Biomass Of Different Components Research Articles

Development of Allometric Equations to Determine the Biomass of Plant Components and the Total Storage of Carbon Dioxide in Young Mediterranean Argan Trees

Morocco’s argan trees, native to forests, are now cultivated in large orchards within the Argan Biosphere Reserve, transforming “Arganiculture”. These orchards are anticipated to bolster carbon storage, but their precise contribution to carbon storage remains unclear. This study introduces for the first time allometric equations for estimating biomass in different components of argan plants within orchards. A total of 89 plant individuals, aged 2 to 6 years, were collected. Their diameter and total height were measured. The biomass, carbon content, and biomass carbon stock of each component were determined. The best-fit allometric equation incorporates diameter, height, growing years, and root-to-shoot ratio to estimate total biomass (R2 = 0.95). The estimated total carbon biomass stock ranged from 0.01 to 0.82 t CO2 ha−1 for plants, at a density of 200 plants ha−1. Between 2021 and 2023, the average annual carbon sequestration was 0.20 t CO2 ha−1 year−1. This model offers valuable tools for use when species-specific equations during the establishment growing stage are unavailable, enhancing carbon sequestration quantification for more reliable results and informing climate change mitigation strategies. The allometric parameters serve as benchmarks for trees resembling the argan tree. The methodology could be adapted for other forest plants undergoing conversion to orchard cultivation.

Exploring 65 years of progress in cotton nutrient uptake, efficiency and partitioning in the USA

Context or problemCotton is a vital crop worldwide, and as increases in population and changes in climate occur, it is critical for breeders to continue to improve lint yields. One area to further investigate is how nutrient uptake and nutrient use efficiencies have changed through time to develop future management and breeding strategies. Objective or research questionTo evaluate the change in nutrient uptake, nutrient use efficiency and yield of 20 cotton cultivars released in the USA between 1953 and 2018. MethodsA field experiment in 2020 and 2021 was carried out to evaluate the nutrient uptake, internal nutrient use efficiency and partitioning of assimilated nutrients among different components of biomass for the twenty cotton cultivars released between 1953 and 2018 in the USA. Linear regression analysis was performed to estimate the rate of gain for lint yield, crop biomass, total nutrient uptake and use efficiency. ResultsThe rate of genetic gain for crop biomass increased 4.3 times faster than the rate of gain for lint yield. The total nutrient uptake and internal use efficiency were significantly different among cultivars, with a consistent increase measured across the span of years of release for the 20 cultivars. Nutrient concentration in vegetative growth either decreased or remained unchanged over time, while concentration in the seed increased. Modern cultivars demonstrate a 27% increase in efficiency, producing more lint per unit of nutrient uptake compared to those from the 1950 s, owing to improved nutrient availability with limited seed partitioning. Partitioning of total assimilated nutrients of N, P and K into the different biomass components were inconsistent over the years. ConclusionsModern cotton cultivars have shown an increased total nutrient uptake but a slower improvement in nutrient use efficiency. The limited changes observed in the partitioning of primary nutrients for reproductive growth, along with the increased concentration of nutrients in seed, suggest potential focus for future advancements in breeding strategies. Implications or significanceThis research offers valuable perspectives on nutrient uptake, partitioning and use efficiency of cotton cultivars released between 1953 and 2018. Differences in nutrient use efficiency among cultivars were observed, highlighting the potential for enhanced nutrient uptake traits in cotton. These findings indicate that improved nutrient partitioning along with associated fertility recommendations could strategically direct future cultivar development.

Error Analysis on the Five Stand Biomass Growth Estimation Methods for a Sub-Alpine Natural Pine Forest in Yunnan, Southwestern China

Forest biomass measurement or estimation is critical for forest monitoring at the stand scale, but errors among different estimations in stand investigation are unclear. Thus, the Pinus densata natural forest in Shangri-La City, southwestern China, was selected as the research object to investigate the biomass of 84 plots and 100 samples of P. densata. The stand biomass was calculated using five methods: stand biomass growth with age (SBA), stem biomass combined with the biomass expansion factors (SB+BEF), stand volume combined with biomass conversion and expansion factors (SV+BCEF), individual tree biomass combined with stand diameter structure (IB+SDS), and individual tree biomass combined with stand density (IB+SD). The estimation errors of the five methods were then analyzed. The results showed that the suitable methods for estimating stand biomass are SB+BEF, M+BCEF, and IB+SDS. When using these three methods (SB+BEF, SV+BCEF, and IB+SDS) to estimate the biomass of different components, wood biomass estimation using SB+BEF is unsuitable, and root biomass estimation employing the IB+SDS method was not preferred. The SV+BCEF method was better for biomass estimation. Except for the branches, the mean relative error (MRE) of the other components presented minor errors in the estimation, while MRE was lower than other components in the range from −0.11%–28.93%. The SB+BEF was more appealing for branches biomass estimation, and its MRE is only 0.31% lower than SV+BCEF. The stand biomass strongly correlated with BEF, BCEF, stand structure, stand age, and other factors. Hence, the stand biomass growth model system established in this study effectively predicted the stand biomass dynamics and provided a theoretical basis and practical support for accurately estimating forest biomass growth.

