Elemental Composition Of Biomass Research Articles

Seeds exhibit the most stable elemental composition with nitrogen addition in an Inner Mongolian grassland

Variation in biomass elemental composition of grassland plants may have important implications for ecosystem functioning in response to global change. However, relevant studies have mostly focused on variation of nitrogen (N) and phosphorus (P) concentrations in plant leaves, while few studies have evaluated other elements and plant organs of grassland species. Here, we examined the effects of N addition on multi-element concentrations, and analyzed their patterns across different organs (leaf, stem, root and seed) of five plant species in a steppe community of the Inner Mongolian grassland. Our results showed that seeds exhibited the most stable elemental composition with N addition, and that manganese (Mn) and iron (Fe) concentrations were substantially more variable than macro-elements in response to N addition. In particular, we identified a set of significant negative relationships between elemental concentrations and their corresponding CVs (coefficients of variation) for all plant organs as a whole and for each individual organ. We further found that changes in soil pH and the availability of soil nutrients contributed mostly to variation in the biomass elemental composition of major plants in this community. These findings are important for accurately assessing the effects of N deposition on the biochemical cycling of nutrient elements in grassland ecosystems, and provide critical clues for developing effective approaches to adaptively managing grassland resources as well as mitigating the impact of global change on the dryland ecosystems in the Mongolia Plateau.

Kinetic and elemental characterization of HAP-based high-rate partial nitritation/anammox system orienting stability and inorganic elemental requirements

Anammox-based processes are attractive for biological nitrogen removal, and the combination of anammox and hydroxyapatite (HAP) is promising for the simultaneous removal of nitrogen and phosphorus from wastewater. However, the kinetics of one-stage partial nitritation/anammox (PNA) in which ammonia-oxidizing bacteria (AOB) and anammox bacteria (AnAOB) exist in a reactor are poorly understood. Moreover, inorganic elements are required to promote microbial cell synthesis and growth; therefore, monitoring of elements to prevent the limitation and inhibition of the process is critical. The minimum amounts of inorganic elements required for a one-stage PNA process and the elemental flow remain unknown. Therefore, in this study, kinetics, stoichiometry, and element flow in the long-term, high-rate, continuous, one-stage HAP-PNA process with microaerobic granular sludge at 25 °C were determined using process modeling, parameter estimation, and mass balance. The biomass elemental composition was determined to be CH2.2O0.89N0.18S0.0091, and the biomass yield (Yobs) was calculated to be 0.0805 g/g NH4+-N. Therefore, a stoichiometric reaction equation for the one-stage HAP-PNA system was also proposed. The maximum specific growth rate (μm) of AnAOB and AOB were 0.0360 and 0.0982 d−1 with doubling times of 19 and 7.1 d, respectively. Finally, the elemental requirements for stable and high-rate performance were determined using element flow analysis. These findings are essential for developing the anammox-based process in a stable and resource-efficient manner and determining engineering applicability.

Use of Artificial Neural Networks to Model Biomass Properties of Miscanthus (Miscanthus × giganteus) and Virginia Mallow (Sida hermaphrodita L.) in View of Harvest Season

Miscanthus and Virginia Mallow are energy crops characterized by high yields, perenniality, and low agrotechnical requirements and have great potential for solid and liquid biofuel production. Later harvest dates result in lower yields but better-quality mass for combustion, while on the other hand, when biomass is used for biogas production, harvesting in the autumn gives better results due to lower lignin content and higher moisture content. The aim of this work was to determine not only the influence of the harvest date on the energetic properties but also how accurately artificial neural networks can predict the given parameters. The yield of dry matter in the first year of experimentation for this research was on average twice as high in spring compared to autumn for Miscanthus (40 t/ha to 20 t/ha) and for Virginia Mallow (11 t/ha to 8 t/ha). Miscanthus contained 52.62% carbon in the spring, which is also the highest percentage determined in this study, while Virginia Mallow contained 51.51% carbon. For both crops studied, delaying the harvest date had a positive effect on ash content, such that the ash content of Miscanthus in the spring was about 1.5%, while in the autumn it was 2.2%. Harvest date had a significant effect on the increase of lignin in both plants, while Miscanthus also showed an increase in cellulose from 47.42% in autumn to 53.5% in spring. Artificial neural networks used to predict higher and lower heating values showed good results with lower errors when values obtained from biomass elemental composition were used as input parameters than those obtained from proximity analysis.

