Lignocellulosic Residues Research Articles

Comprehensive Characterization of Lignocellulosic Biomass and their effective Delignification for Sustainable Bioenergy

The study provides a thorough examination of the biofuel potential of three unique lignocellulosic crop residues: rice straw (Oryza sativa), corn stalk (Zea mays) and sugarcane bagasse (Saccharum officinarum) of Odisha. In the investigation, we explored the compositional, thermal and structural characteristics of these biomass sources, shedding light on their suitability for sustainable bioenergy production. Proximate analysis indicated variances in critical factors in the range of 5.9-14.8% (moisture content), 1.8-19.4% (ash content), 60-72.4% (volatile matter) and 9.6-14.7% (fixed carbon) which contribute to the various energy generating capacities of these materials. An in-depth investigation of cellulose, hemicellulose and lignin concentration revealed the promise of sugarcane bagasse as a cellulose-rich option for bioethanol synthesis. Thermochemical profiling using thermogravimetric and FTIR analysis revealed information about thermal stability and chemical changes, with pretreatment having an important role in increasing biomass accessibility and crystallinity. The significance of pretreatment-induced crystallinity for effective enzymatic hydrolysis and fermentable sugar generation was highlighted by X-ray diffraction (XRD) . Overall, this study advances our understanding of the intricate relationships between biomass composition, structure and bioenergy potential, offering valuable insights for the development of sustainable biofuel production strategies.

Biodegradable films from the lignocellulosic residue of switchgrass

Plastics thrown out as trash are an everlasting threat to our biosphere and ecosystem. A sustainable remedy within our reach is the use of agricultural biomass. Herein, the lignocellulosic residue of switchgrass biomass, extracted using alkaline and bleaching treatments and solubilized in ZnCl2 solution followed by crosslinking with calcium ions, is used to develop biodegradable films. The films have been characterized for color, transparency, thickness, moisture, water solubility, water absorption, water vapor permeability, tensile strength, elongation, and soil biodegradation. Mathematical modeling of the water absorption and biodegradation behavior have also been studied. The films are transparent, possess high tensile strength and low water vapor permeability, and biodegrade completely within 40 days at 30% soil moisture. The tensile strength and whiteness of films increase with CaCl2 concentration, but elongation, water absorption, water solubility, water vapor permeability, and biodegradation decrease. Overall, the strong and biodegradable switchgrass residue-based films open up a new window of opportunities to design and develop reusable, recyclable, and compostable films from underutilized, inexpensive, and abundant agricultural biomass contributing to the circular bioeconomy in a friendly and sustainable manner.

Biorefinery of peanut shell agroindustrial lignocellulosic waste for synthesis of a natural coagulant applied in the treatment of dairy wastewater

Agro-industrial lignocellulosic residue from peanut shell was used to obtain a natural coagulant, cationic hemicelluloses (CH), adding value to the residue through means of biorefinery. The hemicellulose was applied, after its cationization by etherification reaction in alkaline medium with ETA, as a natural coagulant in the treatment of synthetic dairy effluent (SDE). FTIR showed an increase of the methyl group band in 1480 cm-1, degree of substitution DS 0.38 ± 0.05 and the positive zeta potential of +13.1 ± 0.5 mV CH indicating the insertion of ETA in the structure hemicelluloses whose zeta potential was negative of ‐11.4 ± 0.6 mV. The evaluation of the CH was performed with jartest on turbidity, apparent color, and COD for a pHcoagulation range 5–11 and dosages from 50-500 ppm. Coagulation diagrams were determined using the data spatial interpolation method of the adapted Kringing regression model. The maximum performance of CH of SDE by sedimentation and DAF occurred at 50 ppm and pH 11 with turbidity removal efficiency, true color and chemical oxygen demand (COD) of 84.74%/87.48%, 98.75%/99.37% and 99.89%/93.38%, respectively. Flake morphology was analyzed through the application of an image capture non-intrusive method indicated low particle aggregation, with fractal dimension (Df) of the flakes stabilized in the range of 1.68–1.83 ± 0.020 in 15 min with a predominance of flakes with first-class flake diameters (0.022–1.20 mm) for all dosages. That explains the slower sedimentation and occurrence of smaller dispersed flakes which favored subsequent solid-liquid separation by DAF.