Additive Models of Single-tree Biomass Sensitive to Temperature and Precipitation in Eurasia – A Comparative Study for Larix spp. and Quercus spp.

In the context of current climate change, it is important to know the patterns characterising the response of forest trees to the dynamics of air temperature and precipitation. In this study, the first attempt to model changes of additive component composition of genera Larix spp. and Quercus spp. aboveground biomass according to Eurasian gradients of January’s mean temperature and annual mean precipitation is made, taking into account regional particularities of tree age and morphology structure. In the process of modelling, the database of single-tree biomass for forest-forming species in Eurasia is used. According to our results, the factors limiting the biomass of trees differ not only between the two tree genera but also between different components of biomass within the genus. In larches, the reaction of the biomass of all components to an increase in precipitation in cold zones is directly opposite in comparison with oaks, i.e. it decreases as precipitation increases. But in warm areas, the reactions of the two genera to increased precipitation coincide, i.e. precipitation does not affect the biomass of all components, both in larches and oaks. In wet areas, larch biomass components react to temperature increases in the opposite way, i.e. the aboveground and stem biomass increases, but the biomass of foliage and branches decreases. In dry areas, the reaction to the temperature of all larch and oak biomass components is unambiguous and opposite, i.e. there is a decrease in the larch biomass of all components as temperatures rise, and in oak biomass vice versa. This situation is discussed in terms of limiting factors.

Utilization of Spent Coffee Grounds as Media for Stone Pine (Pinus pinea) Seedlings

The present study was aimed at determining the influence of adding different amounts of spent coffee grounds (SCG) on germination percentage (GP) and mean germination time (MGT), seedling characteristics, and seedling biomass of different components of containerized 1 + 0 stone pine seedlings. Six different media were prepared including 100% conventional media, 100% sand, 10% SCG + 90% sand, 20% SCG + 80% sand, 30% SCG + 70%, sand and 100% SCG. While GP is 90% in the media where the SCG ratio is 10%, GP values decrease to 50% as the SCG ratio increases. The greatest seedling height values were found in conventional media (14.4 cm), followed by the seedlings in 100% sand with 11.4 cm and 20% SCG + 80% sand with 11.1 cm. The highest root collar diameter was found in 20% SCG + 80% sand with 3.9 mm. The highest root/shoot ratio (0.7) was obtained in 10% SCG + 90% sand. Total seedling biomass was the greatest in conventional media (2.1 g). As SCG increased in the media, N, K, Mg, and P concentrations increased, and Ca concentration and C/N ratio decreased in all seedling components (needle, main root, lateral root, and stem). Results point to the possibility of using a small amount of SCG to alter seed germination, seedling characteristics, and nutrient uptake for production of containerized stone pine seedlings.

Effects of Fertilization on Biomass and Macronutrient Content of Eucalyptus urophylla S.T. Blake in Arenized Soil of Pampa Biome