The role of biomass elemental composition and ion-exchange in metal sorption by algae

The use of macroalgae, microalgae and cyanobacteria for metal sorption has been widely reported. Still, there are no studies allowing a direct comparison of the performance of these biomasses, especially while evaluating metal competition. The simultaneous sorption of Co2+, Cu2+, Ni2+ and Zn2+ present in a multi-elemental solution by six macroalgae, two microalgae and three cyanobacteria was evaluated. Brown macroalgae were shown to be the most promising biosorbent, with Undaria pinnatifida having a total metal sorption capacity of 0.6 mmol g−1. Overall, macroalgae performed better than microalgae, followed by cyanobacteria. Carboxyl groups were identified as being the main functional groups involved in metal sorption, and all biomass samples were found to be selective to Cu2+. This was linked not only to its higher complexation constant value with relevant functional groups when compared to the remaining metals, but also the Irving-Williams series. The release of K+ and Ca2+ to the aqueous solution during the metal sorption was followed. The obtained results suggest they are readily exchanged with metals in the solution, indicating the occurrence of an ion-exchange mechanism in metal sorption by most biomass. Red macroalgae are an exception to the reported trends, suggesting that their metal sorption mechanism may differ from the other biomass types.

Concept of Batch and Fed-Batch Cultures of Yarrowia lipolytica as a Valuable Source of Sterols with Simultaneous Valorization of Molasses and Post-Frying Rapeseed Oil

Food byproduct streams can potentially be transformed into value-added products such as microbial lipids in bioprocesses based on the non-conventional Yarrowia yeast. The effect of culture conditions of Y. lipolytica KKP 379 wild strain in waste media on the efficiency of lipid accumulation, fatty acid composition, presence of selected sterols, yield and elemental composition of biomass has been studied. Batch and fed-batch bioreactor cultures were carried out in media with molasses hydrolysate (MH) and post-frying rapeseed oil. It was determined that biomass grown in MH contained more minerals than in medium with rapeseed post-frying oil. Considering the PDSC study, the Tmax of oxidation induction ranged from 10.04–26.36 min for the analyzed samples. The biomass from fed-batch cultures with MH had the highest total sterol content (68.40 mg/goil), dominated by ergosterol at 60.16 mg/g. Feeding with post-frying rapeseed oil with new doses of mineral medium promoted maintaining the cellular lipid content at a high level (30.75–31.73%) for 50 h, with maximum yield at 37.50%. The results of the experiment showed that the cellular lipid accumulation efficiency of Y. lipolytica yeast and the content of sterols in the cell membrane can be manipulated by selecting waste substrates and culture mode.

Modelling Biomass Elemental Composition: a Neurofuzzy Approach

Due to growing concerns about energy security and environmental impacts, biomass has been considered as a viable renewable energy source. However, the development of biomass combustion systems that can process biomass from different sources requires an accurate understanding and prediction of the major properties of biomass. Although adaptive neuro-fuzzy inference systems (ANFIS) have been deployed in the prediction of elemental composition, the impact of clustering technique has not been reported despite its significance in optimal model development. In this study, the effect of clustering technique on the performance of standalone ANFIS in the prediction of elemental composition of biomass was evaluated. The minimum proximate parameters which are fixed carbon, ash and volatile matter were considered as the input. Two clustering methods called grid partitioning (GP) and fuzzy c-means (FCM) were compared to generate an optimal fuzzy inference system (FIS) structure. The results show that FCM based ANFIS model performed better in biomass elemental composition prediction. Its performance metrics based on Root Mean Squared Error (RMSE), Mean Absolute Deviation (MAD), Mean Absolute Percentage Error (MAPE), Coefficient of Correlation (CC), Log of accuracy (LAR) and Variable accounted for (VAF) are 0.6856, 0.419, 9.5603, 0.764, 0.001, 0.583 at an optimal computation time (CT) of 5.48s for Hydrogen content; 3.894, 2.442, 5.001, 0.898,0.001, 0.805 at an optimal computation time (CT) 5.55 secs for carbon; 4.381, 2.787, 10.020, 0.895, 0.002, 0.801 at an optimal computation time (CT) 5.95 secs for Oxygen respectively. This technique could be utilized as a quick tool for a reliable and accurate approximation of elemental composition of biomass feedstock.

