Waste Biomass Research Articles

Gasification of mixed plastic-biomass pellets in an updraft fixed bed reactor: a simplified dynamic model

In the context of materials recycling, updraft gasifiers are promising small and middle-scale reactors to obtain building blocks and/or energy from waste plastic and biomasses. To this aim, these kinds of materials can also be mixed and reduced into pellets, while the needed heat enters the process with a heated carrier gas. In order to preliminarily design a gasifier to check its feasibility with an available feedstock, currently available models are inadequate. Thermodynamic ones are useless for the purposes of sizing, while too detailed rate-based models (e.g. based on fluid-dynamic modelling) are too substrate specific, need detailed input data and are extremely time consuming. A dynamic model of a fixed-bed reactor for biomass gasification is presented here. The gasifier is loaded continuously from the top with solid pellets and fed with counter-current air flow. The model considers: i) a one-step gasification kinetics, yielding a product spectrum which matches experimental data from the literature; ii) dynamic gas and solid energy balances and iii) steady-state energy balance for the furnace. The model has been applied to describe a tubular furnace (Ø 40 cm) which gasifies 500 – 1000 kg day-1 of mixed wastes using air heated up to 1200 °C: on the basis of the produced chemicals, the energy consumption was estimated as ca. 2 MJ per kg of solid feedstock. This simplified approach proved robust in describing the overall yields and start-up dynamics, showing higher reliability than equilibrium models in addressing the temperature profiles, at the cost of a simplified reaction kinetic and pellet description with respect to more complex simulation models. The model validation was done by comparison between the calculations results and available pilot-plant data. An overall good fit of the data can be concluded. The solid-gas heat transfer and the bed packing are the main computational criticalities to achieve a reliable process description.

Yeast culture enhances long-term fermentation of corn straw by ruminal microbes for volatile fatty acid production: Performance and mechanism

Ruminal microbes can efficiently ferment biomass waste to produce volatile fatty acids (VFAs). However, keeping long-term efficient VFA production efficiency has become a bottleneck. In this study, yeast culture (YC) was used to enhance the VFA production in long-term fermentation. Results showed that YC group improved the volatile solid removal and VFA concentration to 47.8% and 7.82 g/L, respectively, 18.6% and 16.1% higher than the control, mainly enhancing the acetic, propionic, and butyric acid production. YC addition reduced the bacterial diversity, changed the bacterial composition, and improved interactions among bacteria. The regulation mechanism of YC was to increase the abundance and activity of hydrolytic and acidogenic bacteria such as Prevotella and Treponema, improve bacterial interactions, and further promote expression of functional genes. Ultimately, a long-term efficient ruminal fermentation of corn straw into VFAs was achieved.

Enhanced Electromagnetic Energy Conversion in an Entropy‐driven Dual‐magnetic System for Superior Electromagnetic Wave Absorption

AbstractThermochemical conversion is a highly effective method for upgrading organic solid wastes into high‐value materials, contributing to carbon neutrality and peak, carbon emission goals. It also serves as a pathway to develop energy‐efficient electromagnetic wave absorbing (EMWA) materials. In this study, fish skin to successfully in situ nitrify Prussian Blue into Fe3N under external thermal driving condition, resulting in high saturation magnetization is utilized. The resulting Fe3N@C demonstrates outstanding EMWA property, achieving a minimum reflection loss of −71.3 dB. Furthermore, by introducing cellulose nanofiber, a portion of the iron nitride is transformed into iron carbide, resulting in Fe3C/Fe3N@C. This composite exhibits enhanced EMWA properties owing to wider local charge redistribution and stronger electronic interactions, achieving an effective absorption bandwidth (EAB) of 6.64 GHz. Electromagnetic simulations and first‐principles calculations further elucidate the EMWA mechanism, and the maximum reduction value of the radar‐cross section reached 37.34 dB·m2. The design of multilayer gradient metamaterials demonstrated an ultra‐broadband EAB of 11.78 GHz. This paper presents an efficient strategy for atomic‐level biomass waste utilization to prepare Fe3N, provides novel insights into the conversion between metal nitrides and metal carbides, and offers a promising direction for the development of advanced EMWA materials.