The objective of this study was to quantify the biomass and the macronutrient stock in an experiment of fertilization with Eucalyptus urophylla, planted in arenized soil at 12 months-old, in Rio Grande do Sul, Brazil. The experiment had a completely randomized design with five treatments (T1, T2, T3, T4 and T5) with three replications. The treatments T2, T3, T4 and T5, received increasing doses of triple superphosphate. On the other hand, the T1 treatment was the only one to receive natural phosphate in planting. For the determination of the biomass, fifteen trees were felled and separated in the following components: leaves, branches, stem bark, stem wood and roots. Samples of the components were collected and transported to the laboratory for biomass determination and chemical analysis. The total biomass varied between the treatments, with highest biomass accumulation of 6.83 Mg ha-1 occurring in T5. The T1 presented the highest biomass for roots representing 33.4% of the total biomass. The biomass distribution among the different components in the decreasing order was: roots > stem wood > leaves > branches > stem bark, for all the treatments. The treatment with higher doses of fertilizers (T5) presented the highest amount of nutrient accumulation in the total biomass (131.26 kg ha-1). The concentration and accumulation of nutrients presented the following trend K > N > Ca > Mg > P > S. Analyzing the different components of biomass, the highest amounts of nutrients followed the order: leaves > roots > stem wood > branches > stem bark. Fertilization influenced the biomass production of E. urophylla in arenized soil in the Pampa biome, but without significant differences to date (12 months). The leaves had the highest concentration of macronutrients, with the exception of Ca, which was higher in the bark. The K was the element that presented highest accumulation in whole tree. The plantation of eucalyptus with fertilization management may be an alternative for the economic use of arenized soil.

Modeling and Biomass Quantification in Eucalyptus saligna Smith Stand at the End Rotation in the South of Brazil

The quantification of wood stock and other components of biomass is fundamental for forest planning. Given the difficulty of obtaining these data, the present study aims at the formulation of equations and the estimation of the different components of biomass, volume with and without bark, form factor and height of the trees at the end rotation. The study was carried out in the municipality of São Gabriel state of Rio Grande do Sul, Brazil with Eucalyptus saligna 10-year-old. The experimental design of the inventory and biomass quantification were completely randomized. In the inventory the DBH of all individuals of the 5 plots were measured. After determination of 4 classes of diameter were felled 12 trees and quantified leaves, branches, bark and wood. The selection of the models obtained coefficients of determination higher than 97%. The total biomass was 269 Mg ha-1, of which 89% was wood. The total volume was 546 and 494 m³ ha-1 with and without bark, representing an average annual increase of 54,6 and 49,4 m³ ha-1 year-1. The mean form factor was 0,48. The modeling presented excellent adjustments and certainly serves for future estimates of the stock biomass.

Real-time monitoring biomass pyrolysis via on-line photoionization ultrahigh-resolution mass spectrometry

Identification of pyrolysis intermediates and products is of great significance to better understanding of a pyrolysis process and therefore its further upgrade to practical fuels. We hereby report a real-time analysis of pyrolysis volatiles of biomass in a micro fixed-bed reactor via an on-line near-atmospheric pressure photoionization Orbitrap mass spectrometry (nAPPI Orbitrap MS). The mass spectra suggest the pyrolysis products bear a molecular weight in the range of m/z 50–300. The oxygenated compounds having between 1 and 5 oxygen atoms and with double bond equivalent (DBE) values ranging from 2 to 7 account for more than 90% of the identified peaks, indicating that significant upgrading should be developed towards applications. Pyrolysis products could be clearly distinguished from different components of biomass in the van Krevelen diagrams and DBE versus carbon number plots. The results from the nAPPI Orbitrap MS are further compared to those of off-line pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) and on-line single photoionization mass spectrometry (SPI-MS). The nAPPI Orbitrap MS is a powerful on-line approach with high sensitivity, ultrahigh-resolution, and no condensation or preparation. This analytical protocol is expected to be helpful in complicated thermochemical conversion studies, e.g. pyrolysis of biomass.

Detailed simulations of fast pyrolysis of biomass in a fluidized bed reactor

In the present work, an Eulerian-Eulerian computational fluid dynamics model with an advanced kinetic scheme is used to simulate the fast pyrolysis of biomass in a fluidized bed reactor. The focus of this work is to investigate the influence of pyrolysis temperature and biomass components on the fast pyrolysis of biomass. Initially, the simulations were carried out to validate the model. The results showed that the model could make a good prediction about the fast pyrolysis of biomass. Further simulations were conducted to investigate the fast pyrolysis at different temperatures. The results indicated that the pyrolysis temperature considerably influenced the product yields and reaction rates of fast pyrolysis reactions of biomass and bio-oil compositions. In addition, the ability of different components of biomass to produce pyrolysis products was also studied. The results showed that cellulose had the strongest ability to produce bio-oil, while lignin had the strongest ability to produce char. The energy recovery coefficient of bio-oil obtained at different pyrolysis temperatures was also calculated and analyzed in this paper.

