Original Biomass Research Articles

The ecological and socioeconomic implications of future total allowable catch decisions and illegal fishing scenarios for South Africa’s West Coast rock lobster fishery

The West Coast rock lobster fishery, vital to South Africa, is in a critical state with only 1.1 % of its original exploitable biomass remaining. This study evaluates effects of various total allowable catch (TAC) decisions on biomass and economic performance, taking illegal fishing, currently a serious problem, into account. TAC options included two sustainable options and an option (1500 mt), which could only be feasible if illegal fishing is stopped. Biomass projections, from 2022 to 2050, are modelled from a length-based model incorporating a Beverton and Holt stock-recruit relationship. The impacts of different TAC decisions on biomass, net seasonal incomes (NSI) and net present value (NPV) are assessed. Sensitivity to different discount rates is also considered. Biomass projections suggest an imminent collapse if legal fishing limits are set too high or if IUU fishing is not substantially reduced. The NPVs for the entire sectors are found to be highest under a 1500 mt TAC but unless accompanied by a halt to IUU fishing, would result in unsustainable catch rates and rapidly declining NSI in areas where many quota holders are located. Under the 550 mt TAC scenario, there is less risk of biomass declines but the quotas for many stakeholders would be economically unviable. Lower TAC options are forecast to lead to the functional exclusion of many rights holders and reduction in employment. The most secure and economically successful strategy is considered to be adjusting annual TACs in response to the effectiveness of controlling IUU fishing and changes in biomass.

Effect of Separating Air into Primary and Secondary in an Integrated Burner Housing on Biomass Combustion

Pellet burners, although they are commonly used devices, require high-quality fuels and yet are characterized by relatively high levels of CO and NO emissions and their variability. This article presents a combustion study of an original biomass burner that separates air into primary for biomass gasification and secondary for oxidizing the gasification products, with ducts placed in the housing of the burner. This study introduces a new burner design that separates air into primary and secondary streams within an integrated burner housing, aiming to optimize biomass combustion efficiency and reduce harmful emissions. Two burner designs were proposed, with a high secondary air nozzle (HCrown) and a low secondary air nozzle (LCrown). These two burners were compared with a typical retort burner (Ret). The LCrown burner reduced particulate matter emissions by 36% and CO emissions by 74% with respect to a typical retort burner. This study showed that the distance of the secondary air nozzles from the gasifying part has a significant impact on the operation of the burner and the possibility of reducing emissions of CO and NO. These results highlight the potential of the innovation to significantly improve combustion quality while simultaneously reducing environmental impact.

A Strategic Synthesis of Orange Waste-Derived Porous Carbon via a Freeze-Drying Method: Morphological Characterization and Cytocompatibility Evaluation.

Porous carbon materials from food waste have gained growing interest worldwide for multiple applications due to their natural abundance and the sustainability of the raw materials and the cost-effective synthetic processing. Herein, orange waste-derived porous carbon (OWPC) was developed through a freeze-drying method to prevent the demolition of the original biomass structure and then was pyrolyzed to create a large number of micro, meso and macro pores. The novelty of this work lies in the fact of using the macro-channels of the orange waste in order to create a macroporous network via the freeze-drying method which remains after the pyrolysis steps and creates space for the development of different types of porous in the micro and meso scale in a controlled way. The results showed the successful preparation of a porous carbon material with a high specific surface area of 644 m2 g-1 without any physical or chemical activation. The material's cytocompatibility was also investigated against a fibroblast cell line (NIH/3T3 cells). OWPC triggered a mild intracellular reactive oxygen species production without initiating apoptosis or severely affecting cell proliferation and survival. The combination of their physicochemical characteristics and high cytocompatibility renders them promising materials for further use in biomedical and pharmaceutical applications.