Synthesis of Porous Carbons from Candlenut Shells Using Various Types of Activators for Environmentally Friendly Supercapacitors

Porous carbon is one of the promising electrode materials for supercapacitors due to its unique and engineerable microstructural properties. The study of the synthesis of porous carbon from waste biomass is very important due to the abundance of natural resources, low cost production and contribute to solving environmental problems. In this study, porous carbons derived from candlnut shell with various type of activator was studied the chemical structural, morphological and electrochemical properties then evaluated as electrodes for supercapacitor. We have been successfully synthesized of porous carbon from candlenut shells using three steps of the process, i.e.: carboni-zation, activation and calcination. Carbonization was carried out at 700°C in a furnace using a closed crucible to minimize the oxygen. The chemical activation conducted using three types of activators, i.e. ZnCl2, H3PO4 and KOH then calcination process by heated at 800°C for 1 h under Ar flow. The results of the Fourier-transform infrared (FTIR) analysis show that the carbonization process increases the content of aromatic C=C functional groups and reduce the OH, C-H, C-O and C=O functional groups. The carbonization process has also increased the electrical conductivity of the sample around 0.8525 S/m. The results of Scanning Electron Microscope (SEM) images can be observed that the activation process of carbon has formed which was indicated by the appearance of many pores on the surface area of carbon. N2 adsorption/desorption isotherms (Brunauer–Emmett–Teller (BET)) characterization was indicated that the porous carbon is dominated by mesoporous with a pore size around 2-50 nm. BET characterization also can be determined the surface area of porous carbon around 477 m2/g for ZnCl2, 636 m2/g for H3PO4, and 681 m2/g for KOH. This synthesized materials are further employed in a symmetric supercapacitor using simple glass cell. The best performance of supercapacitor achieved by KOH porous carbons with 16.30 F/g of specific capacitance, 2.26 Wh/kg of energy density and 1038 W/kg of power density.

A Thermogravimetric Analysis of Biomass Conversion to Biochar: Experimental and Kinetic Modeling

This study investigates the pyrolytic decomposition of apple and potato peel waste using thermogravimetric analysis (TGA). In addition, using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), the influence of pyrolysis temperature on the physicochemical characteristics and structural properties of biochar was studied. The degradation of biomass samples was studied between 25 °C and 800 °C. Although apple and potato peel decomposition present similar thermogravimetric profiles, there are some differences that can be evidenced from DTG curves. Potato peel showed one degradation peak in the range 205–375 °C with 50% weight loss; meanwhile, the apple peel exhibited two stages: one with a maximum at around 220 °C and about 38% weight loss caused by degradation of simple carbohydrates and a second peak between 280 °C and 380 °C with a maximum at 330 °C, having a weight loss of approximately 24%, attributed to cellulose degradation. To gain more insight into the phenomena involved in biomass conversion, the kinetics of the reaction were analyzed using thermal data collected in non-isothermal conditions with a constant heating rate of 5, 10, 20, or 30 °C /min. The kinetic analysis for each decomposed biomass (apple and potato) was carried out based on single-step and multi-step type techniques by combining the Arrhenius form of the decomposition rate constant with the mass action law. The multi-step approaches provided further insight into the degradation mechanisms for the whole range of the decomposition temperatures. The effect of temperature on biomass waste structure showed that the surface morphologies and surface functional groups of both samples are influenced by the pyrolysis temperature. A higher pyrolysis temperature of 800 °C results in the disappearance of the bands characteristic of the hydroxyl, aliphatic, ether, and ester functional groups, characteristic of a porous surface with increased adsorption capacity. Therefore, this study concludes that biomass waste samples (apple and potato) can produce high yields of biochar and are a potential ecological basis for a sustainable approach. The preliminary adsorption tests show a reasonably good nitrate removal capacity for our biochar samples.

