Journal of Bioresources and Bioproducts最新文献

The removal of lignin from natural cellulose fibers is a crucial step in preparing high-performance materials, such as compressed high-toughness composites. This process can eliminate non-cellulosic impurities, create abundant compressible pores, and expose a greater number of active functional groups. In this study, biomass waste windmill palm fiber was used as the raw material to prepare holocellulose fibers through various chemical treatments. The structure, chemical composition, Fourier transform infrared spectroscopy analysis, X-ray diffraction analysis, thermal properties, and mechanical properties, particularly fatigue performance, were studied. The sodium chlorite treated fiber had the highest crystallinity index (61.3%) and the most complete appearance structure. The sodium sulfite treated fiber had the highest tensile strength (227.34 ± 52.27) MPa. Hydroxide peroxide treatment removed most of the lignin and hemicellulose, increasing the cellulose content to 68.83% ± 0.65%. However, all the chemical treatments decreased the thermal property of the fibers.

The occurrence of pharmaceuticals in water bodies and drinking water poses risks for the environment and human health, thus it is necessary to study methodologies that allow the efficient removal of these contaminants. In this work, corn cob-derived biochar was obtained by ZnCl₂-activation, and subsequent carbonization at 700 °C. The effect of contact time, temperature, pH, and initial concentration on the adsorption capacity of acetaminophen (ACE) and amoxicillin (AMX) was determined through batch experiments. In addition, the kinetics, isotherms, and thermodynamics parameters were determined. The activated biochar exhibited a maximum adsorption capacity of 332.08 mg/g for ACE and 175.86 mg/g for AMX. The adsorption kinetics and adsorption isotherm of ACE corresponded to the pseudo-second order and Langmuir model, respectively. Meanwhile, pseudo-first-order kinetics and the Freundlich isotherm model were well-fitted to AMX adsorption. The ACE and AMX co-adsorption had a synergistic effect on AMX but an antagonistic effect on ACE removal, achieving a maximum adsorption capacity of 193.51 and 184.58 mg/g, respectively. On the other hand, fixed-bed column experiments showed that the adsorption capacity depends on the influent concentration, and the breakthrough curve fits the Thomas and Yoon-Nelson model. The mechanism adsorption studies showed that surface interactions (hydrogen bonding formation and n-π interactions) are the main driving forces for the adsorption process, and pore filling is the rate-limiting step. In this way, the prepared biochar exhibits a high potential for the adsorption of pharmaceutical compounds from water.

Bacterial cellulose (BC) hydrogel spheroid plays a significant role in diverse fields due to its spatial 3D structure and properties. In the present work, a series of BC spheroids with controllable size and shape was obtained via an in situ biosynthesis. Crucial factors for fabricating BC spheroid including inoculum concentration of 1.35 × 10³ CFU/mL, shaking speeds at 100 r/min, and 48–96 h incubation time during the biosynthetic process, were comprehensively established. An operable mechanism model for tuning the size of BC spheroids from 0.4 to 5.0 mm was proposed with a fresh feeding medium strategy of dynamic culture. The resulting BC spheroids exhibit an interactive 3D network of nanofibers, a crystallinity index of 72.3 %, a specific surface area of 91.2 m²/g, and good cytocompatibility. This study reinforces the understanding of BC spheroid formation and explores new horizons for the design of BC spheroids-derived functional matrix materials for medical care.

The demand for industrial enzymes is continually rising, fueled by the growing need to shift towards more sustainable industrial processes. However, making efficient enzyme production strains and identifying optimal enzyme expression conditions remains a challenge. Moreover, the production of the enzymes themselves comes with unavoidable impacts, e.g., the need to utilize secondary feedstocks. Here, we take a more holistic view of bioprocess development and report an integrative approach that allows us to rapidly identify improved enzyme expression and secretion conditions and make use of cyanobacterial waste biomass as feed for supporting Pichia pastoris fermentation. We demonstrate these capabilities by producing a phytase secreted by P. pastoris that is grown on cyanobacterium hydrolysate and buffered glycerol-complex (BMGY) medium, with genetic expression conditions identified by high-throughput screening of a randomized secretion library. When our best-performing strain is grown in a fed-batch fermentation on BMGY, we reach over 7 000 U/mL in three days.