Statistical optimization of the yield of the oxidation of 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid catalyzed by laccase from Trametes versicolor

Lignocellulosic residues are an interesting alternative to produce furans as 5-hydroxymethylfurfural (HMF), which can be oxidized to produce 2,5-furandicarboxylic acid (FDCA). According to the latter, this research aims to optimize the oxidation yield of HMF to FDCA catalyzed by a Trametes versicolor laccase using TEMPO as a mediator. For yield optimization, a Box–Behnken experimental design was developed with three factors and three levels. The model achieved 90 % fit (R2) with a maximum yield of 100 % FDCA, using 30 mM HMF, 55 mM 2,2,6,6-Tetramethylpiperidine 1-oxyl (TEMPO), and 6 mg laccase. The oxidation kinetics (at 30 and 100 mM HMF) evidenced the presence of the intermediate compound 5-formyl-2-furancarboxylic acid (FFCA), being higher when working at a higher concentration of substrate (100 mM HMF). Optimizing the operational conditions resulted in a notable improvement, boosting the yield of FDCA by approximately 10 % compared to the initial experimentation. Finally, the values of the variables predicted by the program were validated experimentally, reaching 100 % performance.

An assessment of sustainability metrics for waste-to-liquid fuel pathways for a low carbon circular economy

The nexus of solid waste management problems and energy crisis necessitates the utilization of lignocellulosic biomass agro residues and municipal solid wastes for fuel and energy generation. Thermochemical technologies like pyrolysis, hydrothermal liquefaction and gasification are promising options to produce bio-oil, bio-crude and syngas from biomass, which can be further catalytically upgraded to hydrocarbon fuels. While there are technical merits associated with these processes and the products derived from them, the sustainability analysis of the processes from a systems level is imperative to evaluate their commercial viability. This perspective article presents fundamental understanding, importance and analysis of the different sustainability metrics based on mass and energy. The salient properties of biomass and wastes, and that of various fuels derived from them are presented. The three technologies are evaluated based on key metrics such as energy recovery/efficiency, E-factor, process mass intensity and CO2 footprint. The E-factor for different technologies follows the trend: hydrothermal liquefaction (0.14) ≈ gasification (0.13) < pyrolysis (0.5). However, it is clear from the analysis that the E-factor and GHG emissions of the HTL process, a promising feedstock-agnostic pathway, can be further reduced by valorizing the organic-laden aqueous phase and upgrading the bio-crude to hydrocarbons. The key results of process technoeconomics are presented and assessed from a sustainability viewpoint. This study recommends the use of simple sustainability metrics in research works on thermochemical conversion so that the results from different studies can be compared on a common sustainability platform.

PLA reinforced with modified chokeberry pomace and beetroot pulp fillers. Effect of oligomeric chain extender on the properties of biocomposites

Agri-food waste is an exciting way to use as a polymer filler. It is an ecological option for cutting down the material cost, especially relatively expensive biodegradable plastics. In this paper, lignocellulosic residues of chokeberry pomace (CP) and beetroot pulp (BP) are grafted with lactic acid oligomers (OLAs) in direct condensation of lactic acid (LAc) into the lignocellulosic backbone. Biocomposites with modified and unmodified fillers were prepared using poly (lactic acid) (PLA) matrix. Additionally, the influence of an epoxy-based chain extender (Joncryl® ADR 4468 (ADR)) on the properties of the biocomposites mentioned above was checked. SEM was used for the characterisation of modified and unmodified fillers. The success of the grafting reaction was confirmed by FTIR and 1HNMR analyses. DSC, DMA and TGA was applied for the characterisation of thermal properties of produced biocomposites. The influence of chemical modification and introduction of ADR to the biocomposite on water absorption, rheological and mechanical properties were tested. Moreover, the reaction between ADR and the lignocellulosic backbone of the CP filler was studied by FTIR analysis. Results showed, that modification of the filler using OLAs has a significant influence on reducing water absorption by 48.3 and 56.5 % for CP and BP biocomposites, respectively. The tensile strength increased after the modification and introduction of ADR. The chemical treatment of the filler causes an increase in the tensile strength by about 29 and 8 % compared to unmodified CP and BP fillers, respectively. 0.75 % of ADR in CP/PLA biocomposite allowed for an increase in tensile strength by 51 %. Rheological study showed that presence of ADR compensates the consequences of hydrolysis and segment exchange of the PLA chains caused by water and OLAs, respectively. Results are promising for the production of ecological biocomposites with satisfying mechanical, thermal and rheological properties compared to biocomposites with unmodified lignocellulosic filler.