Global biomass maps can increase the precision of (sub)national aboveground biomass estimates: A comparison across tropical countries

Countries within the tropics face ongoing challenges in completing or updating their national forest inventories (NFIs), critical for estimating aboveground biomass (AGB) and for forest-related greenhouse gas (GHG) accounting. While previous studies have explored the integration of map information with local reference data to fill in data gaps, limited attention has been given to the specific challenges presented by the clustered plot designs frequently employed by NFIs when combined with remote sensing-based biomass map units. This research addresses these complexities by conducting four country case-studies, encompassing a variety of NFI characteristics within a range of AGB densities. Examining four country case-studies (Peru, Guyana, Tanzania, Mozambique), we assess the potential of European Space Agency's Climate Change Initiative (CCI) global biomass maps to increase precision in (sub)national AGB estimates. We compare a baseline approach using NFI field-based data with a model-assisted scenario incorporating a locally calibrated CCI biomass map as auxiliary information.The original CCI biomass maps systematically underestimate AGB in three of the four countries at both the country and stratum level, with particularly weak agreement at finer map resolution. However, after calibration with country-specific NFI data, stratum and country-level AGB estimates from the model-assisted scenario align well with those obtained solely from field-based data and official country reports. Introducing maps as a source of auxiliary information fairly increased the precision of stratum and country-wise AGB estimates, offering greater confidence in estimating AGB for GHG reporting purposes.Considering the challenges tropical countries face with implementing their NFIs, it is sensible to explore the potential benefits of biomass maps for climate change reporting mechanisms across biomes. While country-specific NFI design assumptions guided our model-assisted inference strategies, this study also uncovers transferable insights from the application of global biomass maps with NFI data, providing valuable lessons for climate research and policy communities.

Abiotic synthesis of graphitic carbons in the Eoarchean Saglek-Hebron metasedimentary rocks

Graphite in metasedimentary rocks of the Eoarchean Saglek-Hebron Gneiss Complex (Canada) is depleted in 13C and has been interpreted as one of the oldest traces of life on Earth. The variation in crystallinity of this oldest graphitic carbon could possibly confirm the effect of metamorphism on original biomass, but this is still unexplored. Here, we report specific mineral associations with graphitic carbons that also have a range of crystallinity in the Saglek-Hebron metasedimentary rocks. Petrographic, geochemical and spectroscopic analyses in the Saglek-Hebron banded iron formations suggest that poorly crystalline graphite is likely deposited from C-H-O fluids derived from thermal decomposition of syngenetic organic matter, which is preserved as crystalline graphite during prograde metamorphism. In comparison, in the Saglek-Hebron marble, disseminations of graphite co-occur with carbonate and magnetite disseminations, pointing to abiotic synthesis of graphitic carbons via decarbonation. Our results thus highlight that variably crystalline graphitic carbons in the Saglek-Hebron metasedimentary rocks are potential abiotic products on early Earth, which lay the groundwork for identifying the preservation of prebiotic organic matter through metamorphism on Earth and beyond.

Can we see differences between the 14C activities of urban (Zagreb) and rural (Cvetković) sites (central Croatia)?

Radiocarbon (Δ14C) was measured for four years (2019–2022) in Zagreb (Croatia) and in Cvetković village near Jastrebarsko (Zagreb County, Croatia) to see whether there are differences between the city site and the rural one because of the fossil fuel combustion. The δ13CCO2 was measured as grab samples once in a month in period December 2020–November 2022. The bomb-produced 14C has been globally distributed across the planet, but the combustion of fossil fuels that do not contain 14C causes a local effect of lowering Δ14C. Zagreb is considered to be a location with heavy fossil fuel combustion as compared to the Cvetković (rural site). Monthly 14C activity at Zagreb is constantly below the 14C activity at Cvetković. Mean 14C activity at Zagreb (Δ14CZagreb = −18.4 ± 2.6 ‰) is lower than that in Cvetković (Δ14CCve = −2.9 ± 2.1 ‰) due to fossil fuel combustion in the city of Zagreb. This is especially pronounced during winter when the mean value in Zagreb is Δ14CZagreb = −26.0 ± 4.3 ‰ and in Cvetković Δ14CCve = −5.9 ± 3.4 ‰.Natural gas consumption was used as the proxy for fossil fuel combustion, and it shows better correlation with Δ14C in Zagreb than in Cvetković. The Δ14C difference, Δ14CCve ‒ Δ14CZagreb, becomes statistically negligible when natural gas consumption is small.No difference is observed on δ13CCO2; in Zagreb mean δ13CCO2 is −11.0 ± 1.3 ‰, and in Cvetković −11.4 ± 1.4 ‰. Lower δ13CCO2 values are observed in winter (Zagreb −11.9 ± 1.1 ‰, −12.2 ± 1.5 ‰ Cvetković) than in summer (−10.1 ± 0.8 ‰ vs. −10.4 ± 1.0 ‰) at both locations. Together with higher Δ14C in Cvetković, it indicates that at the area of Cvetković biogenic samples of modern origin (biomass, wood) as energy source for heating is more pronounced.