The Role of Biomass Elemental Composition and Ion-Exchange in Metal Sorption from Wastewaters Onto Algae

The Role of Biomass Elemental Composition and Ion-Exchange in Metal Sorption from Wastewaters Onto Algae

Enhancing environmental sustainability through waste to energy conversion of neem leaves

Biomass is a viable alternative to reduced coal and fossil fuels as a clean energy source. This study focuses on the feasibility of using waste neem leaves as the feedstock for downdraft gasifier. The moisture content, volatile matter, fixed carbon, and ash content of waste neem leaves were determined as 12.1%, 60.58%, 9.31% and 18% respectively. The elemental composition of biomass was determined as carbon 41.99%, hydrogen 6.265%, nitrogen 2.823%, sulphur 0.311%, and oxygen 48.611% respectively. The higher heating values of waste neem leaves is 16.85 MJ/kg, which is better than rice husk and coal.

Evaluation of the biochemical methane potential of different sorts of Algerian date biomass

Abstract Date biomass is a renewable natural resource since it can be substituted in a comparatively shorter period. Hence it is considered as a possible feedstock for bioenergy motivations through anaerobic digestion (AD). Despite the fact AD is a fully demonstrated technology, the use of new feedstock necessitates detailed investigation. Worldwide several researchers are evaluating methane yield short of paying much consideration to the source type and structural and elemental composition of biomass. Hence, the current study was intended to relate methane yield to those two structural and chemical composition of biomass. In this sense, biochemical methane potential (BMP) for different date biomass, namely Pedicels, Fibrilium, Petiole, Fruit bunch, Spath, Palm, and a mixture of all biomass samples was tested for 30 days. Among all the experimental variations, higher productivity was observed with Palm as 72.60 mL CH4/g VS/days, followed by Spath (66.61 mL CH4/g VS/days), Mixed biomass (64.57 mL CH4/g VS/days), Fruit bunch (64.34 mL CH4/g VS/days), Pedicels (59.06 mL CH4/g VS/days), Fibrilium (57.42 mL CH4/g VS/days), and Petiole (41.17 mL CH4/g VS/days). From the experimental results, it can be concluded that among all the biomass samples, Palm is the best substrate for higher methane production. However, the remaining experimental conditions produced methane yield was comparatively low. This might be due to the composite nature of the substrate with lignin as an insoluble fraction. Hence, Pedicels, Fibrilium, and Petiole biomasses cannot be recommended as a substrate for biogas production without appropriate pretreatment.

Willow Biomass as Energy Feedstock: The Effect of Habitat, Genotype and Harvest Rotation on Thermophysical Properties and Elemental Composition

Willow biomass is used as a bioenergy source in various conversion technologies. It is noteworthy that apart from the beneficial environmental impact of a willow plantation, the biomass quality is also very important as it has an impact on the effectiveness of its use and emissions produced in various bioenergy technologies. Therefore, this study analysed the thermophysical properties and elemental composition of 15 genotypes of willow biomass from two plantations situated in the north of Poland, harvested in two consecutive three-year rotations. The differences in the moisture content, ash content and the lower heating value were mainly determined by the genotype, i.e., by genetic factors. In contrast, the content of carbon, nitrogen, sulphur and hydrogen was determined by the location (environmental factors), but also by the genotype, and by a combination of these factors. The following were the mean levels of the willow biomass characteristics, regardless of the location, genotype and harvest rotation: 48.9% moisture content, 1.26% d.m. ash content, 19.4% d.m. fixed carbon, 79.4% d.m. volatile matter, 19.53 MJ kg−1 d.m. higher heating value, 8.20 MJ kg−1 lower heating value, 52.90% d.m. carbon, 6.23% d.m. hydrogen, 0.032% d.m. sulphur, 0.42% d.m. nitrogen. The present research has shown that the selection of the willow genotype is important for the quality of biomass as energy feedstock. However, plantation location, as well as successive harvest rotations, can have a significant impact on the biomass elemental composition.

