combustion. • K compounds in biomass promoted the release of Pb, while Cl had little effect. • K 2 CO 3 and KCl could both react with aluminosilicate and release residual Pb. • K 2 CO 3 had a stronger promoting effect on Pb release than KCl. [ABSTRACT FROM AUTHOR]

• The [BHEM]mesy- glycol system had high pretreatment efficiency with 93% lignin removal rate. • The pretreated corn stalk was easy to enzymolysis with 91% cellulose and lower crystallinity. • The viscosity of enzymolysis materials was the key factors limiting the efficiency of enzymolysis by rheometer. • By feed-batch method, the glucose concentration reached 250 g/L with the yield of 100 %. The ethanol concentration is 93 g/L with the yield of 70 %. The transformation of lignocellulose into bioethanol is of great significance for energy security and environmental protection. Traditionally, the concentration of ethanol obtained by fermentation does not exceed 7 % (v/v), resulting in high cost of rectification (about 100 t water are needed to produce 1 t ethanol) and a large amount of wastewater, which is not suitable for industrial production. In this study, producting high concentration bioethanol from ionic liquid pretreated corn stalk integrated by feed-batch method was proposed. The cellulose content and the lignin removal rate of the corn stalk pretreated by [BHEM]mesy-ethylene glycol co-solvent system (rich-cellulose material) were 91 % and 93 %, respectively. The co-solvent system showed stable pretreatment efficiency after amplification of 20 times. Observably, the rich-cellulose material became easier to enzymolysis because the lower crystallinity from XRD, less lignin from CLSM and so on. The optimal enzymolysis conditions were 160 EGU/g cellulose, 50 ℃, pH = 4.8, 96 h, under which the yield of glucose could reach 90 %. The tolerance limit of Saccharomyces cerevisiae to glucose concentration is 0.3 g/L. The viscosity of enzymolysis materials was one of the main factors limiting the efficiency of enzymolysis by rheometer, and the 5 % concentration of materials was the most suitable for enzymolysis. Significantly, by feed-batch method, the glucose concentration reached 250 g/L with the yield of 100 %. The ethanol concentration is 93 g/L with the yield of 73 %. This study provided the possibility for industrialization of bioethanol production. [ABSTRACT FROM AUTHOR]

Appropriate pretreatment plays a pivotal role in biomass pyrolysis as it facilitates high-value utilization of pyrolysis products. In this study, hydrogen peroxide pretreatment with cleanliness, economy, and efficiency was applied for fast pyrolysis of corn stalks. The effects of pyrolysis temperature, hydrogen peroxide pretreatment, and different pHs on the structure of corn stalks and the properties of resultant pyrolysis products were investigated. The results revealed that the pretreatment could effectively promote lignin depolymerization and significantly reduce the reaction activation energy (E). Meanwhile, the pretreatment increased the cellulose content and removed the majority of alkali and alkaline earth metals from the biomass. The removal of lignin and ash by the pretreatment was affected by the pH of the hydrogen peroxide solution. Moreover, the composition of bio-oil changed significantly. Among them, the relative content of levoglucosan in the bio-oil from untreated raw material was only 1.38 %. After pretreatment, the relative content of levoglucosan was up to 14.5 %. The present findings offer valuable guidance for the further exploration and exploitation on hydrogen peroxide pretreatment for depolymerization of woody fibrous biomass as well as for the preparation of high-value chemical products. [Display omitted] • Pyrolysis characteristics of corn straw pretreated with H 2 O 2 were investigated. • H 2 O 2 pretreatment increased the relative content of cellulose. • Significant increase in the relative content of levoglucosan up to 14.50 %. • Acids in bio-oil are greatly reduced, as low as 5.33 %. • Degradation mechanism of corn stalk pretreated with H 2 O 2 was elucidated. [ABSTRACT FROM AUTHOR]