Date palm pit (DPP)-filled poly (-hydroxybutyrate) (PHB) composites were prepared, evaluated, and characterized to determine their thermal insulation ability. Thermal conductivity values ranged between 0.086 and 0.100 W/(m·K). At a maximum filler concentration (50% (w)), the specific heat capacity and thermal diffusivity were 1 183 J/(kg·K) and 0.068 9 mm²/s, respectively. The DPP increased the thermal stability, and the highest compressive strength obtained was 80 MPa at 30% filler content. The PHB-DPP composites exhibited promising water absorption (less than 6%) and tensile strength (6–14 MPa). Date-pit-based PHB composites could be used in sustainable building engineering and cleaner production.

Because of socioeconomic considerations, wide-scale production of biofuel necessitates the utilization of nonedible biomass feedstock that does not compete for land and fresh water resources. In this regard, Salicornia bigelovii (SB) is the most investigated halophyte species. The high oil content in SB seeds has sparked mounting research that aims to utilize SB as an industrial crop in the production of bio-oil, particularly in coastal areas where these plants thrive. However, the oil extracted from the pyrolysis of raw SB seeds is largely dominated by oxygenated fatty acids, most notably 9,12-octadecadienoic acid and 9,17-octadecadienal, typical to that of other crops. The pyrolysate bio-oil of the raw SB seeds exhibited a relative yield of oxygenated compounds that decreased from 57.05 % at 200 °C to 9.81 % at 500 °C, and the relative yield of nitrogenated compounds increased from 4.86 % at 200 °C to 21.97 % at 500 °C. To improve the quality of the produced bio-oil, herein we investigated the catalytic hydrodeoxygenation (HDO) of the fragments that were produced from the thermal degradation of SB seeds. A 5 %Ni–CeO2 catalyst was prepared and characterized by a wide array of methods X-ray diffraction, X-ray photoelectron spectroscopy, temperature programmed reduction, scanning electron microscope, Brunauer-Emmett-Teller analysis, and thermogravimetric analyzer. The catalytic run was executed between 200 and 500 °C in a flow reactor. The deployed catalytic methodology displayed a profound HDO capacity. At 400 °C, for instance, the gas chromatography mass spectroscopy (GC–MS) detected loads of paraffin and aromatic compounds exists at appreciable values of 48.0 % and 28.5 %, respectively. With a total relative yield of 43.2 % (at 400 °C), C₈–C₁₅ species (i.e., jet fuel fractions) were the most abundant species in the upgraded SB bio-oil. The release of H₂, CO, CO₂, and CH₄ was analyzed qualitatively and quantitatively using gas chromatography thermal conductivity detector and Fourier infrared spectroscopic analysis. When the Ni–CeO2 catalyst was utilized, a complete deoxygenated bio-oil was obtained from SB seeds using the surface-assisted HDO reaction. On the basis of the elemental analysis, the biochar's hydrogen and oxygen contents were found to decrease significantly. Density functional theory computations showed mechanisms for reactions that underpinned the experimentally observed hydrodeoxygenation process. Outcomes presented herein shall be instrumental toward the effective utilization of halophyte in the production of commercial transportation fuels.

In this study, the influence of thermoforming conditions on the resulting material properties was investigated, which aimed at developing advanced wood-fiber-based materials for the replacement of fossil plastics. Two bleached softwood pulps were studied, i.e., northern bleached softwood Kraft pulp (NBSK) and chemi-thermomechanical softwood pulp (CTMP). The thermoforming conditions were varied between 2–100 MPa and 150–200 °C, while pressing sheets of 500 g/m² for 10 min to represent thin-walled packaging more closely. As our results showed, the temperature had a more pronounced effect on the CTMP substrates than on the Kraft pulp. This was explained by the greater abundance of lignin and hemicelluloses, while fibrillar dimensions and the fines content may play a role in addition. Moreover, the CTMP exhibited an optimum in terms of tensile strength at intermediate thermoforming pressure. This effect was attributed to two counteracting effects: 1) Improved fiber adhesion due to enhanced densification, and 2) embrittlement caused by the loss of extensibility. High temperatures likely softened the lignin, enabling fiber collapse and a tighter packing. For the Kraft substrates, the tensile strength increased linearly with density. Both pulps showed reduced wetting at elevated thermoforming temperature and pressure, which was attributed to hornification and densification effects. Here, the effect of temperature was again more pronounced for CTMP than for the Kraft fibers. It was concluded that the thermoforming temperature and pressure strongly affected the properties of the final material. The chemical composition of the pulps will distinctly affect their response to thermoforming, which could be useful for tailoring cellulose-based replacements for packaging products.