Elemental Chemical Composition of Forest Biomass at Different Ages for Energy Purposes

ABSTRACT This work aimed to evaluate the elemental composition of different biomass components of the forest species Acacia mearnsii De Wild, Eucalyptus grandis W. Hill ex Maiden, Mimosa scabrella Benth and Ateleia glazioviana Baill, at their first, third and fifth year after planting, aiming at bioenergetic use. The biomass elemental composition was determined by quantifying the levels of carbon, hydrogen, nitrogen, sulfur and oxygen. The three ages, the four species, and the four compartments differ in relation to the elementary constituents. The use of trees at any age allows for energy use. The fifth year presents the best carbon and hydrogen values, being the best age for using the biomass energy of the different species. A. mearnsii presents the highest carbon values for the leaf and A. glazioviana presents the highest hydrogen values for all compartments. The leaf is the best compartment for energetic use.

How increased atmospheric carbon dioxide and ‘The Law of the Minimum’ are contributing to environmental obesity

Abstract Justus von Liebig observed that one could greatly increase agricultural yields by adding relatively small quantities of nitrogen (N), phosphorus (P) and potassium (K) to soils. This finding led to the most recent agricultural revolution. But because most plants and microbes can be non-homeostatic with respect to their biomass elemental composition, adding nutrients can lead to disproportional increases in some macro-elements in organisms, while micronutrient content decreases. Increased CO2 in the atmosphere is an important driver of climate change, but it is also an important driver of changing biomass content and ecosystem stoichiometry. Increased CO2 has contributed to excess carbon in biomass and ecosystems, a state which could be contributing to changes in metabolism which I liken to metabolic diseases and ‘environmental obesity’. Here I defined environmental obesity as excess C accumulation relative to other elements in the environment. A warming climate is certainly motivation enough for humans to do whatever is necessary to decrease use of fossil fuels. However, increased carbon has detrimental health outcomes through effects on our food in natural and agricultural systems and suggests that CO2 is not ‘just an environmental problem’, but also a human health problem.

Effect of preparation of wood raw materials and some processing modes on the output of liquid pyrolysis products

Today, the limitations of traditional energy sources based on oil, natural gas and coal are becoming obvious. Therefore, the search for new sources of energy is a pressing issue both for modern Russia and for the whole world. The alternative sources of energy, based on the use of bioenergy of biomass, begin to play a significant and growing role in the world energy industry. The article presents the curves of changes in the mass yield of products obtained during the pyrolysis of biomass, thermally pre-treated in the temperature range of 180-270 °C without access of oxygen. It has been experimentally proved that pre-heat treatment reduced the total liquid yield in the pyrolysis process: with an increase in the processing temperature, the mass yield of the liquid decreased, but the mass yield of charcoal and gas changed slightly. At the same time, it was found that the temperature affected the yield of the elemental composition of biomass: as the temperature increased, the content of elemental carbon in the biomass increased, while the content of hydrogen and oxygen decreased. It is concluded that the preliminary heat treatment of biomass can improve the quality of the final liquid biofuel by reducing the water content in it and by increasing the heat of combustion. It is also found that pressure reduction during the pyrolysis process increased the yield of the liquid fraction of decomposition products.

Analysis of the elemental composition and uptake mechanism of Chlorella sorokiniana for nutrient removal in agricultural wastewater under optimized response surface methodology (RSM) conditions

Microalgae exhibit large potential as an alternative to advanced biological nutrient removal in wastewater, but treatment efficiency is greatly influenced by process variables. Therefore, it is necessary to determine the optimum operating conditions for nutrient removal. In this study, Chlorella sorokiniana was used to remove ammonium (NH₄⁺) and phosphate (PO₄³⁻) from palm oil mill effluent. Response surface methodology (RSM) was employed to evaluate the interactions of three main influential factors, i.e., light intensity, photoperiod and inoculum size, and their effects on nutrient removal efficiency. The nutrient preference, biomass elemental composition and nutrient removal mechanism of the microalgae were also investigated. Under the optimum conditions (200 μmol photon m⁻2s⁻1 12 h photoperiod and 28% inoculum size), 93.36% of NH₄⁺ and 94.50% of PO₄³⁻ were successfully removed. The microalgae were found to adjust their internal composition in response to the external concentration. Biomass N and P increased from 6.16 to 8.68% and from 1.0 to 2.21%, respectively. The microalgae preferred NH₄⁺ over organic N, and the removal mechanisms involved not only assimilation for growth but also over-uptake for cellular storage. These findings are highly beneficial for maximizing the nutrient removal potential of microalgae in agricultural wastewater.

