Biomass Mixtures Research Articles

Evaluation of biomass-derived solvents and protic ionic liquids as lignin-selective pretreatment agents for poplar fractionation

In this study, mixtures of protic ionic liquids (PILs) and biomass derived solvents; gamma-valerolactone (GVL), levulinic acid (LA) and H2O at different weight percentages were used to pretreat poplar. GVL addition up to 60% enhanced delignification in biomass that is subjected to MEAHSO4-GVL-H2O; cellulose content of the biomass increased from 42% to 74% with 67% lignin removal. Aqueous solution of LA used for the first time to pretreat a biomass performed better than TEAHSO4-H2O. LA-H2O at 80%-20% resulted in 70% lignin extraction and preserved 89% of the cellulose in the structure which were also verified with SEM, FTIR and XRD analysis displaying clear cellulose macrofibers, lignin signals with lower intensities and higher biomass crystallinity, respectively. Accordingly, enzymatic conversion of LA pretreated poplar released 43 g/L glucose at 10% substrate loading. Findings showed the potentials of biomass derived solvents, GVL and LA and PILs and their aqueous mixtures to selectively deconstruct poplar.

Effect of the reactive blend conditions on the thermal properties of waste biomass and soft coal as a reducing agent for silicon production

The reducing agents used for industrial silicon production often suffer from high coking and high consumption of coal, which is associated with high energy consumption, low efficiency, and low output. To overcome these issues, a mixture of biomass and soft coal (SC) was investigated as a new type of carbonaceous reducing agent for industrial silicon production. In this paper, TGA, SEM, XRD, and Raman spectroscopy were used to study the effects of the different proportions of banana peel (BP) and SC on the activity of carbon materials under different fermentation conditions and molding times. The results showed that the pyrolysis temperatures of fermented mixed carbon materials were decreased by 38–55 °C, and the activation energy was reduced by 68–74%. The pyrolysis temperature and activation energy of moldy mixed carbon materials decreased by 49–94 °C and 46–51%. There was a significant synergistic effect between the carbon materials, and the reactivity of SC was increased. The reduction of silica by fermented carbon materials was better than moldy carbon materials; therefore, the fermentation conditions were more conducive to the preparation of carbonaceous reducing agents for the production of industrial silicon.

Green mechano-chemical processing of lignocellulosic biomass for lignin recovery

Lignin extraction from biomass is heavily dependent on chemical processes that are harmful to the environment and the quality of the recovered lignin. Ionic liquid solvents are some of the latest solutions in green processing; however, their implementation for lignin recovery is limited by their high cost, typically high loadings requirements, and long processing times. To overcome these issues, in this study, high loadings of mixed hardwood flour (MHF) were processed with 1-butyl-3-methylimidazolium chloride (BmimCl) in a batch mixer. The rheological behaviour of the biomass and ionic liquid mixture was studied. The mixture had a high complex viscosity (approx. 107 Pa s) at low shear rates and displayed pronounced shear thinning behavior at 50 wt% MHF loading. A 22 factorial design was also implemented to study the effects of MHF solid loading amount and residence time on lignin extraction yield. A maximum yield of 36.6% was obtained at the maximum solid loading amount and residence time (50 wt% and 45 min, respectively). The extracted lignin samples were also characterized in comparison with commercial Kraft lignin and lignosulfonate. The novelty of this study is the successful lignin extraction at high solid loadings and shorter residence times compared to previous biomass pre-treatments with ionic liquids that employs low solid loading and long processing times.

BIOMASS-BASED SOIL IN ECOLOGICAL AGRICULTURE: CHARACTERISTICS AND WHEAT GRAINS DEVELOPMENT TRENDS

The biomass-based soils are used in the ecological agriculture, being already proposed in sustainable organic production systems with reduced costs for assuring the good cropping productivity, and also high quality of the crops. For the elimination of the synthetic inorganic fertilizers’ utilization on soil, the use of certain types of residual biomass in mixture with the reference soil was proposed as they have a positive impact on the adsorption and absorption of nutrients and water for the nutrition of plants. The aim of this paper is to present four mixtures of reference soil and residual biomass, considered as biosoil used as support for development of wheat seeds. These biosoils were characterized in terms of real density, actual and potential pH, content of total organic carbon, humus, exchangeable calcium, total and available nitrogen and phosphorus, and the trends of grain seeds germination and plants growth were registered in association with the evolution of soil pH for a period greater than a month. The results encourage the use of these biosoils (mixtures of soil with residual biomass) as support for plants cropping.