Carbon storage in biomass, litter, and soil of different native and introduced fast-growing tree plantations in the South Caspian Sea

Replantation of degraded forest using rapid-growth trees can play a significant role in global carbon budget by storing large quantities of carbon in live biomass, forest floor, and soil organic matter. We assessed the potential of 20-year old stands of three rapid-growth tree species, including Alnus subcordata, Populus deltoides and Taxodium distichum, for carbon (C) storage at ecosystem level. In September 2013, 48 replicate plots (16 m × 16 m) in 8 stands of three plantations were established. 36 trees were felled down and fresh biomass of different components was weighed in the field. Biomass equations were fitted using data based on the 36 felled trees. The biomass of understory vegetation and litter were measured by harvesting all the components. The C fraction of understory, litter, and soil were measured. The ecosystem C storage was as follows: A. subcordata (626.5 Mg ha−1) > P. deltoides (542.9 Mg ha−1) > T. distichum (486.8 Mg ha−1) (P < 0.001), of which 78.1–87.4% was in the soil. P. deltoides plantation reached the highest tree biomass (206.6 Mg ha−1), followed by A. subcordata (134.5 Mg ha−1) and T. distichum (123.3 Mg ha−1). The highest soil C was stored in the plantation of A. subcordata (555.5 Mg ha−1). The C storage and sequestration of the plantations after 20 years were considerable (25–30 Mg ha−1 year−1) and broadleaves species had higher potential. Native species had a higher soil C storage while the potential of introduced species for live biomass production was higher.

Biomass Equations and Assessment of Carbon Stock of &lt;i&gt;Calligonum polygonoides&lt;/i&gt; L., a Shrub of Indian Arid Zone

Biomass equations of Calligonum polygonoides L. were derived for the arid districts of Rajasthan, India for assessment of carbon stock. Plants varied spatially in growth and biomass (0.03-54.19 kg/plant). Contribution of stems and roots was 45.7% and 48.0% of total biomass respectively. Nonlinear models were found to be the best in predicting biomass of stems, roots, above-ground and total biomass of C. polygonoides using collar diameter as the predictor. Carbon concentration was highest in twigs followed by stems, roots and leaves. Carbon density due to this species ranged between 0.37 and 1.84 t/ha. Conclusively, collar diameter alone is sufficient to predict the biomass of different components of this plant. Varying climatic and human-induced stresses were found to affect the biomass and carbon sequestration by this species.

Allometric models for estimating shrub biomass in desert grassland in northern China

ABSTRACTThe development of shrub allometric models is crucial for accurate biomass assessment, as well as for scientific studies of carbon storage and carbon cycling of desert ecosystems. The aim of the present study was to construct allometric models to predict biomass using easily measured variables for xerophytic shrubs. The 12 most widespread shrub species of northern China were selected and a total of 385 individuals were harvested to obtain the weight of its components (leaves, twigs, branches, and roots), the crown area (CA) and plant height (H). Based on a high coefficient of determination (R2), a low standard error of estimate (SEE), and low Akaike information criterion (AIC) values, 72 species-specific and 24 multispecies models with CA and H as independent variables were developed. The function lnW (biomass of different components) = a + b × lnX (predictor variable) was selected as optimal model. CA was revealed as the best independent variable for the biomass of leaves and twigs, and V (CA × H) was the best predictor variable for branches, aboveground, belowground, and total biomass. In conclusion, for the first time species-specific and multispecies models were constructed with a high goodness of fit of leaves, twigs, branches, aboveground, belowground, and total biomass for 12 shrub species in northern China. Compared to multispecies models, species-specific models had improved accuracy. Since biomass quantification is the basis of carbon stocks estimation, the models presented here can be considered as alternative tool for assessing carbon storage and carbon cycling of desert ecosystems.

A spatially stabilized TDG based finite element framework for modeling biofilm growth with a multi-dimensional multi-species continuum biofilm model

We consider a model for biofilm growth in the continuum mechanics framework, where the growth of different components of biomass is governed by a time dependent advection---reaction equation. The recently developed time-discontinuous Galerkin (TDG) method combined with two different stabilization techniques, namely the Streamline Upwind Petrov Galerkin (SUPG) method and the finite increment calculus (FIC) method, are discussed as solution strategies for a multi-dimensional multi-species biofilm growth model. The biofilm interface in the model is described by a convective movement following a potential flow coupled to the reaction inside of the biofilm. Growth limiting substrates diffuse through a boundary layer on top of the biofilm interface. A rolling ball method is applied to obtain a boundary layer of constant height. We compare different measures of the numerical dissipation and dispersion of the simulation results in particular for those with non-trivial patterns. By using these measures, a comparative study of the TDG---SUPG and TDG---FIC schemes as well as sensitivity studies on the time step size, the spatial element size and temporal accuracy are presented.