Metabolic engineering of Saccharomyces cerevisiae for second-generation ethanol production from xylo-oligosaccharides and acetate

Simultaneous intracellular depolymerization of xylo-oligosaccharides (XOS) and acetate fermentation by engineered Saccharomyces cerevisiae offers significant potential for more cost-effective second-generation (2G) ethanol production. In the present work, the previously engineered S. cerevisiae strain, SR8A6S3, expressing enzymes for xylose assimilation along with an optimized route for acetate reduction, was used as the host for expressing two β-xylosidases, GH43-2 and GH43-7, and a xylodextrin transporter, CDT-2, from Neurospora crassa, yielding the engineered SR8A6S3-CDT-2-GH34-2/7 strain. Both β-xylosidases and the transporter were introduced by replacing two endogenous genes, GRE3 and SOR1, that encode aldose reductase and sorbitol (xylitol) dehydrogenase, respectively, and catalyse steps in xylitol production. The engineered strain, SR8A6S3-CDT-2-GH34-2/7 (sor1Δ gre3Δ), produced ethanol through simultaneous XOS, xylose, and acetate co-utilization. The mutant strain produced 60% more ethanol and 12% less xylitol than the control strain when a hemicellulosic hydrolysate was used as a mono- and oligosaccharide source. Similarly, the ethanol yield was 84% higher for the engineered strain using hydrolysed xylan, compared with the parental strain. Xylan, a common polysaccharide in lignocellulosic residues, enables recombinant strains to outcompete contaminants in fermentation tanks, as XOS transport and breakdown occur intracellularly. Furthermore, acetic acid is a ubiquitous toxic component in lignocellulosic hydrolysates, deriving from hemicellulose and lignin breakdown. Therefore, the consumption of XOS, xylose, and acetate expands the capabilities of S. cerevisiae for utilization of all of the carbohydrate in lignocellulose, potentially increasing the efficiency of 2G biofuel production.

A Comparative Study of Various Substrate Combinations on Mass Multiplication of Trichoderma lexii (T-94a)

The high cost of raw materials has long hindered the large-scale commercialization of Trichoderma sp. conidiophore formulations. This study addresses the need for affordable, nutrient-rich alternatives by exploring the use of lignocellulosic residues, comprising lignin, cellulose, and hemicellulose, as a carbon source for cultivating Trichoderma. These fungi possess unique attributes, such as filamentous growth and prolific spore production, which make them valuable for composting lignocellulosic waste. Using different substrates with a combination of straws effectively helps in the decomposition of straw and enhances the mass multiplication of Trichoderma lexii (T-94a). Different substrates such as broken rice, grounded maize, gram flour, sorghum &amp; broken wheat were used in combination with paddy straws. A combination of Maize + straw induced an early response in the mycelial growth of Trichoderma lexii (T-94a). After 5 and 10 days of inoculation, physical parameters such as growth and sporulation characteristics of T. lexii (T-94a) show highly uniform growth and profuse sporulation on maize and straw combination as compared to broken rice &amp; straw, sorghum, and straw combinations. This finding has promising implications for improving agricultural practices and waste management. Further research can fine-tune the optimal substrate ratios to enhance the efficiency of biocontrol agents and waste decomposition. Scaling up the application of these substrate combinations in real-world farming scenarios and assessing their long-term environmental impact will be essential for realizing the full potential of these sustainable agricultural practices.