Synthesis of low‐cost microporous activated carbon adsorbents for CO2 capture from Palmyra palm fruit shell waste biomass

AbstractUsing chemical activation techniques at dissimilar carbonization temperatures, activated carbon adsorbents were produced from Palmyra palm fruit biomass in this work. X‐ray diffraction, Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, laser Raman spectroscopy, scanning electron microscopy, CHNS‐elemental analysis, and N2 adsorption studies were among the characterization techniques used to assess the characteristics of the carbon adsorbents. The carbon adsorbents from Palmyra palm fruit were used to absorb CO2 in a temperature range of 25–70°C. The findings of the characterization showed that these carbons have a large surface area and microporosity. The temperature of carbonization and the activating agent had an impact on the surface characteristics. The samples with the highest adsorption capacity, 4.70 mmol/g at 25°C, were the activated carbons made by treating them with KOH and then carbonizing them at 750°C. The physicochemical properties of the adsorbents provided an explanation for their high adsorption capacity. The adsorbents showed simple desorption and maintained constant activity during ten cycles of recycling.

Enhancing Sustainable Production of Biodiesel from Xanthoceras sorbifolia Bunge Oil Using Bio-Based Heterogeneous Catalyst

The swift exhaustion of natural oil reserves and worsening environmental issues have prompted the quest for an economical method to produce biofuels. The superiority of heterogeneous catalysis promotes the development of bio-based catalysts. Carbon materials prepared from agricultural and forestry biomass waste have good application prospects in catalysis. In the present study, Xanthoceras sorbifolia shell waste was used as the raw material, Xanthoceras sorbifolia Bunge Carbon (XC) was used as the catalyst carrier, and K2CO3 was used as the activator to prepare a heterogeneous catalyst (KXC). The heterogeneous catalyst was characterized by scanning electron microscopy-energy dispersion X-ray spectroscopy (SEM-EDS), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET) and X-ray photoelectron spectroscopy (XPS) analysis techniques to evaluate its chemical composition, structure, and physical morphology. EDS and XPS revealed the presence of K metal, which provided an alkaline site for the transesterification reaction to produce biodiesel. The biodiesel yield was observed by gas chromatography−mass spectrometry (GCMS). Under the reaction conditions of a methanol-to-oil molar ratio of 12:1, a reaction time of 90 min, a temperature of 65 °C, and a catalyst loading of 4 wt.% using 25KXC-600-4, the yield of biodiesel can reach 95.13 ± 0.82%. After being repeated five times, the yield was still 58.11 ± 3.80%. The catalyst has no waste generation, and has the characteristics of simple preparation and environmental friendliness, which make it a green heterogeneous catalyst for biodiesel production.

Effect of Biomass Burnings on Population Exposure and Health Impact at the End of 2019 Dry Season in Southeast Asia

At the end of the dry season, from early March to early April each year, extensive agricultural biomass waste burnings occur throughout insular mainland Southeast Asia. During this biomass-burning period, smoke aerosols blanketed the whole region and were transported and dispersed by predominant westerly and southwesterly winds to southern China, Taiwan, and as far southern Japan and the Philippines. The extensive and intense burnings coincided with some wildfires in the forests due to high temperatures, making the region one of the global hot spots of biomass fires. In this study, we focus on the effect of pollutants emitted from biomass burnings in March 2019 at the height of the burning period on the exposed population and their health impact. The Weather Research Forecast-Chemistry (WRF-Chem) model was used to predict the PM2.5 concentration over the simulating domain, and health impacts were then assessed on the exposed population in the four countries of Southeast Asia, namely Thailand, Laos, Cambodia, and Vietnam. Using the health impact based on log-linear concentration-response function and Integrated Exposure Response (IER), the results show that at the peak period of the burnings from 13 to 20 March 2019, Thailand experienced the highest impact, with an estimated 2170 premature deaths. Laos, Vietnam, and Cambodia followed, with estimated mortalities of 277, 565, and 315 deaths, respectively. However, when considering the impact per head of population, Laos exhibited the highest impact, followed by Thailand, Cambodia, and Vietnam. The results highlight the significant health impact of agricultural waste burnings in Southeast Asia at the end of the dry season. Hence, policymakers should take these into account to design measures to reduce the negative impact of widespread burnings on the exposed population in the region.