Development of Resistance in Two Wheat Cultivars Against Constant Fumigation of Ozone

Tropospheric ozone (O3) has been recognized as the major threat for worldwide agriculture and wheat production will have a crucial bearing on food security in the coming decades. The present study was conducted to evaluate the response of two wheat cultivars (HUW 234 and HP 1209) at constant levels of elevated O3 and to compare results of the present open top chamber studies (OTC) with free air concentration studies (FACE). Wheat cultivars were exposed to 70 (T1) and 100 (T2) ppb O3 for 4 h daily from germination to maturity. Both the cultivars showed differential and negative responses on photosynthetic pigments, morphological characteristics and total biomass at different stages of sampling. Photosynthetic rate, stomatal conductance and photosynthetic efficiency were negatively affected by the exposure of O3 in both the cultivars. Allocation of biomass in different components of plants was observed to be diverse amongst the cultivars under different treatments resulted into the varied responses yield attributes. Exposure of O3 causes variation in quantity as well as quality of grains of both the cultivars with higher yield reduction in HP1209. Therefore, the findings of the experiments revealed that the continuous O3 exposure developed compensatory mechanism particularly reduced stomatal conductance, altered allocation pattern managed to maintain yield against O3, hence led to less reductions in yield was recorded as compared to OTCs and FACE experiments data.

Two-stage dilute-acid and organic-solvent lignocellulosic pretreatment for enhanced bioprocessing

A two stage pretreatment approach for biomass is developed in the current work in which dilute acid (DA) pretreatment is followed by a solvent based pretreatment (N-methyl morpholine N oxide – NMMO). When the combined pretreatment (DAWNT) is applied to sugarcane bagasse and corn stover, the rates of hydrolysis and overall yields (>90%) are seen to dramatically improve and under certain conditions 48h can be taken off the time of hydrolysis with the additional NMMO step to reach similar conversions. DAWNT shows a 2-fold increase in characteristic rates and also fractionates different components of biomass – DA treatment removes the hemicellulose while the remaining cellulose is broken down by enzymatic hydrolysis after NMMO treatment to simple sugars. The remaining residual solid is high purity lignin. Future work will focus on developing a full scale economic analysis of DAWNT for use in biomass fractionation.

Stable isotope analyses revealed high seasonal dynamics in the food web structure of a peatbog

Stable isotope analysis has become a powerful tool for the study of food web structures in aquatic communities. However, there has been little recognition of the spatial and temporal variabilities of isotopes in food webs in peatbogs. Here, we investigated the structure of food web in peatbog dominated by Sphagnum mosses by analyzing: (i) density and biomass of different components of food webs; (ii) the digestive vacuole contents of Hyalosphenia papilio—the most abundant species of amoebae occurring in peatbog; (iii) the seasonal changes in the carbon and nitrogen stable isotope signatures of particular components of food web. The study was performed in the Moszne peatbog located in the western part of Polesie Lubelskie (eastern Poland). Fieldwork was done on a monthly basis from April to November 2013. The largest total biomass of microorganisms in all of the seasons was noted in testate amoebae. Algae and cyanobacteria were the second largest group of microorganisms. The feeding behaviour of H. papilio varied throughout season. Among the identified prey, the highest frequency was noted in algae, cyanobacteria and ciliates. In spring and summer, prey was dominated by phycoflora, while during the autumn period the main prey consisted of cyanobacteria and ciliates. The results of the study indicate significant seasonal variation in the level of stable isotopes in individual components (bacteria, fungi, protozoa and metazoa) of the food web of peatbog, and thus also considerable dynamics of changes between trophic levels.

Allometric equations for estimating above- and belowground biomass in Tea (Camellia sinensis (L.) O. Kuntze) agroforestry system of Barak Valley, Assam, northeast India