Valorization of ripe banana peels and cocoa pod husk hydrochars as green sustainable “low loss” dielectric materials

The banana and cocoa crops are relevant worldwide and tons of their residues do not enter the industrial value chain. With this in mind, it is imperative to find alternative uses for these residues that could lead to novel and sustainable applications in diverse fields, such as consumer electronics. Lignocellulosic residues can be hydrothermally carbonized to produce a solid fraction called hydrochar. In this work, the dielectric characteristics of ripe banana peels and cocoa pod husks hydrochars are explored. Hydrothermal carbonization (HTC) treatments were carried out at two temperatures (150 °C and 210 °C) and three HTC times (2 h, 4 h, and 6 h). The materials were characterized electrically using a Semiconductor Analyzer under frequency swepts of 1 KHz to 1 MHz. Cocoa pod husk hydrochars (CHH) showed less variability in relative permittivity values compared to ripe banana peel hydrochars (BPH). The relative permittivity values of CHH ranged between 9.83 and 10.29 (150 °C) and 8.25–9.39 (210 °C), while for BPH, these values ranged between 6.89 and 14.14 (150 °C) and 6.39–8.77 (210 °C). In addition, the loss tangent values of CHH varied from 0.034 to 0.041 (150 °C) and from 0.036 to 0.038 (210 °C), while in BPH, these values varied from 0.056 to 0.091 (150 °C) and from 0.046 to 0.051 (210 °C). In both cases, HTC produced highly stable materials with low loss tangent values, making them good candidates for insulation and possessing good dielectric properties that can be further processed for downstream applications in the electronics industry.

From Waste to Resource: Valorization of Lignocellulosic Agri-Food Residues through Engineered Hydrochar and Biochar for Environmental and Clean Energy Applications-A Comprehensive Review.

Agri-food residues or by-products have increased their contribution to the global tally of unsustainably generated waste. These residues, characterized by their inherent physicochemical properties and rich in lignocellulosic composition, are progressively being recognized as valuable products that align with the principles of zero waste and circular economy advocated for by different government entities. Consequently, they are utilized as raw materials in other industrial sectors, such as the notable case of environmental remediation. This review highlights the substantial potential of thermochemical valorized agri-food residues, transformed into biochar and hydrochar, as versatile adsorbents in wastewater treatment and as promising alternatives in various environmental and energy-related applications. These materials, with their enhanced properties achieved through tailored engineering techniques, offer competent solutions with cost-effective and satisfactory results in applications in various environmental contexts such as removing pollutants from wastewater or green energy generation. This sustainable approach not only addresses environmental concerns but also paves the way for a more eco-friendly and resource-efficient future, making it an exciting prospect for diverse applications.

Strategies towards a green solvent biorefinery: Efficient delignification of lignocellulosic biomass residues by gamma-valerolactone/water catalyzed system

Biorefineries promote the integral use of lignocellulosic biomass by separating lignin, cellulose, and hemicelluloses, so environmentally friendly solvents with good efficiency in lignin removal at mild conditions (low temperatures and pressures) are under thorough research. This study evaluates the optimization of γ-Valerolactone (GVL) systems using a solvent complying with the principles of green chemistry as an efficient delignification strategy for lignocellulosic biomass residues such as sugarcane bagasse and pine sawdust. First, depithed sugarcane bagasse was delignified by a solvent system composed of GVL/water and a low concentration of sulfuric acid (SA), considering temperature, reaction time, GVL, and SA concentration in the liquor as variables, organized following a 4-factor Draper-Lin Central Composite Design (CCD). Milder treatments compared with literature were applied, with extreme points at 130–180 °C, 40–140 min, 43–77 wt% GVL, and 0–0.01 M SA, respectively. The experimental conditions involving pine sawdust were assessed at the highest delignification point of sugarcane bagasse. Delignification from 75% to 96% was obtained for sugarcane bagasse. In the same conditions, pine sawdust delignification was slightly lower. The solid fraction characterization involved yield, ISO brightness, crystallinity index, intrinsic viscosity in cupriethylenediamine, structural carbohydrates, and lignin content, whereas sugars, byproducts, and degradation products were analyzed in the liquid fraction. The study compares different properties combined into one single combined severity factor. The evaluation also involved optical properties relevant to some uses, such as dissolving pulps or nanocellulose.