Model investigation of condensation behaviors of alkalis during syngas treatment of pressurized biomass gasification

In order to eliminate problems such as corrosion and ash deposition caused by alkalis, effects of the biomass composition and the pressure of syngas in the downstream process on condensation of alkalis in a wood steam/oxygen blown fluidized bed gasification process are investigated based on a model. This model is established by combining Aspen Plus with SimuSage. Aspen Plus is applied to predict the composition of major gas species formed by C, H, O, N, S and Cl, using empirical correlations to predict the yields of non-equilibrium substances. SimuSage is used to study the release and condensation of inorganics associated with the minor elements (Al, Ca, Fe, K, Mg, Na, P, Si and Ti) based on a customized thermodynamic database. Results show that carbonation reactions between alkalis and CO/CO2 can be occurred during gas cooling, leading to form alkali carbonates in the condensed phase. The temperature window forming melts varies with the change of the downstream pressure of syngas and the elemental composition of biomass. As the syngas pressure in the downstream process decreases, the initial temperature of forming melts during gas cooling is reduced. For biomass lower in K/Cl ratio, the condensate with the largest mass formed during gas cooling is potassium chloride. The condensation rate of Cl increases with the decrease of the K/Cl ratio in biomass.

Entrained-flow gasification of torrefied tomato peels: Combining torrefaction experiments with chemical equilibrium modeling for gasification

The purpose of the present study is to quantify the impact of torrefaction pretreatment on the quality of the product gas arising from the gasification with steam and steam-oxygen mixtures of non-woody biomass in high-temperature entrained flow reactors. To this aim, a chemical equilibrium model for biomass gasification was adopted, which allowed predicting the product gas composition as a function of process temperature, equivalence ratio, steam-to-biomass ratio and biomass elemental composition. A global sensitivity analysis with respect to the model input parameters was performed to assess the impact of torrefaction and gasification operating conditions on the quality of the product gas in terms of heating value and composition metrics typically adopted in the process industry (H2/CO ratio, stoichiometric module, etc.). In particular, the gasification of raw tomato peels and related torrefied solids resulting from fluidized bed torrefaction tests performed under light (200 °C and 30 min), medium (240 °C and 30 min) and severe (285 °C and 30 min) conditions was investigated using ultimate analysis data in the model. Results of this analysis highlighted that the quality of product gas arising from the oxygen-steam gasification of torrefied and untreated tomato peels did not differ very much, although torrefied feedstocks produced more H2 and CO and less CO2 than the parent one. This suggests that, despite the significant benefits it determines in biomass feeding, grinding and storage, the torrefaction pretreatment provides only a marginal improvement in the product gas quality. Equilibrium simulations made available in the present study can be useful for a better understanding of the controlling variables that rule gasification processes in addition to act as a point of reference for more complex simulations of the high temperature entrained flow gasification of biomass with oxygen-steam mixtures.

Growth rate and resource imbalance interactively control biomass stoichiometry and elemental quotas of aquatic bacteria.

The effects of resource stoichiometry and growth rate on the elemental composition of biomass have been examined in a wide variety of organisms, but the interaction among these effects is often overlooked. To determine how growth rate and resource imbalance affect bacterial carbon (C): nitrogen (N): phosphorus (P) stoichiometry and elemental content, we cultured two strains of aquatic heterotrophic bacteria in chemostats at a range of dilution rates and P supply levels (C:P of 100:1 to 10,000:1). When growing below 50% of their maximum growth rate, P availability and dilution rate had strong interactive effects on biomass C:N:P, elemental quotas, cell size, respiration rate, and growth efficiency. In contrast, at faster growth rates, biomass stoichiometry was strongly homeostatic in both strains (C:N:P of 70:13:1 and 73:14:1) and elemental quotas of C, N, and P were tightly coupled (but not constant). Respiration and cell size increased with both growth rate and P limitation, and P limitation induced C accumulation and excess respiration. These results show that bacterial biomass stoichiometry is relatively constrained when all resources are abundant and growth rates are high, but at low growth rates resource imbalance is relatively more important than growth rate in controlling bacterial biomass composition.