Modelling and Statistical Analysis of Plastic Biomass Mixture Co-Gasification

Modelling and Statistical Analysis of Plastic Biomass Mixture Co-Gasification

H2-enriched gaseous fuel production via co-gasification of an algae-plastic waste mixture using Aspen PLUS

Thermo-chemical conversion of biomass is a promising technological alternative for producing renewable fuel and reducing waste disposal. This simulation study includes the first attempt to perform co-gasification of algae-plastic waste for H2-enriched gaseous fuel production. An Aspen Plus-based simulation model was developed to evaluate the influence of gasifier temperature and equivalence ratio on the syngas composition, heating value, and carbon conversion efficiency. Simulation results indicated that the rise in gasifier temperature favoured the H2 and CO formation, and further, plastic loading enhanced H2 production to a greater extent. It was observed that the product (H2 and CO) yield decreased significantly with the rise of the equivalence ratio. At the same time, CO2 formation increased due to more carbon conversion after enhancing O2 content in the gasifier. It was also noticed that the synergy of biomass and plastic waste significantly enhanced H2 content and improved heating value, leading to a produced energy-efficient gaseous product. It is inferred that H2-enriched feedstock acts as an H2 donor to the H2 deficient biomass. Based on the findings, consistency in the simulation results was observed compared with the previous literature. Hence, a mixture of biomass and plastic waste favours obtaining an energy-efficient renewable fuel that could be utilized for different applications.

Component additivity model for plastics—biomass mixtures during hydrothermal liquefaction in sub-, near-, and supercritical water

SummaryWe produced oils via hydrothermal liquefaction (HTL) of binary mixtures of biomass components (e.g., lignin, cellulose, starch) with different plastics and binary mixtures of plastics themselves. Cellulose, starch, and lignin demonstrated synergistic interactions (i.e., enhanced oil yields) with the plastics tested (polypropylene, polycarbonate, polystyrene, and polyethylene terephthalate). Polystyrene exhibited synergy during HTL with the three other plastics as did polypropylene during HTL with PET or PC. We used the experimental results to develop the first component-additivity model that predicts the oil yields from HTL of biomass-plastic and plastic-plastic mixtures. The model accounts for interactions among and between biomass components and plastic components in sub-, near-, and supercritical water. The model predicts 88% of 48 published oil yields from HTL experiments with mixtures containing plastics to within 10 wt%.

Influence of Molding Technology on Thermal Efficiencies and Pollutant Emissions from Household Solid Fuel Combustion during Cooking Activities in Chinese Rural Areas

Resident combustion of solid fuel has been widely acknowledged as a high potential for pollutant reduction. However, there is a marked asymmetry between more pollutant emission and less burned volatiles of biomass and coal in the combustion process. To study the solid fuel optimum combustion form in a household stove, both the pollution reduction and energy efficient utilization of crop straws and coals were investigated. Taking the molding pressure and clay addition ratio as variable process conditions, the research of bio-coal briquette (made from the mixture of anthracite and biomass) was implemented in the range of 15~35 MP and 5~15%, respectively. Biomass and coal work complementarily for each other’s combustion property development. In particular, the pyrolysis gas produced by biomass low-temperature devolatilization is featured with low ignition point and is distributed in the bio-coal briquette. Its own combustion provides energy for anthracite particle combustion. Consequently, a positive effect was identified when bio-coal briquettes were used as residential fuel, and further improvement manifested in reducing more than 90% of particle matter (PM) and achieving about twice the thermal efficiencies (TEs) compared with the mass-weighted average values of coal briquettes and biomass briquettes. 88.8 ± 11.8%, 136.7 ± 13.7% and 81.4 ± 17.7% more TEs were provided by wheat straw–coal briquettes, rice straw–coal briquettes and maize straw–coal briquettes. 93.3 ± 3.1% (wheat straw–coal), 97.6 ± 0.2% (rice straw–coal) and 90.4 ± 2.2% (maize straw–coal) in terms of PM2.5 emission factors (EFs) was reduced. For bio-coal briquette, a 25 MPa and 10% addition were determined as the optimum molding pressure and clay addition ratio. Bio-coal briquettes with higher TEs and lower PM EFs will bring about substantial benefits for air quality promotion, human health and energy saving.