Mathematical Modelling and Optimization for Facile Synthesis of Structured Activated Carbon (ACs) from Adansonia kilima (Baobab) Wood Chips Integrating Microwave-Assisted Pyrolysis for the Elimination of Lead (II) Cations from Wastewater Effluents.

In this research, activated carbon (AC) was synthesized from ligno-cellulosic residues of Adansonia kilima (Baobab) wood chips (AKTW) using two-step semi-carbonization and subsequent pyrolysis using microwave-induced heating (MWP) in the presence of a mild activating agent of K2CO3. The influence of process input variables of microwave power (x1), residence time (y1), and amount of K2CO3 (z1) were analysed to yield superior quality carbon having maximum removal efficiencies (R1) for lead (II) cations from waste effluents, fixed carbon percentages (R2), and carbon yield percentages (R3). Analysis of variance (ANOVA) was used to develop relevant mathematical models, with an appropriate statistical assessment of errors. Level factorial response surface methodology (RSM) relying on the Box-Behnken design (BBD) was implemented for the experimental design. The surface area and porous texture of the samples were determined using Brunauer, Emmett, and Teller (BET) adsorption/desorption curves based on the N2 isotherm. Surface morphological structure was observed using field emission scanning electron microscopic (FESEM) analysis. Thermogravimetric analysis (TGA) was carried out to observe the thermal stability of the sample. Change in the carbon content of the samples was determined using ultimate analysis. X-ray diffraction (XRD) analysis was performed to observe the crystalline and amorphous texture of the samples. The retention of a higher proportion of fixed carbon (80.01%) ensures that the synthesized adsorbent (AKTWAC) will have a greater adsorption capacity while avoiding unwanted catalytic activity for our synthesized final sample.

Vegetable Lignocellulosic Residues and Chitosan as Valuable Resources in the Superabsorbent Bio-aerogel Development for Food Conservation

Vegetable Lignocellulosic Residues and Chitosan as Valuable Resources in the Superabsorbent Bio-aerogel Development for Food Conservation

The integrated production of hydrochar and methane from lignocellulosic fermentative residue coupling hydrothermal carbonization with anaerobic digestion

The popularization of large-scale biogas project makes the disposal of fermentative residue an urgent issue to be solved. Hydrothermal carbonization (HTC) technology is suitable for treating wet biomass to produce carbonaceous materials. In this study, the solid residue from the two-phase anaerobic digestion (AD) was hydrothermally converted in the range of 180–240 °C, and the hydrochar and aqueous components were characterized for subsequent utilization. The heating values of hydrochar were indicated to be increased by 14.2% and 16.6% at 210 °C and 240 °C as compared with feedstock, and also the specific surface areas were 34.8 m2/g and 27.1 m2/g with 17.4- and 13.3-fold enhancement, respectively. The migration of elements such as S, Cl, K to aqueous phase was beneficial for fuel application. The mesoporous pores were dominant in hydrochars with ample oxygenated functional groups. In addition, the wastewater involved organic acids, phenols, and nitrogen-containing compounds, etc. Evaluating the biodegradability by AD, it was found that when the initial concentration was ≤8 g COD/L, the maximum methane yields up to 275.9 mL CH4/g CODremoval and 277.6 mL CH4/g CODremoval were obtained. The enhanced toxicity/inhibition of representative pollutants on microorganisms was significant at higher organic loading, which could be indicated in the microbial structure and diversity. As a conclusion, the integrated production of hydrochar and methane will provide an extended route for further processing of lignocellulosic fermentative residue.

Flowsheet analysis of bio-derived hydrogen as a surplus product at sugar mills and associated biorefineries from processing residues

The novelty was to investigate the self-sufficient integration of bio-derived H2 production at a sugar mill from lignocellulosic residues that is available at 65 tonne/h, using gasification OR anaerobic-digestion with biogas-reforming (ADR) that may include vinasse generated from an annexed ethanol distillery. Thus, the optimal use of lignocellulosic residues should ensure a steam supply of 120 tonne/h to the sugar mill, while also optimising the production of H2. Overall process economic costs were evaluated with the minimum selling price of H2 (MSPH). Thus, gasification processes may have produced 2566 kg/h of H2 at the lowest cost of 6.9 US$/kg, and ADR may have produced 2067 kg/h of H2 at 7.7 US$/kg from lignocelluloses that underwent steam-explosion. Otherwise, annexing ethanol production could allow an H2 selling price under 5 US$/kg, if ethanol trades above 1.6 US$/kg. Generally, the milling season limited the annual H2 production, and hence the annual economic returns.