Atlas of Microscopic Images of Biochar

Derived through the thermochemical conversion of biomass, biochar is a carbon-rich substance recognized for its significance in environmental applications and sustainable agriculture. As interest in its utilization continues to rise, it becomes crucial to comprehend how the source material and pyrolysis parameters influence the properties of biochar and, consequently, to research the suitability of various analytical methods for characterizing it. Despite the current utilization of numerous physical and chemical methods, the untapped potential of reflected light microscopy warrants further exploration. While a few recent studies suggest a correlation between certain microscopic characteristics and selected physical and chemical properties of biochar, the data are limited and difficult to compare. This is primarily due to variations in the types of original biomass used and lack of information about pyrolysis conditions. Moreover, because only a limited number of photographs taken under a reflected light microscope are publicly available to-date, it is difficult to evaluate morphological differences between various biochars and other organic materials such as inertinites from coal, charcoal, etc. To address limited availability of publicly available data, this “Atlas of Microscopic Images of Biochar” presents a collection of more than 300 images contributed by researchers from Poland, the United States, Canada, Australia, Brazil, and Denmark. These photomicrographs capture optical characteristics of a diverse array of biochar, demonstrating its unique morphological and structural features. This visual documentation can serve as a valuable resource for researchers, industry professionals, educators, and enthusiasts interested in investigating the complexities of biochar forms.

Woody biomass waste derivatives in decarbonised blast furnace ironmaking process

Modern ironmaking process relies significantly on fossil-related fuels, which ultimately results in the enormous CO2 emitted into the atmosphere. Biomass of plant origin, as a carbon-neutral energy source, has been considered as an alternative to fossil-based reducing agents such as coke. This study aims to investigate the potential of three woody biomass waste derivatives produced from biomass waste pyrolysis and gasification, namely charcoal, bio-oil, and bio-syngas, as the reducing agents in blast furnace. A model based on heat and mass balance and Gibbs free energy minimisation is proposed to simulate an ironmaking process with assistance of these derivatives. The effects of specific composition of biomass waste derivatives on process operation, CO2 emissions, and coke replacement are explored. Also the effects of H2-rich gas produced from biomass waste gasification on the blast furnace operation are estimated. Results indicate that reactions of woody biomass waste derivatives in blast furnace are complex and greatly dependent on composition. When charcoal has a higher carbon content, lower CO2 concentration is found from the top gas. The higher content of hydrogen in bio-oil will inhibit further reduction in CO2 emissions. Bio-syngas with H2/CO ratio of 1.3 proves to have a remarkable potential to reduce CO2 emissions. From the aspects of available biomass waste resources across the world, woody biomass waste derivatives as reducing agents are more suitable for countries with the limited pig iron production. This study provides a reference on the future of moving forward the decarbonised ironmaking by using woody biomass waste derivatives.

Landings of Sphyrna zygaena (Linnaeus, 1758) in northern Peru indicate a lack of adult specimens

A commercial fishery for the smooth hammerhead shark (Sphyrna zygaena) exists in the waters off northern Peru. Although international and domestic norms regulate this species, adult specimens are becoming rare. Monthly visits to four ports in the La Libertad region were made to measure S. zygaena landings and understand the present state of the fishery. We found that 92% of the specimens landed were juveniles or younger and that 10% of the original biomass remains in the fishery. This highlights that stricter regulations such as protecting breeding areas, establishing a legal catch length, and limiting the catch volume and fishing season are urgently needed to maintain a sustainable fishery.