MCM-41 from rice husk silica as a support for Ni catalyst in the emission-free production of H2 by CH4 cracking.

Selecting a sustainable source of silica from biomass waste was the research challenge that was put forth in this investigation. Herein, the MCM-41 support has been synthesized using a renewable rice husk and explored as a support for Ni-Cu catalyst in the production of zero-emission H2 through CH4 pyrolysis. The role of Cu promoter was investigated by doping different amounts of Cu loading to 30wt%Ni/R-MCM-41catalyst, which improved the catalytic performance in terms of CH4 conversion and stability. An optimum Cu loading of 3wt% addition to 30wt%Ni/R-MCM-41 catalyst demonstrated the best catalytic performance compared to all the catalysts in terms of hydrogen yield (15,218mol H2/mol Ni) and carbon formation rate. The Ni-Cu alloy formation was confirmed by X-ray diffraction, H2-temperature programmed reduction, and pulse chemisorption studies, as demonstrated by decreased H2 uptake (from 41 to 33μmol/gcat) and enhanced N2O (from 89.2 to 138.3μmol/g) uptakes, which results in a significant improvement in the availability of the surface metal species (both Cu and Ni), which in turn contributed to increase the CH4 cracking performance and stabilization of Ni species. Additionally, doping Cu results in better carbon nanotube production, as shown by the lowest ID/IG ratio from the Raman spectroscopic analysis.

The Impact of Biowaste Composition and Activated Carbon Structure on the Electrochemical Performance of Supercapacitors

The increasing demand for sustainable and efficient energy storage materials has led to significant research into utilizing waste biomass for producing activated carbons. This study investigates the impact of the structural properties of activated carbons derived from various lignocellulosic biomasses—barley straw, wheat straw, and wheat bran—on the electrochemical performance of supercapacitors. The Fourier Transform Infrared (FTIR) spectroscopy analysis reveals the presence of key functional groups and their transformations during carbonization and activation processes. The Raman spectra provide detailed insights into the structural features and defects in the carbon materials. The electrochemical tests indicate that the activated carbon’s specific capacitance and energy density are influenced by the biomass source. It is shown that the wheat-bran-based electrodes exhibit the highest performance. This research demonstrates the potential of waste-biomass-derived activated carbons as high-performance materials for energy storage applications, contributing to sustainable and efficient supercapacitor development.

Production of Low Temperature Synthetic Graphite

Synthetic graphite is a material consisting of graphitic carbon which has been obtained by graphitizing a non-graphitic carbon. The growth in demand, particularly in customizing properties for certain usage has brought about research on viable alternative, low-cost, and environmentally pleasant synthetic graphite production. Biomass wastes are amongst appealing carbon precursors which have been broadly checked out as replacement carbon for graphite production. This research aimed to synthesize synthetic graphite from oil palm trunks at low temperatures (500 °C, 400 °C and 300 °C) under controlled conditions to determine the physical properties and properties of the graphite obtained. After the heat treatment process, the obtained samples were then characterized by using XRD, SEM and RAMAN characterizations. Based on SEM and RAMAN characterization, it can be seen that graphite that undergoes a 500 °C pyrolysis process shows the best results compare to graphite that undergoes a pyrolysis process at the temperatures of 300 °C and 400 °C. The graphite flakes and the peaks obtained for 500 °C graphite are obviously present. For XRD characterization, the best samples at 500 °C were chosen to be characterized. From the results, the sample shows slight behavior imitating the commercialized graphite. Hence, from the characterizations of the samples, it can be concluded that the best synthetic graphite produced was from the oil palm trunks heated at 500 ° C.