Co-combustion of RDF and biomass mixture with bituminous coal: a case study of clinker production plant in Egypt

Co-combustion of RDF and biomass mixture with bituminous coal: a case study of clinker production plant in Egypt

The effects of continuous press speed and conditioning time on the particleboard properties at industrial scale

Effects of continuous press speed (580 and 600 mm/s) and conditioning time (0 and 72 h) on some physical and mechanical properties and formaldehyde content of particleboards were investigated. The 18 mm thick boards were manufactured using urea-formaldehyde, with a 50% pine, 40% oak wood, and 10% poplar biomass mixture of the wood materials. According to the results of the unconditioned samples, the density, modulus of rupture (MOR), moisture content (MC), thickness swelling (TS), and water absorption (WA) were increased 0.8%, 4.4%, 0.4%, 4.4%, and 5.5% when press speed increased from 580 to 600 mm/s, while thickness, modulus of elasticity (MOE), internal bond (IB), surface soundness (SS), and free formaldehyde (FF) were decreased 0.3%, 4.9%, 2.4%, 10.6%, and 21.1%, respectively. On the contrary to the results of unconditioned samples, MOE and SS were increased 1% and 1.4%, respectively, and WA was decreased 3.5% with the increase in press speed when samples were conditioned for 72 h. Free formaldehyde content was the most prominent parameter influenced by the increase in press speed both for the unconditioned and 72 h conditioned samples.

A CO2 sink in a tropical coastal lagoon impacted by cultural eutrophication and upwelling

Tropical coastal lagoons are recognized as very productive ecosystems. However, very little is known on the direction and magnitude of their CO2 exchange with the atmosphere. We report on air-water CO2 fluxes and carbon concentrations in a tropical shallow lagoon impacted by cultural eutrophication. During two contrasting field surveys, the first in Nov. 2019 during dry conditions and the second in Feb. 2020 during wet summer condition and intrusion of coastal upwelling waters inside the lagoon. At both seasons, spatial in situ monitoring of temperature, salinity and partial pressure of CO2 (pCO2) reveal the presence of undersaturated pCO2 values (between 60 and 300 ppmv), uptake of atmospheric CO2 (between 0.9 and 9.2 mmol m−2 h−1) inside the lagoon, at salinities between 10 and 32. Temporal monitoring data at the mouth of the lagoon throughout tidal cycles revealed the entrance of cold South Atlantic Central Waters (SACW) from the Cabo Frio's upwelling during flood tides in Feb. 2020 but not in Nov. 2019. The cold SACW with temperatures down to 16 °C were supersaturated in CO2 (pCO2 about 520 ppmv) and a CO2 source to the atmosphere (between 0.2 and 1.4 mmol m−2 h−1). During mixing of this SACW in the most marine compartment of the lagoon, the biological CO2 uptake and enhanced autotrophy overcame the effect of degassing SACW waters by heating. For both cruises, a consistent landward trend consisted in a decrease in pCO2 and dissolved inorganic carbon (DIC) mirrored by an increase of dissolved organic carbon (DOC) (between 4.6 and 19.8 mg L−1), particulate organic carbon (POC) (between 3.3 and 12.3 mg L−1), and chlorophyll a (Chl a) (between 7.6 and 217 μg L−1). POC, DOC and Chl a and the POC:Chl a ratio suggest that, organic carbon in the lagoon is a mixture of phytoplankton biomass produced in the lagoon, domestic wastewater loaded from multiple point sources and pulsated inputs from small rivers. Our study in the Saquarema lagoon confirms recent works in other densely populated tropical coastal ecosystems, revealing that eutrophication enhances the autotrophy of shallow tropical lagoons, making them act as efficient factories for atmospheric CO2 absorption and organic carbon storage in sediments and export to the ocean.