Ultrasound-based strategies for the recovery of microalgal carotenoids: Insights from green extraction methods to UV/MS-based identification

Carotenoids, versatile natural pigments with numerous health benefits, face environmental concerns associated with conventional petrochemical-based extraction methods and limitations of their synthetic equivalents. In this context, this study aims to introduce eco-friendly approaches using ultrasound-based strategies (probe and bath) for the extraction of carotenoids from microalgae, initially focusing on Microchloropsis gaditana and subsequently evaluating the versatility of the method by applying it to other microalgae species of interest (Tisochrysis lutea, Porphyridium cruentum, and Phaeodactylum tricornutum) and defatted microalgal residues. Among the approaches evaluated, the 5-min ultrasonic probe system with ethanol showed comparable carotenoid recovery efficiency to the reference method (agitation, 24 h, acetone) (9.4 ± 2.5 and 9.6 ± 3.2 mg g−1 carotenoids per dry biomass, for the green and the reference method, respectively). Moreover, the method's sustainability was demonstrated using the AGREEprep™ software (scored 0.62 out of 1), compared to the traditional method (0.22 out of 1). The developed method yielded high carotenoid contents across species with diverse cell wall compositions (3.1 ± 0.2, 2.1 ± 0.3, and 4.1 ± 0.1 mg g−1 carotenoid per dry biomass for T. lutea, P. cruentum, and P. tricornutum, respectively). Moreover, the application of the method to defatted biomass showed potential for microalgal valorization with carotenoid recovery rates of 41 %, 60 %, 61 %, and 100 % for M.gaditana, P. tricornutum, T. lutea, and P. cruentum, compared to the original biomass, respectively. Furthermore, by using high-performance liquid chromatography with a diode array detector (HPLC-DAD) and high-resolution mass spectrometry (HRMS), we reported the carotenoid and chlorophyll profiles of the different microalgae and evaluated the impact of the eco-friendly methods. The carotenoid and chlorophyll profiles varied depending on the species, biomass, and method used. In summary, this study advances a green extraction method with improved environmental sustainability and shorter extraction time, underscoring the potential of this approach as a valuable alternative for the extraction of microalgal pigments.

PROCESSING OF OLD SLUDGE DEPOSITS INTO COMPOSITE FUEL

An urgent problem in Ukraine is overcrowded sludge sites with outdated sludge deposits. Due to the food problem, the world needs to maximize the release of land areas that have been under technical use and reclaim them for agricultural land. Therefore, the processing of obsolete sludge deposits makes it possible to reuse land for activated sludge or for reclamation for other needs of the country. The paper sets the task of studying obsolete sludge deposits to create a technology for their processing. Due to the high ash content of old silt deposits, it was proposed to combine them with peat and biomass. This will reduce ash content by 1.5–2.0 times. Since the created composite granules and the sludge deposits themselves have a high moisture of 61–68 %, the drying kinetics was studied on a convective experimental stand to reduce it. The research results showed that composite granules have a drying time of 28–39 minutes to a moisture content of 6–7 %, which is 2.3–3.1 times faster than peat. The equilibrium moisture content of composite granules was determined to be 6–7 % and not exceeding the standard moisture content for fuel granules. The heat of combustion of obsolete sludge deposits, which is 11.8 MJ/kg, and the resulting composite granules based on them, was determined, which is quite high and, depending on the composition, is in the range of 13.4–15.5 MJ/kg. During the study of the combustion of a separate fraction of aged sludge deposits, it was found that the combustion process occurs in the upward convective flow of the oxidant behind the double boundary layer. It was determined that the combustion rate is independent of its size and is the same, but the mass affects the time of ignition. Further studies on the combustion of composite granules showed that the combustion rate of the granules is significantly lower than the combustion rate of the original biomass, but the combustion rate of a separate fraction of silt deposits prevails. Bibl. 32, Fig. 8, Tab. 1.