Cultivation of Aurantiochytrium sp. Using Pickle Seasoning Liquid Waste and Application of the Raw Biomass for Fish Aquaculture

AbstractAurantiochytrium sp. strain L3W is a heterotrophic microorganism that produces docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), which are essential for the growth of marine fish. In this study, pickle seasoning liquid waste was used for culturing strain L3W and the raw biomass of strain L3W was then fed to red sea bream fingerlings (Pagus major) to confirm its usability as a source of DHA and EPA. The strain L3W was cultured on the three pickle seasoning liquid waste samples, Akimurasaki, Hiroshimana, Shisohijiki, diluted with sand-filtered seawater at initial pH values of 4 and 7 under unsterile conditions. The growth of strain L3W was highest at 3.71 g/L on Hiroshimana at an initial pH of 7 with DHA and EPA production at 71.4 and 6.8 mg/g-biomass, respectively. Preparing the raw biomass of strain L3W by the 200 L-scale cultivation using the American Type Culture Collection 790By+ medium because of the DHA and EPA contents close to that produced in the Hiroshimana medium with an initial pH of 7, the raw biomass was spiked to the diet at 3%, 5%, and 10%. The final DHA and EPA contents in the whole body were increased by 4.26 and 3.03 times, respectively, by adding the strain L3W biomass at 10%. These results confirmed the feasibility of a carbon cycling scenario in which the strain L3W is cultivated using liquid food waste with the resultant biomass is utilized as a source of DHA and EPA for fish aquaculture. Graphical Abstract

Utilization of Biomass Waste Through Small-Scale Gasification Technology in the Eastern Cape Province in South Africa: Towards the Achievement of Sustainable Development Goal Number 7

Despite being resource-richly endowed with various energy sources, and despite the connection of 89.8% of the households to the grid in South Africa, the Eastern Cape province, as compared to other provinces, has the lowest level of grid connection of about 64.5%. Some of the rural poor households in the Eastern Cape province supplement their free basic electricity with unclean energy alternatives. Using unclean energy alternatives is not only detrimental to the environment and health of the people, but it is a sign of energy poverty and among the contributing factors to depesantization, deagrarianization, and deindustrialization which prolongs the underdevelopment in rural areas. Innovation in energy technologies is a key ingredient in meaningful rural development. The utilization of small-scale biomass gasification technologies can be a solution to the South African energy crisis in rural areas, and it is in line with sustainable development goal number 7, which is about ensuring access to affordable, reliable, sustainable, and modern energy for all. Alternative renewable energy sources cannot be ignored when dealing with the energy crises in South Africa. Renewable energy sources in the country include biomass, solar, wind, and hydropower. Despite its low utilization in the Eastern Cape province, small-scale biomass gasification technology remains pivotal in reducing energy crisis by producing electricity. However, the affordability of biomass gasification technology also plays a role in whether people will accept small-scale biomass gasification technology. The purpose of this paper is to determine the possibilities of using small-scale biomass gasification technology. This paper gives a comprehensive review of small-scale biomass gasification technology potential in the Eastern Cape province and the link between acceptance of small-scale gasification technology and affordability by evaluating the availability of biomass sources in the province and achievements with regards to small-scale biomass gasification. This paper also covers the impact of biomass gasification technology integration in the energy grid, what needs to be taken into consideration before its installation, its benefits and the barriers to its development in Eastern Cape province.