Disposable face masks are an essential piece of personal protective equipment for workers in medical facilities, laboratories, and the general public to prevent the spread of illnesses and/or contamination. Covid-19 resulted in an uptick in the usage and production of face masks, exacerbating issues related to the waste and recycling of these materials. Traditionally, face masks are derived from petrochemicals, such as melt-blown or spunbound polypropylene. As such, there is a need to find sustainable mask materials that can maintain or improve the performance of petrochemical masks. This paper explores an alternative mask material that utilizes fungal mycelium as self-growing filaments to enhance the efficiency of individual polypropylene mask layers. By engineering the growth pattern and time, breathability and filtration efficiency was optimized such that one layer of the mycelium-modified mask could replace all three layers of the traditional three-layer mask. Additionally, it was found that the mycelium-modified mask exhibits asymmetric hydrophobicity, with super-hydrophobicity at the composite-air interface and lower hydrophobicity at the composite-medium interface. This property can improve the performance of the modified mask by protecting the mask from external liquids without trapping water vapor from the user's breath. The findings from this study can provide a basis for further development of mycelium to create sustainable filtration materials with enhanced functionality.

Passive cooling strategy shows great potential in mitigating global warming and reducing energy consumption. Because of the high emissivity in the atmospheric transparency window (λ ≈ 8–13 µm), cellulose is considered as a good candidate for radiative cooling. However, traditional cellulose coolers generally show poor solar reflection and can be polluted by dust outside, thereby resulting in poor daytime cooling efficiency. To address these drawbacks, we developed sustainable cellulose nanowhiskers (CNWs)/ZnO composite aerogel films with favorable optical performance, mechanical robustness, and self-cleaning function for efficient daytime radiative cooling, which can be achieved via freeze casting and hot-pressing process. Due to formation of multi-level porous structure and chemical bonds (Si-O-C/Si-O-Si), such aerogel film exhibited high solar reflectance (97%) and high infrared emittance (92.5%). It achieved a sub-ambient temperature drop of 6.9 °C under direct sunlight in hot weather. Most importantly, the surface roughness and low surface energy enable cellulose aerogel film hydrophobicity (contact angle = 133°), thereby resulting in an anti-dust function. This work provides insight into the design of sustainable thermal regulating materials to realize carbon neutrality.

Biomass solid fuel (BSF) has emerged as a promising renewable energy source, but its morphological and microstructural properties are crucial in determining their physical, mechanical, and chemical characteristics. This paper provides an overview of recent research on BSF. The focus is on biomass sources, BSF processing methods, and morphological and microstructural properties, with a special emphasis on energy-related studies. Specific inclusion and exclusion criteria were established for the study to ensure relevance. The inclusion criteria encompassed studies about BSFs and studies investigating the influence of biomass sources and processing methods on the morphological and microstructural properties of solid fuels within the past five years. Various technologies for converting biomass into usable energy were discussed, including gasification, torrefaction, carbonization, hydrothermal carbonization (HTC), and pyrolysis. Each has advantages and disadvantages in energy performance, techno-economics, and climate impact. Gasification is efficient but requires high investment. Pyrolysis produces bio-oil, char, and gases based on feedstock availability. Carbonization generates low-cost biochar for solid fuels and carbon sequestration applications. Torrefaction increases energy density for co-firing with coal. HTC processes wet biomass efficiently with lower energy input. Thermal treatment affects BSF durability and strength, often leading to less durability due to voids and gaps between particles. Hydrothermal carbonization alters surface morphology, creating cavities, pores, and distinctive shapes. Slow pyrolysis generates biochar with better morphological properties, while fast pyrolysis yields biochar with lower porosity and surface area. Wood constitutes 67% of the biomass sources utilized for bioenergy generation, followed by wood residues (5%), agro-residues (4%), municipal solid wastes (3%), energy crops (3%), livestock wastes (3%), and forest residues (1%). Each source has advantages and drawbacks, such as availability, cost, environmental impact, and suitability for specific regions and energy requirements. This review is valuable for energy professionals, researchers, and policymakers interested in biomass solid fuel.