Ageing effect on ignition sensitivity of lignocellulosic dust

As the use of biomass as a carbon-neutral energy source increases, so does the need for storage facilities, especially for those that are highly seasonal. Consequently, the stored materials may be subject to a natural ageing process before they are used. Such ageing can modify the deflagration parameters of the materials since it can reduce hygroscopicity, increase stiffness and brittleness and change chemical composition in terms of cellulose, hemicellulose and lignin contents. Hydrothermal treatment is a process that accelerates the ageing of wood and lignocellulosic materials. In this work, several lignocellulosic powders from industrial processes were subjected to accelerated ageing to investigate their influence on flammability properties. Grape marc, cork flour, olive pomace, wood dust and lignocellulosic residues from processing waste were selected based on their morphology, chemical characterization and lignin/cellulose content. Based on literature data, ageing conditions in terms of temperature and humidity were chosen to reproduce naturally aged materials. In this study, the effects of ageing on the minimum ignition energy (MIE) and combustion/pyrolysis behaviour were investigated by chemico-physical screening and thermogravimetric analysis and differential scanning calorimetry (TGA and DSC) in an inert and oxidative atmosphere. Results showed how ageing can change the risk of ignition. For example, the MIE of grape marc decreases, while wood-based samples do not ignite after ageing. The decrease in the case of grape pomace is consistent with the decrease in lignin content and moisture. At the same time, passivation of the particle surface could explain the behaviour of the wood samples.

Metabolite Profiling of Pleurotus ostreatus Grown on Sisal Agro-Industrial Waste Supplemented with Cocoa Almond Tegument and Wheat Bran.

Pleurotus ostreatus is an edible fungus with high nutritional value that uses industrial and agricultural lignocellulosic residues as substrates for growth and reproduction. Understanding their growth metabolic dynamics on agro-industrial wastes would help to develop economically viable and eco-friendly biotechnological strategies for food production. Thus, we used UHPLC/MS/MS and GNPS as an innovative approach to investigate the chemical composition of two strains of P. ostreatus, coded as BH (Black Hirataki) and WH (White Hirataki), grown on sisal waste mixture (SW) supplemented with 20 % cocoa almond tegument (CAT) or 20 % of wheat bran (WB). Metabolite dereplication allowed the identification of 53 metabolites, which included glycerophospholipids, fatty acids, monoacylglycerols, steroids, carbohydrates, amino acids, and flavonoids. This is the first report of the identification of these compounds in P. ostreatus, except for the steroid ergosterol. Most of the metabolites described in this work possess potential biological activities, which support the nutraceutical properties of P. ostreatus. Thus, the results of this study provide essential leads to the understanding of white-rot fungi chemical plasticity aiming at developing alternative biotechnologies strategies for waste recycling.

Application of solid-state fermentation using mushrooms for the production of animal feed.

The increasing growth of agroindustrial activity resulting in excessive amounts of agriwaste has led to the accumulation of a large quantity of lignocellulosic residues all over the world, in particular in deforestation initiatives for the removal of invasive trees in South Africa. These lignocellulosic residues are rich in energy resources and consist of a mixture of natural polymers based on lignin, cellulose, and hemicellulose. The use of lignolytic fungi such as mushrooms in solid-state fermentation could sufficiently degrade the indigestible lignocellulosic components and add medicinal and nutritional value to otherwise unusable, high-energy waste material, which in turn could yield a new method of producing energy-rich fodder for ruminant animals. The digestive type of animal for which the potential feed is developed must be identified and considered before deciding on the bioconversion method and process, as the outcomes for obtaining potentially high-quality feeds for nonruminant and ruminant animals are different. The current study presents data on the bioconversion of lignocellulosic substrate using solid-state fermentation with edible and medicinal mushrooms, Ganoderma lucidumand Pleurotus ostreatus, and a possible new species, to increase digestibility and nutritional value to be applied as ruminant animal feed. The solid-state fermentation process was optimized and the resulting product was analyzed for the degradation of the lignocellulosic components. Results indicated that the solid-state fermentation duration and mushroom species were key components in achieving significant degradation. Data obtained after 18 weeks of degradation indicated a significant (p < 0.05) reduction in the acid detergent fiber, acid detergent lignin, and neutral detergent fiber fractions of the biomass, with up to a 20% reduction in indigestible components. This increase in digestibility could contribute to increased energy availability for ruminant animals.