[Display omitted] • A series of NiS 1.03 @Ni 7 S 6 /carbon composites were prepared. • Corn stalk is used as carbon source in the synthesis process. • The obtained composites exhibited excellent supercapacitor performance. NiS 1.03 @Ni 7 S 6 /carbon composite have been successfully prepared via a simple "adsorption-sulphurization" process by using corn stalk as carbon source. It is found that the morphologies and surface area of the composites are strongly influenced by the amount of NiCl 2 ·6H 2 O. The composite achieves a specific capacitance of 1554.6F/g at 1 A/g when used for supercapacitor electrode. After 5000 cycles, the capacitance retention rate can reach 80.4 %. Furthermore, the NiS 1.03 @Ni 7 S 6 /carbon//AC asymmetric supercapacitor could show high energy density of 41.2 Wh kg−1 at a power density of 750 W kg−1, and excellent cycling stability of 86.8 % capacitance retention after 10,000 cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] • Furfurylamine (FAM) was prepared from pineapple peel via chemobiocatalytic approach. • ChCl:FA:OA–H 2 O catalyzed pineapple peel to 183.3 mM FUR at 170 °C for 10 min. • HNND-AlaDH was created by expression of ω-transaminase and L -alanine dehydrogenase. • Bioamination of furfural into FAM with cheap L -alanine plus isopropylamine. • The yield was 0.58 g FAM/(g xylan in pineapple peel). Biobased furfurylamine (FAM) is a versatile platform molecule for producing additives, pharmaceuticals, and pesticides. Recombinant E. coli HNND-AlaDH was created by co-expressing L -alanine dehydrogenase (AlaDH) and mutated Aspergillus terreus ω-transaminase (HNND), aiming to convert furfural (FUR) into FAM using inexpensive L -alanine and isopropylamine as mixed amine donors. In ChCl:FA:OA (10 wt%), pineapple peel, bagasse, barley shell, peanut shell, and corn stalk could be efficiently transformed into FUR under 170 °C for 10 min. Pineapple peel produced a high titer of FUR (183.3 mM). Additionally, the viscosity, surface tension and polarity of ChCl:FA:OA were explored. The biomass-derived FUR was fully transformed to FAM by HNND-AlaDH with amine donor (1:1:1 of L -Ala/isopropylamine/FUR mol/mol/mol) within 300 min. Accordingly, the FAM productivity was 0.58 g/(g xylan in pineapple peel). This chemobiocatalytic strategy established through the combination of chemocatalysis and biocatalysis could be applied to convert renewable biomass into valuable organic amines. [ABSTRACT FROM AUTHOR]

Highlights • Potassium retention ratio decreases with the increase of gasification temperature. • Coal ash show a remarkable capacity to fixing potassium during biomass gasification. • Coal ash blending can effectively enhance the ash melting temperature of biomass. Abstract This study experimentally investigated the potassium fixation ability and ash fusion characteristics during the gasification of corn stalk coke blended with coal ash in CO 2 atmosphere. The ash samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). FactSage was also employed to calculate the components and quantities of solid and liquid phase. The results show that the ratio of potassium retained in the biomass ash decreases with the increase in the gasification temperature. In addition, the retention ratio increases with more coal ash added. The improvement of potassium retention ratio is due to the reaction of potassium with alumina/silica to form the solid/slag phase of the potassium aluminosilicates. On the other hand, the ash fusion temperatures of the blended ash are increased by adding the coal ash, compared with the biomass ash. The study confirms that coal ash is a potential additive for not only fixing potassium, but also increasing the ash fusion temperatures of easy-to-slagging biomass. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A tandem catalytic bed (TCB) was developed in an analytical pyrolyzer. • CeO 2 was effective in deoxygenating from acids, aldehydes and methoxy phenols. • The TCB of CeO 2 and HZSM-5 enhanced hydrocarbon yield to utmost 85%. • An effective H/C ratio of 0.7 was optimum for producing hydrocarbons in the TCB. • Mechanisms on co-pyrolysis of corn stover and LDPE in the TCB were discussed. Abstract The excessive oxygen content in biomass obstructs the production of high-quality bio-oils. In this work, we developed a tandem catalytic bed (TCB) of CeO 2 and HZSM-5 in an analytical pyrolyzer to enhance the hydrocarbon production from co-pyrolysis of corn stover (CS) and LDPE. Results indicated that CeO 2 could remove oxygen from acids, aldehydes and methoxy phenols, producing a maximum yield of hydrocarbons of 85% and highest selectivity of monocyclic aromatics of 73% in the TCB. The addition of LDPE exhibited a near-complete elimination of oxygenates, leaving hydrocarbons as the overwhelming products. With increasing LDPE proportion, the yield of aliphatics and the selectivity of BTX kept increasing. An optimum H/C eff of 0.7 was superior to that reported in literature. Mechanisms consisting of deoxygenation, Diels-Alder reactions, hydrocarbon pool and hydrogen transfer reactions were discussed extensively. Our findings provide an efficient method to produce high-quality biofuels from renewable biomass resources. [ABSTRACT FROM AUTHOR]