Investigation of the effects of pretreatment on the elemental composition of ash derived from selected Nigerian lignocellulosic biomass

Lignocellulosic biomass is an important source of renewable energy and a potential replacement for fossil fuels. In this work, the X-ray fluorescence (XRF) method was used to analyze the elemental composition of raw and pretreated lignocellulosic biomass of cassava peels, corn cobs, rice husks, sugarcane bagasse, yam peels, and mixtures of cassava peels and yam peels, corn cobs and rice husks and all five biomass samples combined. The influence of particle size on elemental properties was investigated by screening the selected biomass into two size fractions, of an average of 300 and 435 µm, respectively. The total concentration of Mg, Al, Si, P, S, Cl, Ca, Ti, Cr, Mn, Fe, Co, Cu, Zn, Sn, Ni, Br, Mo, Ba, Hg, and Pb were determined for each of the biomass samples before and after the different pretreatments adopted in this study. From the results of the analysis, there was a significant reduction in the concentration of calcium in all the analyzed biomass after the alkaline pretreatment with rice husks biomass having the lowest concentration of 66 ppm after the alkaline pretreatment. The sulfur content of the acid pretreated biomass increased considerably which is likely due to the sulfuric acid used for the acid pretreatment. The fact that a mixture of biomass feedstock affects the properties of the biomass after pretreatment was validated in the mixed biomass of cassava peels and yam peels biomass as an example. The concentration of Mg in the mixed biomass was 1441 ppm but was 200 ppm and 353 ppm in individual cassava peels and yam peels respectively. The results of this study demonstrated that pretreated mixtures of biomass have varied elemental compositions, which could be an important factor affecting downstream processes, especially if a hybrid feedstock is used in a large-scale application.

Combined positive matrix factorization (PMF) and nitrogen isotope signature analysis to provide insights into the source contribution to aerosol free amino acids

Free amino acids (FAAs) are particularly interesting because they play an important role in the atmosphere, but their origins are not well understood. This study measured the concentrations of FAAs and water-soluble ions as well as δ15N values of Glycine (Gly) in total suspended particle (TSP) samples collected at Nanchang in 2017. The correlation of total FAAs concentrations with meteorological conditions and atmospheric oxidants showed that secondary formation processes could be an important contribution sources for FAAs in the atmosphere. Moreover, the concentrations of FAAs in aerosols may be affected by the wind directions and the regions where air mass passed. The correlations of FAAs with water-soluble ions and PMF analysis indicated that the concentration of FAAs in Nanchang aerosols was influenced by agricultural activities and dust sources, mixture of natural origins and biomass burning and mixture of secondary formation process and biomass burning. Interestingly, we also found that coal combustion and vehicle emission are not the sources for atmospheric FAAs. Based on δ15N values of free Gly, a Bayesian model was performed to obtain the individual fractional contributions of free Gly from major sources (natural and biomass burning sources) to aerosol Gly. Subsequently, applying fractional contributions of free Gly from biomass burning obtained by Bayesian model to the analysis result of PMF, the overestimated of the contribution of secondary formation processes and natural sources to atmospheric FAAs concentration caused by biomass burning source could be excluded. Our findings suggest that combining δ15N values of free Gly and PMF analysis could provide further information on the sources of atmospheric FAAs.

Innovative Polycomposite Fertilizer Obtained by Recycling and Processing Three Organic Wastes

The paper aims at testing an innovative organic fertilizer obtained from waste by processing a mixture of marine algae biomass, sewage municipal sludge and farmyard manure. Design of this polycomposite fertilizer is based on adequate conceptual and experimental models by taking into account the complex interactions among these three biomasses. In the first step a detail physico-chemical analysis has been performed on the composition of the three raw materials and also on the soil. In the second phase similar analyses have been carried out on representative samples of soil treated with the compost as compared with untreated soil samples. Analytical methods applied were FT-IR spectroscopy in correlation with organic/inorganic and total carbon (TOC/TIC/TC) analysis. The efficiency of applying this compost on the field at large scale has been assessed by means of fatty acid content of the oleaginous plants cultivated. Based on correlation between production quality and chemical composition of the composted soil, the optimal proportions of the mixture of the three organic wastes will be selected for designing an eco-friendly fertilizer able to improve agrochemical properties of the soil.