Corn Stover Lignin as a Solid Acid Catalyst for the Esterification of Oleic Acid

AbstractThe catastrophic ramifications of fossil fuels on the environment have prompted the search for renewable energy sources. Over the recent decades, biodiesel has garnered attention as a promising direct alternative to diesel fuel; however, reliance on homogeneous catalysts and the requirement for refined vegetable oil feedstocks present financial and sustainability concerns. Thus, there exists a need for the development of sustainable and cost‐effective catalytic solutions. Herein, the application of lignin, an abundant and renewable biomass, as an effective heterogeneous catalyst is reported for biodiesel production via the esterification of oleic acid. Lignin is extracted from corn straw using sulfuric acid, which endows sulfonic acid groups (0.85 mmol g−1) to its structure allowing it to act as an acid catalyst without additional post‐treatments. Conversion of oleic oil to biodiesel is achieved at 97% using a 1:3 oleic acid to methanol molar ratio with a 5 wt.% catalyst loading at 90 °C after only 30 min. Moreover, the catalyst exhibits a remarkable turnover frequency of 2.61 min−1 proving its efficiency. These findings demonstrate that heterogeneous catalysts can be prepared from biomass waste offering a significantly cheaper and less intensive synthesis process and allowing for a paradigm shift to non‐edible and waste cooking oils.

Electric arc synthesis of titanium carbide using carbon obtained from thermal conversion of waste from the power industry

The work presents for the first time the results of obtaining titanium carbide using a vacuum-free electric arc method using various types of biocarbon obtained by classical pyrolysis of biomass waste, such as tangerine peel, pomelo peel, banana peel, pine nut shells, walnut shells. Analysis of X-ray diffraction patterns of the synthesized materials showed the repeatability of the experiment with the receipt of diffraction maxima indicating the formation of a cubic structure of titanium carbide. An analysis of the thermal oxidation of the resulting powders showed that up to a thousand degrees the process proceeds quite slowly, but with increasing temperature the oxidation rate increases significantly. It has been established that during thermal heating in an oxidizing environment, the mass of the studied titanium carbide powders obtained using various types of carbon increases, which is confirmed by thermogravimetric analysis.

Food waste-derived activated carbon for supercapacitors

This research investigates the utilization of activated carbon synthesized from food waste biomass, specifically, peels of orange, apple, cucumber, and onion, as electrode materials for high-performance supercapacitor applications. The peels were first pre-carbonized at 600 °C and then activated at 700 °C with KOH. The research involved developing a supercapacitor using the synthesized activated carbon as the electrode material and 6 M KOH as the electrolyte. The results indicated that electrodes made from orange peel, apple peel, cucumber peel, and onion peel exhibited specific capacitances of 238.5 F/g, 201.2 F/g, 236.9 F/g, and 118.9 F/g, respectively, at a current density of 1 A/g. When the current density was increased to 2 A/g, the elec-trodes maintained up to 90% of their capacitance.

Understanding the Relationship of Closed Pore Structure in Biomass- derived Hard Carbon with Cellulose Regulating Strategy.

Recycling waste biomass to pyrolytic carbon has become a development direction of sodium-ion batteries (SIBs)anodes. However, it remains a challenge to precisely control the composition and structure of biomass to modify the properties of derived carbon. Herein, a strategy of hydrolyzing cellulose in phellem with sulfuric acid is proposed, which can promote cellulose fracture, reduce the graphitization and increase the content of closed pores in hard carbon. Accordingly, after the regulation of closed pore structure, the reversible capacity increased from 207 to 330 mAh g-1 at 20mA g-1, realizing an increase of ≈130 mAh g-1 in the plateau region and the initial Coulombic efficiency (ICE) is enhanced from 78% to 90%. When applied in full cell with O3-Na[Ni1/3Fe1/3Mn1/3]O2, it showed an energy density of 247Wh kg-1. This strategy has certain universality, and it provides the feasibility to use low-value cellulose-containing biomass to fabricate high-performance hard carbon materials.

Optimization of Citrus Pulp Waste-Based Medium for Improved Bacterial Nanocellulose Production.