Highlights • A broader temperature deoxidization pretreatment during 200–390 °C was conducted. • The release characteristics and kinetic of oxygenated gas products were analyzed. • Different kinds of biomass had different optimum deoxidization temperature. Abstract With a first attempt of extension for torrefaction temperature aiming to reducing more oxygen, low temperature deoxidization of cellulose, hemicellulose, lignin, corn stalk and cotton stalk were performed at various temperatures (200, 230, 260, 290, 320, 350 and 390 °C) respectively. The deoxidization properties of both solid and gas products were investigated. As could be inferred from the results obtained that the main deoxygenation temperature range of cellulose, xylan, corn stalk and cotton stalk were 290–320 °C, 230–260 °C, 260–390 °C and 260–350 °C respectively. The deoxidation effect of lignin was not obvious during 200–390 °C, only 14.80% oxygen was removed at 390 °C. At lower temperature (200–320 °C), the oxygenated gas products dominated by CO 2 and H 2 O were mainly from hemicellulose. In the high temperature range (350–390 °C), cellulose deoxidation was mastery reaction and CO 2 was the main product. The release kinetic analysis of CO 2 and CO during 200–390 °C had been performed for the first time, and as could be inferred from the results obtained that the activation energies for CO 2 and CO release of cellulose, lignin, cotton stalk, corn stalk during low temperature deoxidization were 61.32, 38.41, 43.38, 38.62 kJ/mol and 120.62, 60.55, 83.24, 72.27 kJ/mol, respectively. The release activation energies of hemicellulose in the temperature ranges of 200–290 °C and 320–390 °C were 63.32 and 10.21 kJ/mol for CO 2 and 115.75 and 20.65 kJ/mol for CO respectively. [ABSTRACT FROM AUTHOR]

Highlights • Deoxygenation and decarbonization of corn stalks torrefaction were studied. • Solid, liquid (water and tar), and gaseous products were collected and analyzed. • Oxygen in the corn stalks migrated primarily into H 2 O, followed by CO 2 and CO. • Gas formation dominated the decarbonization of corn stalks torrefaction. • 7.05%-57.25% of oxygen and 3.31%–27.26% of carbon were removed from corn stalks. Abstract In this study, the torrefaction of corn stalk was performed at 200–290 °C for 30 min. The solid products (torrefied corn stalk), liquid products (water and tar), and gaseous products were collected and analyzed, and the migration of oxygen and carbon during torrefaction was discussed. Results showed that as the torrefaction temperature increased from 200 °C to 290 °C, the relative content of aromatic/aliphatic carbon (C C, C C, and C H) in the torrefied corn stalk increased from 55.66% to 69.90%, while the content of ether or hydroxyl/phenol groups (C OR) obviously decreased from 21.96% to 8.79%. This result was also confirmed by ultimate analysis, indicating that increasing in the torrefaction temperature resulted in a sharp decrease of the oxygen content and a gradual increase of carbon content of corn stalk. During the torrefaction process, oxygen of corn stalk was released in the form of CO 2 and CO in the gaseous products, and H 2 O and oxygen-containing compounds like acids and phenols in the liquid products. In the temperature range of torrefaction experiments, 7.05%-57.25% of oxygen in raw corn stalk migrated into the liquid and gaseous products in the form of H 2 O, followed by CO 2 and CO. Along with the deoxygenation process, a small amount of the carbon (3.31%–27.26%) from raw corn stalk was transferred into the gaseous products, followed by tar. These results indicated that the dehydration reactions and gas formation dominated the deoxygenation and decarbonization of corn stalk torrefaction, respectively. [ABSTRACT FROM AUTHOR]