Biomass Densification to Improve Management Efficiency and to Obtain High Value Products in México

In México, the utilization of fast-growing plant species for biomass production presents transportation-related issues such as freshness reduction, the transportation of large volumes with minimal weight due to low density, limited storage availability, and logistical challenges. To enhance understanding in this field, the research aimed to evaluate the densification potential of a variety of organic materials, with a specific emphasis on the biomass derived from eight species of rapidly growing plants, three animal species’ manure, and concentrated feed. After conditioning, 100 g samples underwent particle size analysis and were categorized into seven sizes. Pellets and briquettes (40 g, 10% moisture, 15 MPa pressure, 5 min processing, 80 °C temperature) were produced and evaluated for bulk density (BD) and pellet (PD) and briquette durability (BDU). The predominant particle sizes were 0.850 mm and 0.425 mm. Original biomass bulk density (OBBD) varied notably, with ovine manure (0.50 g cm−3) and cattle feed (0.49 g cm−3) exhibiting the highest values. Caprine manure (0.83 g cm−3) and ovine manure (0.78 g cm−3) yielded the densest pellets at 1.76 and 1.84 g cm−3, respectively. Apple tree pellets achieved premium quality with the highest hardness (97.9%). Cattle manure (1.25 g cm−3) and cattle feed (1.25 g cm−3) had the densest briquettes, with notable BBD/OBBD ratios in pine sawdust (4.6) and corn (4.5). Caprine manure and Acacia biomass briquettes showed premium quality with the highest hardness (99.1%), emphasizing densification variations and the need for tailored approaches based on organic material characteristics.

Advancing safe bioenergy production from cadmium-contaminated sweet sorghum through mild synergistic pretreatment

Phytoremediation is an eco-friendly and cost-effective method for treating cadmium (Cd)-contaminated soil. However, safe disposal of harvested hyperaccumulators remains scarce. Herein, a mild synergistic pretreatment combining dilute acid and alkali pretreatment was developed for safe biorefining of the Cd-containing sweet sorghum, and Cd was centrally extracted into the acid pretreatment liquid in the first step. The results showed that the synergistic pretreatment was more effective in removing Cd from the biomass and overcoming biomass recalcitrance. During the synergistic pretreatment, the Cd concentration in biomass dramatically decreased from 4.03 to 0.00626 mg/kg, and a considerable amount of lignin and hemicelluloses in biomass was removed, facilitating enzymatic saccharification and safe bioenergy production. The optimal conditions of the synergistic pretreatment resulted in a total sugar yield of 81.6 wt %, which was 4.7-fold higher than that of the original biomass. This strategy holds promise for reducing the cost of industrial saccharification and is a valuable inspiration for the safe handling and resource utilization of Cd-containing biomass.

Comparison of Waste Biomass from Pine, Eucalyptus, and Acacia and the Biochar Elaborated Using Pyrolysis in a Simple Double Chamber Biomass Reactor

Using waste biomass is considered one of the ways to reduce climate change. Arboreal waste biomass from pine, eucalyptus, and particularly invasive plants (Acacias) would make it possible to transform this natural resource, but needs to be adjusted to current and innovative technologies. The production of high fixed carbon biochar with this biomass would improve not only environmental aspects, but also the use of currently not susceptible materials for other types of exploitation. The objective of this study is to develop biochar from three different waste biomass materials and compare their parameters with those of the original biomass. Thermochemical conversion processes were used in a simple double chamber reactor developed for this study. Temperatures between 400 and 500 °C during 280 min were achieved and allowed to transform the initial biomass in a biochar with a high content of fixed carbon. By comparing the original biomass with the final biochar through tests of humidity, density, calorific values, fixed carbon, and cationic and elemental analysis, an increase in the parameters was confirmed. Fixed carbon of 70%, 77%, and 71% with pine, acacia, and eucalyptus biomass have been obtained, respectively, with yields between 30% and 40%. The results are favorable, particularly with acacia invasive plants, and could help in their difficult silviculture management.

Performance and mechanism of benzene adsorption on ZnCl2 one-step modified corn cob biochar.