Tea (Camellia sinensis (L.) O. Kuntze) agroforestry has widespread implications for the earnings and food security for a large fraction of population in NorthEast India. It also has immense potentiality to act as a considerable reservoir of biomass carbon providing climate change mitigation options. In the present study an attempt was made to develop allometric equations for above- and belowground biomass estimation specific to Tea [C. sinensis (L.) O. Kuntze] in Barak Valley of northeast India. Relationships were developed through destructive sampling and regressing diameter alone and along height, wood density, crown area, branch count with biomass. Allometric power function equation and linear equivalents have been developed. Diameter singly could predict significantly aboveground biomass (AGB) root biomass (BGB) and total Tea biomass (TB) with over 95% accuracy. Whereas incorporation of height, crown area, wood density, branch count with diameter influenced the model in terms of modified coefficient of determination and minimized estimation errors. Branches, stem and leaves accounted 50, 21 and 6% of AGB respectively. Root biomass (BGB) contributed 23% of the total Tea bush biomass. The samples exhibited overall BGB/AGB ratio of 0.30 ± 0.08 and biomass expansion factor (BEF) by 4.23 ± 1.6. Biomass of different components significantly differs in varied diameter sizes.

A disaggregated dynamic model for predicting volume, biomass and carbon stocks in even-aged pedunculate oak stands in Galicia (NW Spain)

A model was developed for predicting current and future disaggregated volume, biomass and carbon stocks in even-aged pedunculate oak (Quercus robur L.) stands in Galicia (northwestern Spain). In the model, the stand state at any point in time is defined by age (A), dominant height (H), number of trees per hectare (N) and stand basal area (G). A dynamic model project H, N and G over time by using transition functions in algebraic difference form. A number of static relationships are used to estimate other quantities as functions of the stand state. A disaggregation system, which comprises a diameter distribution function and a generalized height–diameter relationship, enables prediction of the number of trees in each diameter class and their average height. A taper equation, developed in a previous study, is used to estimate total and merchantable volume. A set of additive equations is used to predict total aboveground biomass and biomass of different components. Finally, carbon stocks are predicted from the average C content (%) in the different biomass components. The equations in the model were developed under tenable statistical assumptions: a base-age invariant method, which accounted for autocorrelation, correlated errors and different number of observations between the transition functions; and simultaneous fitting of the biomass system, which accounted for heteroscedasticity and inherent correlations between biomass components and the lack of leaf data in some trees. Critical errors of 13, 16 and 11 % were obtained in H, N and G predictions for a projection interval of 3 to 9 years. Biomass equations explained between 78 and 98 % of the observed variability. The average amount of C stored was approximately 48 % of total dry biomass. The proposed model can be used by forest managers as part of a decision support system that enables consideration of production and environmental aspects related to climate change (biomass and C stocks).

Exportação de carbono e nutrientes pela colheita de Acacia mearnsii De Wild aos quatro anos de idade na Depressão Central, RS

The aim of this study was to estimate the content and export of carbon, macro and micronutrients inthe different components (leaf, alive and dead branch, bark, wood and roots) of the Acacia mearnsiitrees with 4 years old of age in Arroio dos Ratos-RS, in order to provide the forest management,based on the criterion of minimum export of nutrients. After determining the diameter distributionand its division into diameter classes (seven classes), three trees were selected in each classes. Usingthe 21 trees felled, the biomass of different components of trees was estimated. It was observed thatwood, which represents about 64% of the biomass, contains 50% of accumulated Ca, 21% N, 27% P,30% K, 37% Mg, 45% of S, 25% B, 37% Cu, 9% Fe, 26% Mg and 41% Zn. While the leaf, which represents3% of total biomass, contains 20; 18; 12; 5; 10; 10; 17; 18; 5; 19 and 6% N, P, K, Ca, Mg, S, B, Cu, Fe,Mg and Zn, respectively. The export of nutrients from the crops of A. mearnsii can be minimized withretention of crop residues on the soil removal only of wood and bark.

Use of Empty Fruit Bunches from the Oil Palm for bioethanol production: A thorough comparison between dilute acid and dilute alkali pretreatment

In the present work, two pretreatment techniques using either dilute acid (H2SO4) or dilute alkali (NaOH) have been compared for producing bioethanol from Empty Fruit Bunches (EFBs) from oil palm tree, a relevant feedstock for tropical countries. Treatments' performances under different conditions have been assessed and statistically optimized with respect to the response upon standardized enzymatic saccharification. The dilute acid treatment performed at optimal conditions (161.5°C, 9.44 min and 1.51% acid loading) gave 85.5% glucose yield, comparable to those of other commonly investigated feedstocks. Besides, the possibility of using fibers instead of finely ground biomass may be of economic interest. Oppositely, treatment with dilute alkali has shown lower performances under the conditions explored, most likely given the relatively significant lignin content, suggesting that the use of stronger alkali regime (with the associated drawbacks) is unavoidable to improve the performance of this treatment.