Contribution of deep-sourced carbon from hydrocarbon seeps to sedimentary organic carbon: Evidence from radiocarbon and stable isotope geochemistry

Sulfate-driven anaerobic oxidation of methane (AOM) limits the release of methane from marine sediments and promotes the formation of carbonates close to the seafloor in seepage areas along continental margins. It has been established that hydrocarbon seeps are a source of methane, dissolved inorganic carbon, and dissolved organic carbon to marine environments. However, questions remain about the contribution of deep-sourced carbon from hydrocarbon seeps to the sedimentary organic carbon pool. In this study, we analyzed carbon quantity, radiocarbon content (as percent modern carbon, pMC), stable carbon isotopic compositions (as δ13C) of organic matter enclosed within seep carbonates from the Gulf of Mexico and the South China Sea to assess if sediment organic matter may be used as a proxy for methane seepage intensity. The δ13C values of organic matter (δ13Corg) exhibited a large range from −81.4‰ to −23.9‰. Radiocarbon contents of the carbonate-bound organic matter in seep carbonates ranged from 6% to 28% pMC, suggesting organic matter of the carbonates is a mixture of marine particulate organic matter (δ13C = −22‰ VPDB and 90% modern carbon) and biomass resulting from methane oxidation (assumed to have 0% modern carbon). Assuming constant productivity in the marine photic zone, it is proposed that seepage intensity and duration are the most important factors controlling the contribution of methane-derived carbon to the sedimentary column. This study reinforces the potential for using δ13C values of organic carbon to discern methane-rich environments in ancient sedimentary environments where authigenic carbonate is not present and to constrain the record of AOM through Earth history.

Composition of gas produced from the direct combustion and pyrolysis of biomass

Biomass is considered to be one of the most easily available and high-potential renewable power sources. Pyrolysis and combustion are the most common ways of utilizing biomass. A complex multiple-criteria analysis to identify the most promising technology of using various types of biomass has never been previously performed. The study is focused on comparing two typical techniques of utilizing agricultural and forestry biomass for bioenergy and valorization. In this paper, the direct combustion and pyrolysis of biomass were experimentally studied. The environmental and energy performance parameter of the investigated processes were determined for separate biomass components (leaves, straw, sawdust) and a group of mixtures from them. It was established that the biomass mixtures combustion has better environmental characteristics. Thus, the main anthropogenic emissions decreased by 8–66%. In addition to that, the pyrolysis of a biomass mixture from a group of components has a 30% higher yield of combustible gases. The analysis of relative efficiency indicators of two processes where biomass was used as an energy resource showed that a biomass-derived composite fuel is more efficient than its individual components.

Optical and Microphysical Properties of Aged Biomass Burning Aerosols and Mixtures, Based on 9-Year Multiwavelength Raman Lidar Observations in Athens, Greece

Mean optical and microphysical aerosol properties of long-range transported biomass burning (BB) particles and mixtures are presented from a 9-year (2011–2019) data set of multiwavelength Raman lidar data, obtained by the EOLE lidar over the city of Athens (37.58° N, 23.47° E), Greece. We studied 34 aerosol layers characterized as: (1) smoke; (2) smoke + continental polluted, and (3) smoke + mixed dust. We found, mainly, small-sized aerosols with mean backscatter-related (355 nm/532 nm, 532 nm/1064 nm) values and Ångström exponent (AE) values in the range 1.4–1.7. The lidar ratio (LR) value at 355 nm was found to be 57 ± 10 sr, 51 ± 5 sr, and 38 ± 9 sr for the aerosol categories (1), (2), and (3), respectively; while at 532 nm, we observed LR values of 73 ± 11 sr, 59 ± 10 sr, and 62 ± 12 for the same categories. Regarding the retrieved microphysical properties, the effective radius (reff) ranged from 0.24 ± 0.11 to 0.24 ± 0.14 μm for all aerosol categories, while the volume density (vd) ranged from 8.6 ± 3.2 to 20.7 ± 14.1 μm−3cm−3 with the higher values linked to aerosol categories (1) and (2); the real part of the refractive index (mR) ranged between 1.49 and 1.53, while for the imaginary part (mI), we found values within 0.0108 i and 0.0126 i. Finally, the single scattering albedo (SSA) of the propped particles varied from 0.915 to 0.936 at all three wavelengths (355–532–1064 nm). The novelty of this study is the provision of typical values of BB aerosol properties from the UV to the near IR, which can be used in forecasting the aerosol climatic effects in the European region.