CO2 capture by microporous carbon based on Brazil nut shells.

The increase in burning, deforestation, and the exorbitant use of fossil fuels have contributed to the increase in carbon dioxide emissions; this gas is responsible for the intensification of the greenhouse effect and radical climate changes. In this way, it becomes necessary to find alternatives to reduce its emission. Porous carbon materials synthesized from lignocellulosic waste can be employed in technologies for capture and utilization of CO2 due to the advantages such as selectivity, low-cost synthesis, high surface area and pore volume, and thermal and chemical stability. Considering the availability of Brazil nut biomass residues in the Amazon region, this article proposes to synthesize activated carbon from the lignocellulosic residue using physical and chemical activation methods for CO2 capture. The analysis of N2 adsorption-desorption isotherms proves the predominance of a microporous structure when using the two synthesis methods described here. In physical activation, the surface area was 912 m2/g, while, in chemical activation, it was 1421 to 2730 m2/g. The sample treated via the chemical method (BS6-K1) showed better performance in CO2 adsorption, with adsorption results of 3.8 and 6mmol/g of CO2 at 25 ℃ and 0°C, respectively, at 101kPa. CO2 adsorption capacity is due to the high volume of ultramicropores. It is believed that the microporous carbon material synthesized from Brazil nut residues is an alternative precursor for carbon materials used as CO2 capture.

Suitability of maize crop residue fermented by Pleurotus ostreatus as feed for edible crickets: growth performance, micronutrient content, and iron bioavailability.

Small-scale farming of edible insects could help combat public health challenges such as protein energy malnutrition and anemia, but reliable low-cost feeds for insects are needed. In resource-limited contexts, where grains such as maize are prohibitively costly for use as insect feed, the feasibility of insect farming may depend on finding alternatives. Here, we explore the potential to modify plentiful maize crop residue with edible mushroom mycelium to generate a low-cost feed adjunct for the farmed two-spotted cricket, Gryllus bimaculatus. Mushroom farming, like insect agriculture, is versatile; it can yield nutritious food while increasing system circularity by utilizing lignocellulosic residues from row crops as inputs. Pleurotus ostreatus, is an edible basidiomycete capable of being cultivated on corn stover (Zea mays). Mushroom harvest results in abundant "spent" substrate, which we investigated as a candidate feed ingredient. We created six cricket feeds containing fermented Pleurotus substrate plus an unfermented control, measuring cricket mass, mortality, and maturation weekly to evaluate cricket growth performance impacts of both fungal fermentation duration and mushroom formation. Pasteurized corn stover was inoculated with P. ostreatus mycelium and fermented for 0, 2, 3, 4, or 8 weeks. Some 4 and 8-week substrates were induced to produce mushrooms through manipulations of temperature, humidity, and light conditions. Dried fermented stover (40%) was added to a 1:1 corn/soy grain mix and fed to crickets ad libitum for 44 days. The unfermented control group showed higher survivorship compared to several fermented diets. Control group mass yield was higher for 2 out of 6 fermented diets. Little variation in cricket iron content was observed via ICP-spectrometry across feeds, averaging 2.46 mg/100 g. To determine bioavailability, we conducted in vitro Caco-2 human colon epithelial cell absorption assays, showing that iron in crickets fed fruiting-induced substrates was more bioavailable than in unfruited groups. Despite more bioavailable iron in crickets reared on post-fruiting substrates, we conclude that Pleurotus-fermented stover is an unsuitable feed ingredient for G. bimaculatus due to high mortality, variability in growth responses within treatments, and low mass yield.