Bacterial nanocellulose (BC) has attracted significant attention across a wide array of applications due to its distinctive characteristics. Recently, there has been increasing interest in leveraging waste biomass to improve sustainability in BC biogenesis processes. This study focuses on optimizing the citrus pulp waste (CPW) medium to enhance BC production using Komagataeibacter sucrofermentans. The screening of initial medium pH, yeast extract, CPW sugar and inoculum concentrations was conducted using the Plackett-Burman design, with BC yield (mgDW/gCPW) as the model response. The significant parameters, i.e., CPW sugars and yeast extract concentrations, were optimized using response surface methodology, employing a five-level, two-factor central composite design. The optimized CPW-based growth medium resulted in a final yield of 66.7 ± 5.1 mgDW/gCPW, representing a 14-fold increase compared to non-optimized conditions (4.3 ± 0.4 mgBC/gCPW). Material characterization analysis indicated that the produced BC showed high thermal stability (30% mass retained at 600 °C) and a crystallinity index value of 71%. Additionally, to enhance process sustainability, spent baker's yeast hydrolysate (BYH) was assessed as a substitute for yeast extract, leading to a final BC titer of 9.3 ± 0.6 g/L.

Hemp cellulose-based aerogels and cryogels: From waste biomass to sustainable absorbent pads for food preservation

This study presents a circular economy approach utilizing hemp stems and rice straw, typically perceived as low-value agricultural waste, to develop a sustainable alternative to traditional plastic absorbent pads for food packaging. The development of an active material was achieved through the utilization of hemp cellulose and a bioactive extract isolated from rice straw. In addition to reducing plastic pollution, this material demonstrates the potential to enhance food preservation. This research provides evidence of the benefits of repurposing agricultural by-products to create valuable and environmentally-friendly products. Hemp cellulose was extracted, characterized, and processed to develop stable aerogels and cryogels through supercritical CO2 drying and freeze-drying. The water stability and internal structure of the materials were guided via TEMPO-mediated oxidation and high-pressure homogenization. Both materials showed versatile physicochemical and mechanical properties. Nevertheless, with higher water sorption (2.20 mL/g), minimal dimensional changes, and lower shrinkage, cryogels were suitable for meat absorbent pad application. To enhance the cryogels functionality, they were impregnated with a rice straw bioactive extract in two different concentrations. The incorporation of the extract did not affect the structure of the cryogels, improved their mechanical properties and the antioxidant activity remained stable after drying (63.89–78.96 %). Finally, the performance of the developed materials was compared to commercial plastic pads and pristine meat preservation challenge test during 9 days at refrigeration conditions. The incorporation of rice straw extract improved meat color preservation. While moderate extract concentrations (75 mg/g) showed a protective effect against lipid oxidation, higher levels (187.5 mg/g) induced pro-oxidant reactions. This research highlights the potential of hemp cellulose-based cryogels as sustainable and functional packaging materials for meat products.

Biomass-Derived-Carbon-Supported Spinel Cobalt Molybdate as High-Efficiency Electrocatalyst for Oxygen Evolution Reaction.

Ananas comosus leaves were converted to a porous graphitized carbon (GPLC) material via a high-temperature pyrolysis method by employing iron salt as a catalyst. A cobalt molybdate (CoMoO4)-and-GPLC composite (CoMoO4/GPLC) was then prepared by engineering CoMoO4 nanorods in situ, grown on GPLC. N2 adsorption-desorption isothermal curves and a pore size distribution curve verify that the proposed composite possesses a porous structure and a large specific surface area, which are favorable for charge and reactant transport and the rapid escape of O2 bubbles. Consequently, the as-synthesized CoMoO4/GPLC shows low overpotentials of 289 mV and 399 mV to afford the current densities of 10 mA cm-2 and 100 mA cm-2 towards the oxygen evolution reaction (OER), which is superior to many CoMoO4-based catalysts in previous studies. In addition, the decrease in current density is particularly small, with a reduction rate of 3.2% after a continuous OER procedure for 30 h, indicating its good stability. The excellent performance of the CoMoO4/GPLC composite proves that the GPLC carrier can obviously impel the catalytic activity of CoMoO4 by improving electrical conductivity, enhancing mass transport and exposing more active sites of the composite. This work provides an effective strategy for the efficient conversion of waste ananas comosus leaves to a biomass-derived-carbon-supported Co-Mo-based OER electrocatalyst with good performance, which may represent a potential approach to the development of new catalysts for OER, as well as the treatment of waste biomass.