Char in-situ (charis) obtained from corn stalk pyrolysis was evaluated as a catalyst to upgrade corn stalk pyrolysis vapors. A catalyst evaluation device was introduced to conduct the experiments. The effects of reaction temperature and charis dose on catalytic performances in biomass pyrolysis were evaluated. The results showed that the char in-situ had a remarkable effect on the pyrolysis products. Under the action of charis, the primary compounds of pyrolysis vapors were catalytically converted into phenolic products, such as phenol and 4-ethyl-phenol, while the acetic acid content was evidently reduced. The product selectivity was not dependent on the polar functional groups on the charis's surface according to the Fourier transform infrared (FTIR) results, but might have been dependent on the mesoporous structure and the basicity sites of the charis as well as the metallic species in the charis. A possible reaction mechanism for phenols production and acetic acid inhibition was proposed. [ABSTRACT FROM AUTHOR]

To study the release and transformation of fuel K during rapid pyrolysis of biomass, wheat straw, corn stalk and rice hull are pyrolyzed in a fixed-bed reactor system during 400–1000 °C, and weight measurement, elemental composition analysis, and chemical fractionation analysis are performed. The effects of fuel type, pyrolysis temperature, co-pyrolysis of different fuels, and water washing pretreatment are discussed. The results show that for all biomass fuels, the released K is far less than the water-soluble K and a sudden increase occurs in the fraction of ion-exchangeable K at 400 °C, whereas a significant increase happens in the fraction of insoluble K above 800 °C. Wheat straw releases less than 5% of K at 400 and 500 °C. As temperature rises, the K release increases abruptly and around 40% of K enters the gas phase at 1000 °C. Rice hull has a slow and linear K release with increasing pyrolysis temperature. Corn stalk has the lowest K release during 400–800 °C. Co-pyrolysis of wheat straw and rice hull reduce the K release at 1000 °C, and the biggest decrement is 0.76 mg g −1 . Water washing removes all the water-soluble K of corn stalk and part of ion-exchangeable K enters the gas phase during pyrolysis of the washed sample. Water washing decreases the K release from 2.77 to 0.18 mg g −1 at 1000 °C. [ABSTRACT FROM AUTHOR]

Although the study of co-pyrolysis of coal and biomass have dominated the primary chemicals production in the field of renewable energy utilization, it is still challenging for tar to become lighter. Here we design a set of experimental programs, including the individual pyrolysis, staged catalytic pyrolysis and the co-pyrolysis of physical mixture to investigate the effects of feedstock arrangement on pyrolysis product characteristics. We demonstrated that the experimental results of co-pyrolysis of physical mixture indicate some synergetic effects on pyrolysis products rather than the superposition of individual pyrolysis process of lignite and straw, thus the subsequent tar composition and char structure were characterized. Based on the existing catalytic cracking mechanism, we obtained the staged catalytic pyrolysis have a more pronounced catalytic cracking effect on heavy components compared with the co-pyrolysis of physical mixture, which enables the formation of light oil, naphthalene oil, tar with the lower oxygen content and higher benzene. The Raman spectra of char in catalytic bed exhibits the total peak area of char and the amount of large aromatic ring formed by polymerization increased with the increase of pyrolysis temperature. Simultaneously, the role of catalytic cracking of straw char was stronger than that of lignite char remarkably has been confirmed from the point of view of the chemical structure of char. [ABSTRACT FROM AUTHOR]

Modeling of lignocellulosic biomass pyrolysis processes can be used to determine their key operating and design parameters. This requires significant amount of information about pyrolysis kinetic parameters, in particular the activation energy. Thermogravimetric analysis (TGA) is the most commonly used tool to obtain experimental kinetic data, and isoconversional kinetic analysis is the most effective way for processing TGA data to calculate effective activation energies for lignocellulosic biomass pyrolysis. This paper reviews the overall procedure of processing TGA data for isoconversional kinetic analysis of lignocellulosic biomass pyrolysis by using the Friedman isoconversional method. This includes the removal of “error” data points and dehydration stage from original TGA data, transformation of TGA data to conversion data, differentiation of conversion data and smoothing of derivative conversion data, interpolation of conversion and derivative conversion data, isoconversional calculations, and reconstruction of kinetic process. The detailed isoconversional kinetic analysis of TGA data obtained from the pyrolysis of corn stalk at five heating rates were presented. The results have shown that the effective activation energies of corn stalk pyrolysis vary from 148 to 473 kJ mol −1 when the conversion ranges from 0.05 to 0.85. [ABSTRACT FROM AUTHOR]