Operation mode and external carbon dose as determining factors in elemental composition and morphology of aerobic granules

Abstract The elemental composition and morphology of aerobic granules in sequencing batch reactors (GSBRs) treating high-nitrogen digester supernatant was investigated. The investigation particularly focused on the effect of the number of anoxic phases (one vs. two) in the cycle and the dose of external organics loading (450 mg COD/(L·cycle) vs. 540 mg COD/(L·cycle)) on granule characteristics. Granules in all reactors were formed of many single cells of rod and spherical bacteria. Addition of the second anoxic phase in the GSBR cycle resulted in enhanced settling properties of the granules of about 10.6% and at the same time decreased granule diameter of about 19.4%. The study showed that external organics loading was the deciding factor in the elemental composition of biomass. At 540 mg COD/(L·cycle) the granules contained more weight% of C, S and N, suggesting more volatile material in the granule structure. At lower organics loadings granules had the higher diameter of granules which limited the diffusion of oxygen and favored precipitation of mineral compounds in the granule interior. In this biomass higher content of Mg, P and Ca, was observed.

Respuesta de la biomasa y la composición C:N:P del primer nivel trófico de un arroyo Pampeano a la mayor sequía de los últimos 20 años: un estudio de caso

Benthos, epiphyton, seston, free-floating filamentous algae and aquatic plants provide food and shelter to the rest of trophic levels of the stream. Here we studied the effect of an extreme drought on the biomass and elemental composition of La Choza stream in the Pampas by comparing a wet (2007, ~1200 mm/yr) and a dry year (2008, ~600mm or 40% less than the long term mean). Given that the abundance of these communities depends mainly on the mass transfer in the boundary layer at low speeds and the drift downstream, we postulate (H1) that a dry year creates unfavorable conditions for aquatic plants and seston but favors free-floating, epiphytic and benthic filamentous algae. As Pampean streams are rich in nutrients, we also postulate (H2) that there are no significant inter-annual changes in the elemental composition of biomass. Low flow rates of 2008 resulted in a higher conductivity, pH and available light, without appreciable changes in the typical high nutrient concentrations. The drought resulted in lower discharges (<50 L/s) and velocities (<9 cm/s), accompanied by declines in the amount of plants (2±0.3 g/m 2 ) and seston (20±8 g/m 2 ) and increases in free-floating but not in filamentous algae, partial supporting H1. Nutrient composition of the biomass did not change as proposed by H2, being highly variable in the case of seston and periphyton. The impact of a full-year drought on the Wet Pampa could affect animal communities as plants and seston biomass decreases in favor of increase of free-floating algae, compromising food and shelter.

Physiological, biomass elemental composition and proteomic analyses of Escherichia coli ammonium-limited chemostat growth, and comparison with iron- and glucose-limited chemostat growth.

Escherichia coli physiological, biomass elemental composition and proteome acclimations to ammonium-limited chemostat growth were measured at four levels of nutrient scarcity controlled via chemostat dilution rate. These data were compared with published iron- and glucose-limited growth data collected from the same strain and at the same dilution rates to quantify general and nutrient-specific responses. Severe nutrient scarcity resulted in an overflow metabolism with differing organic byproduct profiles based on limiting nutrient and dilution rate. Ammonium-limited cultures secreted up to 35% of the metabolized glucose carbon as organic byproducts with acetate representing the largest fraction; in comparison, iron-limited cultures secreted up to 70 % of the metabolized glucose carbon as lactate, and glucose-limited cultures secreted up to 4% of the metabolized glucose carbon as formate. Biomass elemental composition differed with nutrient limitation; biomass from ammonium-limited cultures had a lower nitrogen content than biomass from either iron- or glucose-limited cultures. Proteomic analysis of central metabolism enzymes revealed that ammonium- and iron-limited cultures had a lower abundance of key tricarboxylic acid (TCA) cycle enzymes and higher abundance of key glycolysis enzymes compared with glucose-limited cultures. The overall results are largely consistent with cellular economics concepts, including metabolic tradeoff theory where the limiting nutrient is invested into essential pathways such as glycolysis instead of higher ATP-yielding, but non-essential, pathways such as the TCA cycle. The data provide a detailed insight into ecologically competitive metabolic strategies selected by evolution, templates for controlling metabolism for bioprocesses and a comprehensive dataset for validating in silico representations of metabolism.