Utilizing cost-effective corn cob, zinc chloride-modified biochar was synthesized through one-step method for benzene adsorption from air. Study on impregnation ratio impact showed optimal benzene adsorption at ZnCl2:CC ratio of 1.5:1, with capacity reaching 170.53mgg-1. Characterization using BET, SEM, FTIR, and XPS was conducted. BET results indicated specific surface area of Zn1.5BC at 1260.63 m2g-1 and maximum pore volume of 0.546 m3g-1. SEM analysis revealed microporous-mesoporous structure in Zn1.5BC, marking significant improvement over original biomass. DFT pore size distribution and FTIR analysis suggested post-modification dehydration and elimination reactions, leading to volatile compound release, functional group reduction, and pore widening. XPS analysis showed decrease in O = C-OH content with increased impregnation ratio, enhancing biochar's π-π electron diffusion for benzene. Langmuir isotherm and pseudo-second-order kinetic models effectively described experimental data, indicating multilayer benzene adsorption on biochar controlled by complex physicochemical adsorption and pore diffusion. Adsorption condition assessment, including adsorption temperature (20-120℃) and benzene concentration in inlet phase (159.73-383.36 mg L-1), was performed. Yoon-Nelson model fitting indicated adsorption site loss at higher temperatures and reduced capture ability due to increased adsorbate molecule kinetic energy. Higher adsorbate concentrations aided adsorption molecule diffusion to biochar surface and internal pores, increasing adsorption rate and shortening equilibrium time. Overall, zinc chloride-modified biochar facilitates benzene adsorption through pore filling and π-π interactions, with pore filling as primary mechanism. Produced biochar shows excellent regeneration properties and reusability.

Dinâmica estrutural em uma floresta tropical sazonalmente seca sob diferentes sistemas silviculturais

ABSTRACT Considering the importance of evaluating the compatibility between the exploration system usually used in the Caatinga and the vegetation regeneration process, this study aimed to evaluate the feasibility of recovering structural parameters in an experimental unit subjected to different management systems aged 9, 12, 16, 20 and 26 years post-exploitation. The area was subjected to clearcutting (CC) regimes and three types of selective cuttings (SC1 – selective cutting 1, cut of trees with diameter at the base – DAB < 15 cm; SC2 – selective cutting 2, cut of trees with DAB > 10 cm; and SC3 – selective cutting 3, cut of trees with DAB between 5 and 10 cm). In permanent plots of 20 m × 20 m, individuals with a circumference at breast height (CBH) ≥ 6 cm and a total height greater than 1.0 m were measured. Over the years of monitoring, the CC presented the lowest values of density, dominance, and volume, not obtaining a recovery in basal area and volume even after 26 years of regeneration. Treatments SC2 and SC3 stood out regarding recovery of the original woody biomass stock, presenting values higher than the original ones and indicating that the initial data did not correspond to the site's maximum potential. The forest dynamics pointed to the insufficiency of the 15-year clearcutting cycle in terms of recovering this region forest composition and structure.

Biomass Pyrolysis-Derived Biochar: A Versatile Precursor for Graphene Synthesis.

Graphene, a two-dimensional carbon allotrope with a honeycomb structure, has emerged as a material of immense interest in diverse scientific and technical domains. It is mainly produced from graphite by mechanical, chemical and electrochemical exfoliation. As renewable energy and source utilization increase, including bioenergy from forest and woody residues, processed, among other methods, by pyrolysis treatment, it can be expected that biochar production will increase too. Thus, its useful applications, particularly in obtaining high-added-value products, need to be fully explored. This study aims at presenting a comprehensive analysis derived from experimental data, offering insights into the potential of biomass pyrolysis-derived biochar as a versatile precursor for the controlled synthesis of graphene and its derivatives. This approach comprehended the highest energy output and lowest negative environmental footprint, including the minimization of both toxic gas emissions during processing and heavy metals' presence in the feedstock, toward obtaining biochar suitable to be modified, employing the Hummers and intercalation with persulfate salts methods, aiming at deriving graphene-like materials. Material characterization has revealed that besides morphology and structural features of the original wooden biomass, graphitized structures are present as well, which is proven clearly by Raman and XPS analyses. Electrochemical tests revealed higher conductivity in modified samples, implying their graphene-like nature.