The management and final disposal of agro-industrial wastes are one of the main environmental problems. Due to the presence of silica in some agricultural by-products, it is possible to convert waste into materials with advanced properties. This contribution was aimed to extract and characterize silica materials from various feedstocks including sugarcane bagasse (SCB), corn stalk (CS), and rice husk (RH). Silica yields of 17.91%, 9.39%, and 3.25% were obtained for RH, CS, and SCB. On the other hand, the textural properties show that the siliceous materials exhibited mesoporous structures, with high silica composition in the materials due to the formation of crystalline SiO 2 for SCB and CS and amorphous for RH. XPS spectra demonstrate the presence of Si4+ species in RH, and Si3+/Si4+ tetrahedra in SCB and CS. [Display omitted] • High purity silica was synthesized from agricultural waste. • The thermochemical process used is low-cost and environmentally sustainable. • The surface characteristics of biosilica are related to the biomass structure. • CS and RH silica presented better BET area and lower crystallinity than SCB silica. • The properties of CS biosilica are attractive for its valorization and application. [ABSTRACT FROM AUTHOR]

The development of corn stalk-based carbon materials presents a promising approach towards sustainable energy storage and agricultural waste valorization. However, the impact of varying portions of the cornstalk on electrochemical performance has been previously disregarded. An innovative strategy is proposed herein for the preparation of supercapacitor electrodes from different fractions of the same corn stalks via hydrothermal carbonization and KOH activation. The potential of the resulting composition, morphology structure, and electrochemical performance was analyzed to evaluate its suitability for supercapacitor electrodes. The capacity of CC-carbons could reach up to 133.32 F g−1 at 1 A g−1 and exhibit excellent electrochemical properties owing to their highly specific surface area (812.84 m2 g−1) in combination with their abundant active sites. Moreover, the leaf blade (LB) was found unsuitable for preparing porous carbon. The results further revealed that the high lignin content increased the material's defects and active sites. Additionally, inorganic components present in raw materials may remain in the activated carbons in the form of ash through mineralization reactions, thereby affecting pore formation and charge ion transport. The outcomes of this study provide a novel perspective on the high-value utilization of corn stalks. [Display omitted] • Activated hydrochar for supercapacitor electrode from different cornstalk fractions. • High lignin content was prone to increase the defects and active sites. • Corncob and stem-skin were prone to form abundant pores due to their smooth surface. • Ash remained in activated carbons affected pore formation and ion transport. • High temperature treatment negatively impacted electrochemical performance. [ABSTRACT FROM AUTHOR]

Biomass densification impacts pretreatment efficacy and subsequent biochemical conversion to biofuels and other biobased chemicals. Pelleted corn stover was used to evaluate the soaking in aqueous ammonia (SAA) pretreatment efficacy at high solid loadings with reductions ammonia concentration, temperature, and pretreatment time. Pretreatment resulted in 70% greater delignification of stover pellets than loose stover. Glucose yields from enzymatic hydrolysis were 49% higher for the pelleted stover and yields did not change with a twofold increase in pretreatment solid loadings. Hydrolysis yields were modeled as a function of pretreatment conditions and the developed model predicted a maximum 24-h hydrolysis glucose yield of 96% at a pretreatment temperature of 60 °C, for 4 h, with 18% ammonia. Pretreatment severity can still be reduced while maintaining 90% or higher yields with different combinations of temperature, time, and ammonia concentration. Temperature was the most important pretreatment parameter within the design space for achieving high glucose yields. FTIR and SEM analysis of SAA-pretreated corn stover pellets illustrated that the pelleting process increases pretreatment efficacy by modifying the biomass structure, disrupting the lignin-hemicellulose linkages, and partially removing lignin. Using pelleted biomass can reduce the required severity of SAA-pretreatment while still producing glucose yields above 90%. Using pelleted corn stover as a biorefinery feedstock has potential to lower pretreatment costs in addition to the improved handling and transportation. [ABSTRACT FROM AUTHOR]