Will mixing rule or chemical reactions dominate the ash behavior of biomass mixtures in combustion processes on laboratory and pilot scales?

Mixing biomasses has a good potential to solve operational problems in thermochemical valorization processes related to ash behavior. Chemical reactions within the ash of the blend, and not only a mixing effect without reaction, need to take place to form new solid phases in the mixture at the expense of getting rid of the problematic liquid one to decrease the slagging tendency. The present work focuses on assessing the presence of a chemical reaction in comparison with a simple mixing effect within the ash of mixtures of wheat straw - oak bark biomass and ash in two laboratory setups and in a fixed and in a moving bed pilot combustion reactors. The operating conditions were varied to study their effects on the reactivity of the ash within the mixtures. This aimed to optimize the ash reactivity and to assess the capabilities of the laboratory test to predict the ash behavior in pilot-scale reactors.Mixing without reaction effect was more evident when mixtures of biomass were used on both laboratory and pilot scales. In this case, the simple mixing rule was able to simulate the general ash behavior of biomass mixture to a certain extent that exact prediction was always limited by the presence of certain chemical reactions. However, chemical reactions effect was dominant when mixtures of ash of biomass were applied as feedstock. Solid crystalline phases K2Ca2Si2O7 and K2Ca6Si4O15 were the direct end products of these chemical reactions. Their relative proportion was inversely proportional to the problematic amorphous phase in the final ash. Hence, optimizing the blend proportion to increase their concentrations has the potential to solve slagging problematic. These two compounds were mostly stable at 1000 ℃, at which equilibrium was reached after 6 h. However, they existed at a lower proportion at 850℃ and disappeared at 1200℃. The developed laboratory pellet test was also able to predict very efficiently the pilot ash behavior of both individual biomasses and their mixture in terms of crystalline and amorphous composition and proportion along with agglomeration distribution.

Lignin-Mediated Preparation of Hierarchical ZSM-5 Catalysts and Their Effects in the Catalytic Co-pyrolysis of Softwood Biomass and Low-Density Polyethylene Mixtures

Lignin-Mediated Preparation of Hierarchical ZSM-5 Catalysts and Their Effects in the Catalytic Co-pyrolysis of Softwood Biomass and Low-Density Polyethylene Mixtures

EFFECT OF BIOMASS ADDITION BEFORE SEWAGE SLUDGE PYROLYSIS ON THE PERSISTENCE AND BIOAVAILABILITY OF POLYCYCLIC AROMATIC HYDROCARBONS IN BIOCHAR-AMENDED SOIL

There is a lack of studies dealing with the effects of co-pyrolyzed biochars produced from different materials on the persistence of polycyclic aromatic hydrocarbons (PAHs). This research aimed to determine the persistence (based on extractable Ctot) and bioavailability (based on freely dissolved content, Cfree) of PAHs in soil amended with biochar derived from sewage sludge (SL) or a mixture of SL and biomass (SLW). Biochars produced at 500, 600, and 700 °C were applied to the soil (podzolic loamy sand) at a rate of 2% (w/w) and incubated for 180 days. The content and changes of PAHs differed between the experiment with SL, SL-derived biochar, and SLW-derived biochar. In the soil with the SLW-derived biochar, the losses of Ctot Σ16 PAHs were lower (between 13 and 38%) than in the soil with the SL-derived biochar (from 27 to 74%). Compared to Ctot, a completely different trend was observed for Cfree PAHs. The decrease of Cfree PAHs in the soil with the SLW-derived biochar was higher than or similar (from 4 to 18%) to the losses of Cfree PAHs in the soil with the addition of the SL-derived biochar. The differences between the individual treatments resulted from the difference in the physical and chemical properties of the biochars, which affected the persistence and bioavailability of the studied compounds.