Interactive influence of particle size and carbonization temperature on Silicon availability in Rice husk biochar

ABSTRACT This study examined the influence of rice husk (RH) particle size, carbonization temperature, and their interaction on the availability of Silicon (Si) in RH biochar obtained from the carbonization of different particle sizes of RH (≤1 mm, >1 mm, and the original size, i.e., the unmodified RH biomass (O_RH)) at varying carbonization temperatures from 300 to 700°C. Silicon content in the biochar was extracted with 0.01 M CaCl2. Results showed that the influence of RH particle size on available Si is modified by temperature. The maximum available Si from the RH biochar were 2145 mg kg−1 at 700°C for O_RH, 2428 mg kg−1 at 600°C for > 1 mm RH and 2562 mg kg−1 at 500°C for ≤ 1 mm RH. These were an increase of 171%, 207% and 224% respectively, compared to the uncarbonized original rice husk (790 mg kg −1). Smaller particle sizes attained the maximum values of available silicon at lower temperatures compared with the original RH probably due to the efficient heat transfer to the smaller RH particle surface because of the smaller packing/void volume between the particles. Thus, the carbonization of smaller particles of RH will produce higher available Si content at a lower carbonization temperature than that required to achieve the same effect in the original RH biomass, thereby saving energy and time.

The influence of biomass type on hydrothermal carbonization: Role of calcium oxalate in enhancing carbon sequestration of hydrochar

Addressing climate change through effective carbon sequestration strategies is critical. This study presents an investigation into the hydrothermal carbonization (HTC) and co-hydrothermal carbonization (Co-HTC) of invasive plants (IPs) to produce hydrochars to unveil the significant impact of biomass type and unique mineral on the stability of hydrochars. Nine hydrochars were produced from six IPs, utilizing both single and mixed biomass. A key finding is the observable that calcium oxalate forms as a surface mineral during HTC through different characterization techniques, the presence of which notably influenced the stability of hydrochars, resulting in enhanced thermal (highest R50 = 0.81) and chemical (lowest carbon loss rate = 4.02%) stability of hydrochars, possibly acting as a protective layer. Besides, a positive correlation was established between the yield of hydrochars and the lignin content of the original biomass. It is also observed that Co-HTC of plant materials rich in Ca2+ can enhance the formation of calcium oxalate minerals. This is likely due to their synergistic role in the HTC process, promoting the release of more C2O42− and Ca2+. Our results signify the crucial role of biomass composition in the HTC process and spotlight the potential of calcium oxalate in augmenting hydrochar stability. This study offers valuable insights that bolster the theoretical framework for employing hydrochar derived from IPs as a potent material for carbon sequestration.

Comprehensive Characterization of Some Selected Biomass for Bioenergy Production.

There is a lack of information about the detailed characterization of biomass of Nigerian origin. This study presents a comprehensive characterization of six biomass, groundnut shells, corncob, cashew leaves, Ixora coccinea (flame of the woods), sawdust, and lemongrass, to aid appropriate selection for bio-oil production. The proximate, ultimate, calorific value and compositional analyses were carried out following the American Standard for Testing and Materials (ASTM) standards. Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy with energy-dispersive X-ray spectroscopy, and X-ray fluorescence were employed in this study for functional group analyses, thermal stability, and structural analyses. The H/C and O/C atomic ratios, fuel ratio, ignitability index, and combustibility index of the biomass samples were evaluated. Groundnut shells, cashew leaves, and lemongrass were identified as promising feedstocks for bio-oil production based on their calorific values (>20 MJ/kg). Sawdust exhibited favorable characteristics for bio-oil production as indicated by its higher volatile matter (79.28%), low ash content (1.53%), low moisture content (6.18%), and high fixed carbon content (13.01%). Also, all samples showed favorable ignition and flammability properties. The low nitrogen (<0.12%) and sulfur (<0.04%) contents in the samples make them environmentally benign fuels as a lower percentage of NOx and SOx will be released during the production of the bio-oil. These results are contributions to the advancement of a sustainable and efficient carbon-neutral energy mix, promoting biomass resource utilization for the generation of energy.